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■(Od OCTOBER, 1917 

REAOER~When you flnlih reading tliK nt ga/ine pla e a I - ent ilamp 
SSr ]oldl"r. or Mor.Tl'hi"ront 

MO wrapping —NO ADOr^ESS 

_ A. S BURLESON. P«j%tm3iter ( rnefal. 









Tins is ihc KIcctricnl A^e, and this wonderful new profession is callinof you. The 
dcinand for exj)crt Electricians is greater every 3 'car and the salaries Ih^lier. Elec¬ 
tricity is truly the orrcalest motive power in the'world, to-dav, and now is the time to 
enter this profession. 




$36$!! TO $100$$ A WEEK 

^ on can earn $36 to $100 a week and more as an Expert Electrician. If you have a 
common scho< I education J can train >oli in a few months at liome. liiduiii" and 

power companies, municipalities, and mami faclurers are .ilwavs seeking iraiiied nien to 
liandle their I'.lectrical problems. 

I Guarantee Satisfaction 

E\'ery student receives our Sealed Guarantee Eond, which guarantees to return every penny of his 
mone\ if he is not entirely satisfied. No oilier school has made this wonderful offer, hut 1 know the 
success I have brought to hundreds()f my student s. ami 1 know what lean do for an\ ambitious young 
man who will give me a little of his spare lime each day. 



Dept. II 

CIIII'.F FXfilXEEK, (‘hicapo Enf^iiiccrinR W’urks, 
439 Cass St.. ('liioJiKo. Illni' s. 

\\ ithout oblig.itinn c» niv part kin lly 
particul.Trs of up Cunipletc Practical 

tricity. - * • 

send ;it f»ret>iid. 

II IM.- 

Name . 

“ d' 

Address ... 

Town .. ' 

’*'■ V, i V mcHtienii)^ '‘Tixe hi 

F ; tiu next 30 <la\s I ani Kivnif* each student ;iu 0\itht of 
I'UhUrmI lt>iinjT I iiMru’iiciUs, 'luols. Electrical materials, .and 
Ml t r ah.Mihite > rret. M> instruction is h\ practical nietluids and 
this u\itht IS iiscil in workii't; out the le.ssons. Practical training 
with the tlie' rj' ni. kc.s pertVii I am Chief Engineer of the ('hicago 
Engineering W iks. an 1 g ve >ou the train ng (hat wili l.and 
the big and hold them. 

««iE ' earnc'-t I want to send yi i my new Hook—• 

Ilnw ti> Hecunv' .an Electrical Expert." It’s free, Xo ni.atter 
lu»w iiKiny other scln ids jou write ii I want >iu to li.ive my book 
It s d nerctu beiau>e i*’s practical — W'rite today. 



Dept. 41 :: 439 CASS STREET. CHICAGO, ILL. 

efrieu/ l .it'cr\mcntcr'* uhen u rit\ng to ao~^ert\sc> s. 

October, 1917 



S OONER or later you will l)e standing In front of 
the mahogany desk. The big man reclining in his 
office cliair will gaze earnestly at yon while his keen 
gray eyes “take you in/’ 

\Mien this hig moment comes, can you make good? 
Will you “come through”? Will you he just another 
one of the million “little fish” trying hard to land a 
small job at $15.00 a week, or will you be one of the men 
that DU things, at a salary running into four figures? 

Suppose the man behind the desk bombards you with 
(piestions, such as these; “Cuit you 7<irt' a stoitchboard/ 
Can you lay out o 500 lujbl /’orccr installation on the 
drafting boardt Can you rescind o 10 If. /^ Direct 
Current dynamo armature/ Can you plan and install 
a private telephone installation and 75 phones in a new 

W'ill you withstand such a bombardment? 

No, Sir. Not if you have no actual experience in back 
of you? 

WHAT’S r>.\CK OF YOU? Just a little personal 
dabbling in your attic at home, a few books and some 
magazines ? Ur have you actually done these things 
yourself with your own hands, in a place where such 
things are done every day? The keen eyed man behind 
the desk will know in less than a minute. You cannot 
hlufif him. HE know^. He wants an expert, not a 
dabl)ler. It’s experience that counts toda}. It’s ex¬ 
perience that brings the big coin. 

Learn by Doiiig 

The only way you can become an expert is by doing the 
very work under competent instructors, which you will be called 
upon to do later on. In other words, leant by doittg. 

That is the method of the New York Electrical School. 

Our concentrated work with actual apparatus under 
actual conditions will put you abreast of men with 
from 5 to 10 years* e.vperience in the electrical field. 

4,500 of our sludeiits nave gone forth into electrical 

I.E.XRX BY DO 1X0. This method makes yon an 
expert, able to command a high salary. All instruc¬ 
tion is individual. You go ahead as fast as you can 
learn. (roo<l students complete the course in seven 
months. Send today for FREE 64-page book. 

L se the handy coupon below and send it today. 

You will never regret it. 

School of'cn to z'isitors 
mWlllll from 9 A. .1/. to 9 P. M. 

”Yes, Sir, ICs Experts 
We Want - - - When 
Can You Start ? ’ ’ 



29 W. 

Please send l^'KE 



obligation'to mJ^’Our 64-page 

You benefit by mentioning ^'The Eleetricol Extcrimenler'' tvhen xvriting to odicrli.tcrs. 



October, 1917 


Columbia Electric 
Grafonola 225 
Price S 225 . 

Cabinet of mahogany, satin 
ZK'alnut, or quartered oak in 
all finishes, measuring 49^ 
inches high on eastors, and 
2254 X 24 inches. All ex¬ 
posed metal parts heavily 
plated in 18 karat gold. 
Drop-tray reeord cradles to 
hold 60 records. 

Columbia Graf onolas 

af $125, $135, $175, and $225 

T he Columbia Electric Grafonola 125 E is equipped with an electric 
motor that is a marvel of accuracy and precision. It operates per¬ 
fectly on any standard current, whether direct or alternating, and can 
be attached to any socket—Price $125. Same^model equipped with 
Columbia Individual Record Ejector—Price $135. 

"I'he Columbia Eilcctric Grafonola 175 E is designed to give satisfaction under any 
and all conditions. It provides the highest possible tone-quality and every refine¬ 
ment of mechanism, form and finish to correspond. Price $i 75 - 

With its electrical and mechanical improvements, the Columbia Electric Grafonola 
225 E is an instrument embodying the most perfect reproducing qualities and refine¬ 
ment and one that will be as well a harmonious part of the best appointed music 
rooms. 'I'he liiotor, a marvel of silence and smoothness, holds the tone absolutely true. 
Price ^225. 

You l^encfit hv menttottinQ "The Electrical Exferifnenter" when writitKj to advertisers. 

Tlhie Electrical Experimemiter 


Pubh'shl by Experimenter Publisbinfj Company, Inc. (JI. Gernsback, President; S. Gernsback, Treasurer;) 233 Fulton Street, New York 

Vol. V Whole No. 54 OCTOBER, 1917 

No. 6 


From a painting by George Wall 

SAME TIME . 365 



Rv GcorRe Holmes 369 




Ry IL Wiuheld Sccor, E.E. 372 


By H. Rosenthal 373 




By F. F. Mace 380 


Hv F. T. Forster 382 


ASPECT.S .Bv Dr. Humbert Bizzoni 383 


By George W. Vinal 385 


By John J. Furia, A.B., .M.A. 386 


GENH S.By C. W. Geiger 



Ry !!. C. X'aij Rr nthuvscii jtid .Max I. Rlack 


Ry F. A. Hart 


Ry R. U. Clark, 3rd 


Ry Thomas Reed 


Ry Albert H. Rciler 



Ry Albert \\'. WiUdon 























HEX reviewing]: the various methods which 
are in use, or whicli have been proposed 
to combat the submarine, we invariably 
are led back to the microphone. Indeed 
our officials are coming to recognize the 
microphone more and more each day, and 
just now at least, it seems to be in a fair 
way towards ultimate succes.s. 

Of course, we must admit, the difficulties encoun¬ 
tered are enormous, and the ideal microphone for sub¬ 
sea work as yet does not exist. 

In order to guide workers in this field we will en¬ 
umerate several points, not well understood by the man, 
who has never worked with sensitive microphones under 
water. Tlie information which we publish in the inter¬ 
est of all, and which has not appeared in print before 
has been secured from experts who have actually worked 
on the prol)lem for months. 

To begin with, a microphone working on dry land 
is a totally different instrument from the one work¬ 
ing under water, .Thus it will not d(j, for instance, to 
take any sensitive microphone and after waterproof¬ 
ing it, simply sink it into the ocean. A microphone as 
a rule has a sensitive vibrating diafrani. Imagine sink¬ 
ing it fifty feet below water where the pressure is some 
21 lbs. per square inch- -the diafram would of course 
cave in. For that reasf)n microphones as a rule arc 
not actually sunk in the water, hut arc fastened against 
the inner steel shell of the ships, d'his naturally is a 
poor way, as much of the instrument's valuable sensi¬ 
tiveness is lost thereby. Mowe\'er, means have already 
Ijccn found to actually keep the diafram in physical 
contact with the ocean. Nevertheless improvements are 

If an ordinary .siii)er-sensiiivc microphone is mounted 
on a ship witliout special attachments it will he found 
to be worse than useless. To l>egin witli. tlie noise 
of the ship's engine, the walking about of the crew, 
the noise of the waves pounding against the ship, all 
make it imi)ossihlc to hear anything else in the ’phones. 

If on the other hand we sink the microphone clear 
of the ship, only supported by cables, our troubles are 
far from ended. The first thing wc find that wc 

Sub-Sea Microphones 

must sink the sensitive microphone at the very least 
35 feet below the ocean level. Failure to do so will 
bring a con.staiit dull pounding into the cars of the 
man at the ’phones, due to the noi.^e created by the 
everhreaking and rolling ocean waves above. Even at 
35 feet below, trouble awaits iis. If the microphone 
remained perfectly stationary it would he a fine thing, 
but if suspended from a moving vessel, the rush of 
the water against the microphone casing produces a lot 
of unwelcome noise, hard to get rid of. 

2^1 ost of these troubles are slowly licing mastered, 
but far too slowly. What is needed are many more 
investigators who are willing to actually perform experi¬ 
ments under water. Land experience with microphones 
is valueless. 

To cite a few more points. The average microj)hone 
works well only if in one i>osition. Incline it> face 45"^ 
and it will cease operatin.g almost entirely. This of 
course is due to the shifting carbon grains. Make- 
shifts, i. c., suspending the instrument in gimhahrings 
like a compass, will not always do under water; what 
is wanted, is a sensitive microphone which is not in¬ 
fluenced when turned iii»side down. 

It has also been found, and this is an important point 
to remember, that using a “sca-diafram*’ which in turn 
vibrates a layer of air, the latter acting on tlie inicro- 
jihone diafram, will not work at all. 

Another very interesting point is that wlicn mount¬ 
ing microphones on eacli side of a vessel, the loudness 
of the incoming sound is c(inal in both telephone re¬ 
ceivers, /. r„ if a submarine is on the starboard side 
of the ship, it will he heard just as loud from the 
port side. But, the difference can he readily detected 
and very accurately loo, l>y tlie phase ditterenec as 
heard in the 'phones. In other words, the sound wilt 
he heard a fraction of a secimd earlier in one ear 
than in tlie other. Small as this difference is, even a 
green operator will delect it at once. 

Finallj', the motors of a '^uhinarine do not give a clear 
I'ote of a certain freiiuencv in ihe listener's ’phones. 
Rather we hear a dull rninliling n^ise. Lnid, hut with¬ 
out any definite pitch. 

H. Gernsback. 


^THE ELECTRICAL EXPERIMENTER Is imlitlsht on flio l.^ih of ea<‘h tnontli at •J.'IS 
Kulton Strt't‘1. New lork. Tlipro are 12 nuinhers j»rr year. ^Juhscrlpliou price is Sl.-IO a 
year In r, S. and possessions. ('aiuulH. unU rnreUn (•(uuiiries. 42.00 n year. U. S. coin 
as well as U. H. stamps* ucccpJcd (no forcUn coins nr SitiKle copies, 15 ceiit.s 

each. A .sMoplu copy will he sent unit Is on rennesf. Checks juul money orders should ho 
«lrawu to order of TIIK KXI'HRl.MKNTKU ITRl.lSIlINt; CO.. INO. If you «<hanK 0 your 
(uMress notify tis promptly. In order (hat edjiles are not ndsearrleil or lost. A preen 
wrapper Indlcatas expiration. No copies sent after expiration. 

All communication? snd conlrllmtlons l<7 this lounml should bo addrest lo: Editor. 
THE Et.hVTRlCWL EXPERl.MK.NTEU, Fulton Street. New York. I’nacceptevl eon- 

tributhms cannot Iv returned uiih'ss full posta^re has Inm iiieluded, A 1.1. a»Tepttsl 
contributions are paid for nn publication. .\ sptvlal rate Is (laid fur novel exi>erhnrnis: 
itood photORfaphs accoiupato hiR them arc liighb* deslrutde. 

THE Kl.E('TRir.\L EXI’ERTMENTTR ^lonthh* Enlere*! as second-class matter at 
the New 1 nrk I’ Ofhee. under .\ct nf t’onRn‘**s of .Mareh Title resistercsl f s 

1‘alint iMMi-e ( ujiyrik’ht. lUlT. by El P Co.. lue . .New I ork. The contents of this 
megazlpo are copyrighted and must not be reproduced without givinp full credit to tha 

THE EI.Errr.irAL EXPERBIENTER is for .sale at all n.-wsstands In the United Stales 
an<I Canada; also at Rrentano's 37 Avciiue <!<* I'Dpera. Pans. 




October, 1917 

CHEMCRAFT No. I Price Delivered $1.25 

West of the Mississippi and Canada $1.50 
This is a dandy sei at a very reasonable price. 
With it you can work lots of wonderful experiments 
each one of which ean be repeated many times. 
There are 14 different (’hemicals. test tubes. <dass 
tube, measures, etc., tOKotlier with the >>o. 1 

t'lunicraft book which gives comtilete directions, 
explains all the experiments in a clear, interesting 
' manner, and tells niany wonderful and interesting 

things about CheniiPtry. ^ j 

Willi Chenicraft No. 1 you can make Are ink and 
fuses: you can bleach colors, test water, prepare 
chlorine, manufacturo ammonia, gun powder, col¬ 
ored fires, black and colored 
inks; you can prepare 
magic inks and papers, 
change w.aler Into wine and 
wine into water, pour ink 
and milk from same 
vessel and do 
no end of 
' other w o n- 
d e r f U 

Prica Delivered $2.50 

West ol Ihe Mississippi and Canada $3.00 
Chemcraft No. 2 is much larger than the 1 
set. It contains 32 different Cheuiic^s and a lib¬ 
eral assortment of Apparatus and eQUipmem. 

There are many rare and valuable Chemicals in¬ 
cluded in this outfit wliieh represents the biggest 
value ever put on market for such a low price. 

The instruciiun book which coine.s with this set 
gives direcUons fur working nearly a hundred won¬ 
derful experiments and after you have used the 
set for a little wliile you will be able to devise 
countless additional experiments of your own. 

Every purchaser of Chenicraft No. 2 receives a 
Chemcraft service card, and is entitled to a free 
suhscnption to the Chemcraft Chemist. Tills is 
the biggest kind of a help in carrying on your ex- 
perimeniiug and. no one should overlook this offer. 

Prica Delivered $5.00 

We«t of the Mlsslsslpo! and Canada $6.00 
Tlie No. 3 ('hemcraft is iha biggest and most 
complete Chemical set on the market. This set 
contains 4S different Chemicals all of which are 
carefully chosen because of their many iiitere.stlng 
reactions. A large assortment of valuable appara¬ 
tus is included, among which is a blowpipe, alcohol 
lamp, 8 test tubes, test tube bolder, test tube 
brush, measures, measuring spoon, gas delivery 
tube and s«oprer. glass tube, stirring rod. and 
other miscellaneous eouipment. 

Tlie Chemcraft book for outfit No. 3 is complete 
in every detail. It contains 230 experinien*s and 
gives the user a complete course in Chemistry in 
addition to furnishing all kinds of fun. 

Every owner of the No. 3 Chemcraft set is also 
entitled to Chemcraft service and a free subscrip¬ 
tion to the Chemcraft Chemist. 

Your local dealer probably has the Chemcraft outfits in stock. In case hs hasn’t, however, 
we will supply you direct upon receipt of price. Prompt delivery guaranteed. 



Do you have a chemical laboratory? No experimenter should be without one. A knowledge 
o( Chemistry will always be of greatest value to you and there Is nothing more Interesting than 
chemical experiments. 

Wa are specially equipped to meet the requirements of the experimenter tor chemical sup* 
plies. Let us know your wants. Our catalog lists nearly 200 chemicals, all kinds of apparatus, 
many books on chemistry, and gives valuable tables and other Information. Sent to any address 
upon receipt ot lOc in U. S. stamps or coin. 

THE PORTER CHEMICAL CO. Dept. B. Hagerstown, Md. 

You benefit by mentianiii^ "The Eleetricol Exterimenter'’ when writing to odxertisers. 



Office and Factory 

Cable Address: 

TYPE RJll—2500—12000 METERS, $33.00 


TYPE VC4—PRICE $20.00 

’his Condenser is similar to our commercial type but is cn- 
loscd in an oak cabinet. It has 35 semi-circular aluminum 
lates. The maximum capacity is approximately .0025 M, r. 


O.scilHon Telegraph, ^capable of trans¬ 
mitting the voice 15 miles, or tele¬ 
graphic messages 40 miles. Larger 
transmitters for greater ranges. 

TYPE EJ2— PRICE. $32.00 
it i* not a dntcctar in any form. 

At Last! 

Electromagnetic waves of any 
length from an incandescent 

TYPE **S” —$60.00 

De Forest ‘‘OscUHon’^ 


Generator of absolutely undamped oscillations of 
any frequency. Permits Radio Telephone speech 
surpassing in clearness that over any wire. For 
Laboratory and Research Work has a field utterly 
unfilled. Patents issued and pending. 

October, 1917 



H/(SERM5BI^CK editc7R 
H. W. /issDcmTE editc7R 

Vol. V. Whole No. 54 

October, 1917 

Number 6 

How Lord Northcliffe Heard Two Oceans at the SameTime 

A REMARKABLE demonstration of 
the wonderful telephone network 
which extends over the entire 
United States was recently made 
for the benefit of Lord North¬ 
cliffe and his party on the occasion of their 

had for the occasion been extended to a 
telephone transmitter on the shore of the 
Pacific -at the Golden Gate. Another tele¬ 
phone was connected to a line extending to 
a transmitter on the shore of the Atlantic. 
Thus by placing his ear to one receiver 

per wire. There are 870 pounds of copper 
wire in each circuit mile and 2,960 tons in 
the entire line. The line crosses thirteen 
States and passes thru Salt Lake City, Den¬ 
ver, Omaha, Chicago, and Buffalo, with a 
branch that runs thru Pittsburgh, Wash- 

Lord Northcliffe, During His Recent Visit to the Offices of Theodore N. Vail, In N^^w York City. Had the Pleasure of Listening to the 
Atlantic and the Pacific Oceans Simultaneously, Over the Trans-continental Telephone Line, 3,400 Miles in Length. 

^i>it to the offices of Theodore N. Vail, 
l^resident of the American Telephone 
Telegraph Company, in New York City. 

A point of liistorieal interest was the 
listening hy the distinguishefi visitor to the 
roar of the Atlantic and Pacific oceans 
simultaneously. A telephone instrument 
was connected to the trans-continental line 
reaching to San Francisco where the line 

and then to the other. 1 ord Northcliffe was 
able to hear first one ocean and then the 
other, and hy placing a receiver to eitlier 
ear he was al)le to hear both nrciiii.r siinul- 

In this remarkable telephone line iliere 
are two physical and one phautoni circuits 
aiul in each physical circuit there are two 
wires and (>.800 miles of hard tlrawn cop- 

ington and Philadelphia. In the main line 
there are IJO.(XX) poles. 

The power that sends tlie human voice 
out over the teleplione is scarcely greater 
than that of a breath, yet it can he picked 
up by a delicate iustruinent, conserved over 
a distance of 3.4(X) miles, and reproduced 
perfectly and instantly across the con¬ 



October, 1917 

The accompanying photo shows the lat¬ 
est thing in aeroplane guns from France. 
It is operated by an electro-magnet thus 
giving the aviator-marksman instant con- 

electric cooking apparatus includes novel 
designed soup kettles and boiling vessels, 
varying from fifty liters capacity to four 
hundred liters. These kettles shown in the 
accompanying photograph have insulating 
shells for retaining the heat, as well as 


Photo from Underwood & Underwood 

The Machine Gun In This French Aeroplane Is Fired by Means of An E’sctro-Magnet 
Controlled From the Aviator’s Seat. Great Rapidity of Fire Is Thus Obtainable, As We!l 

As Increased Accuracy. 

trol of the gun, no matter at what angle 
it may be mounted. 

The little French Nieuport ’‘scout’* plane 
is a great fighting machine and is equipt 
with an electric rapid fire gun which is 
worked from the pilot seat by a special 
switch. The machine is furnisht with all 
the latest apparatus evolved from three 
years of intensive air fighting. ^ 

With the Nieuport, French airmen have 
repeatedly shown the German birdmen that 
there is not room for two brands of fight¬ 
ing men in the air and the Germans have 
acquired the knack of being “dropt.” 

a clever system of utilizing oil, electrically 
heated, between the casings, similar to the 
system of double boilers ordinarily using 
water for cereal cooking. 

It may be stated that these oil-heated 
vessels have the electric heating element in 
the bottom arranged with two and three 
sets of windings providing for twelve kilo¬ 
watts, twenty-four kilowatts and thirty-six 
kilowatts as desired.* -The roasting and bak¬ 

ovens require a current of eight kilowatts 
and measure three thousand four hun<ired 
millimeters long, one meter wide and one 
thousand two hundred and fifty millimeters 
high. The electric broilers are mounted on 
three tables and measure four hundred _mm. 
by six hundred mm., with a depth of sixty- 
five mm., each requiring seven kilowatts. 
The capacity of these broilers is two hun¬ 
dred cutlets per hour, while the total ca¬ 
pacity of this kitchen is three hundred por¬ 
tions for each noon-day meal. 

The electric coffee vessels have a ca¬ 
pacity of five hundred liters and vary in 
size from seventy-five liters, capable of 
serving three hundred cups of coffee, to 
one hundred fifty liters having a capacity 
of seven hundred cups of coffee per hour. 
The smaller coffee pots of seventy-five liters 
require twelve kilowatts, while the larger 
ones use eighteen kilowatts. The hot water 
is supplied from electrically heated vessels 
at three temperatures automatically con¬ 
trolled to forty degrees Celsius, sixty de¬ 
grees Celsius and one hundred degrees 
Celsius. The electric water heating boilers 
vary in size from 1.5 cubic meters to 6.5 
cubic meters and the kitchen is equipt with 
a great varietj^ of other cooking utensils. 

The electric dishwashing apparatus is 
most complete, with electrically operated 
pumps for circulating the water thru the 
dishwashing machine, electric conveyors 
and electric drying oven. It will be seen 
that the kitchen is well ventilated with 
electric fans mounted in the wall and win¬ 
dow casings conveying the fumes from 
cooking outside the building. 

The cost of electric cooking in this in¬ 
stallation is said to be extremely low, not 
exceeding 2.15 pfennig (1/2 cent) per capita 
per day, including the total current con¬ 
sumption for all purposes, while for cook¬ 
ing alone the cost does not exceed 1.53 
pfennig (1/3 cent) per capita per day. 


Mrs. Elizabeth K. Baker, of Paris, a 
daughter of Commodore Norman W. Kitt¬ 


By Frank C. Perkins. 

T he electrical connections and the gen¬ 
eral design of the electric cooking, 
roasting and baking equipment of the 
largest electric kitchen in the world, in 
operation at Siemensstadt near Berlin, Ger¬ 
many, may be noted in the accompanying il¬ 
lustration. This remarkable electric kitchen 
has a capacity for serving three thousand 
persons in four groups of from seven to 
eight hundred workmen in each group be¬ 
tween the hours of 12 noon and 2 P. M., 
one-half hour being allowed for each group. 
The electric cooking installation was de¬ 
cided upon after a careful study of the use 
of gas, coal and steam cooking in the va¬ 
rious plants of the Siemens Schukert 
Werke, in otlier cities and other suburbs 
of Berlin, where the office forces as well 
as the workmen have been served with 
meals for a number of years during the 
noon hour. 

This new electric kitchen is the most 
thoroly equipt kitchen cooking installment in 
the world, as well as the largest, being pro¬ 
vided with a modern cold storage and re¬ 
frigerating plant operated by electric com¬ 
pressors, electrically driven kitchen uten¬ 
sils of every description, including coffee 
grinders, knife sharpeners and meat slicers, 
and vegetable cutters, as well as electric 
potato paring and slicing machines. The 

Remarkable Electric Kitchen In Operation at Siemensstadt, Germany, With a Capacity of 
3,000 Persons. The Food Is Prepared by Electrical Machines Besides Being Cooked by This 


ing equipment are of special interest, and 
may be noted in the background in the ac¬ 
companying photographs. The baking 

son, is receiving the income from a $175,000 
trust fund by wireless because of the war 

October, 1917 



Electric “Zig-zagger’" Aids Ships to Foil U-Boats 

A ctual experience in the latest 
game—“dodging tlic siihinarincs”— 
has proved the efficacy of putting 
^ a ship over a zig-zag course once 
a hostile U-boat has been encoun¬ 
tered. It has been recommended by ma¬ 
rine experts that cargo vessels, whether 
armed or unarmed, pursue a zig-zag course 
or better still, a progressive scries of such 

a rapid-fire gun of from three- to six-inch 
caliber, the U-boat, once it has come within 
the elTcctivc range of the gun, must stay 
l)clo\v. The U-hoat commander prefers to 
get within one thousand yards of a ship 
before he attacks, and, if he can make it, 
he will get within five to seven hundred 
yards. The preferred position for attack 
is about two points forward of the beam. 

were based; his maneuver for getting into 
firing position goes for nothing, and he 
lias to try again. Unless he is satisfied 
that his guns can greatly outrange the 
enemy, the U-boat commander does not 
dare to use his surface speed, and below 
the surface he has not sufiRcient speed to 
overhaul the merchant ship. One or two 
misjudgments of this kind will lose so much 

Instead of Relying Entirely on the Human Factor in “Zig-Zagging*^ the Course of a Ship Attacked by a Submarine, the Automatic Elec¬ 
trical “Course Zlg-Zagger“ Here Shown Is Proposed. Electric Motors Swing the Rudder to Port or Starboard As the Case May Be, These 

Course Changes Being Made Automatically by a Special Electric Clock Switch. 

courses. Rut the captain of such craft is 
not over fond of following such a pro¬ 
cedure ordinarily and would much rather 
take a cliance on “beating it” along a 
straight course. Also, he is apt to argue, 
“why should I follow a zig-zag course, 
which is several miles longer than a straight 
one, and allow* the submersible time to catch 
up to me?” Again, zig-zagging is rather 
a nuisance anyway, and liable to get the 
ship's “log” all out of sorts; unless such 
courses arc accurately sailed there is a 
chance that the ship’s true position will be 

\Vhen all is said and done, however, zig¬ 
zagging has a protective value which it 
did not have before merchant ships were 
armed. Now* that the tramp is apt to carry 

On sighting an approaching sliip, the sub¬ 
marine heads to intercept her course, sub¬ 
merges, and then takes an occasional look 
at her, bringing its periscope above water 
for a few* seconds only. The U-boat com¬ 
mander estimates the speed and course of 
the ship; submerges, aJid Jays his oztm 
course by compass zvhile belotc, so' as to 
bring his boat zvithin torpedo. range at a 
point, preferably forzvard of the beam. 

Now consider that while the submarine 
is below*, the merchant ship changes her 
course, say thru an angle of 45 degrees, 
the former, on coming up for a few sec¬ 
onds’ look at the ship, finds that, instead 
of converging to meet him, the merchant 
ship is sailing in a direction entirely dif¬ 
ferent from that on which his calculation.s 

time, that the ship will have a good chance 
to pass him and steam beyond torpedo 
range; indeed, it will soon have gained a 
lead which the U-boat cannot overcome, 
except by coming up and usinc: his surface 

So we come back once more to the zig¬ 
zag course problem. Not only is more 
distance covered, hut the navigating 
officer may forget to make the change 
of course from one leg to the next at the 
proper time, and so throw the whole zig¬ 
zag into such confusion that the ship will 
not know' w here she is w'ith regard to her 
true course. To circumnavigate this, and 
with a view to making the running of the 
zig-zag course popular with ship captains, 
(Continued on page 414') 

// / 

^1 U'.f. 




,» fi™ 

SL iii 





The Training of the Young Man in Industry 

By E. M. Herr, President of the \Vestmghouse Electric & Mfg* Co. 

Written exclusively for the “Electrical Experimsnte* 

S uccess in the electrical industry is attained 
just as is success in any other industry, 
primarily by the development of general char¬ 
acter and trustworthiness followed by ina. tcry 
of the details of the particular branch of the in¬ 
dustry in which the young man is engaged. 

The men who do great deeds are those who have 
been again and again tried in stress and strain of 
hardships and ditticulties, perhaps in an entirely in¬ 
conspicuous way, but who have worked thru, never 
shirking, and have willingly taken up greater and 
greater burdens as they came to their hands, being 
most concerned not with the immediate rewards to 
be gained but with the feeling that progress was be¬ 
ing made in the work entrusted to them and that 
they had succeeded in their immediate task w'itli the 
result that their character, knowledge, training and, 
more important still, their courage and tenacity were 
strengthened for overcoming still greater dilhculties 
and bearing more and larger responsibilities. 

Great knowledge and learning will not alone suf¬ 
fice for attainment of success in the industrial world, 
for if they w'ould, w'e w'ould see the great scholars 
bearing the greatest responsibilities. History show’s 
us that its greatest men were generally not men 
possest of unusual learning, or, if they were, other 
great qualities of mind and character were present to 
an even more remarkable extent. 

Experience and a broad contact w’ith affairs is 
not all that is required, for many men of widest 
experience and who have been in touch with world¬ 
wide affairs are ineffective and frequently unable to 
assume great responsibilities depending * on their 
own efforts and initiative. 

Much good effort is often wasted and many a 
valuable man fails to make good because. use 

the old familiar phrase, he is “a round peg in a 
square hole”—by persevering, possibly, in a most 
admirable manner, in a position for which he is 
unfit; w’hcreas, were he placed in a position to 
which his talents were better suited, his entire 
source of energ>' would be devoted to an attain¬ 
ment of a high degree of perfection. 

The gradual assumption of more and more diHi- 
ciilt work with its attendant troubles, and the success- 
tul solution of them liy his owai efforts all tend to 
the development of the successful man. 

.A young man should perform his daily task for 
the satisfaction of its accomplishment rather than the 
expectation of an immediate reward. A reward, and 
a rich one, wdll surely come to him w ho can and does 
excel his fellow in doing things, no matter how bur¬ 
densome or onerous, provided they are w’orthy, and 
especially if such excellence is in w'ork or methods 
more difficiilt than is usually encountered. 1 he re¬ 
ward mav not come when expected—it may even be 
delayed until the w’orker feels great discouragement 
and can see no prospect of the recognition and reward 
he has justly earned. 

Experience, how'cver, shows that reward for unusu¬ 
al and successful efforts must come and if deferred, 
as it often is by uncontrollable circumstances, it wnll 
ultimately be paid with interest well compounded. 

The W'estingliousc Electric &: Manufacturing Co. em¬ 
ploys at the present time approximately 25,000 people. 
'The capital stock is $75,000,000. The gross sales for 
last year w^ere approximate!) $00,000,000 and will be 
considerably in excess of that this year. The plaiit'^ 
occupy approximately 100 acres of floor space. The 
company controls several thousand patents. 



October. 1917 




I'anncrs arc constantly hearing of the 
advantages of electricity on the farm, what 
it will do for them and its wide application. 
Some of this has been rather vague and 
The Society for Electrical Development 
has prepared a list of some 104 applications 
appended here. 

Of course, every farm will not find it 
economical to install all the equipment 
listed, but every farm will find profitable 
use for some of it. Many of the applica¬ 
tions can be handled best by a community 
<tf interests, for instance, electric thresh¬ 
ing and harvesting machinery, hulling ma¬ 
chinery, oil concentrating plants, hay balers, 
etc. High priced machinery used only for 
short periods during the year is applicable 

to this community 

Oat Crushers 
Alfalfa Mills 
Horse Groomers 
Horse Clippers 
Hay Cutters 
Clover Cutters 
Corn Shelters 
Ensilage Cutters 
Corn Crackers 
Branding Irons 
Currying Machines 
Feed Grinders 
Failing Machines 
Livestock Food W.arm- 

Sheep Shears 


Grain Graders 

Root Cutters 

Bone Grinders 

Hay Hoists 

Clover Hullers 

Rice Threshers 

Pea and Bean Hullers 

Gas-Electric Harvesters 

Hay Balers 

Portable Motors for 
Running Threshers 
Fanning Mills 
Grain Elevators 
Huskers and Shredders 
Grain Drying Machines 
Binder Motors 
Wheat and Corn Grind¬ 

Milking Machines 
Sterlizing Milk 

Cream Separators 
Butter Workers 
Butter Cutting-Printing 
Milk Cooling and Cir¬ 
culating Pumps 
Milk Clarifiers 
Cream Ripeners 
Milk Mixers 
Butler Tampers 
Milk Shakers 
Curd Grinders 
Cassin Grinders 
Bottle Cleaners 
Bottle Fillers 
Concrete Mixers 
Cider Mills 

Cider Presses 
Spraying Machines 
Wood Splitters 
Auto Trucks 
Electric Bells 
Ice Cutters 
Fire Alarms 
Electric Vehicles 
Electro Cultures 
Water Supply 
Water Sterilizers 
Fruit Presses 
Blasting Magnetos 

Interior Telephones 
Pocket Flash Lights 
Ice Breakers 
Emery Wheels 
Forge Blowers 
Drop Hammers 
Soldering irons 
Glue Pots 
Cord Wood Saws 
Egg Testers 
Burglar Alarms 
Bell Ringing Trans¬ 

Devices for Killing In¬ 

Machine Tools 
Molasses Heaters 
Vacuum Cleaners 
Portable Lamps to At¬ 
tract Insects 
Hot Plates 

Percolators (Coffee) 



Toilette Articles 
Water Heaters 

Egg Boilers 
Heating Pads 
Dish Washers 
Washing Machines 
Curling Irons 


At the last meeting of the British As¬ 
tronomical Association at Sion College an 
application of X-rays to obtain by analogy 
a te<^t of a theory of the sirnctnre of “ring" 
nebula* was shown by Mr. \V. H. Steaven- 
son. His idea was that the "ring" appear¬ 
ance did not necessarily imply the shape of a 
ring, but could he produced by a hollow 
globular form, the suggestion being that the 
absence of light in the interior of the "ring" 
is due to the thinness of the shell, which 
appears much thicker, and, consequently, 
brighter, just outside the central portion. 
X-ray photographs of rubber tubes showed 
a very similar appearance, rubber globes of 
sufficient thickness not being available. 

“Zig-Zag”—A New Thriller for the_Sea Shore 


TE ALL enjoy going to the sea- 
m/\/ shore, when the summer comes 
W V around each year, and all look 
^ * for thrills, be they young or old, 
grown-ups as well as kiddies, it*s 
bound to get us all—this beat-it-from-the- 
city spirit—to get out in the great outdoors 
and let loose! 

The attraction recently invented by an 

and begins its <lescent from the top of 
the tower with a zig-zag motion, from which 
the attraction derixes its name. 

The cars after leaving the top descend 
by gravity, traveling oxer a series of in¬ 
clined rails which are arranged one pair 
above the other in a vertical zig-zag line 
in such a manner, that the traveling seats 
are brought to a stop at the lower ends of 

The Latest Electrically Operated Thriller for Pleasure Resorts Is Known as the “Zig-Zag.” 
The Passengers Are Hauled to the Top of the Tower by a Motor-driven Cable. They Then 
Start Their Ziz-Zag Downward Journey by Gravity. 

Eastern man, Mr. Hartman, called the “Zig- 
Zag," will soon be seen by the crowds at 
pleasure resorts. 

The main part of the device is a large 
steel tower about a hundred feet high, an 
object of beauty and awe. especially at 
night, when hundreds of lamps shall blaze 
forth ox'er the entire structure. At the 
top of the toxver there will be a large ball 
of revolving lamps and searchlights to en¬ 
hance the scene. 

The passengers are seated in a small car 
which is drawn by an endless sprocket chain 
to the top of the tower. W hen the car 
reaches the top it is automatically released 

each pair of parallel running rails, drop a 
certain predetermined distance upon the 
ne.xt lower pair of rails and then travel 
along such rails in the op])osite direction 
doxvnxvard, until they reach in a zig-zag line 
the lowest pair of rails. A further swing¬ 
ing movement is obtained at the sudden 
temporary stops by the living force of the 
traveling suspended -^eats. 

.•\ close inspection of the illtistration will 
give the reader a good conception of how 
the mechanism works. 

Mr. Hartman docs not state how the pas¬ 
senger’s "inside mechanism” xvorks during 
the trip, but we presume people xvill like it. 

DATE OF ISSUE.— As many of our readers have recently become unduly agitated as to ivhcn they could obtain The Electrical 
E xrtRtMENTER, ICC ziHsli to stotc that the newsstands haz^e the journal on sale beizveen the fifteniih and the eighteenth of the month in 
the eastern port of the United States and about the tzventieth of the month zvest of the Mississippi Riz'cr, Our subscribers should be in 
possession of their copies at these dates. Kindly bear in mind, hozvever, that publicotions are not handled zcith the same dispatch by the 
Post Office as a letter. For this reason delays are frequent, therefore kindly he patient and do not send us complaints as to non-arriz’al 
of your copy before the tzvcnty-fifth of the month. 



October, 1917 

Firing Bombs by Electricity 

By H. Gernsback 

M odern bombs as used in trench 
warfare are divided in two class- 
es, namely: the “time-fuse*’ bomb, 
and the “contact'* bomb. The 
former, which at the beginning 
of the war was a rather crude affair, has 
now been greatly improved upon, and as 
a rule will go off five seconds after its re¬ 
lease. This tj'pe has a kind of trigger 
which is presst against the body of the 

“if you hold it too long, you jeopardize 
your own chances of being able to throw it 
at all.” 

As mentioned, this refers to the old tim¬ 
ers, lit by a match or a cigarette, and does 
not hold true for the modern type, timed 
to go off in five seconds. 

But the trouble with the modern type is 
that it is impossible to make it go off the 
moment it enters the enemy’s trench; it 

ically. We have a bomb weighing from 
five pounds upward, to be thrown in the 
enemy’s trench precisely as any other bomb. 
It can be thrown by means of catapult or 
other suitable means. The construction of 
the bomb is shown in Fig. 1. It has a hol¬ 
low center which contains in a shell a reel, 
upon which is wound a thin flexible electric 
cable. This reel runs free on ball bearings 
so as to give a minimum of friction. It 

Why Take Chances With Time-fused Bombs When This Newly Devi “"H El'^c^rir Bomb Is Sure to Explode at Exactly the Time Desired. 
When the Bomb. Filled With Explosive or Chloroform, Reaches theDesired Point, a Switch Is Closed and the Missile Is Detonated. They 

Are Thrown With a Catapult iii the Manner Illustrated. 

bomb; thus when the latter is released it 
will take the trigger just five seconds to 
ignite and consequently explode the bomb. 

The second bomb, as its name implies, 
goes off the moment it strikes a hard body, 
showering destruction all about it. For 
trench warfare, bombs are highly effective, 
and if the enemy’s trenches are “bombed” 
in a systematic manner, the men as a rule 
become very much demoralized. 

Bombs vary in size from the small hand 
bomb, the size of a baseball and containing 
from six to ten ounces of high e.xplosive. 
to the large cylinder-shaped affair contain¬ 
ing as much as thirty pounds of Trinitro- 
Toluol. The latter kind of course cannot 
be thrown by hand on account of their 
weight, but are projected thru the air either 
by a modern spring operated catapult or 
by a mortar'type ''Mincnivcrfcr*' first 
brought out by the Germans. 

The chief trouble with the old time fuse 
type, to quote Captain Ian Hay Bcitli, i.s 
that if the bomb is thrown too* soon “the 
other fellow has plenty of time to pick it 
up. and throw it back to the sender,*’ in¬ 
cidentally killing him. On tlie other hand. 

cither explodes a few seconds too soon or 
a few seconds too late. In the former 
case the bomb does not do much harm, 
but merely sprinkles the trench with steel 
fragments. In the latter case the men in 
the trenches find time to run for cover: 
f. c., dodging the homb. In both cases not 
very much harm is done. It is on record 
that it takes almost thirty bombs to kill one 
7nan} This certainly' is low efficiency. Also 
not all bombs go off, this being particularly 
the case with contact bombs: if the latter 
hit a soft body, such as straw or mud, the}* 
often fail to explode. Hence the great 
waste and low efficiency of the present 

With a view to rectifying several of 
these defects, as well as gaining certain new 
important improvements, the electrically 
fired bomb is suggested. At first blush the 
idea of putting a “string** on a bomb seems 
foolish, awkward, as well as troublesome. 
But if wc study the idea, it will be found 
that the new improvements probably greatly 
overbalance the imaginary defects, if such 
there are. 

Our front co\er illustrates the idea graf- 

will thus be seen that as tlie bomb prozeeds 
in its flight thru the air, the thin electric 
wire is played out, without in any way re¬ 
tarding or impeding the flight of the bomb. 
Naturally, the reel must contain a sufficient 
wire supply to reach from our own to the 
enemy’s trench. 

The space between the shell containing 
the wire reel and the bomb body proper 
is packed with the usual high explosive. 
The ends of the wire cable inside of the 
bomb are inserted into the explosive; the 
latter can therefore be set off by means of 
a fine platinum wire electrically heated to 
incandescence or by any other well-known 
firing method. 

The electric cable being of rubber in¬ 
sulated stranded wire can be quite thin, 
there being almost no strain whatsoever 
on the wire cable. This will be understood 
after a second’s reflection, for mechanically 
the bomb has nothing to do with the cable. 
The wire reel having ball bearings simply 
unwinds as the bomb moves on, therefore 
there can be no strain beyond the zveight 
(Continued on ^age 416) 

October, 1917 






mouth (by using a spoon for example; 
and al>o to employ a sufficiently high-fre¬ 
quency 'fcsla current. Such a current, os¬ 
cillating at say 100,000 cycles per second, 
will exert no muscular effects and simply 
passes over the skin of tlie lecturer. 

The interesting effect shown in the cen¬ 
ter top photograph, is attained by cutting 
out a cardboard figure and covering it 
with tinfoil. This may be laid on a pho¬ 
tographic plate and charged for a second 
with a high-frequency electrode. If de¬ 
sired a larger figure may be cut out of 

T HUS do our friends, the theatrical 
managers, announce the electrical 
star of theaterdom—he of the flash¬ 
ing sparks and mastodonic Tesla 
coils. Air. Ford is one of the most 
successful scientific lecturers in the coun¬ 
try and is now on a Chautauqua tour. 

“The late Elbert Hubbard described elec¬ 
tricity as ‘the juice.' Since Benjamin 
Franklin brought it from the sky with a 
kite, no better, or more scientific definition 
has been made. Yet the remarkable mis¬ 
understanding of the nature and properties 

r-J. P* 

Here Is Shown a Remarkable Demonstration of Electrical 
Welding Thru Two Human Bodies. Stiff Iron Wires Are 
Forever Welded, the Current Flowing From the Lecturer to 
An Assistant. Capable of the Simplest Explanation, This 
Experiment Is Nevertheless An Awe-Inspiring One. 

The Photograph Shows the Lighting of An Ordinary Candle 
by Means of a Stream of Water. In Connection With This 
Experiment, the Lecturer Becomes a Human Dynamo, Light¬ 
ing Arc Lights by Holding the Carbons In His Hands and 
Handling 3,000,000 Volts of Electricity. 

of electricity seems to be general and per¬ 
manent. In the entire realm of popular 
education no one thing can be of more im¬ 
portance than to educate the people on \yhat, 
to them, are the mysteries of electricity. 
To do this in a scientific, yet plain and 
thoroly entertaining way, is no small ac¬ 
complishment. The management, after 
much search and many discouragements, has 
found, in the person of Burnell R. Ford, 

such a man,'’—so reads our program. 

One of the startling experiments per¬ 
formed by the lecturer is that of welding 
by current, which is made to pass thru 
the human body. Stiff iron wires are 
solidly welded as shown above, the 
heavy current flowing from the lecturer’s 
mouth to that of his assistant. The essen¬ 
tial thing to be watched in making this ex¬ 
periment is to have metal contact with the 

thin wood and coated with tinfoil. When 
this is exhibited against a dead-black back¬ 
ground and properly excited by connection 
to a powerful Oudin or Tesla high-fre¬ 
quency coil the effect on the audience is 
truly remarkable. The foil-covered figure 
should be charged, preferably from the 
live terminal of an Oudin coil. 

The right top view shows a mystify- 
{Continued on page 422) 

At Right:—Lighting a Candle by a Spark 
From the Tongue—A Mystifying Electrical 

Frequency Currents Past Thru the Body. 

Above:—The Lecturer Lights Up a Bank of 
Lamps to Full Brilliancy, the Current Flow¬ 
ing Thru His Body. 



October, 1917 

Free Electricity from the Wind 




\'||| 5a!fl>ejr/nf 


W IND pressure as a natural source 
of power has been in practical 
use for driving grist mills and 
pumps for the last six hundred 
years. The efficiency and utility 
of the wind-motor has increased along with 
the development of modern manufacture 
until the all-steel wind-motor of to-day is 
a highly efficient machine, giving more 
power for every dollar of capital invested 
than either steam, gas, or waterfall. The 
great drawback to the development and 
general use of wind power has been the 
intermittent character of the power. At¬ 
tempts have been made in the past to gen¬ 
erate electricity with wind power and store 
the electricity for lighting purposes. 
Theoretically, this combination should be 
perfect, but many difficulties have been ex¬ 
perienced by those who have tried to put 
this combination into practise. The low 
speed of the wind-wheels rnade it difficult 
to get a satisfactory transmission of power 
from the wind-wheel to the dynamo. To 
operate at high efficiency the wind wheel 
had to run slow and the dynamo at high 
speed, thus introducing a dangerous ele¬ 
ment in the way of high speed gearing. 

In the new type wind motor plant here 
illustrated this difficulty is claimed to have 
been overcome. A special slow-speed 
dynamo has been designed to couple direct 
on to the driving axles of the wind-wheels, 
and a strong gear of simple design con¬ 
nects them together. 

The inventor. Air. Al. A, Atulrony, of 

Australia, has designed two sizes of rural 
lighting outfits of this type, and which for 

work together, like two horses, in pulling 
along their common load—the dynamo. 
When the two wind-wheels start turning, 
the dynamo, which is direct geared to the 
differential, starts generating electricity, 
and as soon as the electric pressure of the 
dynamo rises higher than 
that of the storage batters^ 
an electric valve trips, and 
the electricity begins to 

Every Suburban Dweller 
Ought to Have Electric 
Lights These Days, and 
to Make This Dream a 
Reality an Australian In¬ 
ventor Has Perfected the Practical Wind-motor Dy¬ 
namo Plant Here Shown 





Brt . c / iarg //^ 


Sectional View of Newly Perfected Wind-Motor and 
Dynamo Unit. The Storage Battery Keeps the Volt¬ 
age Even. The Plant Stands Any Wind Pressure. 

purposes of comparison we shall term as 

The small plant with a capacity' for light¬ 
ing fifteen 16-candle power lights 
for a period of four hours per day, 
and a storage capacity to operate 
fifteen 16-candle power lights for 
six days without any wind at all. 

The large plant has the same 
specification as the small plant ex¬ 
cept that it has a capacity to light 
twenty-five 16-candle power lights 
per day. * 

The electricity may be used to 
operate electric fans, electric vacu¬ 
um cleaners, sewing machine mo¬ 
tors, electric pumps, electric toasters, 
and small electric irons. The in¬ 
ventor has adopted twenty-five volts 
as standard pressure. The storage 
battery consists of 14 cells con¬ 
nected in series. This insures easy 
charging from the dynamo, as there 
is practically no resistance in the 

The wind-motor has two wind- 
wheels as will be observed, one be¬ 
ing a little larger than the other. 
The smaller wheel of the two always 
faces to the wind, and maintains its 
position in front of the larger or 
back wheel. The wind first presses 
against the vanes of the smaller 
wheel, and starts this wheel turning 
in the direction of the hands of a 
clock. The whole force of the wind, 
however, is not exhausted on the 
wheel, but a part of the wind pres¬ 
sure passes thru to the back wheel, 
and again is turned into rotary mo¬ 
tion. The back wheel also turns in 
the same direction as the hands of a 
clock. The two wheels are on sep¬ 
arated axles, hut are coupled to¬ 
gether by a differential gearing in 
similar fashion to the back axle of 
a motor car. This differential allows 
each wheel to . rotate practically as 
it it had no connection with the 
other, and in this way brings about 
an excellent equalizing effect and a 
balance of power. The two wheels 

pour into the storage battery, and con¬ 
tinues to do so until the wind pressure fails. 
When this happens the electric valve im¬ 
mediately trips and disconnects the wire 
carrying the current, thus preventing the 
electricity from escaping back thru the 
dynamo. The above operation can be 
likened to an ordinary windmill driving a 
pump, and pumping water from a well into 
a tank. When the wind fails the valve 
in the pump closes, and prevents the water 
from the tank running back into the well. 

The operation of this plant is claimed to 
be absolutely automatic, and a hand is not 
needed near it for six months at a time. 
In high winds and low winds alike, all ad¬ 
justments as to wind direction, speed, turn¬ 
ing out of the wind, etc., are made auto¬ 
matically. The application of the gyro¬ 
scopic principle ensures that the mechanical 
operation is automatic. 

The dynamo is a special and original de¬ 
sign, and forms the supporting base for the 
wind-motor unit. The armature is of pe¬ 
culiar shape, being much longer for its 
diameter than usual. This feature gives 
the dynamo its remarkable characteristic of 
generating electricity at exceptionally slow 
speed. {Continued on page 422) 

Output of Type M l Fifteen 
Light Plant 

\Z 600 
•5 550 
z 450 
. 400 

5 350 

6 300 
5 250 

o eoo 









i 4 6 6 10 Q M 16 10 20 S ;4 A U 30 3e 34 U 

Wind Pressure in Miles per Hour 

Typical Electrical Out-Put Curve for 15 
Light Wind-Motor Dynamo Plant at Vari¬ 
ous Wind Pressures. 

October, 1917 



New Electro-Therapeutic Apparatus 


A t the convention of the American 
Medical Association held at the 
Hotel Astor in June at New York 
^ City, the exhibit of electric appa¬ 
ratus showed many interesting new 
developments, particularly those to be used 


supported on a rod of molybdenum and a 
cathode consisting of a tungsten spiral, 
which was heated electrically from a low 
voltage circuit from the primary of the 
transformer. The X-ray tube suppresses 
any current in the direction that does not 
make the hot filament cathode. It there¬ 
fore is capable of rectifying its own cur¬ 
rent. In order to make the conditions 
stable a large set of air cooled ventilating 
vanes arc made part of the anode of the 

The gasoline engine unit which operates 
the transformer is so designed with an 
electrically controlled solenoid that it can 
be placed some distance from a base hospi¬ 
tal or tent, thus eliminating the unpleasant 
noise. The entire equipment is so arranged 
as to be portable for immediate transporta¬ 

X-Ray Accessories 

Some of the newer developments in the 
accessories to be used in connection with 
X-ray work include the Hydrex tube, Fig. 
2. This tube operates on the principle of 
having an auxiliary' chamber filled with 
hydrogen and sealed from the top by a 
mechanically operated mercury^ valve. This 
valve is opened by drawing the mercury 
past two porous blocks, thereby leaving a 
passage for a certain amount of hydrogen 
to enter the tube. To open the valve a 

in connection with hospitals and field hos¬ 
pitals at the front. 

One very ingenious X-ray equipment con¬ 
sisted of a portable table for laying the 
patient upon to be X-ray'ed; the outfit also 
included a small gasoline engine generating 
set, a closed core transformer, this trans¬ 
former being used in connection with a 
regulating device to operate a new type 
of X-ray tube. This tube, about four inches 
in diameter (see illustration, Fig. 1), had 
an anode terminal of solid tungsten metal 

One type of tabic was so nicely counter¬ 
balanced that very little effort was needed 
to obtain almost any position an operator 
would wish. It was also arranged with 
a small motor, foot controlled, which would 
raise the table or lower it in an angular 
position, according to the will of the 

Fig. 7. This Miniature Electric Incubator for 
Microscope Stages Enables the Physician to 
Study “Live’* Bacteria Organisms. 

small suction pump is provided and is 
clamped directly on to the glass bowl, or 
any' other convenient place, so the rubber 
tube can be attached 
to the hydrogen 
chamber. To lower 
the vacuum the 
plunger is pulled out 
to its full length 
and released imme¬ 
diately. To raise the 
vacuum all that is 
necessary is to dis¬ 
connect the anode 
and connect it to 
cathode and run a 
weak current thru 
the tube. 

Very elaborate 
tables of new devel¬ 
opment were shown 
for lay'ing the pa¬ 
tient upon and so 
equipt as to be used 
either for examina¬ 
tion with a fluor6- 
scopc or to be used 
directly' in taking 
X-ray plates. 

Fig. 5. A Recent Type of Anesthetizing Ap¬ 
paratus, Driven by a Small Electric Motor. 

Another tyi^e of table was fitted with 
accessories necessary for making charts of 
the heart and lungs, these charts or tracings 
being made directly by examining the pa¬ 
tient with a fluoroscope and by means of 
an automatic device. 

A duplicate of the X-ray equipment sup¬ 
plied to the N. Y. Bellevue Hospital was 
also shown, being the largest X-ray plant 
in the United States, 

(Continued on page 42n 

Hydrogen Thro 
Hydrogen Thru 

a Mercury Valve. Vacuum Is Adjustable, 
a Mercury Valve Vacuum Is Adjustable. 


October, 1917 



Cheap living and plenty of it; wide va¬ 
riety; wholesome, clean, nourishing food; 
prepared quickly with little labor and trou¬ 
ble in your own home—by your own hands! 
An electric fan and a kitchen knife are 

immediately at a cost of about $4,000,000 
and that water power would not be used. 

Informally officials explained that the 

announcement did not mean that the idea 

of building a water-power nitrat plant had 
been permanently abandoned, although it 
would not be pressed at present. Several 
years would be 
required to 
build the enor¬ 
mous plant re¬ 
quired for the 
utilization o*! 
water power, 
and for that rea¬ 
son it was de¬ 

termined that' 
for urgent war 
purposes it 
would be neces¬ 
sary to adopt 
one of other 
processes of pro¬ 
ducing nitrats. 

A New Use for the Electric Fan In Drying 
Which to Help Win the 

the only ^‘tools'’ necessary. Drying can be 
done in home-made box trays, a table top, 
sheet, strings (apples, pears, etc.), and 
dozens of other ways. Just like grand¬ 
mother did, only quicker, cleaner and bet¬ 
ter tasting] 

The U. S. Department of Agri¬ 
culture says (Bulletin No. 

^1) : ‘‘The fan method has 
a marked advantage in that 
the product keeps cool, owing to 
evaporation while it is being dried, 
thus tending to retain the color 
and eliminate spoilage.’’ 

Almost all the vegetables and 
fruits can be treated and stored 
away—even the most juicy, like 
tomatoes. And besides—this new 
way of drying eliminates the big¬ 
gest part of the work. It does 
away with a lot of canning—and 
that’s good, for jars and contain¬ 
ers are very scarce and mighty 
high in price. 

All summer long, at odd times, 
the housewife can pick up choice 
bargains at the markets, prepare 
them in a few minutes, and the 
drying goes on while she attends 
to something else. By cold 
weather time she can have her 

Another Way 


By the time an applicant for the position 
of motorman or conductor on the Brooklyn 
Rapid Transit System has past thru their 
school for employees he has had it brought 
home to him that a man must have at least 
the qualifications of good character, a clean 

rate detail of the mechanical equipment 
from which the men receive their instruc¬ 
tion, are most impressive; and the entire 
array of massive and handsome exhibits, 
while attracting and holding the interest, 
might seem to defy the layman’s under¬ 

Here spread out before you are the vitals 
of the trolley" car, dissected and labeled. 
(See accompanying illustrations.) No de¬ 
tail is left in darkness or obscurity. All is 
revealed. Even the little boy who for years 
has yearned to crawl under a car to see 
what it looks like inside would be satisfied. 
For in very truth he would see one turned 
upside down, and working just the same in 
spite of the awkwardness of this position, 
as a turtle sometimes keeps on working 
when you turn it over on its back. Be he 
schoolboy or grown man, any visitor would 
enjoy a trip around the motormen’s room 
with one of Instructor Duffy’s classes. 

Emphasis is laid on the regular inspection 
of his car which a motorman is required to 
make before going on the road, special at¬ 
tention being called to the life guard, by 
which about ninety per cent, of persons 
knocked down by the front of a car have 
been saved. 

Every part of the equipment is in its 
standard location, many of them bearing 
metal signs to accustom the men to calling 
things by their right names. Fare col¬ 
lection, door operation, buzzer signals, 
thermostat control of heaters, use of 
switches, replacement of fuses, etc., are 
also demonstrated. The use of the electric 
automatic track switch is taught in connec¬ 
tion with the center entrance 
car, switch levers, semaphores 
and lights all working just as 
they would in actual service. 

^ Step by step the men in the 

schoolroom become familiar 
with the elaborate mechanism 
that passes into their keeping 
when hand and controller 
meet. The “demonstration 
board,” which shows the 
course of the current and the 
operation of the control from 
trolley wire to rail, is a toy 
which could not fail to fas¬ 
cinate any human being be¬ 
tween the ages of six and 
sixty. When this board has 
been explained to him the stu¬ 
dent has a remarkably clear 
idea of how the electric cur¬ 
rent operates and how it is 
controlled .—Photos courtesy 
B. R. T. Monthly, 

home stocked up like a siege fort 
—for the longest, hardest kind of 
a cold, long winter. _ 


Orders aggregating 1,000 lines of auto¬ 
matic central office equipment and 1,000 
telephones equipt with the dial, have just 
been placed to be used as additions to the 
automatic exchanges in Australia. This is 
the second such order placed since the be¬ 
ginning of 1917, the first one, for 1,800 
lines, being received in February. 

The progress of the automatic in Aus¬ 
tralia has been most rapid. Only five years 
ago there was a single 1,100-line exchange 
in operation, at Geelong. Today there are 
nearly a score of exchanges and a total of 
practically 35,000 lines of automatic equip¬ 
ment in service thruout tlic commonwealth. 
No “central” is required and thus misun¬ 
derstandings a re eliminated. 

U. S. TO SPEND $4,000,000 FOR NI¬ 

Secretary Baker has announced that a 
plant for the production of nitrats from 
atmospheric nitrogen would be constructed 

record, good 
health and a pre¬ 
sentable appear¬ 
ance before he is 
even given a 

This frame of 
mind receives a 
new impulse 
when the stu¬ 
dent enters the 
B. R. T. Surface 
School Room, 
for here he finds 
himself in a place 
where there is 
manifestly much 
to learn—more, 
perhaps, the 
average appli¬ 
cant might feel 
at first glance, 
than he could 
ever hope to 
learn. The in¬ 
tricacy and elabo¬ 

Two Views of the Brooklyn Rapid Transit Company’s School for Motormen. 
Every Part of a Trolley Car Is Dissected and Demonstrated in Working 


October, 1917 




When a woman is sulky aivl 

will not speak. /i.rcfri'r 

If she gets too excited. Controller. 

If she talks too long. ... Interrupter. 

If her wa\' of thinkin • is not 

yours . Converter. 

If she is willing to cone half 

way. Meter. 

If she will come all the way Receiver, 

If she wants to go further.. Conductor. 

If she w’oiild go still further Dispatcher. 

If she wants to be an angel. Transformer. 
if you think she is unfaithful Detector. 

If she is unfaithful. Lever. 

If she proves your fears are 

wrong . Compensator. 

If she goes up in the air... Conden.^er. 

If she wants chocolates.... Tcoder. 

If she sings wrong. Tuner. 

If she is in the country. Telegrapher. 

If she is a poor cook. Discharger. 

If her dress unhooks. Connector. 

If she eats too much. Reducer. 

If she is wrong. Rectifier. 

If she is cold to you. Heater. 

If she gossips too much ... Regulator. 

If she fumes and sputters. .. insulator. 

If she becomes upset. Reverscr. 

stand men in many parts of the countrj'. 
L. Ahlberg, an Alaskan, has invented a 
machine which brands frtiit by electricity. 
The California Fruit (Growers Exchange 
has bought an option on the exclusive rights 
for the use of the machine in connection 
with shipments of ‘'Sunkist** citrus fruits 
to all parts of the United States, Canada, 
England and Ausralia. 

The machine can be used in branding 
an}' fruit that has a waxy skin. It will 
brand oranges, lemons, apples, pears, water¬ 
melons and cucumber.^. The device con¬ 
sists of a big wheel with IS spokes in it. 
At the end of each spoke is a shoe in which 
there is a die which stamps the name of 
the fruit into its check. As the wheel re¬ 
volve.^, a small nipple at the top drops a 
little ink upon each die, and a felt wheel 
distributes it. An automatic device turns 
on the electricity or shuts it off whenever 
the temperature of the die rises above or 
drops below a certain point. The dies are 
prest down upon the fruits ns they are 
carried along beneath the wheel on an end¬ 
less bell of metal saucers, and each die 
makes its hot imprint into the cheek of 
the friiit. 

The heat of the die melts the wax in 
the skin of the fruit, causing it to flow' 
into the imprint of the die and fill up any 
breaks which might be made in the skin, 
at the same time taking up the ink from 
the face of the die. 

Citrus growers in Southern California, 
where the machine has been operated in 
packing houses on an experimental basis 
ft)r twenty months, declare that it gives 
absolute satisfaction. It is capable of 
branding two carloads of orangc< or lemons 
per day. 

Photo Courto^sy of MlchUtan Stai© Auto School. 

The Electric Dynamometer In Use for Testing Horse-power of Gaso¬ 
line Engine In the Laboratory of Progressive Western Auto School. 

in communicating 
w’ i t h suspicious 
\' e s s e 1 s . 


J. H. Johnson, an Associated Press oper¬ 
ator in Boston, w'hile working at ^lan- 
cliester, X. H., a year ago, devised an in¬ 
genious method of determining the amount 
of work performed by him in one night. 


By Harold J. Wood. 

O XE of the new^est wTinkles under the 
sun is the idea of branding oranges, 
lemons and apples to protect them 
from the unscrupulous methods of fruit- 

The Fruit Growers Have Solved the 
Problem of Indelibly Marking Their 
Brands by Means of An Electrically 
Heated Revolving Die. It Brands Two 
Carloads of Oranges Per Day. 


One of the leading auto schools of the 
w'cst has installed in its testing laboratory 
the modern electric dynamometer here illus¬ 
trated. The students are thus enabled to 
make very accurate tests on any type of 
gasoline engine w'itli regard to the horse- 
pow'er output and other characteristics. 
The electric dynamometer represents the 
highest form of prime mover testing device 
available to-day. The dynamo unit is mov- 
ably swung in substantial pedestal bearings 
as shown, the turning effort of the engine 
connected to it for test being indicated on 
suitable scales and electrical indicating in¬ 

Aeroplane engines are now tested by a 
similar apparatus. No guess work enters 
the tests as carried out with the dyna¬ 
mometer, the results being accurate to with¬ 
in a fraction of a per cent. There will be 
a very large demand for engine drivers and 
e.xperts this Fall. 

exprest in mechanical terms says Telegraph 
and Telephone Age. By rigging up a postal 
scale in a special manner he found it re¬ 
quired a pressure of ten ounces on the type¬ 
writer keys to print each letter, and in the 
course of a night, with an average report 
of 14,000 words, allow'ing five letters to^ a 
word, the total pressure exerted w'ould lift 
700,000 ounces, or 2IJ4 tons. 

This computation w'as the result of a dis¬ 
cussion which arose in the office of the 
Manchester paper as to which man on the 
paper w’orked the hardest. 

The award \vcls made to another man, but 
Air. Johnson, not being satisfied with it, 
made the investi¬ 
gation of his owm 
work on his own 
account, with the 
result that he was 
declared to be the 
hardest w'orker in 
the office. And yet 
they do say truck 
drivers are the 
only men that do 
real w'ork! 


A secret wireless 
station has been 
discovered on the 
coast of the terri¬ 
tory’ of Cliubut by 
the Argentine Na¬ 
vy Department. 

The authorities 
believe the station 
W'as to be used 

A mong the hundreds of new devices and appliances publisht monthly in The Electrical Experimenter, there are several, as 
‘ B rule, which interest you. Full information on these subjects, as well as the name of the manufacturer, will be gladly 
furnisht to you, free of charge, by addressing our Technical Information Bureau 



October. 1917 


An investigation into the suitability of 
chromium steel for permanent magnets has 
recently been carried out in Germany and 
reported upon to the Physikalische-Tech~ 
nische Reichsanstadt. Figures are given for 
five bars of chromium steel, these being 
compared with five bars made of tungsten 
steel, the product of remanence and coercive 
force being taken as a criterion of quality. 
The remanence of the chrome steel bars 
was further tested under 20 hours' heat¬ 
ing at 100°C, six heatings up to I00®C. and 
20 falls from a height of 2^ metres on to 
a wooden block. It is concluded that care¬ 
fully prepared chromium steel is a suitable 
substitute for tungsten steel. 


The electrical engineering department of 
the State Agricultural College of Manhat¬ 
tan, Ks., is at present engaged in conduct¬ 
ing a series of experiments with a view to 
improving the prevailing methods of gen¬ 
erating electricity from windmill power. In 
the present test the generator is mounted 
on the head of the mill and geared directly 
to the source of power, instead of being 
belted to the mill at its base, as is usually 
the practise. The main need at present 
seems to be a mill that requires a lower 
wind velocity to start those now available 
since the latter are idle for long periods at 
a stretch, and therefore necessitate the em¬ 
ployment of large storage batteries. 

Unique Revolving Dancing Floor 

Do you like to dance? Well, here’s a new 
one in gay New York that has the old- 
fashioned “barn dance” of our grand-dads 
beat forty ways. 

gages this rack. The shaft is connected 
thru numerous reduction gears and at¬ 
tached to a 54 horse-power electric motor 
which slowly revolves the floor; not faster 

A New York Restaurant Has Provided a Real Novelty for Its Patrons in a Re- - 

volving Dancing Floor. An Electric Motor In the Basement Turns It Slowly 

While the Diners Enjoy the Novel Sensation. NOVEL MEDICAL COIL IS CON¬ 


When you are in town don’t fail to take 
a trip to Murray's, one of the city’s show 
places and cabarets, where between courses 
you may dance, dine and wine with your 
partner upon a floor that slowly revolves 
’neath your feet, giving a pleasing and novel 
sensation as you whirl to the strains of 
the Jazz Band. 

In the center of the revolving floor is a 
circle of beautifully colored glass, under 
which are myriads of lights and as one 
whirls around, flickering shadows are cast 
upon the dancers. 

The writer, who did not know about the 
revolving floor feature, one day last month 
visited this restaurant and took a seat at 
one of the tables placed at the circumfer¬ 
ence of the revolving floor. At another 
table two feet away, but on terra firma, he 
noticed an acquaintance. A few pleasan¬ 
tries were exchanged, whereupon the writer 
buried his face in the voluminous bill-of- 
fare. It took several minutes to decipher 
the French dishes ct al, after which he ad- a few more words to his ac¬ 
quaintance, not taking the precaution to 
look at him first. ‘‘Sir, how dare you!” 
spoke up an angry looking female, at the 
spot where the acquaintance was supposed 
to sit, hut alas, sat no more! You see 
the floor had revolved smoothly and sil¬ 
ently some six feet, and the writer’s ac- 
(piaintancc was now that far behind! It 
took the writer a few seconds to realize 
what had happened, and the expression on 
his face while apologizing to the insulted 
damsel, must have been anything but in¬ 

Now to let the render in on how all this 
is done—Presto. The floor is on a pivot 
under which are numerous wheels care¬ 
fully set and oiled so as not to make any 
sound when the floor is ino\’in‘r. Along 
the outer edge of the floor (which is reallv 
a large disc twenty-five feet in diameter) 
is a toothed rack carefully concealed un¬ 
der the flooring. A pinion on a shaft that 
passes thru the floor to the basement en¬ 

than one complete revolution every half 
hotir. By referring to the sectional diagram 

ContactJor rCo/oree^ g/oss 

tight chfi \jamp5s^ 






How Electric Motor Rotates Novel Dancing 

a good idea of the mechanism may be ob¬ 
tained. — 

A gasoline engine driven dynamo that 
is entirely automatic in its action is at¬ 
tracting attention in England. 

The United States Bureau of Standards 
has developed a delicate thermo-electric 
test for the purity of platinum. 

The accompanying illustration shows one 
of the latest electro-medical coils which is 
extremely compact as will be evident. The 
small induction coil, as well as the dry bat¬ 
tery and regulating attachment, are all built 
into the tubular electrode handles which 
are connected together by a flexible con¬ 

To use the apparatus the patient has but 
to hold the two electrodes in the hands and 
by pressing a small sliding switch on one 
of the electrodes, the current is turned on. 
The strength of the current may be in¬ 
tensified by means of a sliding tube pro¬ 
jecting from one of the handles. If it is 
desired to apply the current by means of 
a dampened sponge electrode, then this de¬ 
vice is inserted in a socket on one of the 
handles, and the current may then be 
switched on to the sponge instead of to 
the handle shell by depressing a switch but¬ 
ton provided for the purpose. The com¬ 

plete outfit is very neat in appearance, and 
a new dry balterN can be replaced in a few 

This Latest Idea in Compact Electro-Medical Coils Comprises a Small Induction Coll, 
Switches and Battery, Which Are All Contained Within the Two Electrode Handles. 

October, 1917 




'1 he applications of electricity for re¬ 
lieving botli man and woman of tedious 
work and drudgery are gradually being ex¬ 
tended. One of the most irksome duties 
conneeted \vith the keeping tidy of large 
buildings and institutions, is the scrubbing 
of floors. Not only is this a laborious and 
disagreeable task, but it takes a great deal 
of time to go over a large surface of floor¬ 
ing with scrub brush or even with a mop. 

The solution of this problem is the elec¬ 
trically driven floor scrubbing machine. 
A device of this character which has been 
tried out and found very satisfactory is 
illustrated herewith. The machine is en¬ 
tirely self-contained and, considering its 
large capacity, is quite compact. Its di¬ 
mensions are 28 inches long, 20 inches 
w'ide, 16 inches high. The weight of the 
outfit is 100 pounds. The entire machine 
is made of metal except the revolving 
brush. The upper portion of the machine 
consists of a tank for holding clean water. 

The machine wets, sweeps, scrubs and 
dries the floor at a single operation. It 
requires only a single attendant who mere¬ 
ly pushes the machine forward and guides 
it. He controls the amount of water dis¬ 
tributed on the floor by means of the 
handle. This water is immediately swept 
up by the cylindrical brush which is 16 
inches wide and has a circumference of IZ 
inches. This brush is driven by a one- 
fourth horsepower motor thru a silent 
chain and sprocket so that the brush re¬ 
volves at about 600 revolutions per min¬ 
ute. The brush does the actual scrubbing 
and carries all of the dirt and soiled water 
over an apron into a separate receiving 
pan so the scrubbing is always done with 
clean water from the upper tank. An up¬ 
right is attached to the machine which 
carries a cord reel at the top’ to permit ot 
taking in and letting out the cord by means 
of which it is connected to any ordinary 
lighting outlet. 

A ‘4 H.P. Electric Scrubbing Machine for Use In Large 
Buildings and Halls. It Reels Up or Unreels Its Electric 
Supply Cable as It Goes Along. 

This machine has an extraordinary ca¬ 
pacity. It has been found that if the at¬ 

tendant pushes the outfit forward at a generators. 


Contracts totaling approximately $2,000,- 
000 have been placed recently with the 
W’^estinghouse Electric & Mfg. Company, 
by the New York Shipbuilding 
Company, for furnishing the 
necessary electrical equipments 
for the propulsion of the new 
Superdreadnaughts '‘Colorado'' 
and *‘lVQShington/' 

The equipments to be fur¬ 
nished are practically^ duplicates 
of that contracted for by the 
Navy Department for the U. S. 
S. ‘'Tennessee!' now building 
at the New York Navy Yard. 
The four propellers, as in the 
case of the “Tennessee!' in¬ 
stead of being mechanically 
connected to driving engines or 
turbines, are to be driven by 
individual motors. The current for the 
motors will be furnished by two turbine 

rate of one mile per hour, it wdll scrub an 
area of nearly 7,0(X) square feet per hour, 
1 'his is about ten times as much floor area 
as an experienced janitor can scrub clean 
in the the same length of time. Not only 
has this machine exceptional capacity, but 
it leaves the floor much cleaner and more 
evenly scrubbed than can be done by hand. 

Naturally the greatest field for a ma- 
ehine of this type is in cleaning corridors, 
halls and large rooms in public buildings, 
office buildings, etc. In such places the 
janitor work is iisuallv done at night. Be¬ 
cause the machine cleans the floors so 
rapidly, it results also in considerable sav¬ 
ing in current used for lighting the prem¬ 
ises during cleaning. 


The annoyance of groping about blindly 
for the keyhole on cold (or "large sized” 
evenings) nights will become a thing of the 
past if the invention illustrated here comes 
into general use. The device is that of an 
Ohio man. By pushing a button on the 

Blank - Blank - Where In - 

Is That Keyhole?!! Push the Button In This 
Electric Knob Device and the Keyhole Be¬ 
comes Instantly illuminated. 

door knob a small electric light just above 
the keyhole is flashed on and finding the 
keyhole then is an easy task. 


The accompanying illustration shows a 
new tvpc of electric cigar lighter for use in 

An Electric Spark Ignites a Wick 
Soaked with Gasoline in This Cigar 
Lighter. It May Be Operated by Bat¬ 
teries or From the Lighting Circuit. 

cigar stores, or for private use. This de¬ 
vice can be operated either from a lighting 
circuit or from batteries placed within the 
box supporting the lighter. This lighter 
insures a continuous stream of sparks which 
flow to the wick until it takes fire. The 
arnount of electrical energy consumed for 
this purpose is very small. The only oper¬ 
ating expense is the cost of 1 gallon of gas¬ 
oline for feeding the wick. For this pur¬ 
pose 1 gallon of gasoline will last a full 
year. When used with batteries, a special 
control lever allows the device to use cur¬ 
rent only when the lighter is in actual use. 
This feature reduces the current consump¬ 
tion to a minimum. In case of wear or in¬ 
jury, any part of the lighter can be readily 
replaced at moderate cost. 

In addition to the main generating equip¬ 
ments and propelling motors, the contracts 
include auxiliaries for the main turbine 
generators and smaller auxiliary turbine 
generators for supplying light and power 
thruout the ships, A multitude of electric 
motors will also be utilized for doing near¬ 
ly all the work on board from raising the 
anchor to steering. 

60,000 COPIES "E.E,” 
arc now sold every month on the principal 
news-stands in the U. S. and Canada; and 
over 5,(X)0 readers are disappointed every 
month because the news-dealer says: “Sold 
out!" How often did it happen to you? 
Why not order a copy from the news¬ 
dealer NOW? It costs you nothing to do 
so, and your copy will be waiting for you 
next month. 

The greatest 15c worth in the U. S. 

Intercommunicating telephones, electric 
lights, call bells, and a complete fire alarm 
S3'Stcm are installed in modern farm build¬ 
ings on the estate of a wealthy Long Isl¬ 



October, 1917 


For over fifty years, the treatment of 
root canals has been a nightmare to care¬ 
ful and conscientious dentists. Recent 
scientific investigation shows that the dan¬ 
ger from the sort of treatment still in 
vogue among 99 per cent of operators, and 
the distress and mortality resultant from 
carelessness, improper methods, crude and 
inefficient instruments, are little short of 
appalling and certainly de- 
plorable. To make root- 
canal operations a success 
the canal must be ade¬ 

Dr. Funk and His Newly Invented Electrical 
Broach Wrapper for Dentists which Bids Fair to 
Save Many Lives Annually by the Antiseptic 
Conditions It Brings About. It Ensures a Per¬ 
fectly Clean Broach for Every Patient. 

quately enlarged to permit thoro cleansing, 
which* means^ that ever>' vestige o£ dead 
nerve and bacteria, which is liable to be 
present, must be removed and the canal be 
perfectly filled, the most difficult part of the 
entire operation being the removal of debris 
under aseptic conditions. 

The only method by whicli root canals 
can be cleansed is purely mechanical and 
consists of wrapping cotton on steel 
needles, which have a fork or notch on the 
end. The notch is very important, other¬ 
wise the cotton would slip up on the shank 
of the needle and the cleansing cotton 
would not reach the base of the root, there¬ 
by leaving it uncleansed so that putrifica- 
tion would sooner or later take place, sub¬ 
sequently forming an abscess, which is 
liable to cause distressing, if not fatal di¬ 
sease. such as rheumatism, heart trouble, 
neuritis, blindness, insanity, and a host of 
other constitutional ills. 

The old method of wrapping treating 
cotton on dental needles was accomplished 
by twisting it on the needle with the fin¬ 
gers: this is an uncleanly and dangerous 
procedure, the cotton being contaminated 
with dead cuticle, perspiration, and any 
germs that may have been present on the 
fingers of the operator. 

Assuming there are 40.000 dentists in 
the United States, six patients per dentist 
per day. 240.000: three hundred days per 
year, 72.000.000 sittings: five applications 
per sitting. 360.000.000. to be conservative, 
divide this by two. 180.000,000. If one cares 
to be ultra-conservative, halve it again, 
90,000.000 and re-halve it if you please, 

leaving 45,000,000 chances of infection due 
to digital contamination. This should still 
be sufficient reason to strive for safer and 
better methods. Many attempts were 
made to produce an effi- 
cient machine for^ wrap- 
ping needles, and given up 
in despair. It seemed, for 
a time, to be a mechanical 
impossibility to distribute 
microscopic threads of 
cotton on a hair-like needle 
suitable for den¬ 
tal purposes. 
However, after 
years of experi¬ 
menting, Dr. L. 
L. Funk has fi¬ 
nally succeeded 
in perfecting a 
machine that ac¬ 
complishes the 
work in a most 
perfect, sa¬ 
and sanitary 
manner: the 
cotton at no 
time coming in contact with the fin¬ 
gers of the operator. The machine 
is self sterilizing and there can be no 
chance .of infection due to faulty 
mechanism, since materials do not 
come in contact with germs during 
the process of wrapping, sterilizing 
would seem unnecessary; however, 
on the principle of safely first, last, 
and always, the machine is provided 
with five sterilizers, practically every 
method known to science, to be used 
in conjunction with the wrapper. The 
machine is simple to operate. A child 
ten years of age with ordinary in¬ 
telligence can wrap broaches more 
quickly and perfectly than it can pos¬ 
sibly be done by hand. 

In view of the awful carnage now 
rampant thruout the world, and from 
a humanitarian standpoint I desire to 
offer what service I can, con¬ 
sistently, to the United States 
Government, by d o n a t i n g these 
Broach Wrappers to be used in Government 
Infirmaries, says Dr. Funk, with the hope 
of at least preserving one life for every life 
destroved in battle. 


The accompanying photograph shows a 
sturdy 3]/2 horsepower electric motor run¬ 
ning under water. This motor was first 
put under water in September, 1909, at a 
Machinerv Exhibition in Cleveland, where 

A V /2 H.P. Electric Motor Running Under 

it attracted such great attention that it was 
decided upon as a sort of trade mark for 
the manufacturers. 

The motor has repeatedly been used in 
installations where it is subject to condi¬ 

tions fully as severe as this. One salt 
works in Cleveland has had a number of 
these motors in operation for oyer ten 
years, and the wet salt has caked into the 
windings, until they are scarcely visible: 
still there has been no motor failure in all 
this time. It takes a particularly husky and 
well-built motcr to withstand’ any such 
treatment as this. 


The rectifier shown in the accompanying 
illustration is designed for the charging 
of small storage batteries, such as used 
with automobile ignition, lighting and 
starting sets. The single-circuit type is a 

One of the Jobs We All Hate to Tackle 
Is Charging Storage Batteries. In This 
Simple Automatic Device a Motor Drives 
a Commutator in Such a Way that the 
Alternate -F and — A. C. Pulses Are 
All Rectified or Converted Into Direct 

self-contained charging plant that will 
charge from one to five batteries (or up 
to a total of fifteen cells). By keeping the 
rectifier running twenty-four hours a day 
and taking out each battery as soon as 
fully charged, on an average, a total of 
thirteen 3-cell batteries, it is claimed, can 
be given a full charge in twenty-four 
hours, allowing for the average amount 
of residual charge. The rotating commu¬ 
tator principle is employed. Current from 
the alternating-current supply is brought 
to two terminals at the back of the switch¬ 
board. From these terminals the current 
passes thru the line switch to a special in¬ 
duction-type motor. On the extended shaft 
of this motor are two collector rings and 
beyond them a commutator. The s>m- 
chronous motor is of such design that no 
further attention need be given in starting 
than to simply close the line switch, at 
which time the motor, will start readily and 
fall into synchronism, remaining so, it is 
said, even at a great reduction in voltage. 


Important experiments on the applica¬ 
tion of electricity to agriculture are being 
made, under government grant, at Hunt¬ 
ington. in Hereford, England. As is well 
known, high-tension discharge accelerates 
the growth of plants, and may lead to a 
considerable increase in the yield of crops 
from a given area. Associated with these 
experiments are Prof. T. H. Blackman, 
Mr. \V. Duddell and Mr. I. Jorgensen, a 
Danish expert. Mr. \V. J. Kerr, city elec¬ 
trical engineer of Hereford, is also con¬ 
cerned with the movement. . . 

October, 1917 



Have You Scratched Victrola Records Now 
and Then While Trying to Adjust the Needle? 
The Record-llte Was Designed to Obviate 

This Difficulty. It Works on Batteries. 

attachment, that comes complete and ready 
for use. The installation is simplicity it¬ 
self—the light is slipt over the end of 
a taper tube or tone arm, until it snaps 
into position and is ruggedly and per¬ 
manently fastened. The battery box is set 
in the left-hand rear corner of the ma¬ 
chine, or may be concealed inside the ma¬ 

The operation is equally as 
simple. The second finger of 
the left hand rests naturally on 
the contact spring when oper¬ 
ating the machine and the light 
illuminates the record, where the 
needle rests. As soon as the 
hand is removed, the light auto¬ 
matically goes out. The equip¬ 
ment includes a three-cell dry 
battery, and a four-volt flash¬ 
light battery lamp. 


The oscillator principle followed in de¬ 
signing the new electric washing machine 
here shown utilizes both suction and com¬ 
pression force of air within its vacuum 
chamber. When in use the dasher oscil¬ 
lates in up and down motion something 
like a child’s teeter-totter. It is available 
in either electric motor drive or gasoline 
engine drive. 

As the dasher raises out of the water 
the vacuum chambers fill with air—when 
it goes down into the water the force of 


H By Thos. W. Benson. 

The binocular magnifier has 
been designed to enable medical ^ 

men, zoologists, geologists, bot- Electricity Has Reduced Wash-day Labors to Child’s 
anists, art metal workers, watch- Play, Thanks to the W<Jtor 
makers, and odiers called upon « 

to examine small objects with a 

low magnification, to do so con¬ 
veniently and with both eyes 

Binocular vision in such a device has 
always been desirable in order to gain 
perception of depth, but optical means here¬ 

Thls Binocular Magnifier Is Fitted 
with a Small Electric Battery Lamp 
for Illuminating Dark Cavities. 

tofore available proved insufficient to pro¬ 
vide it. Binocular vision correctly applied 
not only results in better definition, but 
allows the operator to observe the object 
in relief, giving practically a natural per¬ 

the air compression drives the hot suds 
thru the clothes—then on its upward swing 
the air suction draws the suds back thru 
the clothes. All the washing is therefore 
done thru the use of air pressure and 

suction. This eliminates all rubbing, 

swishing around on pegs 
and other mechanical action 
that wears and tears clothes. 

The machine is said to 
wash anything that can be 
washed with soap and wa¬ 
ter, cleaner and quicker 

than by any other method. 

The most delicate fabrics 
being washed without per¬ 
ceptible wear. All gearing 
is enclosed for the protec¬ 
tion of the operator. 

Included as part of the regular equip¬ 
ment is a swinging wringer—also a spe¬ 
cial folding bench. Also there is provided 
quick wringer release, safety hand control, 
safety foot control—the complete outfit 
wrings and washes at the same time. 


A great convenience in a bedroom is to 
have a reliable alarm clock to arouse the 
sleeper in ample time for the day’s duties. 

Automatic Electric Alarm Clock with Nlte- 
llte Attachment for Illuminating Dial. 

Such a clock, electriplly operated and 
with a special electric-light attachment, has 
now been made by a New York concern. 
As shown in the illustration, this is a 
handsome clock which adds to the appear¬ 
ance of any dresser or other bedroom fur¬ 
niture. The clock is electrically wound. 
In the bottom of the clock case is a dry 
cell which furnishes current for operating 
the clock, for ringing the alarm and for 
lighting the lamp shown just below the 
dial. This lamp is controlled by a push¬ 
button connected to a cord of considerable 
length, the button being placed near the 
bed so that by pressing it the dial is il¬ 
luminated and the time observed at any 
period of the night without getting out 
of bed or other discomfort. 


Wire-clamp connectors for circuits, 
fixtures and grounding purposes which are 
desigried to connect four wires or less of 
different sizes without the use of heat 
are now being offered. To connect the 
wires the screws of the device arc loosened 
slightly and each wire is inserted in one 
of the four loops and securely connected 
by tightening the screws. A knurled sur¬ 
face is provided on the nut threaded on 
each screw so it will grip the wire and not 

A Clever Wire Clamp Which Requires No 
Solder. Particularly Useful to Electrical Ex¬ 
perimenters for Making Various Circuit 
Changes Quickly. 

turn when the screw is drawn up. Thes 
connectors are also made for groundin 
work. They are very useful to electricj 
experimenters for making connections i 
the laboratory and among instruments. 


The miniature electric light for phono¬ 
graphs here shown is a neat, ornamental 

'I'his condition is fulfilled in the binocu¬ 
lar magnifier illustrated herewith by ar¬ 
ranging two rhombohedric prisms so as to 
reduce the distance between the two fields 
of view and thus place them within com¬ 
paratively small convergent angles. 

The magnifying lens system is arranged 
so that any desired magnification can be ob¬ 
tained by inserting the proper lenses. The 
maximum magnification recommended is 
three diameters, which allows of a large 
range of working distance. 

The eye-piece caps are made of ebonite 
shaped to fit snugly over the edges of the 
orbit, the entire instrument being held in 
place by an adjustable elastic or special 
fiber head-band fitting around the head. 
Apertures are provided in the cye-pieces 
for ventilation and to prevent moisture col¬ 
lecting on the lens surface. 

To facilitate the examination of cavities 
and dark uneven specimens, etc., an illumi¬ 
nating appliance can be fitted to the head- 
band. This consists of a small incandes¬ 
cent lamp operating on dry cells, as shown. 



October, 1917 

Are There Currents About A Magnet? 

By F. F. MACE, Superintendent of Public Schools, Dallas, Texas 

I N a previous article in regard to Mag¬ 
neto-graphs it was demonstrated be¬ 
yond controversy that there is actual 
motion, that there are actual currents, 
about a magnet, even a permanent 
magnet, and that this motion, these cur¬ 

rents, are of sufficient potentiality to affect 
a photographic plate and to penetrate wood, 
thin sheets of metal, and other substances. 
In the present discussion further proofs of 
these facts will be added and 
the direction and the character 
of these currents will be given. 

{See il/ay, 1917, 

In order to follow the sub¬ 
ject in a perfectly logical man¬ 
ner I should begin with an ex¬ 
periment in regard to currents 
surrounding a charged wire, 
which experiment will be given 
later, but that this demonstra¬ 
tion may be at once striking 
and convincing I shall first set 
out other experiments the con¬ 
clusions from which are too 
obvious to be overlooked or 

In Figure 1, at “A” is shown 
a cork thru which are thrust 
straight, flat pieces of iron or 
steel. “B” is the same except 
that round iron wire is used 
in the place of the flat strips. 

“C” is an iron wire bent at 
right angles to its axis when 
hanging. “D” is an iron wire 
bent at an obtuse angle to its axis when 
suspended. When A is suspended by 
a thread of unspun silk or a hair over the 
electro-magnet “F” and the current passing 
thru the coil of the magnet is alternately 
made and broken by means of a key, A will 
revolve rapidly. If the direction of the cur¬ 
rent is such as to make the upper pole a 
North pole the rotation will he counter- 
clock-wise. If by means of a pole reverser 
the upper pole is made a South pole the 
revolutions will be clock-wise. This rota¬ 
tion may be checked and reversed at any 
point by reversing the current so as to re¬ 
verse the poles: the only precaution neces¬ 
sary being to hold the current for an instant 
at the point of reversal so that the rotation 
is stopt. The revolutions may he continued 
to any length in one direction provided the 

torsion of the thread does not become too 
great. With a powerful magnet the rota¬ 
tion may be even continued to the breaking 
point of the thread. But the revolution is 
always counter-clock-wise over the North 
pole and clockwise over the South pole. 

B, C, and D 
may be made to 
revolve in the same 
manner and the di¬ 
rection is 'always 
the same. “E” in 
the same figure is 
a helix without an 
iron core. The 
same result may be 
obtained with this 
as with the electro¬ 
magnet F. 

If A, B, C, and 
D are suspended as 
before and a per¬ 
manent bar magnet 
is brought under¬ 
neath and rapidly 
thrust up and 
down, they will ro¬ 
tate as before; that 
is, counter-clock¬ 
wise over the 
North pole and 
clock-wise over the 
South pole. 

Here then, if it 
had not already 
been proven by the 
effect of the mag¬ 
net upon a photographic plate, is proof that 
there is motion—that there are currents — 
about the poles of a magnet and that these 
currents are the same about an electro-mag¬ 

net and a permanent magnet. Moreover, it 
is plainly indicated that these currents not 
only move toward the magnet but that they 
also rotate in their forward progress coun¬ 
ter-clock-wise over the North pole and 
clock-wise over the South pole. A moment’s 
consideration will show 
that these currents thus 
form a continuous 
spiral about the magnet 
and that this spiral con¬ 
forms to the direction 
of the current about an 
electro-magnet in both 
the electro-magnet and 
in the permanent mag¬ 
net. No one capable of 
logical thinking, even if 
it liad not already been 

proven that there are currents about the 
magnet, and currents capable of penetrat¬ 
ing substances and affecting photographic 
plates, will doubt that, here is motion— 
currents—and that these currents are rotary. 
Lines of stress, or any other assumption 
can not account for this motion of the 
objects. Even a child recognizes the effect 
of currents in the moving straws and de¬ 
termines the direction of the currents by 
the path of the straws. 

Nor would an assumption that this motion 
of the objects is produced by an attempt 
of the partially ma^etized iron to set it¬ 
self tangent to the lines of force about the 
magnet appear to be tenable. In Fig. 1, A 
may be made with strips of soft iron or it 
may be made with steel magnets. The 
magnets may be arranged in pairs with 
their poles in the same direction, or they 
may be arranged in pairs with their poles 
neutralizing each other. In any arrange¬ 
ment the result is the same, and the direc¬ 
tion of rotation is the same. If “D” is 
used instead of “A,’' the magnet will tem¬ 
porarily impart to the lower end of the 
wire a magnetism opposite to that of the 
pole of the magnet. The tendency then is 
for the lower end of the wire to be strongly 
attracted to the magnet and to point to the 
center of the pole, but instead of this it 
swings in ever-widening circles about the 
pole of the magnet, the point of the wire 
becoming further and further from the 
magnet. Then we may go further. A loose 
“snarl’’ of soft iron wire may be suspended 
in the place of the other objects. The 
result is the same. Yet it would take quite 
a stretch of imagination and a decided de¬ 
termination to adhere to “it has been so 
written,” to assume ma^etic poles for a 
snarl of wire or that there 
would be any tendency to set 
itself tangent to the lines of 
force. Go even further. Sus¬ 
pend an iron ring in the same 
manner. Assume that it be¬ 
comes magnetized or that it 
does not become magnetized. 
If it becomes magnetized the 
poles correspond to a continua¬ 
tion of the line made by the 
thread. But in any case the 
ring revolves as do the other 

It has been customary to 
“map the lines of force about a 
magnet” by sprinkling iron fil¬ 
ings on a sheet of glass or card¬ 
board placed over a magnet and 
then tapping the glass or card¬ 
board. Now it is a well kno^vn 
fact that powder or iron filings 
may be made to arrange them¬ 
selves in lines on glass or other 
substance by tapping or by 
stroking with a fiddle bow, etc. 
The character and direction of these lines 
will be determined to a great extent by the 
nature of the disturbance. The same is true 
when we tap the glass over the magnet only 
that here we have a resultant of forces. 
Tanning the glass just right will produce 

Fig. 2.—Showing the Lines of Force—or Rather a Map of the ‘'Cur¬ 
rents'* About a Powerful Magnet. Taken by Means of Iron Filings 
Sprinkled on a Sheet of Glass Under Which the Magnet Is Placed. 
Then the Current Thru the Coll Was Made and Broken. 

October, 1917 



the conventional lines about a magnet; tho 
it requires a great stretch of imagination 
to see the closed curves passing from one 
pole to another. Aside from this, different 
tapping, even when the magnet is used, will 
produce different results. A half score of 
'‘fields of force'’ can be produced in this 
manner. So easy is this of demonstration 
by anyone that it is not worth while to re¬ 
produce any of these fields here. But Fig. 
2 shows a map of the lines of foree—or 
more properly a map of the currents — 
about a magnet produced without jarring 
or touching the plate in any manner. In 
this experiment the electro-magnet “F*' in 
Fig. I, an electro-magnet thirty-eight centi¬ 
meters in length, was used. This magnet 
was placed under a sheet of glass on which 
iron filings were sprinkled and the lines 
shown in the figure were produced by mak¬ 
ing and breaking the current in the coil 
about the magnet. These lines begin to 
form as soon as the circuit is closed. A 
little examination will show that the old 
‘‘conventional” lines were erroneous and 
that the theories and conventions founded 
upon them were still more so. Note care¬ 
fully the direction and continuity of these 
lines. In no place are they continuous 
from the North pole to the South pole of 
the field. At A, A, A, A, the lines actually 
make a sharp reverse curve and from curv¬ 
ing inward toward the magnet show a ten¬ 
dency parallel to the magnet and more in 
the direction of the poles. At B, B, B, B, 
the lines are only slightly curved. At C, 

C, C, C, no curve can be detected. At 

D, D, D, D, there can be no question in 
regard to their being straight lines and that 
under no circumstances would they meet 
the lines from the other pole. Even at the 
center of the field, these lines do not form 
absolutely closed curves. At E, E, they 
show a tendency to meet each other, the 
lines from the opposite poles, at an angle. 
With some lines the angle is quite apparent. 
Here, then, is proof that the lines of force 
—currents—do not move in closed curves 
from the North pole to the South pole. 
That these are currents and not lines of 
tension will be further emphasized by the 
next experiment. 

Place the electro-magnet under a tank of 
water (I used a glass bottomed tank placed 
over a magnetic field already produced by 
the magnet) and in the water place a small 
piece of iron attached to a cork. When 
the cork is placed over a point on the line 

E, E, and the circuit of the magnet is 
closed, the cork will remain almost if not 
quite stationary, or will even exhibit a 
slight tendency to drift away from the mag¬ 
net. If placed a few millimeters to the 
right or left of this line, it at once moves 
in the direction of the nearest magnetic 

pole following closely the direction of the 
line over which it is placed. Note care- 
fully that the cork follows the curves shown 
in Fig. 2. ] f a magnetic needle is sub¬ 

stituted for the iron the action is the same 
except that the needle is attracted or re¬ 
pelled along the lines according to its pola¬ 
rity. A magnetic needle placed over one 
pole so as to be repelled will often move to 
the center of the field and there stop. If a 
large bar magnet is substituted for the 
electro;;magnet underneath the water the 
result is the same. Here, then, is proof of 
two facts: first, that there is actually motion 
about the magnet, currents, and that these 
currents do not‘move from one pole to 
another but that the currents originate near 
the center of the field (that is, those not 
entering from the directions of the ends of 
the poles) and move toward both poles. 
Also that in the center of the field between 
the two poles of the magnet is a point of 
neutrality or of actual repulsion, a point 
where the currents are outward. 

If further proof is needed that there is 
an outward flow of currents from the 
center of the magnet it is furnished by 
the photographic plate. Fig. 3. is such a 
plate, taken underneath the bend of a 
LJ-shaped magnet. “A” shows the position 
of the plate, the objects, and the magnet. 
“B” shows the result, the plate being taken 
under the same conditions as those de¬ 
scribed for the other Magneto-graphs (See 
first paper in May issue.) Now a current 
flowing upward would affect the photo¬ 
graphic plate but would not produce an 
image of the objects, for the reason that 
it would be flowing toward them and would 
pass thru the plate before reaching them. 
In order to penetrate the objects and thus 

Fig. 5.—Apparatus for Measuring the 
Strength of the “Interior Current" of a 

make their impression 
on the plate it must be 
passing downward; 
that is,must be flowing 
outward from the bend 
of the U magnet. The 
plate speaks for itself. 

So far only the ex¬ 
terior currents of a 
magnet have been ex¬ 
amined. The interior 
currents show equally 
interesting results. 
Place the solenoid 
"E” in Fig. 1, on its 
sitle and place a plane 
of cardboard inside on 
a line with the diam¬ 
eter Place a small 
piece of iron on the 
end of the cardboard 
plane and as soon as 
the circuit is closed 
the iron will spring to 
the center of the coil 

and to one side. Place a piece of iron at 
both ends and when the circuit is closed 

Demonstrating that There Is an Outward 
Flow of Currents from the Center of a Mag¬ 
net, To Make a “Magnetograph” Several 
Objects Are Placed on a Photograph Plate 
Beneath the “U“.Bend, and Left in the 
Dark for Several Weeks. 

Fig. 3-B.—“Magnetograph" Obtained by 
Above Arrangement. 

they will meet in the center of the coil, but 
it should be noted that one alone will move 
to the center. This shows that there are 
currents moving inside of the solenoid and 
that the attraction of the solenoid is not 
at the poles but at the center and toward 
the sides. This is also proven by the photo¬ 
graphic plate for photographic plates ex¬ 
posed inside a helix bearing a current give 
results similar to the magneto-graphs al¬ 
ready shown. 

Again, place inside the solenoid “E” the 
cardboard plane as before and cover it with 
a soft but not rough paper. If an iron 
ball is placed on the cardboard at “A”, 
Fig. 4, and the circuit is closed the ball 
is drawn inward and to one side. If the 
same is repeated by placing balls in suc¬ 
cession at ”B”. “C”, “D” and “E”, and at 
; A\” “BV' “C,” and “E*” the result 

is the same. The balls must be placed on 
the card one at a time and the circuit 
closed and opened again before another is 
put on. If several balls are placed on the 
card at the same time and the circuit closed, 
their tendency is to cluster together. If 
these balls are coated with oil and lamp 
black they will leave a faint trace of their 
several paths. Fig. 4 is the reproduction 
of an actual tracing made on cardboard in 
this manner. 

The existence and strength of these cur¬ 
rents is emphasized by another experiment. 
The solenoid here shown is twenty centi¬ 
meters in length. Fig. 5 shows apparatus 
for measuring the strength of the interior 
current of this solenoid. “A” is a small 
piece of iron of known weight which is 
fastened to the wooden arm “B”. “B” is 

pivoted to the crossbar arm “C”, at “D”, 
and so arranged by means of a set screw 
as to be lowered or raised inside the sole- 
(Conttnued on page 417) 



October, 1917 

New Portable Electric Lamp For Miners 


Pittsfield Works, General Electric Company 

W ITH the advent of coal mining it was 
discovered that open flames in mines 
were sometimes dangerous, owing to 
the fact that explosive mixtures of methane 
gas frequently occurred. This led to a series 
of investigations to pro¬ 
duce a lamp that would 
primarily prevent explo¬ 
sions and secondly de¬ 
tect the dangerous gas. 

The electric incandes¬ 
cent lamp naturally 
obviates the objections 
found in the open-flame 
t}'pe miner’s lamp. While 
the electric lamp will not 
detect gas, this can easily 
be accomplished by em¬ 
ploying a few Davy 
lamps for this purpose. 
Special electric gas de¬ 
tectors are now being 
developed and it will 
probably only be a matter 
of a few months before 
thoroly reliable devices 
of this type will be on the 

A glowing lamp fila¬ 
ment has been proved by 
the Bureau of Mines to 
be dangerous. It is there¬ 
fore necessary to supply 
each device with a safety 
switch that will break, or 
otherwise discontinue, the 
current thru the filament 
when the bulb is broken. 

Tests with light and 
heavy blows in the direc¬ 
tions most likely to cause 

- failure are applied to 

^ach device and it must 
iviTn^rs not fail on any test in 

order to pass, for obvi¬ 
ously one failure in a mine might mean 
death to many miners and much damage to 

Batteries must be proved by test to pos¬ 
sess a capacity sufficient to burn the lamp 
through an entire shift of 8 to 10 hours 
with a margin of safety. 

The first requisite of a mine lamp is to 
give light for the miner to find his way 
thru the various unlighted passageways 
to his work and then to enable him to 
perform that work in an efficient manner 
during the entire shift. It is therefore 
quite necessary that the light should 
decrease as little as possible in brillian¬ 
cy during the time the miner is “in¬ 
side.” This is accomplished by using 
an ironclad storage battery whose 
voltage characteristic is very even. 
Except for the sudden small decrease 
in voltage which takes place in the 
first few minutes on a freshly charged 
battery, the change over 9 hours is 
only 6 per cent, or less than 1 per 
cent per hour. 

The distribution of light is excep¬ 
tionally good. A porcelain reflector 
of irregular shape is used, thereby 
eliminating those sharp changes in 
brilliancy tliat are characteristic of 
polished metal reflectors. 

The cap shell is fitted with hooks 
for mounting the lamp on the 
miner’s cap at such an inclination 
forward as to throw the beam of 
light directly upon .the work which the 
miner is doing. 

In this type of minersMamp, the safety 
feature consists of two flexible contacts 
which hold an elliptical-shaped bulb hav¬ 

ing a contact at either end with the fila¬ 
ment extending thru the lamp between its 
two contacts. The illustration shows this 
safety device lamp mounting for holding 
the bulb. Any blow which will break the 
bulb in any manner will force the lamp 
out of the contacts. 

Much depends upon the battery, of 
course. If it does not supply current to 
light the lamp for the full working time 
the miner will have to stop work sooner 
than otherwise, thus decreasing the output 
of coal for the mine owner and causing 
a loss of pay to the miner. It may also 
be difficult for him to find his way out of 
the mine if he does not have assistance 
from someone who has a lamp. With the 
ironclad battery, a reliable source of power 
is assured. The lead battery plates are 
very rugged and have established a repu¬ 
tation in mine locomotives and heavy trucks 
for their ability to withstand heavy duty 
conditions and severe shaking. The plates 
are contained in a strong, well-designed, 
semi-hard rubber jar that will stand an 
unusual amount of abuse. By making the 
metal containing case of proper design for 
the conditions under which the equipments 
are to operate, no trouble has been experi¬ 
enced from cracked or broken jars. The 
cover is fastened to the jar by a double 
cauillary seal, which is acid-tight. 

The filling and venting scheme is very 
simple and effective. To fill the battery the 
vent plug is removed, which gives free 
access to the cell space, and the level of 
the electrolyte is brought to within a small 
distance below the edge of the plug open¬ 
ing. The vent plug is very effective in 
preventing spilling of the electrolyte and 
is securely sealed in place by a quarter- 
turn of the plug, which draws it down 
against a rubber basket in a suitable seated 
surface on the jar to prevent any leakage 
of acid. The electrolyte, which is the usual 
battery acid (sulfuric), is corrosive in its 
action on metals and will damage all kinds 
of cloth except pure wool, yet on acco.unt 
of the degree of perfection which has 
been obtained in making a strong non- 
breakable jar, a perfectly seated vent plug, 
and a non-spilling vent no acid can escape. 


Costa Rican Government authorities have 
dismantled a powerful wireless station at 
Heredia that is supposed to have been used 
by Germans. It was found on the property 

New Electric Miner’s Lamp Disassembled. 

of the former Governor of Heredia Prov¬ 
ince, Dr. Marcos Rodriguez, an intimate 
friend of the deposed President, Alfredo 
Gonzales, and of the latter’s adviser, J. 


This dock, unlike an ordinary time¬ 
piece, is not actuated by either weights or 
springs. The motive force is a current of 
electricity obtained from a pair of plates 
buried in old Mother Earth, and which 
are connected with the clock by wires. 

The current 
is applied by 
means of an 
electro - magnet 
direct to the 
pendulum, s o 
that the pendu¬ 
lum drives the 
clock, instead of 
the clock driv¬ 
ing the pendu¬ 
lum, as is the 
case where 
weights or 
springs are 

The current 
is reversed at 
each swing of 
the pendulum 
by an automatic 
switch, and this 
switch is so ad- 
justed as to 
prevent the pen¬ 
dulum being 
moved in either 
direction b e - 
yond a given 
point. It is the 
application o f 
this principle 
which secures 
correct time and 
overcomes any 
slight variation 
in the strength 
of current, and 
it is this which 
makes the 
Earth - Driven 
Clock a distinct 
advance upon 
electric clocks 
a s previously 

An interesting 
report has been 
given on this 
clock by Profes¬ 
sor Silvanus P. 

Thompson, F.R.S., the world-renowned 
electrical expert, who has minutely exam¬ 
ined the clock. The following are extracts 
from his report:— 

“Having had the opportunity—both 
to see the earth-driven clock at work, 
and to examine the specifications of 
patent on this invention, I beg to re¬ 
port as follows: 

“The pendulum is both the govern¬ 
ing part and the driving part of the 
clock. I made various simple tests 
on the clock with a milli-ampcre meter 
attached to the circuit. If I pur¬ 
posely gave the pendulum, by hand, a 
large impulse so that it swung too 
far, at once the automatic action of 
the contact device became evident, 
and after a few swings the current 
returned to its normal value, and the 
pendulum to its normal swing. 

“It is, as will appear from the 
above description, entirely automatic 
and self-contained. 

“I see no reason to doubt that with 
an earth battery properly laid, it will 
continue to go for years without stopping. 

“I have used earth batteries many years 
ago, and know them to be extremely con¬ 
stant if they are properly laid down in the 
earth once for all.” 

The Electric Clock We 
Have All Dreamed of. 
It operates on Electric 
Current from the Earth, 
No Battery Required. 

October, 1917 




Several new and excellent features are 
embodied in the new motor-driven mixer 

The Day of the Hand-Made Mdk Shake Is 
Past, Thanks to the Always-Ready Electric 

here illustrated. The entire base and 
column is finished in white porcelain 
enamel. It can be easily kept clean and 
dispensers will appreciate this sanitary 

The niotor which drives the mixing 
spindle is stationary on the head of 
the column, only the mixing spindle 
moving up and down. The spindle is 
light and the mixer is very easily oper¬ 
ated. The current is automatically 
turned on when the spindle engages 
with the driving disk on the motor and 
is shut off instantly when the spindle 
is raised. This does away with the 
splashing of the contents outside of the 
container as is experienced with other 
types of mixers. 

Another advantage of this mixer is 
that the spindle raises to a height of 
inches, enabling the largest con¬ 
tainer or mixing glass to be set under 
the spindle without tipping the con¬ 


With the machine here shown eras¬ 
ers are cleaned right in the school¬ 
room or in the corridor. No need to 
throw them into a basket and take 
them outside or into the basement. A 
small girl can operate the device and 
get the erasers thoroly clean. 

Turning the switch sets a rapidly re¬ 
volving brush in motion. This loosens 
the dust and the suction developed by the 
motor extracts all of the dust from the 
surface and crevices of the felt. The dust 

is drawn into a section of the base. The 
air created by the strong suction is filtered 
before it comes out of the exhaust. This 
is one way of solving the black-board and 
chalk problem, but it’s a wonder to us 


Electricity Now Cleans the Germ-Laden Black- 
Board Eraser In a Thoro and Sanitary Manner. 

that some genius has not perfected a more 
cleanly and scientific school-room appurte¬ 
nance than the “black-board eraser.” 

The Effect of Ultra Violet Rays on Milk and Other Aspects 


T he actions presented by the ultra 
violet rays on animal substances, or 
to state better, the changes produced 
on infinitesimal life by the ultra 
violet rays, are such as to leave 
much^ doubt and supposition as to their 
qualities as a friend of man. Still their 
chemical, physical and biological actions 
are not as yet known well enough that we 
might say a (priori that they are detrimental 
or beneficial. The transformations pro¬ 
duced by these rays are evident and show 
their existence, but just how this action 
forms or develops is yet to be explained, 
and it would be hazardous to state a fact 
on a subject which can be clast only in 
the same category' with the undiscovered 
merits of the X-Ray. 

In 1912, Holland had averred that the 
ultra violet rays were an enormous microbi- 
cidc on animal substances, and they imme¬ 
diately adopted the ultra violet rays to 
sterilize their milk by passing it from one 
container to another in a thin film or 
stream upon which was projected the ultra 
violet ray. This was supposed to have the 
action of sterilization and preserv^ation. 
The fact of sterilization existed, but while 
certain microbes were destroyed in this 
manner, especially tliose which are injuri¬ 
ous to liiiman life, it did not prevent the 
milk from turning sour; on the contrary 
the development of the germs under the 
action of the ultra violet rays was so great, 
that they seemed to find themselves in a 
most favorable environment, which was 
clearly seen under microscopic inspection. 
In fact, upon projecting an ultra violet ray 
on a vessel containing milk, it would be 
seen that the section upon which this ray 
touched becomes a veritable tumultuous 
life of rnultiplication of germs. This 
clearly indicated that while the microbicidc 

idea of the ultra violet rays exists, its 
application is on a different principle. 

It has always been commonly believed 
that milk curdles owing to the change of 
temperature and that by using ice this dif¬ 
ficulty would be overcome, but this pre¬ 
caution does not take away the primal cause 
which, while it remains latent under the 
unfavorable environment of perhaps zero 
degree, develops immediately upon being 
brought in contact with light and a more 
productive environment, namely, the mo¬ 
ment that the ultra violet rays come in 
contact with the infinitesimal life their de¬ 
velopment begins, and while it is true that 
some microbes are destroyed by the ultra 
violet rays, it has been found that the 
inferior organisms generally develop more 
rapidly under the influence of these rays. 

The milk of the Bulgarians, well known 
all over the world for its superior nutri¬ 
tive quality, is made by exposing it to the 
sun, the rapid development of the germs 
under the action of the ultra violet rays 
being such that when it becomes dry they 
are in highly concentrated form. 

The difficulty of transporting milk from 
one city to another is well known, and I 
had occasion of demonstrating my beliefs 
on the action of the ultra violet rays by 
an experiment at which were present the 
representative commissioners of milk of 
Miilhauscn, Alsace. It was midsummer 
(July) and wc took milk directly from the 
cow, without it having had any exposure 
to the light, and placed it in two cans, one 
of which had been previously protected 
against the sun's ultra violet rays; the 
other canteen was left as it had been. 
The canteens were then placed on an un¬ 
covered freight car without any ice or other 
protection against the sun and shipt to 
Colmar, a trip of about four hours. Upon 

arriving at our destination the cans were 
then examined; the milk in the can not 
protected had already turned sour, while 
the milk in the other can was as sweet and 
fresh as tho it had been hardly drawn. 
The fact that the ultra violet rays could 
not penetrate the protective covering of 
the canteen prevented any action on the 

To substantiate my theory^, Dr. Stahel of 
the Internationale Cellulose Ester Gesell- 
schaft of Sydowsaue had also asked for a 
patent of a product which was precisely 
against the action of the ultra violet rays, 
preventing the decomposition of diverse 
animal substances influenced by these rays, 
following several discoveries made from 
various observations of the action of the 
ultra violet rays. 

The cerebral substances are decomposed 
by the ultra violet rays, causing sunstroke, 
and not by heat as generally believed, and 
to substantiate this statement it is not 
thought remarkable that we never hear of 
cases of so-called heat prostration among 
the workers in foundries, glass and pottery 
factories, etc., where an excessive heat 
temperature equal to mid-summer in the 
torrid zone is continually preserved, and 
where the man goes back and forth to and 
from his labor year after year unaffected. 
Yet this same man may be taken with a 
sunstroke in a moment's time upon ex¬ 
posure to the sun, when its rays are suffi¬ 
ciently powerful to react on the body. 

In 1913 I had submitted an experiment 
for the protection of men and horses 
against the effects of the ultra violet rays 
by the application of a protective coating 
against these rays placed in the inside of 
hats and horse bonnets. Upon the success 
of the same the French Government used 
(Continued on page 421) 



October, 1917 


The new electric fire detector is a ther¬ 
mometer constructed of a steel tube for a 
mercury receptacle, to which is attached the 
lower contact screw, also the regulating 
screw by which the detector is set to any 
given degree from zero up to as high as 

An Electric Fire Detector Which Can Be 
Left at Any Point Desired, Such as In the 
Kitchen, and as Soon as Blaze Occurs the 
Alarm Bell Rings. It Utilizes a Fine Mer¬ 
cury Column, Which Expands When Heated, 
Thus Closing the Bell Circuit. It Will Also 
Announce a Drop in Temperature. 

conditions require. A fiber tube carries 
the upper contact screw. This fire detec¬ 
tor and alarm may be termed almost *‘su- 
per-human,” never failing to give an alarm 
of fire when in its incipiency and which 
can be extinguished with a pail of water 
or small portable fire extinguisher and be¬ 
fore it has gotten beyond individual con¬ 
trol. The detector will not give a false 
alarm when properly set, it is claimed. 
The portable outfit shown is for use in 
kitchens or other localities. 

The possibilities of this detector are un¬ 
limited, giving a positive alarm of fire at 
the opportune time; the absolute automa¬ 
tic control and closing of fire-doors and 
shutters; the announcement of rising tem¬ 
peratures in refrigeration plants and the 
absolute control of open-head sprinkler sys¬ 

As a valuable equipment for the pre¬ 
vention of disastrous fires, the detector 
gives an alarm long before the automatic 
sprinkler will operate; thus not only pre¬ 
venting fire loss, but eliminating the water 
damage to a very large degree. For ware¬ 
houses and holds of ships where cotton is 
stored, an alarm is given when the cot¬ 
ton first begins to smoulder. This also ap¬ 
plies to uncured hay and rubbish. 

The apparatus is peculiarly adapted for 
the regulation of temperature in refriger¬ 
ation plants, being regulated to announce 
the rise in temperatures on an annunciator 
in the chief engineer’s office, which obviates 
the necessity of continuall}^ making the 
rounds to read the thermometers. 

The detectors can be set to show a rise 
of a fraction of a degree and a warning 
of this change given as above described. 
The detectors for protection in hotels, 
theaters, homes, apartment houses, office 
buildings and buildings of like character are 
5 et to operate at say 110® and are furnished 

with ornamental guard of nickel-plated non- 
corrosive metal, which makes a neat, at¬ 
tractive outfit, but these can be more elabo¬ 
rately decorated to architect’s specifica¬ 

Each detector will under ordinary con¬ 
ditions cover an area of 250 square feet of 
floor space. In a room say 12 by 15 feet, 
one detector would be sufficient, but if fas¬ 
tened to side walls, two would be required. 

There is a very great need in the navy 
just now for radio operators, according to 
the Buffalo office of the Naval Reserve. 
These operators are to be used on the giant 
merchant marine that is shortly to be put 
in service. The men in this service are 
well paid. There are several classes in this 
service so that the beginner has a chance 
for enlistment. 


g IVc have a great variety of electri- g 
g caf scientific and radio articles in M 
g preparation for the “November* g 
^ number. You can rest assured that ^ 
M you zvill find a big 15 cents zvorth of J 
g reading matter in that issue. If you M 
^ are interested in zvar-tinie inventions ^ 
M in this field, you must not miss read- ^ 
g ing the up-to-date and authoritative ^ 
^ articles on these topics, a host of g 
m zvhich we publish every month. Here J 
g are a fezv of the ‘’November** feat- g 

J g 

g “The Use of the Telephone and g 
^ Telegraph in Battle.'* g 

g “Action at a Distance as E.xhihited g 
= in Sele7iium Crystals,** by Prof. F. C. M 
g Brozim, Ph. D. g 

^ “The Marvels of Radio-activity,** g 
g Port HI. by Jerome S. Marcus, B. Sc. ^ 
J “Forcing the Grozvth of Plants with ^ 
g High-frequency Currents. g 

^ “Historic Electrical Apparatus,** by g 
g H. Winfield Secor. g 

g A new electrical story, by C. M. g 
^ Adams. g 

g “A Nezv Military Application of g 
g Electricity,** by H. Gernsback. § 

g “Are There Electric Currents About S 
g a Magnet?** Part HI,'by F. F. Mace, g 
^ “Science and the IFor*’—In the g 
g “Movies,** They Do It. g 

g “E.vperi)nental Physics—Lesson 9,” g 
g by John J. Furia, A.B., M.A. g 

g “Chemical Action of Storage Bat- g 
g terics,** Part ll, by Albert W. Wils- g 

g “Hozv to Make an Electrically g 
g Played Mandolin,** by McClure Al- ^ 
g bright. g 

g The Construction of a IVheatstone J 
g Bridge,** by Thomas IV. Be^ison. g 

Class A is for amateur operators who 
can send and receive the Continental code 
at least ten words a minute and can write 
legibly. Class B is for first-grade com¬ 
mercial or amateur operators, receiving and 
sending twenty words a minute. Third- 
class electricians rating are in this class. 
Class C men must have commercial licenses 
and must have served at least one year as 
operator aboard ship and must send and re¬ 
ceive at least twenty-seven words a minute 
in Morse and Continental. They get rat¬ 
ings of electricians, second class. Class E 
is for men who have worked on ocean¬ 
going boats as operators for at least four 
years and who can repair any break of ap¬ 
paratus. The rating is that of chief elec¬ 
trician. The pay ranges from $33 a month 
for third-class men to $65 a month for 

chief electrician. Board, lodging and cloth¬ 
ing allowances are given in addition to the 
regular salary. 


Altho 30,000 volts of electricity past thru 
the body of Neil Hansen of Trenton, N. J., 
recently, he will live. 

Hansen was cleaning a generator in the 
distributing station of the Public Service 
Corporation when he received the full force 
of the current. His left thumb was burned 
off, his hands and arms were burned and 
the top of his head was blistered. 

For a time he lay as tho dead. After he 
was revived he could not remember his 


Something new in push buttons has been 
invented at last by an eastern man that bids 
fair to send the old dry batteries now in 
use to ring your front door bell, to the ash 
can. It is quite a simple arrangement, and 
it is strange that no one should have 
thought of such a simple device. The but¬ 
ton itself is connected to a rod that is 
geared to a small dynamo, and when the 
button is pushed the dynamo armature ro¬ 
tates ill the field of a permanent magnet, 
thereby generating enough electricity to 
ring the bell. The whole unit hardly takes 
up more space than the ordinary push but¬ 
ton, and does away with the constant ex¬ 
pense of renewing batteries. By referring 
to the photos a good conception of the 
principle involved and also the mechanism 
can be obtained. 

Weill Well! It Does 
Seem That Our Bat¬ 
tery Bill Will Shrink 
Now. Bless Us, If 
Here Isn’t a “Work¬ 
ing Model’’ of the 
Latest Non-Battery, 
Automatic, Self-Gen¬ 
erating Door Bell 
Outfit. Push the 
Button—the Dynamo 
Spins — the Bell 
Rings. Selah! 

Here’s the Secret of the Battery-'Mess” Bell 
Ringer. By Means of a Special Nut and 
Worm, the Dynamo Spins Merrily at Every 
Push of the Button. 

October. 1917 



Some Electrical Properties of Silver Sulfide* 


N A']'1\’E silver sulfide is seldom pure 
but the sulfide may be prepared 
chemically in the form of a black 
powder which has a melting point of about 
S25°C. It was found that the sulfide so 
melted could be rolled into thin strips or 
drawn into short wires like a metal. At a 

Fig. 1. Outcropping of Silver In Middle of 
Sulfide Strip. The Direction of the Electric 
Current Was Approximately Parallel to the 
Direction of the Lines of the Silver. This 
Picture Suggests the Possibilities of the 

Formation of Native Silver in the Earth. 

temperature of about 200°C. it becomes 
very malleable and may be hammered out 
on a hot plate or drawn thru a heated draw 
plate. VVorking the sulfide at this tem¬ 
perature changes its electrical properties. 
In the form of a strip which has been rolled 
cold this substance is both a metallic and 
electrolytic conductor at the same time. 

• ?5ummary of a forthcominR Scientific Paper of 
the National Bureau of Standards. 

W’hcn drawn hot it acts like a metallic con¬ 
ductor with nearly zero temperature co¬ 

In making experiments with the sulfide it 
was necessary to find some means of mak¬ 
ing good electrical contact between it and 
copper lead wires. It was not found pos¬ 
sible to solder to the sulfide directly and 
brass clamps are not desirable, but it was 
found possible to silver-plate the ends of a 
piece in a silvcr-potassium-cyanidc solution. 
After this is done a copper wire can be 
soldered on with little difficulty. 

When the sulfide is rolled at room tem¬ 
perature it has a large negative temperature 
coefficient of resistance, similar to an elec¬ 
trolyte. Wffien w'orked at 200°C the tem¬ 
perature coefficient is approximately zero. 
It is not easy to explain why the mechanical 
working makes so great a difference in the 
electrical properties, but it seems likely that 
roiling at room temperature may produce 
minute cracks, whereas wire which is drawn 
hot is probably homogeneous. 

The material rolled at room temperature 
was found to have different resistance 
when tested with direct and alternating cur¬ 
rent. When alternating current is applied 
the resistance increases, when direct cur¬ 
rent is applied the resistance decreases but 
shows a tendency to recover upon standing. 

The specific resistance at 25°C was found 
to be 17,300 microhm-centimeters or about 
10,000 times the resistivity of copper. 

As resistance measurements indicated 
electrolytic conduction of the cold-rolled 
strips, e.xperiments were made to discover 
any electrochemical decomposition. Direct 
current was applied to a strip having cop¬ 
per leads soldered to its silver-plated ends. 
An initial current of 25 milliamperes gave 
no visible effect. The current was increased 
at intervals until with 200 milliamperes a 
discoloration of the plate at the anode end 
was noticed. A still larger current ap¬ 

peared to destroy the silver plating and 
finally burned off the terminal, but before 
this happened a myriad of little shiny silver 
crystals appeared on the black surface of 
the sulfide as shown in Fig. 1. The ap¬ 
pearance of these crystals was studied under 
the microscope and it was found that they 

Fig. 2. Anode End Showing Where the 
Terminal Burnt Off. After the Silver Plating 
Was Destroyed by the Sulfur, the Outcrop¬ 
ping of Silver Took Place. Magnified 50 

occurred to within a small fraction of a 
millimeter of the anode terminal as shown 
in Fig. 2. The appearance of some of these 
crystals suggested that they had been ex¬ 
pelled from the interior of the strip with 
considerable force. The strip appeared to 
be made up of a multitude of tiny electro¬ 
lytic cells between which metallic conduc¬ 
tion occurred. The cross-section of this 
strip was 0.3 b}’* 0.01 centimeter. 


A very simple signal projector having a 
range of some twenty-five miles is shown 
iif the illustration herewith. It consists of 
a wooden box 12 in. long and 5 in. square, 
made of wood. This box contains 

a 5-in. Mangin mirror. 

At the focal point of this ^ 

mirror is mounted a 6-volt, 

1 1 / 2 -ampere Mazda lamp, hav¬ 
ing a maximum concentration 
filament. (A 1^/2 ampere auto¬ 
mobile lamp could be used, but 
the range will not be so great 
as with the maximum concen¬ 
tration filament lamp.) In the 
lower compartment of the box 
arc four standard dry batteries 
connected in scries and to the 
lamp thru a standard tele¬ 
graph key .—Photo Courtesy 
Ceu. Elec. Rev. 


In a recent paper before 
the Ilhiniinating Engineering 
Society, Mr. R. B. Chilas 
analyzes the conditions affect¬ 
ing the efficiency of optical 
projection in the cinemato¬ 
graph. He estimates that in 
the most favorable circum¬ 
stances tlie screen docs not re¬ 
ceive more than 5.8 per cetit. 
of the light from the arc, while 
in many cases it does not ex¬ 

ceed 1 per cent. Various arrangements of 
carbons with a view to avoiding the shadow 
cast by the negative have been tried, but 
with the present lens systems it is difficult 
to utilize more than 17 per cent, of the 
light from the crater. On the other hand, 
it is suggested, an improvement might be 
made by reverting to an old idea explained 

in a Swiss patent by S. Schuckert, as far 
back as 1889. This involves the use of an 
ellipsoidal mirror, the crater being at one 
focus, the objective lens at the other, and 
the film in between. Theoretically as much 
as 75 per cent, of the light from the crater 
can thus be collected. 

A Military Signal Projector Having a Range of 25 Miles. It Is 
Fitted with 5-In. Mangan Mirror and 6-Volt 12-c.p. Mazda C 
Lamp. A Telegraph Key Controls the Lamp Circuit. 


An interesting description is 
given by a Russian officer of 
one of the numerous little mo¬ 
bile field wireless outfits oper¬ 
ating near the front. The 
whole wireless station can be 
unloaded from its auto truck, 
rigged up and be ready for 
work in twenty minutes. The 
^cventy-foot masts are hollow 
and made in sections, which are 
screwed together when taken 
otT the truck. 

The simple peasant soldiers, 
many of whom come from re¬ 
mote villages where wireless 
has never been heard of, are 
greatly fascinated by the sta¬ 
tion, and like to stand around 
when they can get a chance and 
watch the fiasliing of the spark 
and listen to its song. “It 
sounds like butter in a frying 
pan,“ they say. They have 
coined a nickname for the men 
in the wireless crew, which, 
p near as possible in English, 
is “sparkers” or “the spark 



October, 1917 

Experimental Physics 


JOHN J. FURIA, A. B., M. A. (Columbia University) 



OST people have the erroneous 
idea that light passes instantan¬ 
eously from the source to the 
observer. In the year 1675 Olaf 
Roemer, a Danish astronomer, 
found that his prediction of an eclipse was 

Due to the Difference In Time Elapsed Be« 
tween the Eclipses of One of Jupiter’s 
Moons, Roemer In 1675 Deduced That This 
Deviation Was the Time Required for Light 
to Travel Across the Earth’s Orbit. 

in error. He had observed and noted pre- 
fully the instant when one of Jupiter’s 
moons jM (Fig. 35) past into Jupiter’s 
shadow when the earth was at E, and by 
computation predicted the exact instant 
when another eclipse should occur six 
months later when the Earth was at E\ 
Actually the eclipse occurred 996 seconds 
later than at the time predicted, and Roemer 
concluded that the delay represented the 
time required for the light to travel across 
the Earth’s orbit, a distance %vhich was 
known to be about 180,000,000 miles. Thus 
it was found that light travels about 186,000 
miles per second. This speed is so great 
that it W'ould carry light nearly eight times 
around the Earth in one second, so it is no 
wonder that the idea prevails that light 
travels instantaneously. However to the 
astronomer who deals with the enormous in¬ 
terstellar distances the speed of light seems 
as the speed of a 1903 model Ford with only 
one cylinder irr working order. It takes 4 
and one-half years for light to travel from 
the earth to the nearest star. If one of us 
should be up on the Pole star with a tele- 

The Principle of Light Reflection; Angle “I”, 
Incident Angle Always Equals "r", the 
Angle of Reflection. 

scope powerful enough to see events on the 
earth, he would not see the battle of Gettys¬ 
burg, which occurred July, 1863, until Jan¬ 

uary, 1918, the Pole star is so far away, 
EXPERIMENT 46. One of the most 
important properties of light is that of re¬ 
flection. When a billiard ball strikes the 
sides of the table obliquely, it rebounds in 
such a manner that the angle made by the 
ball on striking and the angle made on re¬ 
bounding are equal. In Fig. 36, A is the 
position of ball before being struck by the 
cue, B is the point on the cushions of the 
billiard table where the ball strikes, and C 
is the position of the billiard ball after re¬ 
bounding. Angle 1 equals angle 2. If BN 
ij a line perpendicular to the cushion, angle 
i equals angle r. Angle i is called the in¬ 
cident angle and angle r the angle of reflec¬ 
tion. The law of reflection is usuallv stated 
TION. The fact that the law of reflection 
holds true for light makes possible the use 
of many instruments, one of the most im¬ 
portant at the present time being the peri¬ 
scope. The writer learned the law of re¬ 
flection at school long ago on those occa- 

How a Person at “E” Can See a Candle, In¬ 
visible at “C”, and Apparently Burning In¬ 
side a Bottle of Water at “M.” 

sions when the sun shone into the room and 
the teacher pulled down the shades. A beam 
of sunlight would enter the room from the 
sides of the shades and the writer by means 

Illustrating the Principle of the Submarine’s 
Periscope, Mirrors Reflect the Image Down 
the Tube and Around Corners. 

of a pocket mirror would reflect it so that 
the angle of incidence being equal to the 
angle of reflection, and the teacher’s face 
being along the angle of reflection, it would 
become illuminated, to the extreme discom¬ 
fort of the teacher and the unbounded 
pleasure of the pupils. Things would have 
fared very well had not the teacher also 
known the law of reflection, and hence been 
able to locate the innocent culprit. (Inno¬ 
cent according to the pupils, and culprit ac¬ 
cording to the teacher.) When a surface is 
smooth as in the case of a mirror each point 
of an object is regularly reflected, and a 
sharp image is formed. When the reflector 

is rough, as in the case of ordinary paper 
or the walls of a room, each particle of the 
surface reflects regularly, but since the par¬ 
ticles are not all on a level stretch, the re¬ 
flected light is scattered, and this is known 
as diffuse reflection. Some girls’ noses are 
smooth and shiny (regular reflection) but 

Analysis of the Principle of Mirrors. Each 
Point of An Image In a Plane Mirror Is As 
Far Behind the Mirror As the Corresponding 
Point of the Object Is In Front of the 

after an application of face powder, the 
noses are no longer smooth and shiny but 
rough (diffused reflection). The Sun, a 
gas flame, etc., are visible because of the 
light they emit, while ourselves, books, 
chairs, tables, etc., are visible because of the 
light reflected. All bodies except those emit¬ 
ting light are visible because of the light 
they reflect diflfusely. 

W hen light meets the eye from a polished 
surface we do not see the surface. Hence 
it is possible at Coney Island to create a 
great deal of amusement by having “mazes” 
(smooth polished plate glass) into which 
the unsuspecting victim will walk. Black 
bodies send no light to the eye but they cah 
l>e seen because their outlines are disting¬ 
uished by the light zvhich comes from the 

EXPERIMENT 47. To locate the image 
of an object in a plane mirror. Stand a 
small rectangular pocket mirror on its side, 
over a piece of paper. Draw an arrow in 
front of the mirror !MM at AB. If now 
the eye is placed behind A, behind B and to 
the right of B respectively, in the positions 

Due to the Change of Velocity of Light Rays 
Passing Thru a Denser Medium—Water In 
This Case—An Object Appears As Tho Bent 
or Misplaced. 

El, Eo, Es, the image A' of the point A, will 
be found on the straight line EiA prolonged 
(Continued on page 424) 

October, 1917 



Radio-Controlled Torpedo Devised by California Genius 

A \MZARD of electricity, whose in¬ 
ventions may revolutionize warfare 
both on land and sea and win vic- 
tory for America in the great war 
against Germany, was discovered 
in the person of Henry H. Hyder, of Los 
Angeles, Calif., ostensibly an automobile 
man, but in reality a miracle worker with 
wireless and electricity. 

Seated in his little workshop several 
miles away, Hyder can explode any one of 
a field of mines, either in the ocean or on 
land. He can choose which mine to ex¬ 
plode or he can blow them all up—by wire¬ 
less. No other wireless can interfere with 
his to set the mine off prematurely or to 
prevent the explosion. (We are not so sure 
about this.—Editor.) 

In the same way Hyder can release a 
torpedo at a ship twenty miles off the coast, 
choose the time to explode it or in case it 
fails to reach its mark, lock the torpedo, 
prevent the explosion and bring the costly 
instrument back to the place from which 
it started. 

dio Electrician, applicants must be able to 
receive at least ten words per minute in 
the continental code, write legibly and spell 
correctly at the rate of twenty-five words 
per minute, and have a grammar school 
knowledge of arithmetic. 

(b) To be enrolled as Electricians 3d 
Class (Radio), applicants must qualify as 
in (a) and must be competent first grade 
commercial and amateur operators who can 
receive twenty words per minute in the 
continental code. 

(c) To be enrolled as Electricians 2nd 

Class (Radio), applicants must have com¬ 
mercial licenses, must have served at least 
one year as radio operators on merchant 
ships with a discharge from such ships, 
showing excellent service and good reasons 
for such discharge, and must be able to 
receive in continental and .\merican Mor>e 
code at the rate of twenty-five words per 
minute. ' ^ 

(d) To be enrolled as Electricians, 1st 
Gass (Radio), applicants must qualify as 
in (c) and must be radio operators who 

It may be the means of dealing the death 
blow to the submarine menace. 

It is possible that it will mean the scrap- 
ping of the giant super-dreadnaughts of 
the world’s great navies because of their 
helplessness when attacked by a torpedo 
controlled in everj^ way by wireless. It will 
also mean a great saving in that an ex¬ 
pensive torpedo which misses fire can be 
brought back and used again. 

Hyder is only 33 years old and he was 
born on a farm in Missouri. All of his 
electrical knowledge has been obtained thru 
his own efforts, for neither he nor his as- 

’ Photos from C W. Geicer 

This California Radio and Electrical Inventor Claims to Have Solved Many Problems of Great Value to U. S. War Department. He Has 
Succeeded In Lighting Lamps by Wireless Power and Has Perfected a Radio-Controlled Torpedo Which Cannot Be Interfered With. 

All of these things that he claims to be 
able to do he demonstrates with working 
models in his little workshop with the help 
of his assistant, Arthur H. McClelland. 

For more than four months Hyder and 
his assistant have been working night and 
day to perfect the invention so that they 
can take it to Washington to place it before 
the Naval Advisory Board. Now they are 
about ready to demonstrate it and expect to 
leave for Washington within a short time. 

The invention for which Hyder claims 
so much is not, however, the result of only 
four months’ work; it is the culmination 
of fifteen years of hard study and drudgery, 
inspired by enthusiasm and hope. Team 
work has played an important part, for 
McClelland, Hyder’s assistant, has worked 
with him during all of the fifteen years. 

Hyder’s torpedo arid mine construction 
have not been his only accomplishment. He 
has perfected a system of lighting lamps 
by wireless which he believes will be utilized 
in the future to prevent ships from col¬ 
liding in the fog and will eliminate the block 
system on the railways. By wireless he 
can light several lamps wired in serie.s and 
keep part of them lighted when some of 
them are removed. 

What Hyder terms his torpedo and mine 
construction is most important at this time. 

sistant went to college—but. then, neither 
did Edison. Study will Ive all problems. 


NCLE SAM is offering exceptional 
opportunities to young men who will 
join the service at thi.s time, states 
Mr. Fred Mueler, Gunner (R) U. S. N. 
R. F, At the present time the U. S. Navy 
Department desires to enroll in the U. S. 
Naval Reserve Force radio men who are 
willing to volunteer for general sea ser¬ 
vice and who possess the following quali¬ 
fications : 

(a) Must be citizens of the bhiited 

(b) Must be able to pass a physical and 
mental examination before enrollment. 

(c) Must be able to send and receive the 
continental code and possess some tech¬ 
nical knowledge of radio-telegraphy. Ra¬ 
dio men are particularly desired and those 
applying for enrollment as radio operators 
will be assigned to active duty upon quali¬ 

The following is a list of qualifications 
required for enrollment in the various 
grades of radio operator: 

(a) To be enrolled as landsmen for Ra- 

have serced at least two years on a mer¬ 
chant ship and possess a considerable 
knowledge and acquaintance with radio 

(e) To be enrolled as Giief Electrician 
(Radio) applicants must qualify as in 

(d), must have a broad knowledge of ra¬ 
dio-telegraphy. must have served on ocean¬ 
going steamers for at least four years, and 
must pass an examination by a board of 
at least three officers, of which two shall 
be radio operators. 

The rates of pay for the above grades 
of radio operator arc as follows: 

Giief Electrician ( radio) ... .$72.00 
Electrician (radio) 1st class. 61.(K) 
Electrician (radio) 2nd class 52.00 
Electrician (radio) 3rd class 41.00 
Electrician (radio) Landsman 
(for training) . 32.00 

Men who are enrolled in any of the 
above grades will be assigned to active dut>" 
under instruction at one of the U. S. Naval 
Reserve Radio Schools, where they will be 
given a course under experienced Navy in- 
{Cottiitiucd on page 417) 



October, 1917 

Brown University Trains Radio Experts 


Radio Students At Brown University, Providence, R. 1., Studying the Ins and Outs of Wire¬ 
less Transmitting Apparatus. 

half a hundred amateurs have been stud}’- 
ing one and two nights a week under Prof. 
Watson, who is the father of wireless at 
Brown. Almost wholly with his own hands 
he built the plant on the hill and put the 
college on the wireless map. 

Up to the beginning of the war Brown 
had one of the best college wireless plants 
in the East. Prof. Watson and his stu¬ 
dents placed the apparatus, strung the 
wires; in short, did everything except build 
the towers on Maxcy and University Halls. 

The apparatus had a radius of between 
200 and 300 miles, and from the time of 
its installation “listening in” was a sport 
that attracted many students who pre¬ 
viously had sho^yn little interest in elec¬ 
tricity in general and wireless in particu¬ 
lar. For them the wires far above the 
middle campus hummed a lively and en- 
gaging tune. To listen to it once was to 
come again and again. 

The closing of the plant did not greatly 
interfere with the training of future oper¬ 
ators. Prof. Watson is too much of an 
enthusiast to let such a trivial matter up- 
his efforts. In his new quarters in the 
Engineering Building he straightway set up 
all necessary apparatus, rigged dummy 
aerials and kept going as if nothing had 

His night class caught this enthusiasm. 
Its students have been eager and industri¬ 
ous. A few started as fair amateur oper- 
1 only dabbled in the art. 

The larger number knew nothing at all 
weeks evervbody 
added to his practical knowledge of radio. 

Of all the instruments in the room the 
omnigraph sender is of the greatest in¬ 
terest. It is a small mechanical device 
having metal discs—-a whole series of them 
fitting one on top of the other—that show 
peculiar, irregular, edges. These edges are 
nothing more or less than the dots and 
dashes of the code. As the discs revolve 
the listeners pick out the dots and dashes 

room to another in the building and by 
means of them the more advanced stu¬ 
dents send and receive messages. The 
visitor always finds it interesting to ad¬ 
just the headgear and listen in on what 
may be coming from a distant corner. 

“We hope to encourage,” said Prof. Wat¬ 
son, in a recent inter\dew, “the formation 
of groups of students who will train in 
sending messages as well as in receiving. 


This concern has been given a contract 
by the United States Navy Department for 
the construction and delivery within nine 
months of 250 additional radio transmission 
telegraph sets, at $988,000, which with the 
other contracts from the Government held 
by the company makes a total of 315 sets, 
at a cost of $1,112,000. The contract calls 
for 200 one-kilowatt and 50 two-kilowatt 
transmission sets for the use of the Navy 
Department. It is understood some of these 
are to be installed on naval vessels, while 
probably the most of the order will be for* 
equipping the vessels of the United States 
Shipping Board Emergency Fleet. 

Evening Radio Class at Brown University. Ev en the Young Women Have Caught the Fever, 

As This Picture Shows. 

Our time is all too short for full training, 
but we shall try to give every student a 
good grounding in the first principles and to 
advance the real amateurs, the ones who 
have worked with home sets, to a fair 
degree of proficiency.” 

A wireless station with a night range of 
700 miles has been installed at Cape May, 
N. J., by E. M. Murray, a Philadelphia 
Marconi engineer, and E. M. Hartley of 
the Miami station will be superintendent. 

Brown University has helped to train 
radio experts during the past summer, con¬ 
ducting a radio class under the direction 
of Professor Arthur E. Watson, instruc¬ 
tor of electrical engineering, ^klore than 

and write them down, as correctly as they 
can, in letters. 

Other students practise with telephone 
head sets operating on dummy aerials. 
Prof. Watson has strung wires from one 

The fortitude of a wireless operator in 
sticking to his instrument made possible the 
rescue of forty-six men out of fifty, on the 
American steamship Orleans ^yhen she was 
torpedoed unawares by a German subma¬ 
rine, according to Capt. Allen Tucker, com¬ 

“We saw nothing and heard nothing,” 
Capt. Tucker said, “until the torpedo struck 
ns amidships and burst with such force that 
it seemed to tear the ship asunder. It was 
a fairly clear night, but ^e water was verj^ 
black. I gave orders to launch the boats 
immediately, and we got all but one, which 
had been smashed by the explosion, into 
the water in record time. 

“Meanwhile L. F. Larson, our wireless 
operator, was sitting up in his cabin and 
sending off S O S calls as coolly as tho 
they were merely commercial messages. He 
finally got into radio touch just as the stern 
began sliding under the water. 1 ran in, 
pulled him out on deck and practically 
threw him overboard, knowing he could 
swim. Tlien I followed and we both swam 
like hell to get away from being dragged 
under the sinking ship. 

“The Orleans sank within ten minutes.” 





H. Gerrxsback, Manager 


IV. H. Kirwan, Master of Radio Relays 

The Amateur’s Opportunity 

By the EDITOR 

T he letter which we publish here¬ 
with is one of the many that come 
to the editor’s desk during the 
course of a week. 

It clearly illustrates one of the 
strangest situations created by the war, and 
it likewise has a very pointed moral. The 
elosing of America’s radio stations by our 
Government has liad the unfortunate 
result in bringing to life several hun¬ 
dred thousand “sore heads,’’ who in 
peace times were fond of calling tliem- 
selves Radio Aaiafeiirs. 

These good people, whose patriotism 
has suddenly gone bankrupt, always 
forget that the same government that 
granted our radio amateurs greater 
liberties than any other nation on the 
face of the earth certainly has some 
rights of its own. 

Where, Oh! where, is our far- 
famed American patriotism? Where 
is our highly lauded fair-play? Where 
is our gratefulness? Sore-headedness 
seems to be one of our latest acquired 
national diseases—at least in our 
.American radio amateurs. And we 
cannot but condemn it in the harshest 
possible terms. 

Why not make the best of it, partic¬ 
ularly as the present radio situation is 
of course only temporary? Sore- 
headedness and bitter remarks about 
the Government do not in the least im¬ 
prove matters, but rather tend to make 
them worse. We all want our stations 
back after the war; we all want the 
ether free for all. But the way ama¬ 
teurs are acting now certainly tends 
to bring the whole fraternity into bad 
repute at Washington. As if amateurs 
had not been disliked enough before 
the war, with all the Q.R.M. nuisance going 
on in the ether continuously! Why make 
ourselves disliked still more? WTat’s the 
matter with the American amateur any 
way? Where is his logic? 
common sense? 

And last, but not least, 
where does the amateur 
come in with his silly, non¬ 
sensical kicks? What .about 
the wireless manufacturers 
who have been put out of 
business — wiped off the 

Governmeul? Indeed not, they gladly do 
their “bit” for their country. 

Then amateurs, zvherc do you come in? 
Now, we realize that this is rather plain 
talk, and it is not pleasant to write it. but 
trutli as a rule is never pleasant and we 
hope that our amateurs will see that we are 
working in their very best interest. 

. S. Navy f^ecruiting Station 



Aug. Ifl. 1917. 

Ur. H. Gera*baek, 

Editor Sxparlmeatar Fahlleblog Co. 
flow York City, B.Y. 

Uy door sir; 

7bo Ualtod Steteo Bory Doportnoot hoe loatruetod 
thlo roomltlog offloo to siciko ovary effort to oaliot moa 
for oervloo la the radio bronoh of tha flovy. 

Tbaae maa are waotad Imadlotaly for ootlre ear- 


7e ora onabla to flad a oomplata Hat of oil rodlo 
oparoton lo tbe 3t. Loala Dlatrlot whlob comprloee tbo ao> 
tiro atota of Ulasoarl, with tba axoaptloQ of Jookooa o&d 
Boeboaoo Countlae, lo addltloo to two boontlee of IlllDOla, 
Uadlooa aad St. Clolr. 

Ooa of yoor ouheorlboro to tha Bloctrlool flxperliBaQtat 
auggastad to DO that yoa would bo la a poeltloo to furolob do 
with a oomplata Hat of all lloaoead radio oparotoro la thla 
4iotrlot, and lo addltloo. thoaa mao who ora amataora but who 
boTe oot yat baan Hoeosad. 

Too may ba aura that aoy Informatloo glvao oa will 
ba^hlghly oppraolatad. 

Youra vary truly. 

Llautaoaot U.3.B. 

W’here is his 

The Editor of this journal has a record 
of having championed the amateur’s cause 
ever since 1908. It was due solely to his 
efforts that the American amateur was offi¬ 
cially recognized, and that a law was framed 


I Herewith Propose 

map? Are they going about 
the land lamenting their 
cruel, cruel fate? Not 
much. They know that war 
is synonymous with sacri' 
fice. They are doing their 
bit—their big bit, rather. 

What about the radio and 
technical magazines, whicli | I 
lost 90% of their wireless | I 
advertising? Take this I I 
magazine for instance, f | 
which .since its start never : = 

made any money. When h ..*. 

war was declared it lost 
$1,200 worth of radio advertising in a heap, 
and it will be losing this amount ez'ery month 
as long as tlie war lasts. Have these maga¬ 
zines, the Experimenter included, ever as 
much as raised their voices against the 

I call upon every radio amateur in America to do his “bit” 
in this war. Amateurs, this is the most important message to 
you I have ever written. I consider it more important than my 
Editorial in the November. 1908, issue of “Modern Electrics.” 
which was the direct cause of placing the American Radio 
Amateur into the Radio Law of 1912, thereby giving you the 
free use of the ether. Amateur Wireless owes a large debt to 
America.. Now is the time to repay that debt with interest. 

Will you do it? 

for the amateur’s benefit, giving him the 
free use of the ether. 

The Editor will continue to work in the 
interest of the American amateur, hut he 
cannot do so without the latter’s undivided 

interest and his full enthusiasm. It is not 
pleasant to work for a lot of sore^heads, 
and the amateurs certainly do not wish the 
Editor to wash his hands of the whole 
matter, and “chuck up the job*’ in disgust. 

What we want is ENTHUSIASM and 
plenty of it!!! Let’s pull ourselves together 
and let us show the world what stuff we 
are made of. Let’s all do our bit in this 
war, to make the world free and safe 
forever. To do it Uncle Sam, besides 
his soldiers and sailors, needs oper¬ 
ators—operators and then some. \\> 
have them. Thousands of them. The 
country’s full of ’em. The order of 
the day is to get them out into the 
open. And we’ll do our best, or perhaps 
our worst, to get them to come out. 

Uncle Sam just now does not re¬ 
quire radio experts so much who can 
send and receive 50,000 words a min¬ 
ute ; rather he wants boys who have 
a fair knowledge of radio and who 
like the work. Your Uncle Samuel 
will make an expert out of you in 
no time, and he ivill pay you zchile he 
is doing it. Radio work in the army 
and navy is comparatively safe, and 
while we do not in the least wish to 
imply that radio amateurs are cowards, 
we do wish to go on record with the 
statement that as a rule the radio 
man stands on a higher plane of in¬ 
telligence than the average plain sol¬ 
dier or sailor. 

Recognizing this. Uncle Sam pays 
the radio operators and signal-corps 
men more money than to the soldier 
or sailor of the rank and file. Now 
if this does not spell opportunity for 
you, we’ll eat a 5-K.\\’. transformer, 
spark gap, wires and all! 

Amateurs, again we'll tell you, you don't 
rcalhe hozv really valuable you are to your 
country. So why hide yourselves awav? 

Now then, here is our plan, and we ex¬ 
pect full co-operation from every one of 

.... you, even if you can’t send 

or receive more than five 
dots and si.x dashes per 

We are going to compile 
the most complete file of 
Radio Amateurs in the 
country, zvho are zvilling to 
do their '*hit." The files of 
the “Radio League of 
America” now contain some 
16,600 name s—a pitiful 
amount compared to the 
total of some 300,000 ama¬ 

W'e want this list so that 
when Uncle Sam writes to 
the Editor asking him for 
names of radio operators, 
we will be in a position to 
send him thousands, where 
wc send him dozens 
now. Take for instance 
the letter publisht here: all we could send to 
L’t. C. H. McCann was forty names. A fine 
showing, that—not! Now to make it in¬ 
teresting for you. amateurs, beginning 
{Continued on page 415) 



October, 1917 

A Radio Controlled Model Boat 

F R02^I time to time in the Electrical 
Experimenter we have read articles 
on wireless control. Wt have taken 
much^ interest in publications along 
this line, having constructed a selec¬ 
tive control set in the summer of 1916 our¬ 
selves ; yet we have not run across a set 

Appearance of Model Boat Fitted With Wire¬ 
less Control Apparatus. This Kind of Work 
Is Bound to be Highly Remunerative and 
Radio Experimenters Will Do Well to Inves¬ 
tigate the Many Unsolved Problems In This 

that has mentioned as great a range of use, 
this set^ having been used in a small dem¬ 
onstration wireless controlled boat, con¬ 
trolling t 03 ' reversible electric trains, shoot¬ 
ing fireworks—in fact it can be used with 
any machine which is controllable by elec- 

In July, 1916, this apparatus was installed 
in a six-foot electrically propelled boat and 
on the 4th of that month a demonstration 
of “The Wireless Control of a Boat” was 
given at Riverside Park, on the James 
River, at Mitchell, S. D. In April, 1917, 
the same apparatus was used for a dem¬ 
onstration and talk on the “Science of Tel- 
automatics,” given before the Mitchell Sci¬ 
ence Club, a branch of the South Dakota 
Academy of Science. 

This selective set is simple and easilj'' con- 

Detail of Sounder and Ratchet Wheel Mech¬ 
anism for Successively Switching In and Out 
of Circuit the Rudder Control Magnets, Pro¬ 
peller Control, Etc. 

By H. C. Van Benthuysen and Max I. Black 

structed. The controlling apparatus is an 
ordinary coherer set, the relay of which 
actuates a sounder to which is attached a 
ratchet wheel control for a second sounder. 
This second sounder operates an eight- 
l)oint rotarv switch of the commutator t^pe. 
When used in the boat two segments of 
this switch are blank. The other six 
operate two solenoid reversing switches 
and one solenoid cut-off, which controls 
the helm motor only. It is possible to use 
the two blank segments for a solenoid cut¬ 
off for the propeller motor altho we did 
not find it necessary. The order of the 
points are ‘Jorzvard,'" ''on/' 
"starboard/' ''port'' and "og." The "on" 
and ''og" control the helm motor so it will 
not b e i n 
ope ration 
ly. The helm 
motor is 
geared down 
by means of 
a w o r m 
drive which 
also keeps 
t h e rudder 
rigid. This 
also gives 
the operator 
a chance to 
skip over the 
and port 
without al- 
t e r in g the 
course of the 
boat. W^ith 
this arrange- 
m e n t the 
operator has 
control over 
the boat. 

For the se¬ 
lective con¬ 
trol of a 
m i niatu re 
electric train 
a four - rail 
track is used 
(two rails 
for the field 
and two for 
the brushes 
so the train 
may be re- 
versed ). 

W^ith o n 1 y 
one revers¬ 
ing switch 
being neces- 
sar\% thus 
giving four 
blank points 
on the eight- 

point rotary switch, instead of two, as in 
the case of the boat. W^ith these connec¬ 
tions switching can be demonstrated with a 
toy electric train. 

The radio apparatus is made up of a pre¬ 
cision coherer, and a fift}*^ ohm ponj' relay 
with an ordinary bell decoherer. The 
sounder switches are any ordinary fifty 
ohm sounders with an extension arm which 
operates a ratchet wheel. (See diagram.) 

The solenoid magnets for the reversing 
switches and the cut-off switch are made of 
a core consisting of one layer of zinc 
(woiind on a pencil for uniform diameter). 
Each core is about three inches long. The 
ends are split and folded out to hold on 
the fiber ends of the coil. W’hen the core 
and ends are assembled wind on three lay¬ 

ers of No. 24 D.C.C. magnet wire. Wrap 
the whole coil with a layer of tape. The 
armature is an iron rod about five inches 
long and just large enough to slide easily 
in the core of the solenoid. The solenoids 
are placed in such a position on a suitable 
base that when the armature is clear in, 
the end will be about one-half inch from 
the outside end of the core. 


In response to a request from the central 
department signal office of the United 
States Army, the Iowa State University 
will give during the next school year a 

course of training for telegraphers and 
wireless telegraphers. The work will be in 
charge of the head of the electrical engi¬ 
neering department and will be open to 
young men of the state, without regard to 
entrance requirements usually made of 
students by the University'. The course 
for the individual will last only until he 
has mastered the art of telegrapliy suffi¬ 
ciently to pass the government’s examina¬ 
tion in the subject. 

“The need of telegraphers in the sigiial 
corps is serious,” declared Lieut. Col. Wild- 
man in a letter to President Jessup. “The 
available supply has been exhausted and 
new men must be trained to complete the 
present organization and prepare for all 
future increase.” 

October, 1917 



Measurements of Radio Antenna on Shipboard 
and Some Interesting Comparisons 

By I'. A. HART 

\ariations of capacity, inductance and 
fundamental wave-length have been selected 
by the author from measurements taken 
on a large number of vessels, and covering 
at the same time as broad a range as pos¬ 
sible, These data should be of interest to 
marine engineers and advanced experimen¬ 
ters, especially in the case of aerials erected 
on roofs, such aerials being under ver>^ 
similar conditions as regards effect from 
near-by metal, stays, etc., which materially 
affect the capacity of the aerial. 

In connection with ship stations a great 
deal has been said about compass trou¬ 
bles, generally attributed by masters to 
the nearness of the aerial lead-in wires in 
each specific case. It might be well to 
point out that exhaustive tests have been 
made from time to time, and absolutely 
no disturbance noticed, says F. A. Hart 
in The Electrician, London. On the other 
hand, the proximity of a motor-generator or 
other large mass of iron to the compass 
would tend to have some effect. 

The lengths used in the table are given 
in feet, capacity in micro-farads, inductance 
in centimetres and natural wave-length in 

For simplicity, each type is designated 
by a number. The overall or total length 
of wire from apparatus of the “L’' aerials 
is taken as the horizontal plus the vertical, 
and in the ‘"T” aerials half the horizontal 
plus the vertical. All these aerials are 
comparatively small in actual amount of 
wire compared with aerials in coast sta¬ 
tions. and a good many should compare 
very nearly with many amateur receiving 
aerials, some of which are of even greater 

Aerials such as Nos. 6, 9 and 28 are the 
least efficient for 200 and 300 metre waves, 
as the fundamental is ver>' large, the ca¬ 
pacity low, the radiation resistance high; 
and in order to reduce the aerial to small 
wave-lengths the series condenser would 
have to be less than 0.0004 mfd. As both 
capacities are so small, the radiation from 
any set less than one kilowatt would prob¬ 
ably not be greater than one-half ampere. 
Judging by the results, for those who wish 
to transmit efficiently on 200 or 300 meters, 
the aerial should be made a “T” where the 
horizontal length is 120 ft. or over. As 
a rule, the most efficient working wave¬ 
length wdiere a scries condenser is not 
used is about 0.9 of the natural wave-length. 
For instance, in the case of No. 23 the 
natural is 230; taking 0.9 of this value 
and adding it to 230 nvc get 437, w'hich 
should give the greatest radiation for that 
particular size of aerial. 

In the case of Nos. 15 and 16, these 
measurements are identical, w'ith the excep¬ 
tion of a trifle greater height and 55 ft. 
more wire in the horizontal length of No. 
16, Everything being equal in both cases, 
except the relation of the vertical wdres 
to the bridge railings and metal stay in No. 
15, this apparently makes up for the 55 
ft. of extra length in No. 16. 

The most marked of deck and w'ork ef¬ 
fects is in Nos. 38 and 39, the vertical 
length in No. 39 running parallel with 
three stays from the top of the mast to 
the wireless cabin. In No. 38 they run 
practically the same, also considerably in¬ 
creased by the nearness of the funnel. The 
“T'* type aerial has been found as a whole 
to give the best all-round results, and is 
less likely to be affected by foreign mat¬ 
ters. The spring stay should be removed 
and all other stays cither grounded or 

broken up with insulators to ensure against 
induction and the most effective work 
from the radio apparatus. 

Aerials in which stays, decks or other 
metal work figure largely are Nos. 18, 19, 
20, 21, 22, 30, 33, 34, 35, 36 and 37, in every 
case affecting the vertical length. The 
ground lead in all examples given docs not 
average over 3 ft., and is sometimes less. 

No. 1 is a very good type of aerial for 
amateurs who wish to transmit. No. 40 
is also in line with No. 1 ; the capacity 
runs higher, altho the lengths are very 
small, and the nearness to all metal work 
and the large number of wires has helped 
to increase this. 

One can readily see from the table how 
important it is to keep the overall lengths 
as small as possible wdiere there is any 
possibility of metal increasing the capacity. 

Txvo-U'ire Aerials. 




.S Lengths. o 

It. a > 


























































































Four-wire Aerials. 








































































































































Six-znre Aerials. 


























































































































































Ten zinre Aerial. 
















Having an open desk on which my radio 
set was mounted, and being greatly troubled 
wdth dust, I hit upon the following simple 
but efficient method of protecting it from 
dust. A shade roller, three feet long in 
my case was mounted on the wall about six 
inches above the desk. A cloth three feet 
wide and long enough to cover the entire 
set wdicn fully extended w'as nailed to the 
shade roller. It operates as follow^s: When 
ready to use set, take hold of cloth and pull 
away from the roller and then let go. The 
cloth will wdnd itself about the roller. An 
ordinary shade wdll do, but I use a cloth 
because it presents a neater appearance 
and is besides more flexible than the ordi¬ 

nary shade. Rollers can be obtained of any 
length for a nominal price. 

Contributed by CARL BERNHARDT. 


The great trouble with ordinary buzzers 
used for detector tests, is that they do not 
emit a high tone. I found that if tightly 
folded pieces of paper were placed between 
the magnet and armature and betw^een the 
armature and spring that carries the con¬ 
tact, the tone was thereby raised. The 
best thickness of the paper must be found 

Put PdfDer Here 


Any Buzzer Can Be" Made to Give a High 
Tone By Placing ^>Paper on Either Side of 
the Arrrfature, As Shown. 

by experiment.-'^lso, the contact screw’ must 
be regulated to get the highest tone. Rubber 
bands may also be used. These are snapt 
around the buzzer in such a way as to 
pass thru the same points as occupied by 
the paper. 

Contributed by E. D. PAPKEE. 


Two lamps are connected across the line, 
the wire betw'een the lamps being grounded 
thru the third lamp. With low powers 

A Kick-Back Preventer Made From Lamps 
Properly Connected. 

there will be little danger of the lamps be¬ 
ing burned out. and in the case of higher 
pow’crs. two lamps may be connected in 
parallel in place of only one lamp. Car¬ 
bon lamps are capable of carrying heavy 
overloads and are good for. the purpose. 

Contributed by THOS. W'. BENSON. 



October, 1917 

A Key That Will Handle 1 K.W. for $1.00 

Following is a description of a wireless 
key that is easily made. With a wooden 
base it costs about $1.00. 

The lever, shown in detail in Fig. 1, is 
made of a 54 inch brass slider rod about 

piece or stretching it, until it is the right 
length, thus eliminating the thumb nut ‘’F.” 

The binding posts G, G, the thumb nuts 
F, F, and the key knob I. may be purchased 
from any electrical supply house for about 
6 cents each. 

The base may be 
made of wood, fiber, 
hard rubber or mar¬ 
ble. The latter im¬ 
proves the looks of 
die key considerably, 
but it comes rather 
high and does not im¬ 
prove the working of 
the kej*. Nickel plat¬ 
ing improves the ap¬ 
pearance also. This 
key will take care of 
a 1 K.W. set, and if 
carefully made will 
equal a $6.50 key. 

Contributed by 

Details for Making a First-Class Radio Key Suitable for Transfor¬ 
mers Up to 1 K. W. Capacity. 

7 inches long, bent as in the drawing. This 
can be done by placing it in a vise and care¬ 
fully tapping it with a hammer. The bear¬ 
ing rod (Fig. 2-c) is made of a short piece 
of 5/32 inch brass or steel rod. This is 
forced thru a hole in the lever inches 
from the end. A little solder will hold this 

The '* What to do with 
your Radio Set” Contest 

When the Xavy De¬ 
partment declared all 
radio stations closed, it 
seemed as if I would 
have to pack my instru¬ 
ments away for about six 
months or more, as there 
seemed to be no further 
uke for them. 

However, I decided to 
use my instruments in 
some other w a y than 
ascribed for them in their 
original use. Finally I 
evolved the idea of 
building a very sensitive 

The following instru¬ 
ments are used: A wire¬ 
less telephone transmitter 
(or an ordinary telephone 
transmitter), an Audion 

amplifier set and phones. The Vi4re from the aerial 
is used to connect the different instruments. Where 
one wire crosses another, the insulators can be 
used to insulate them. If this set is to be put up 
between two buildings, a return wire can be used 
by the ground usually used in v^dreless. —JACOB 

Radio Instruments Useful in Electro-Chemistry 

in place or it may be pinned in position. 
The bearing posts are of Yi inch square 
brass rod, see Fig. 2-b. The contacts D— 
D-f-, Fig. 2, consist of uvo pennies and two 
dimes soldered together. The upper con¬ 
tact D— is then soldered to the lever. Fig 
1. The lower contact is then soldered to a 
short piece of copper or brass bar wdth 
a binding post mounted on the end. Bind¬ 
ing post G. Fig. 4, maj^ be connected io the 
lever in numerous ways. 

.A well-known \vireless key makes use of 
a bronze spring pressing up against the lev¬ 
er. Another way is to connect to the bear¬ 
ing post. The tension spring “E’' requires 

no e.xplanation, except that it may be made 
of brass spring wire instead of piano wire. 
This spring may be adjusted before the final 
assembling of the key by cutting off a small 

Any up-to-date wireless outfit may be used in 
the study of ‘’electro-chemistry.” The amateur 
can make use of nearly all his instruments. The 
transformer and spark gap will make a fine little 
electric furnace or open arc. Electrolysis, electro¬ 
plating, and eIectrot>T)ing are easy. Delicate in¬ 
dicators and variable instruments he of use 

in electromotive force tests. The effects of mag¬ 
netism and various waves on chemical actions is 
interesting. Battery jars and electrodes come in 
handy. The resourceful American amateur would 
need only glass-ware, some common chemicals, 
and a text-book, to make a complete laboratory* 
The Experimenter might take the place of the 
text-book. I have made a good chemical labora¬ 
tory of my wireless room, and am leaching some 
grammar school boys the mysteries of chemistry. 
Electro-chemistry is as instructive and interesting 
as wnreless itself, and I recommend it to all other 
amateurs.—J. FR.\XK- 

Miscellaneous E.xperi- 
ments for the ’’Radio- 

Imagine yourself to be 
an amateur who has been 
presented with an effi¬ 
cient sending and receiv¬ 
ing outfit; time—Xmas. 
Time flies as you perse¬ 
vere over the code. Feb. 
3, 1917, U. S. breaks re¬ 
lations N\Tth Germany. 
You are able to hear 
XAA give out reports 
and gossip over the war. 
April 6. 1917, U. S. declares war on the German 
Imperial Government. April 7, 8, 9, Radio in¬ 
spectors arc around sealing stations. This happens 
just when you were on the road to Radio fame.' 
Wouldn’t it jar you? 

View of Assembled Radio Transmitting Key. 

Cheer up! Perhaps this will help you. These 
ideas of mine enable the “Radio-Bug” to use his 
apparatus in war time without evading the Federal 

The apparatus used is as follows: 

Key, batteries, coil or transformer, gap, con¬ 
denser and helix. 

Variable or fixt condenser, loose coupler, de¬ 
tector, ’phones, and buzzer, perhaps a tuning coil 
and potentiometer. 

Idea Xo. 1 enables you to learn ^ the code or 
gives you practise so that you won’t get out of 
trim. Uncover that soap box and get out a key, 
some batteries, a buzzer, ’phones and detector, 
and the tuning coil or potentiometer. Connect up 
according to diagram 1. The tuning coil or 
potentiometer act as rheostats and increase or 
decrease the pitch of the huzzer. The condensers 
absorb the spark usually present at the contact 
point of the buzzer. This is a modified buzzer 
test. A two station buzzer line has been in¬ 
stalled in our high school and we certainly have 
fun. Here, a key, batteries, buzzer and ’phones 
are used. (Fig. 2.) 

High frequency experiments may he tried and 
currents obtained by using a transformer or spark 
coil, batteries, gap and helix. The transformer 
takes the part of the Tesla coil or Oudin resonator. 
Look up your old E. E.’s for H. F. experiments. 
Then get to work, persevere and enjoy yourself.— 

A Simple Buzzer Set for Practising the Code. 

An Efficient Buzzer Telegraph System Good 
for Several Miles. 

Fig. 3. Old Tuning CoMs or Loose Couplers 
Can Be Used As High-Frequency Oudin 


1 Can you write radio articles dealing 

= with the practical problems of wireless 
p operating? We can use some good 
^ papers on such subjects as “the tuning 
i of radio transmitters”; “the use of the 
W wave meter, including its application 
= to measuring the frequency, wave 
5 length and decrement”; “operation of 
§ commercial transmittiog and receiving 
^ sets”; “the operation of army trunk 
^ sets”; “improved ways of receiving 
M undamped wave signals,” also new 
^ ideas and short-cuts for learning^ the 
codes. We pay well for all articles 
M accepted. Help yourself, your maga- 
g zine and your country. 

^ '- HI nnBt!—ITTCIK 

^lllllllllllllllllllllllllillillllllllllllllllllllll'lilllllllll^^ III! iillllKlIllllllllllillllllK'*' 

October, 1917 



A Simplified Variable Condenser 

By R. U. CLARK, 3rd 

^LTIIOUGII tliere arc a great many 
forms of variable condensers on the 

r~\ market today, there are few types 
JL wliicli can be readily constructed 
by the average experimenter, which 
will approach the compactness, and good 
appearance embodied in many stock articles 
of this nature. 

A condenser constructed on the general 
lines of the one described herein should 
comply with the above requirements, and 
as can be seen from the sketches will re¬ 
quire but few materials and little work for 
its completion. 

As various capacities will be desired by 
the different amateurs who may decide to 
make this instrument, no definite dimen¬ 
sions will be specified in the following notes, 
except to show the general relation, in re¬ 
gard to size between the different parts 
which enter into the construction. 

Very few parts are necessary for the 
work in hand, the complete list of materials 
is as advised at this point. 1 round tubular 
fiber or composition case. 1 round top, of 
metal, fiber, or hard rubber, etc. A small 
quantity of lead. A few feet of thin brass 
or copper ribbon, about one inch wide, pre¬ 
ferably of soft metal. Several pieces of 
paper tape, about three-fourths of an inch 
wide, by about one^ sixty-fourth thick. 2 
short lengths of 1 inch half round fiber. 
Brass screws, about one-quarter inch long, 
two small brass screw-eyes, 2 binding 
posts, a short round brass rod and small 
composition knob, complete the list with 
tlie exception of a short length of flexible 
copper ribbon. 

In order to construct the condenser it 
is necessar>^ to cut the brass or copper rib¬ 
bon into two equal lengths, each one inch 
wide, and with a few of the small brass 
screws mentioned, fix one end of each 
piece to the flat surfaces of the half round 
fiber, one piece of brass to one of fiber. 
This should be done in such a manner that 
the end of each brass strip comes to 
within about 1/Sth inch of the center of the 
fiber, on the flat surface, both brass strips 
also being positioned near the center of 
the fiber, in regard to tlie distance from 
each end. 

The two flat surfaces of the fiber are 
now fitted together in such a manner that 
the two pieces form one round rod, with 
a brass ribbon apparently passing thru the 
center. One of the pieces of brass should 
now be wound part way around the rod, 
till it comes into contact with the other 

When the above steps have been taken, 

the fiber rods should be slid along on each ^ 
other, so that if the metal ribbon is wound " 
around the rods, the pieces will overlap at 

each end l/4th of an inch, thus forming a 
winding 1-1/2 inches wide. Before the 
winding is commenced however, two pieces 
of paper tape should be placed between the 
brass strips, and two additional pieces made 
fast to the outside surface of the second 
metal ribbon, in such a position that when 
the several layers of metal and 
paper have been wound into a 
tight coil, there will be an 
empty annular space yith of an 
inch deep between the brass 
strips at eacli end of the coil, 
the remaining ^ths inch near 
the center being filled with the 
paper tape, as shown in Fig. 1. 

in order to wind the paper 
and metal in the manner speci¬ 
fied, it will first be necessary 
to clamp both ends of the fiber 
together. After the coil has 
been completely wound, it 
should be bound with paper 
tape, until the outside diameter 
of tlie paper ring thus formed 
is equal to the inside diameter 
of the tubular condenser case. 

Both ends of the fiber can now 
be sawed off flush with each 
other, one end being sawed off 
about J4tb of an inch from 
the end of the coil. The other 
end should extend about ^ths 
inch beyond the end of the 
coil; see Fig. 1. 

The clamps can now be re¬ 
moved from the fiber ends, 
and the condenser case split 
over the coil, which should be 
pushed into position, so that 
the short end of the fiber 
pmes to within about ^th 
inch of the top end of the case. 

Molten lead should now be 
poured in to fill the remaining 
space to the top of the case, 
after a short strip of very 
thin copper ribbon, about one- 
fourth inch wide, has been in¬ 
serted in the space betweu the pieces of 
fiber. This piece should be bent over once 
at the lower end before being inserted, so 
that when the lead has been poured, the 
copper ribbon cannot be witlidrawn. 

The condenser case should now be moved 
along over the coil of metal and paper tape, 
until the other exposed ends of the fiber 
pieces extend beyond the case about l/8th 
of an inch. This should cause the upper 
lead casting to move down about 1 inch. 

Several layers of paper tape should next 
be wound around the lower end of the case 
to form a mould for the lead base which 
is integral with the metal portion which 
holds the lower set of spiral plates as 
shown in Fig. 2. 

The various parts are now removed from 
the case, and the two sets of spiral plates 
are carefully pulled apart, the paper tape 
being removed at the same time. If these 
parts are now placed in their original posi¬ 
tions in the case they sliould .slide freely 
in and out of each other. In the event of 
the friction being too great to allow free 
movement, the lead and fiber on the mov¬ 
able portion of the plates can be filed down 
a little to permit unobstructed movement. 

The top piece for the condenser should 
now be slotted to allow the copper ribbon 
to pass thru, the latter being then .attached 
to the round brass rod, mentioned in the 
list of materials. 

The top is next fastened to the case by 
means of a brass screw eye on one side, 
and a small screw binding post on the other. 
The brass rod mentioned above is then 

put into place, being slipt thru the screw 
eye on tlic right hand side, as in Fig. 2, 
and using for its other support a second 
screw eye held in the binding post as shown. 

A composition or rubber knob placed on 
one end of the brass rod, and a small bind¬ 
ing post fitted to the lead base, complete 

the construction of the condenser. 

In operation the plates are separated by 
turning the knob, the weight of the movable 
plates causing them to sink into place be¬ 
tween the fixt plates, when the knob is 
turned in the proper direction, and the fric¬ 
tion on the rod, brought about by com¬ 
pressing the bearings, prevents the plates 
from moving on their own account. 

This condenser can be shellacked around 
the bottom joint and filled wdth oil to in¬ 
crease its capacity, and in this maner a very 
compact and simple instrument will be ob¬ 
tained which will give excellent results. 


Fearing that he would arrive too late to 
enlist in the Eighteenth engineers, railway, 
United States Army, Warren A. Taylor, a 
railroad man of Cordova, Alaska, recently 
wirelessed Col. J. B. Cavanaugh, com¬ 
mander of the regiment, to hold a place 
for him, Taylor arrived in time to enlist 
at the Kighteenth’s emergency recruiting 

For the last seven years Taylor has been 
an engine man on tlie Cooper River North* 
western. On learning that the United 
States was organizing nine railway regi¬ 
ments to send to France, lie began prepara¬ 
tions for the trip to Seattle to enlist. He 
was delayed, but decided to take a chance 
on getting into the regiment on the eve 
of its departure for Europe. When the 
steamship Alaska was two days out he sent 
the wireless asking for a "reservation.” 

Fig. 2. Unique Variable Condenser, Suitable for Radio 
and Other Circuits. The Movable and Stationary Plates 
(Spirals of Brass Ribbon) Are Both Held by Molded 
Lead at Top and Bottom of the Condenser, As Shown. 
Oil Dielectric Can Be Used, Giving As High As Five 
Times the Capacity With Air. 



October, 1917 


The drawing is that of an aerial which 
is insulated wdth material which is com* 
monly found around any work shop. By 
looking at the illustration you will see that 
it comprises merely two porcelain knob 

Clever Way of Utilizing Porcelain Knobs in 
Supporting Antenna or Other Line Spans. 
The Knobs Are Bolted to the Spar in Pairs 
as Shown. 

insulators, fastened on the spreader by a 
bolt of sufficient length. This is a cheap 
but neat insulator and will work very nice¬ 
ly for receiving or small sending stations. 
Contributed by 



To make this key first take an electro¬ 
magnet that has a tapt hole in one end and 
rewind with wire that is hea\^ enough to 
stand full load current of the transformer, 
grounding one end firmly to the core. (Al¬ 
low 800 circular mils per ampere for cross- 
section of wire.) Then rivet a piece of 
silver on the end of the core opposite the 
hole and mount on a suitable base by a 
bracket B, formed by bending a piece of 
hea\y sheet iron into the shape of an L 
but before bending drill three holes in 
it, two to hold it to the base and one to ac¬ 
commodate a screw to support the coil, as 
shown. Then make two more brackets, B, 
and Bj, similar to B, of heavy sheet brass. 
To B^ (see drawing) is soldered the arma¬ 
ture, which is made of a piece of thin sheet 
steel. On to this is soldered the other silver 
contact which corresponds to the one on the 
end of the coil. 

The third bracket may be made exactly 
like B, and will be used to hold the helical 
spring and its means of adjustment, as 

Due to the Fact that the Alternating Cur¬ 
rent from the Transformer Line Flows Thru 
the Key Magnet Coll, the Final “Break” of 
the Circuit Occurs at the Zero Part of the 

shown. The other end of the spring is 
soldered on to the armature, as soon. 
Three binding posts should be provided and 

connected, as indicated by dotted lines. The 
external connections are also shown. 

Now, if the key is deprest, current will 
flow thru the key, transformer and relay 
coil, the current thru the latter causing it 
to attract its armature, which will alter¬ 
nately open and close the silver contacts, 
which are shunted across the key, due to 
the alternating character of the current 
flowing in it, the armature flying back when 
current approaches zero, to be attracted 
again when it increases af^ain, etc. 

Now, if the ke}* is releast when the value 
of the current is great enough at that in¬ 
stance to attract the relay armature, the 
circuit will not be opened by the key, there¬ 
fore no spark occurs at its contacts; nor 
will the circuit be opened until the value 
of the alternating current has reached a 
value so low that it can no longer hold the 
armature, which then flies open, opening the 
circuit when there is very little current flow¬ 
ing, which means practically no spark at 
the relay contacts. 

The difference in time between the open¬ 
ing of the key is so short that it is unno- 
ticeable, being less than 1-1/120 part of a 
second when 60 cycle current is used. 

Contributed by LOREX AXSLOW. 


Owing to the high cost of hard rubber, 
vulcanized fiber and other suitable ma¬ 
terials, many amateurs use wood, with the 
result that the instruments are not efficient, 
due to the fact that wood easil}^ absorbs 
moisture. I would suggest that greater use 
be made of ordinary roofing slate instead 
of wood, as it can be worked almost as 
easily as the latter. 

The slate is cheap and can be easily pro¬ 
cured. It is cut to the desired size with an 
ordinary wood saw (lubricate with water), 
preferably one having about ten teeth to 
the inch. A hack saw will make a very 
clean cut but will cut very slowly. I would 
suggest using a cheap saw such as can be 
procured in a five and ten cent store, as 
a good saw would be ruined, or would, to 
say the least, need “some’' re-filing. After 
the slate has been cut the edges are 
smoothed and beveled with a file and the 
whole well rubbed down with fine sand¬ 
paper and a block. If the slate is not 
thick enough, two pieces may be cemented 
together with thick shellac or may be held 
together by means of the screws holding 
the instruments. Holes for binding posts, 
switches or instruments can be drilled 
easily with a diamond point or twist drill. 
Before fastening on the instruments the 
slate is again well rubbed down with fine 
sand paper or emer>' cloth and given a coat 
of varnish or shellac. The finished base 
will look very much like hard rubber. 
Many slate switchboards are simply rubbed 
up thoroly with linseed oil. Others are 
given a coat of some good insulating var¬ 
nish such as black armalac. 

Contributed by JOSEPH BACKERT. 


Federal authorities recently found a se¬ 
cret wireless plant aboard the interned 
steamship Appam, which was taken pos¬ 
session of by United States Marshal Saun¬ 
ders at Newport News, soon after the 
severance of relations with Germany. 

A fine wire was found strung beneath 
the pipe leading to the whistle on the 
smokestack of the Appam and e.xtending 
above it as do the antennae of wireless 
plants. The wire led to the interior of 
the vessel where the lighting plant dynamos 
were kept running. \Vhen the Appam was 
first brought into port, the dynamo in the 


The carbon ring used in making this 
potentiometer may be sawed off the bot¬ 
tom of an old wet cell carbon cjdinder. 
It should be about or Yz" in thick¬ 

An Efficient and Finely Adjustable Potentio¬ 
meter Constructed from a Ring of Battery 
Carbon and a Switch Blade. 

ness. After filing and sand-papering the 
top smooth, it then should be glued 
to a base with a wire connecting to one 
binding post. In the center of the carbon 
circle so formed, mount a hard rubber 
knob and switch lever so as to make con¬ 
tact with the ring. 

This potentiometer is verj* easily and 
cheaply constructed. A large number of 
them may b6 made from one carbon 
cylinder. They will prove useful in con¬ 
trolling the current in radio and electrical 

Contributed by BURT CLARK. 

wireless room was removed by the Fed¬ 
eral authorities. Later, however, Lieuten¬ 
ant Berg ran a wire to the wireless ap¬ 
paratus from the dynamo in the boiler 
room of the steamship and connected it so 
that he could either send or receive mes¬ 

From the wireless room another wire led 
to Lieutenant Berg’s private room in ^ot- 
folk. Alessages were flashed to him in the 
Morse code on his electric light bulb b}^ the 
simple process used in flashing messages 
between battleships at sea. 


After having trouble with the connec¬ 
tions to the moving member of a rotary 
switch on a loose coupler, 1 adopted the 
following scheme: 

r—p fp 


.H s 


V/77JT p!afe 
^ ^ M sofdere(f 

Effective Arrangement of Rotary Switch 
Blade to Ensure Positive Contact at All 

In figure “A" is a phosphor bronze spring, 
bent as shown, so as to bear on the pointed 
end of the threaded rod of the switch knob. 
The contact is kept bright by the constant 
turning of the switch. 

Contributed by AS.A S. KELLER. 


Making An Electric Clock 


Part II.—Wheels. 

MEAN clock-wheels, not the ones in 
your head. Clock works are pretty 
hard to make unless you have a 
lathe, but you can fudge up some¬ 
thing that will do out of the works 
of a kitchen clock. I mean the old-fa¬ 
shioned woodcn-casc clock with the peaked 

top, whose works are simple and rugged. 
You discard, of course, tlie power-wheel 
(spring or weight) and any other wheels 
which occur on the power-side of the min¬ 
ute-hand arbor. 

If you were going to use a pendulum 
of tlie same short length as the kitchen 
clock, you would have pretty plain sail¬ 
ing; but 1 assume you want a seconds- 

the old-fashioned clocks this was apt to 
be the fact, and that wheel was the one 
just preceding the 'scape-wheel. So the 
thing to do is to take the 'scape-wheel off 
its arbor and put it in place of the gear 
on the preceding arbor. 'That isn’t so hard, 
but you can’t have a second-hand on, un¬ 
less you want one running backward. If 
you have a lot of old clock- 
wheels, perhaps you can pick 
out two that are exactly alike, 
and transfer the motion equal¬ 
ly but in opposite directions 
from your minute-arbor to 
your old ’scape-wheel arbor, in 
which case it will run right 
and come thru fairly symme¬ 
trically on your main dial. To 
extend the arbor in order to 
carry the second-hand, you can 
buy some very, very small brass 
tube (it’s made, I assure you) 
and tuck a piece of it over the 
end of the arbor, reaming the 
front hole out to correspond; 
or you can make up a little 
tube yourself if you’re careful. 
I made an entire new arbor by 
filing while rotating in the 

Also, the ’scape-wheel you 
use must have 30 teeth. Per¬ 
haps it seems too much to ex¬ 
pect of an old clock to satisfy 
so many requirements, but lots 
of them do have 30-tooth 
'scape-wheels. Junk-stores usu¬ 
ally' have several of these old 
clocks for sale cheap, and 
you’re pretty apt to meet up 
with one that passes the test. 
If worse comes to worst, you 
can use an odd gear-reduction, 
and make up an odd-length 
pendulum, experimentally, to 
match it. 

Now about the escapement. 
A plain ratchet-and-pawl is 
what one first tliinks of, with 
an extra click to prevent its dragging 
backward; but that isn't satisfactory, as 
occasionally the pawl will ride over a tooth, 
or fail to catch it- -you can’t tell why. 
Fig. 1 sliows a reliable construction, which 
is a reversal of the so-called gravity es¬ 
capement. When the pendulum lifts the 
lever on tlie right, the one on the left 
drops, forcing the pallet P between the 
teeth A and H, with a sliding motion into 
the space C. and moving the 
wheel 1/2 tooth ahead. On the 
return swing, the right-hand pal¬ 
let P‘, drops between teeth D 
and E. hut can’t move the wheel 
until the left-hand pallet P is 
lifted an instant later: then pal¬ 
let P‘ drops into space F. moving 
the wheel another pS tooth in the 
same direction as before. The 
pallets have to he adjusted to 
each other to work coincidently, hut you 
only have to make one of them adjustable, 
of course (see Fig. 2). It isn’t vitally im¬ 
portant what part of the circumference the 

pallets meet. The pallets are made of steel, 
and as highly polished as possible. The 
size varies with the 'scape-wheel teeth; the 

Electrical Experimenters Take Our Advice, 
Build a Home-Made Electric Clock. You 
Will Always Be Proud of It. 

base of the wedge should be quite a bit 
wdder than the space between the teeth. 

In Fig. 1, the escapement bars are hung 
from arbors, and tlie impulses are given 
by tlie little weights—W, W. The same 
result could probably be accomplisht by 
mounting the escapement bars on springs, 
whicli would be an easier construction for 

Recess now for a “wrinkle." It’s about 
oiling clocks. Use toilet z aseline. I know 
all tile old clockniakers will liowl in uni¬ 
son at this, for they say use the “runniest" 

Handy Jig For Matching Up Gears and De¬ 
termining Their Correct Spacing Between 
Arbor Centers Before Drilling the Main 
Fra me. 

Ho. 6 

Special Tapered Stud to Hold Hand-drill Chuck In Lathe. 
The Arbor Burr, Fig. 7, Is Then Held In This Chuck. 

pendulum (see Sept, issue), and that makes 
it hard. In the first place, the works must 
have been designed so that one of the 
wheels revolves in just one minute. In 

Phantom View of the Modified Clock Movement As 
Adapted to Be Driven by Electricity. Fig. 7 Shows 
Detail of Steel Burr for Milling Ends of Arbors. 



October, 1917 

Side View of Complete Electric Clock Movement 
trating Suspension of Pallet Levers, Escape 
and Pendulum. 

oil there is; but I’ve tried vaseline and 1 
know. Thin oil tends to run out of the 
bearings and spread on the plates. My 
clock was deficient in depth of the counter¬ 
sinkings, which are supposed to hold the 
oil by capillarity, and 1 had to re- 9 il it 
everv 6 months or so; but now, with a 
little*^ daub of vaseline on each arbor-end 
and on the pallets, 1 never have to touch 
it. 1 added a little grafite scraped from 
a hard lead-pencil, but really I don’t know 
whether that improved it or not. Vaseline 
stays where you put it. 
and doesn’t gum. Td 
laugh if it should prove 
a popular lubricant for 
clocks on my recommen¬ 
dation. I remember 1 
used it on my bicycle 
years ago, when all the 
wiseacres said it was 
the worst thing you 
could do. and would 
bring down on the pa¬ 
tient tin steed ^ some 
mysterious calamity re¬ 
sembling the Curse of 
Miildoon in direness. 

Everybody’s doing it 

If YOU have a lathe 
with a self-centering 
chuck, you’ll want to 
make your own works, 
so I give you the detail 
drawings of mine (Figs. 

3, 4, 5, 0). As to the 
gears—you buy ’em. The 
various gear companies 
publish nice illustrated 
catalogs from which you 
can select gears and 
pinions with the proper 
sizes and numbers of 
teeth. 1 could tell you 
here the name of one 
good Gear Works, but 1 
won’t, because 1 think 
they ought to advertise 
in “E. E.”! It’s up to 
the Editor to go get ’em. 
already has, I judge he has some irresistible 
method of pulling ’em in, so 1 shouldn’t be 
surprised if we heard a peep or two from 

that quarter shortly. 

(\''oice from the deep: 

In 1915-16 four gear 
people advertised in the 
“E. E.” They all quit, 
because ‘’E. E.” readers 
did not buy any gears, it 
seems. Moral: “E. E.” 
readers support adver¬ 
tisers ! Editor.) 

WrinkleThe pinions, 
or small gears, come in 
rods, which you have to 
cut up and drill concen¬ 
trically: so it your chuck 
has three jaws you can 
practically only use a 6- 
toothed pinion, other¬ 
wise it won’t center 
right. If you are adept 
in lathe work, however, 
you can drill any pitch 
gear, concentrically by 
placing a piece of steel 
or brass strip around it 
and then tightening up 
the chuck. A piece of 
thin sheet lead is excel¬ 
lent, as there is less 
chance of damaging the 
teeth. But this is no 
obstacle, as you can ap¬ 
portion the teeth of the 
larger gears to ^ obtain 
the proper reduction. A 
good proportion (60-6 
and 36-6) is shown in 
the drawings. 

Of course the gears referred 
to are not the broad-faced 
kind, but the thin clock-gears. 

The Gear Works sell them and 
if there’s any choice, get the 
thinnest and tiniest ones you can, as there’s 
no power on them. You can also buy 30- 
tooth 'scape-wheels — “star-wheels” —- with 
the teeth radiating from the centre (Fig. 1) 
instead of inclined like those of mechanical 
clocks. Just as good either way. 


Here, ‘’Bugs,” We See the Arrangement of 
the Electric Clock Gear Train. It’s Simple We 
Assure You. 

Bv the “ads” he 

One thing you can't buy, tho, and that’s 
the hand-wheels—those re-entering gears 
which reduce the minute to the hour speed. 
You’ll have to bone them from some ex¬ 

Details of Escapment Mechanism Shovy^ing How the Pal¬ 
let’s P and Rotate the Star Wheel, As the Weighted 
Levers Are Moved Alternately by the Swinging Pendulum 

isting clock. 

About reducing the ends of the arbors 
to the size of the bearing-holes, you can 
do this in the lathe with a file all right, 
and then, after polishing, ream out your 
holes to fit. The holes ought to be drilled 
j,small and reamed 
tbroached) anyway, as a 
plain drill-hole is pretty 
rough. A little young 
reamer for such small 
holes costs only 10 cents 
or so. Any watch or clock- 
maker will sell you one 
of these tapered reamers 
—called broaches. If you 
want to take the trouble, 
instead of filing you can 
make yourself a small 
steel “burr” (Fig. 7) 
which isn’t difficult, and 
then your arbor-ends 
will all be the same size, 
and true. Only you have 
to hold the burr in a 
drill-chuck set in the 
tail-stock. MTinkle: 1 

use the little chuck off 
of my hand-drill, having 
made for it a tapered 
stub with the proper 
thread (Fig. 8). It’s 
the handiest thing there 
is about the house, and 
if I lost it I’d give way 
to despair and get me to 
a nunner>’ — well, you 
know what I mean, the 
other kind. 

To mill your clock- 
arbor, you hold it in the 
head-stock chuck, and 
while in motion run the 
burr up on one end at a 
time, till the distance between the shoulders 
is the same as that between the front and 
back plates—with an allowance^ for ease. 
{Coutxnucd on page 425) 

o ^ 

Stud ^ 

% O 









I O 


Rear View of Clock Plate. The Pal¬ 
let Levers Are Moved by Pins on 
Either Side of Pendulum. 

October, 1917 



Buildinj^ a Good Carbon 

A rheostat tliat will serve over a wide 
range of uses may be made from a number 
of pieces of sheet carbon. Anyone who has 
tried water rlicostats knows tliat it is very 
difficult for tlicsc rlicostats to keep a con¬ 
stant resistance, owing to Uie fact that par¬ 
ticles of tile electrodes cither float in the 
electrolyte or settle at the bottom of the 
container, and thus 
increase tlic conduc¬ 
tivity. The longer 
they are used the 
lower tlicir resis¬ 
tance becomes, and 
of»tcn considerable 
damage is done due 
to this fact. Rheo¬ 
stats made of resis¬ 
tance wire, besides 
being rather expen¬ 
sive, require some 
time and trouble in 
order to make suit¬ 
able contacts and a 
more or less elabo¬ 
rate contact arm to 
swing over them. 

A carbon rheostat 
is cheap and easy to 
make, will keep a 
practically constant 
resistance and is not 
likely to burn out 
when overloaded. 

The one to be de¬ 
scribed has a range 
from about J /2 to a 
few hundred am¬ 
peres at a pressure 
of volts, tho the 
details of construc¬ 
tion may be varied to 
which it is to be used. 

The materials needed are a piece of 14" 
sheet carbon 12" by 12", 2 brass rods 3/16" 
in diameter and 6 ^^ 4 " long, 2 pieces of 2" 
by 2" sheet fiber, about a foot of 5/16" 
fiber tubing (outside diameter), some 
sheet steel or copper, a fiber wheel 2 " in 
diameter and thick, a heavy brass screw 
(see illustration), some washers, 4 nuts and 
4 flat-headed No. 10-32 brass machine 
screws. Two pieces of 2" by 2" brass, 

(iron or copper 14 inch thick will do) thick 
will also be needed. 

Secure a suitable baseboard about 7" by 
4" by Vi*. A piece of marble, slate or as¬ 
bestos board will be excellent but any hard 
wood will do. For high amperage, it is 
advisable, if the base is to be of wood, to 
fasten some heavy asbestos sheeting to the 

Compression Rheostat 

top of the base. A slate base is good. 

Lay off the sheet carbon in 2 inch squares, 
and drill holes in each piece as indicated. 
After the holes are drilled, the squares 
should be cut out, making 36 of them in 
all. This may be done by carefully cutting 
the carbon with a hack saw, or a sharp 
pointed scriber may be run along the guide 

lines a few times and the carbon will then 
break quite easily. 

The brass rods should be threaded with 
a No. 10-32 die which fits them exactly. 
The two brass plates which are thick 
must have holes drilled in them so as to, 
permit the brass rods to pass thru them. 
Holes thru their ends also are drilled and 
tapt to facilitate screwing into the base. 
All the other square pieces, whether of cop¬ 
per, fiber or carbon, have holes drilled 
in them in the position indicated. 

Securely fasten one of the brass 

plates on end, to the base. Slip tlie rods 
thru it and fasten 
with washers and 
nuts. Then slip a 
piece of fiber tubing 
5fs" long on to each 
rod. The square 
pieces are then slipt 
over the fiber tubing 
and rods in the fol¬ 
lowing order: First 
a piece of fiber, 
then a piece of cop¬ 
per with an ear on 
it, then the 36 car¬ 
bon plates, then the 
other copper plate 
with the car on it, 
then the other piece 
of fiber, then the 
piece of sheet iron. 
( See avS s e m b 1 y 
drawing.) The 
fiber tubing 
should now project 
above all the 
plates and the rods 
should project thru 
the tubing. Slip 
washers on the rods, then put on the last 
pieces of brass plate. This last piece 
has a 54 " hole drilled and tapt thru its cen¬ 
ter to receive the heavy brass screw. Now 
slip another washer on each of the rods 
and screw down with nuts. Then secure¬ 

ly fasten the 54 " brass i^late to the base. 

The fiber compression wheel is fastened 
to the heavy brass screw with machine 
screws which arc countersunk in the fiber. 
The head of the brass screw has 4 holes 
drilled and tapt in it for this purpose. The 
threads are No. 10-32. 

Binding posts arc fastened to the 
holes of the projections of the copper 
plates, and serve as the terminals of the 
rheostat. The re¬ 
sistance of the rheo¬ 
stat decreases the 
more the fiber wheel 
is screwed down, 
and vice versa. For 
smaller loads the 
rheostats may be 
made more sensitive 
by using more car¬ 
bon plates. Carbon 
rheostats arc used 
for many purposes 
and in a great many 
places. They are 
used by standardiz¬ 
ing laboratories such 
as the Governmentaf 
laboratories and in 
the Universities. 
They are used by 
testing departments 
of practically all 
kinds of electrical 
supply companies, 
whether electric rail¬ 
way or electric light¬ 
ing, and provide a 
simple and satisfac¬ 
tory method of regu¬ 
lating direct current 
for test purposes, 
if they are proper¬ 
ly made. This rheostat provides as in¬ 
dicated in the article, statisfactory control 
for currents from .5 to a few hundred am¬ 
peres at battery potential of 1.5 volts. (40 
to 50 amperes per square ineU of earbon 
plate surface is a fair value for a steady 
load: 75 to 80 amperes may be past for 
short periods. 

Contributed by ALBERT H. BEILER. 


This display is to be used chiefly as a 
flash-light window decoration. It is to rep¬ 
resent a large flash-light. A, is a piece of 
stove-pipe. P, is a piece of wood cut cir¬ 
cular to fit end of stove-pipe. M, is a 
40-watt electric lamp. N, is socket to hold 
lamp. E, is a reflector. K, is an imita¬ 
tion push-button. S, is stand to support 
display. W, is concealed wiring. L, is the 
lens and H is a front glass taken from an 

This Nifty Electrical Window Attraction 
Comprises a Large Dummy Flash-Light, the 
Lamp Within It Being Winked On and Off 
By a Flasher. 

automobile. The drawing will explain it¬ 
self. A flasher can be put into tlie circuit, 
to give a more novel effect. 

This display is worth anyone’s time, and 
the cost is small. 

Contributed by OTTO G. CLAWSON. 

Plan View of a Compression Type Carbon Plate Rheostat of Many Uses. It Will Handle 
Currents of From .5 Ampere to 200 Amperes. The Resistance Is Lowered by Compressing 
the Carbon Plates and Vice Versa. 

suit the purpose for 

Dimensions of Carbon Plate Units, Compression Screw, Etc., for 
Rheostat Illustrated Above. 



October, 1917 

How to Make a Magnetic Polarity Indicator 

By Samuel Cohen 

It sometimes happens that the polarity 
of a current in a line is required and no 
available means is at hand. The writer 

was in this predicament at one time and 
hurriedly constructed an instrument which 
served the purpose verj* well, and thought 
it worth while to show the readers of this 
journal how to make one of them. 

The accompanying photograph shows the 
instrument complete. Note the relative 
size of the same. The instrument consists 
of a watch case, in which a dial, supported 
on a pivoted permanent magnet, is enclosed. 
This magnet is acted upon by a magnetic 
held produced b}' a small electro-magnet 

The constructional details are given. It 
will be noted that actual sizes are not 
shown, as it depends mainly upon the size 
of the watch case. The field or exciting 
magnet consists of a core made as indi¬ 
cated in Fig. 1. The length A is equal to 
the inside diameter of the watch, while 
the width B should not exceed ^ of an 
inch. The width of the pole pieces C will 
depend upon the general features of the 
case. The height is determined hy the 
depth of the case. It should be made as 
high as space permits, in order to enable 
one to close the back of the case with the 
cover. The winding of this field will de¬ 
pend on the character of work you desire 
to use the meter for. The following table 
has been made to facilitate matters. The 
resistance of the coil for the three volt¬ 
ages should be as follows: 110 volt cir¬ 
cuit — 1100 ohms : 32 volts — 256 ohms ; and 
6 volts — 25 ohms. The number of turns 
and size of wire is greatly dependent on 
the size of the magnet and the figures 
can readily be obtained from any wire 

The indicating face of the watch is 
removed and in its place another circular 
brass disc 1, Fig. 2 is placed. The mag¬ 
netic vane 2 is made as shown, the length 
of which should be three-quarters the 
diameter of the disc 1 and the width 5/16 
of an inch. It is made of the best tool 
steel, preferably spring steel, and should he 
magnetized in the usual manner bj" the 
application of a strong permanent or elec¬ 
tro-magnet. A pivoted rod 3, is fastened 
to the center of the magnet as shown. 
This is used to support the magnet be¬ 
tween the standard 4, which is a piece of 
stiff brass bent as indicated and soldered 
to the rear of the plate 1. A small hole 
is made on the interior face of this stand¬ 

ard and exacth' opposite this anotlier hole 
is made on the plate 1, in order to hold 
horizontally the pivoted magnet shaft 3. 
A paper dial 5, is fastened to the ends of 
the magnet. Two dial holes 6,6 are drilled 
in the plate 1. These should so be situ¬ 
ated that they cover the ends of the dial 5. 

The field or exciting magnet A, is placed 
in a horizontal position while the magnet 
2, is stationed in a vertical position. By 
the passage of a current of electricity thru 
the coil in one direction, the needle will 
be displaced in one direction, but it will 
change its direction if the terminals of 
the coil are reversed. 

If a known polarit>' indicator is on hand 
so as to show the direction of current in 
the line, it is very easy then to calibrate 
the instrument or the following simple 
chemical polarity indicator can be used. 
Place the two current terminals in a sliced 
potato and the surface about the wire 
which bubbles indicates the negative ter¬ 
minal. Connecting the same two wires to 
the magnetizing coil and knowing their 
polarity, it is easy to mark either the lower 
or upper wire as the negative or positive. 
So if the lower wire is positive, then indi¬ 
cate by (4-) on the lower part of the 
dial. WTien the current is flowing thru 
the coil and as soon as the current is re¬ 
leased the indicating mark will disappear. 
The whole arrangement should be placed in 
the watch case and the coil terminals 


Detail of Magnetized Needle and Electro- 
Magnet Used in Making Polarity Indicator. 

should be led thru the bottom and top of 
the case by boring a hole in each end and 
properly insulated. 

The time spent in building this instru¬ 
ment will never be regretted by the ex¬ 
perimenter as it will amply repa}^ him in 
future service. 


A recent bulletin of the Canada Depart¬ 
ment of Mines gives an account of some 
tests by H. T. Kalmus and K. B. Blake on 
non-corrosive cobalt alloys. The addition 
of cobalt or nickel to iron proved bene¬ 
ficial as far as non-corrosive qualities are 
concerned. Cobalt is somewhat better than 
nickel in this respect. The extent of cor¬ 
rosion appears to be dependent on time of 
exposure, but is not a simple function of 
the cobalt content. A small addition of 
copper also seems to reduce the atmospheric 
corrosion of American spigot iron. 


I think 1 have an improvement over Mr. 
Schultz’s invention as described in the 
April issue. Instead of using buoys I pro¬ 
pose that a submarine cable be laid on the 
exact route of the ship. This would be a 
guide lor the vessel as well as a means 
of communication with the shore by means 
of an mduction system. Thus the ship will 
always be on the safe route by constantly 
communicating with the shore, especially 
in a hea\w fog and gale. In war time a 
guiding scheme like this would save many 
a ship from being blown up by mines. A 
scheme like this would be invaluable on 
a route running among dangerous rocks 
and reefs. In time of danger, help can be 
summoned without delay. This idea, I 
think, is as good as wireless telegraphy, if 
not better, because wireless telegraph}' will 
not guide a ship in dangerous \vaters or be 
so efficient. By means of my proposition 
the use of buoys in dangerous waters would 
be eliminated, and buoys can’t always be 
depended upon. 

Contributed by HARRY E. FUCHS. 

{This scheme u'ould be feasible if the 
cable was but a short distance underneath 
the ship. But to obtain an inductive effect 
over 500 to 2,000 feet of depth is not pos¬ 
sible for the reason that, first, the iron clad 
cable absorbs jnost of the inductive currents 
and, second, because only a few volts and 
less than 1/100 of an ampere can be used for 
sub?narine telegraphy. IVhen stronger cur¬ 
rents are used, the coble—zchich is nothing 
but an immense condenser^breaks down, 
as happened to several of our first trans¬ 
atlantic cables .— Editor.) 


In the absence of a more expensive in¬ 
strument, a frequency indicator which gives 
good results has been constructed, as shown, 
says an Electrical World writer, from a 
telephone receiver as follows: Eight strips 
of 0.006 in. spring steel 5/64 in. wide by 
2 in. long marked (1) in the side view of 
the receiver shown in the accompanying 
illustration were clamped radially between 
two burrs (6) on the cork (3) by means 
of a wood screw ( 7). The contacting metal 
surfaces were tinned and sweated together. 
The whole was then mounted on the 
diatram of a telephone receiver (5) by 
means of beeswax. The magnet had been 
previously removed from the receiver, and 
the brass screw (S) replaced by one of 

For use with 110 volts it was found nec¬ 
essary to use a 400-ohm resistance in series.’ 
In calibrating this device a motor-generator 
of adjustable frequency was used in con¬ 
nection w’ith a standard instrument. After 
setting the machine at 56 cycles, one of 
the springs was carefully dipt off at the 
end, piece by piece, until it set up a strong 
vibration. The machine was then raised 
to 57. and the operation repeated with the 

Properly Calibrated. 

next spring, and so on up to 63 cycles. 
Each spring thereafter vibrated only in re¬ 
sponse to the frequency to which it was 

October, 1917 




By George Sutton, Jr. 

F irst I procured a card-board tube" in 
which a Pyrene fire extinguisher was 
packed, at a local auto supply store. 
The size of mine is 10 in. long and 4 in. in 
diameter. Next I painted the card-board 
cylinder with 3 coats of orange shellac to 
make it stiff. Then I constructed the wood¬ 
en heads; they may be turned up on a 
lathe or with a compass saw if no lathe is 
available. One head measures 4^ in. in 
diameter and the other liead in. in 

diameter. The smaller head is eventually 
fastened to the base to hold the cylinder in 
place. I turned the top head, which is 
made all in one piece as shown, and put 
the heads on the cylinder and mounted it 
between the centers of my lathe. The 
cylinder was wound with one layer of No. 
26 enameled magnet wire, between the turns 
of which I wound a layer of heavy linen 
thread to separate the turns. I started Y in. 

Plan View of Small High Frequency Coll of 
the Oudin Type. 

from the top and finished \]4 in. from bot¬ 
tom; this will take about eight hundred 

Details of Small Oudin Coll Suitable for Use 
with Vi K.W. Step-Up Radio Transformer or 
6 to 8 Inch Spark Coil. 

turns. Two holes are punched, one at A 
and one A'. The top turn is run thru the 
hole A, and connected to the brass ball on 
top; the bottom^ turn is run thru hole A' 
and thru hole A* and connected to binding 
post E. After the cylinder is wound it is 
necessary to coat it thoroly with several 
coats of shellac, as this prevents the sparks 
from jumping between turns and also holds 

the wire m place. Now comes the base; 1 
used a piece of yellow pine 12 in. square, 
^■4 in. thick, then gave it several coats of 
black asphaltum paint. The brass ball may 
be obtained from a bed-post or may be 
purchased from a local hardware dealer. 
The secondary cylinder was put in place, 
the bottom turn of secondary connected 
with binding post E, and the top turn con¬ 
nected with the brass ball. I then con¬ 
structed the primary; first I took a ring of 
card-board 5 in. inside diameter and 1 in. 
wide and fastened one end of the brass 
tape by binding it with friction tape. The 
primary is made of 8 or 9 turns of 1 in. 
brass or copper ribbon separated by a layer 
of corrugated card-board. When the pri¬ 
mary is completed it is bound by winding 
some friction tape around the outside; the 
inside turn of primary is also connected to 
binding post; this flexible wire has a clip 
attached to it and is connected to binding 
post D, and run thru hole F, so as not to 
interfere with making connections \vith 
as many turns of the primary as may 
be needed. Four standard porcelain 
insulators are used for feet. Sparks from 
8 to 12 in. long can be drawn from this 
Oudin transformer when excited by RJ K. 
W. wireless transformer. 

Connections for Oudin Coll, Showing How 
the Secondary and Primary Windings Are 
Connected Together. 

Trials of a Troubleshooter 

H ave you ever indulged in that great 
indoor sport of “trouble-shooting." 
Especially that brand of trouble that 
infests the network and web of a telephone 
system in a large town. NO? 

Never stood by when a cable “blows up"; 
when pair after pair goes bad? Never 
held your breath as that infernal meter on 
the test table swings over and in its cold, 
impersonal way quietly shows “dead pairs," 
“shunts," “opens," “grounds," and what not, 
knowing meanwhile that you are going out 
to shoot the said trouble? Great life! 
Take it from your Uncle Dudley. 

Paradise, according to the late Elbert 
Hubbard, is a town with only one telephone 
system. Perhaps so, but you can stake 
your last jitney against a cancelled postage 
stamp that the said system keeps the record¬ 
ing angel busy at times, even more so wdien 
old Jupe Pluvius lets drive with a rain 

But there are some troubles that seem to 
have no rhyme or reason. This is the case 
when transmission is poor. There are sev¬ 
eral million different things that can cause 
this and the majority are not in the text 
book, it is simply a case of pulling wires 
and tightening screws till the trouble goes 

For instance, a certain 'phone goes bad 
and you jump over to see wliat the “hug” is. 
But, curses, the instruments test O.K. The 
cord seems to have a light shunt on it so 
you put in a new cord. But behold, next 
day the same 'phone is on your bogey wdtli 
the same trouble. An examination shows 
that the cord is at fault again. And that 
was a perfectly good cord when put in a 
few hours before. Well, we wdll put an- 


other one in and see how that w'orks. 
Test table reports clear and away you go. 

But, the next day sees you back at the 
old stand. Now what in the name of a 
bald-headed South African flea is wrong? 
The cords look perfect, not wet or spotted. 
(It is practically impossible to pick up a 
single wet spot on a cord.) A new cord 
and the 'phone is reported clear. Yes, you 
are now shooting trouble w’ith a great 
big “T.” 

Perhaps this will continue till you hap¬ 
pen in on the 'phone and find that blamed 
pet poddle snapping at the cord. Yep, 
those toy hounds can wet that cord suf¬ 
ficiently by biting on it till the relay at 
central drops over and flashes up on the 

Of course you can’t warn the dog off, 
but you would he surprised at the number 
of times you have to warn off the “PEE- 
PUL.” They seem to think that a tele¬ 
phone cord makes a good washline to dry 
handkerchiefs, or support wet umbrellas, or 
use it for a pincushion. I suppose it does 
take all kind of people to make up our 
old planet. Sometimes they decide to 
shorten the cord and use a safety pin for 
the purpose. Of course that means a call 
from the 'phone Doctor who has to oper¬ 
ate and remove the obstruction from the 
path of speech. 

But, as in the previous case obstruc¬ 
tions do not always stand up and holler 
at the “Doc.” No indeed not; take the 
case of the “Mysterious Shunt." 

Tests from the table showed that a per¬ 
fect shunt existed on a certain 'phone. 
On arriving the troublcman took down the 

receiver and found everything O. K. No 
shunt or anything else seemed to be in 
that vicinity. The test table swore that 
was the 'phone reported in, but now it 
tested clear. 

But it came to pass, as the stories go, 
that an equally good short made itself 
apparent the following day. Again there 
was no trouble when “Doc" arrived. “The 
man is crazy,” was his diagnosis of the 
trouble. And still it came and went, on 
one day, clear for a while, then on again. 
Pairs were changed at the cable box. 
“Hah, faulty pair." was the troubleman’s 
exultant exclamation, as the 'phone was 
clear for several days. But—that shunt 
still hung around and dropt on after a 

“Doc" made up his mind he would kill 
that trouble or stay there the rest of his 
days. He fust around, asked for a ring 
that meant something and finalh-' noted 
that the shunt would go on as soon as the 
'phone was called and drop off later. This 
looked like a case of renewing the fuses in 
the lightning arrester and he started up 
to see if they were faulty. Having looked 
at these previously' they were alright, but 
on this day he noted the fact that a new 
curtain had been hung over the window 
above which the lightning arrester was 
located. And said curtain had a brass 
rod that just about touched the ends of 
the fuses. When a ring came it would 
jump thru the lacquer on the rod and 
short-circuit the line and mate; the least 
little vibration would then break the cir¬ 
cuit and the line cleared up. Yes, you 
could almost count the number of rings 
(Coii/iMru’d oti page 427) 



October, 1917 


By Geo. Sturley. 

Have you an old integrating watt-meter 
among the things you do not use? If so, 
perhaps you can make good use of it by 

Practically All Tests On Alternating Cur¬ 
rent Circuits Call for an Indicating Watt- 
Meter. Here is a Way to Make One from an 
Old Integrating Watt-Hour Meter. 

tr 3 'ing the following. The idea is to re¬ 
build an integrating meter into an indicat¬ 
ing one. This is done by removing all the 
gear-trains and dials of the integrating sys¬ 
tem and attaching to the shaft of the ro¬ 
tor a hair-spring taken from an alarm clock. 
Then the twisting effort at the shaft will 
rotate the cylinder part way around against 
the tension of the spring. ^ A paper scale 
(Fig. 1.) marked with drafting ink is glued 
on the cylinder and all desired calibrations 
marked on it. 

The writer made such an instrument 
from a Fort Wayne Type K meter of 5 
ampere rating and it reads up to 750 watts. 
And when the scale shows a reading of 100 
watts or better, the meter is sensitive to 3 

A paper scale was made from a strip of 
good ink paper three quarters inch wide, 
and long enough to reach around the 
cylinder. Lines about 1/8 inch apart were 
drawn for scale divisions. The magnets 
in the meter were left in place as they 
greatly improved the damping of the in¬ 
strument. As this meter has a revolving 
scale, the pointer is arranged stationary, and 
is nothing more than a heavy cross-line 
drawn on a piece of card board which is 
fitted in the glass window where the dials 
used to be. Fig. 2. When the meter is 
not indicating, the zero on the scale is right 
in line with the pointer. The meter was 
calibrated by a lamp bank, using different 
numbers and sizes of lamps for the calibra¬ 
tions desired. With a 5 ampere meter it is 
inadvisable to calibrate higher than 750 
watts. This Fort Wayne style of meter is 
the easiest form to remodel. In the case 
of changing a meter having a disc-rotor, 
you will have to turn it bottom-end up for 
a front, and a circular scale having radial 

markings w’ill be required. Also a hole will 
have to be cut in the bottom to view the 
scale thru. 

The meter can be used in connection 
with a wireless sending set to conveniently 
read at any time how much pow’er is be¬ 
ing used. When anyone asks, “How^ much 
power (in true watts) are you using?", you 
can tell the amount at once. Fig. 3 is a 
hook-up whereby the meter is permanently 
wired in with the primary of the "bug”, 
and a snap switch when closed shunts the 
current coils in the meter out when no 
readings are desired. When a reading is 
desired, open the snap switch and hold 
down the key. Also the meter may prove 
useful in determining the power-factor in 
your transformer primary circuit, if you 
have a volt meter and ammeter. The power 
factor is determined by dividing the actual 
watts (watt-meter reading) by the apparent 
zvatts (volts X amps). If you aim to im¬ 
prove your set, this power factor if kept 
up to a high value will mean your trans¬ 
former is actually handling more power. 


In the May, 1916, issue, there was de¬ 
scribed a magnetic rectifier, and finding it 
rather troublesome to have to use bat¬ 
teries for the permanent field excitation, I 
found that if a steel bar-magnet was sub¬ 
stituted instead of the electro-magnet, the 
device would work as well and save tlie 
trouble and cost of the batteries. [Mote: 
By referring to the May. 1916 , issue, full 
description will be found.] 

Contributed by A. ALLIN. 

Extremely Simple Form of Vibrating A.C. 
to D.C. Rectifier Made With a Permanent 
Magnet Armature. 


The experimenter whose purse is no 
deeper than the average will need to ex¬ 
temporize much of his apparatus, and if 
carefully made such appliances will be quite 
as serviceable as the shop-made article, 
tho probably lacking in finish. No oppor- 
tunit} should be lost to secure unclaimed 
oddments of household utensils. An ex¬ 
cellent electroscope can be made from a 
lamp chimney, plugging the top with sul¬ 
fur and embedding the wide end in paraffin 
w’ax contained in a flat tin; part^ of a 
broken window' makes a good fulminating 
pane if the sharp edges are rubbed down 
with a file or emer}' cloth, and many other 
examples might be quoted. 

Contributed by H. J. GRAY. 


Following is a description of an electrical 
release for camera shutters, to be used in 
photographing wild animals and birds from 
a distance. It can also be used when the 
experimenter desires to take his owm pic¬ 
ture, etc. 

In the accompanying drawing (Fig. 1), 
A is the main part of the frame, or base. 
It is made of ^-in. square brass rod, about 
6 in. long. It is bent at right angles about 

4 in. from one end, and has a 1/16-inch 
slot cut in the end of the short leg. 

B is the clamp to hold the release in 
place on the bed of the camera. It also 
is made of ^-in. square brass rod, and 
is bent as shown. These bends CANNOT 
be mode cold. 

C is the movable lever, of %-in x 1/16- 
in. brass strip, about 5 in. long. It is 
drilled at the places shown in drawing, and 
has a short slot cut where the rivet 7 
passes thru. The part X of lever C, in¬ 
dicated by dotted lines, is turned up to a 
horizontal position. This forms a broad 
striking surface for the release, and is 
covered with leather. 

D is a solenoid, size 1 in. x V/i in. It 
is formed of an old hard rubber foun¬ 
tain pen barrel or other tube haying an 
inside diameter of in., fitted with two 
1/16-in. fiber washers, of lj4-in. diameter, 
wound with No. 22 gage enameled magnet 

E is the core of the solenoid, of J4~in. 
soft iron rod, l>^-in. long. It has a 1/16-in. 
slot cut in its upper end and a hole drilled 
for rivet 7. 

F is a spring to draw lever C upward, 
away from the solenoid. The upward 
movement of lever C is limited by G, 
which is a short section of cheap watch 
chain or other small chain, the upper end 
of which is fastened to a hole in C, and 
the lower end to screw 5. 

H is a block of hard fiber, V/i in. x 1 in. 
X % in., on wdiich are mounted binding 
posts 1. 

I is the clamping screw% made of an 
8-32 battery binding post screw, with the 
head filed flat and the lower end fitted 
tightly in a fiber washer for ^ a handle. 
2, 3, 4 and 5 are 6-32 brass machine screws. 
6 and 7 are small rivets. 

A small dashpot added behveen the 
solenoid and the upright part of frame 
will make the action much smoother and 
soften the jar to the camera, but it is 
not absolutely necessar>L 

Fig. 2 is given merely as a suggestion 
for a method of mounting the solenoid. A 
piece of sheet brass is cut to the shape 
shown at A, and is bent on the dotted 

A Good Form of Magnetic Shutter Release 
for Cameras Is Here Shown. It Can Be At¬ 
tached and Detached In a Few Moments. 

lines to the shape of B. It is then slipt 
over the solenoid and fastened to the frame 
by a screw' dropt thru the solenoid into 
the small hole in clip and screw'ed into 
the frame. This will hold the solenoid 

Contributed by J. E. HENDERSON, JR. 

October, 1917 



Chemical Action of Storage 


M any experimenters have fre¬ 
quently used storiise batteries 
but have possibly never stopt to 
inquire as to the action which 
takes place in them. To obtain 
best results in any branch of endeavor, it is 
necessary to understand the fundamental 
principles which govern each individual 
case. This is also true as regards storage 
batteries. If improperly taken care of or 
handled, they will not give satisfactory re¬ 
sults, the same as if a gas engine were to 
be permitted to be run without water, oil 
or cleaning. 

The lead storage battery in the charged 
state consists of a positive plate of lead 
peroxide (PbOO and a negative plate of 
finely divided lead, both being introduced 
into sulfuric acid (H3S04) of about 1.2 sp. 
gr. When discharged the surface of the 
plates has been changed to lead sulfate 
(PbSO*)- The plates may be brought back 
to their original condition by sending a 
current tliru the battery in the reverse di¬ 

During the formation the plates are fre¬ 
quently permitted to stand in some corrod¬ 
ing solution of acids that produce a thick 
layer of lead sulfate (PbS04), for a certain 
time. The lead sulfate may then be re¬ 
duced electrolytically to lead, or oxidized 
to lead peroxid (PbOa). When acids other 
than sulfuric are used, these must be 
thoroly washed out before the battery is 
ready for use. For instance, a mixture of 
nitric and sulfuric acids would have the 
effect of producing a layer of sulfate. 

By another method the plate is elec¬ 
trolyzed as an anode, but lead peroxid 
(PbOj), which would protect the plate 
from further action, is prevented from 
forming by adding some salt or acid to the 
solution, the union of which separates at a 
lower potential than the peroxid ion and 
causes the production of sulfate. Lead 
sulfate (PbS 04 ), being a non-conductor, 
requires the lead below to be penetrated by 
the current, and as much sulfate may be 
produced in one step as is desired. Such 
additions are acetates, tartarates, chlorids, 
nitrats, chlorats, perchlorats, and the cor¬ 
responding acids. 

Peroxid is not always formed on a lead 
anode in sulfuric acid, even when no sub¬ 
stance is added to the solution to prevent 
it, which is made apparent by the fact that 
the lead plate, which is the anode, on dis^ 
charging, becomes covered with sulfate. If 
therefore, a lead plate is short-circuited in 

Function of the Acid Concentration. 

a solution of sulfuric acid wdth a peroxid 
plate, it will become covered with sulfate, 
proportional in amount to the current that 
Hows thru the plate. 

In the Faurc Wpe storage cell the plates 
consist of lend with about 5 per cent of 
antimony. The active material is made by 
making a paste of lead oxid (PbO) and 
sulfuric acid, and applying it to grooves 

cast in the supporting grid. The paste sets 
and becomes hard, after which it is changed 
to lead sponge and peroxid by electrolysis 
in a solution, which may, or may not be, 
sulfuric acid. 

The theory of the lead storage battery 
which is generally accepted, is known as the 
“sulfate theory”, and is due to Gladstone 
and Tribe. Sulfuric acid combines with the 
plates on discharge, and is set free on 
charge, according to this theory. On dis¬ 
charge hydrogen is deposited on the lead 
peroxid which reduces it to lead oxid 
(PbO), which is changed to lead sulfate 
CPbS 04 ), as represented by the equation: 
( 1 ) 

Pb02 -r Ha -I- HaSO* = PbSOi -f 211,0 
Lead Hydrogen Sulfuric Lead Water 
Peroxid Acid Sulfate 

At the same time the sulfate radical 
(SO4) is deposited on the lead plate and 
changes to lead sulfate:— 

( 2 ) 

Pb -I- SO 4 = PbS 04 
Lead Sulfate Lead 

Radical Sulfate 

The sum of these two equations is the 
total change in the storage battery on dis¬ 
charge :— 

( 3 ) PbOa -f Pb -f 2H2SO4 = 2PbS04 -h 2H2O 

Lead Lead Sulfuric Lead Water 

Peroxid Acid Sulfate 

When in the discharged state both plates 
are covered with sulfate. Upon charging, 

the reaction on the positive plate is:— 

(4) PbS 04 -f SO 4 + 2H«0 = PbOa -f- 2 H 2 Sp 4 

Lead Sulfate Water Lead Sulfuric 

Sulfate Radical Peroxid Acid 

While in the negative plate:— 

(5) PbS 04 -f Ho = Pb -{- H 2 SO 4 

Lead Hydrogen Lead Sulfuric 

Sulfate Acid 

The sum of the last two equations (4 
and 5) represents what takes place in the 
whole battery on charging;— 

(6) 2PbS0* -f 2HoO = PbOo -f Pb -h 2 HnS 04 

Lead Water Lead Lead Sulfuric 

Sulfate Peroxid Acid 

This equation is just the reverse of the 
.ntm of the first two equations (No. 3), and 
the changes taking place both on discharge 
and charge may be represented by the fol¬ 
lowing reversible equation :— 

(7) PbOa -h Pb H- 2H2S04 2PbS04 2 H 2 O 

Lead Lead Sulfuric Lead Water 

Peroxid Acid Sulfate 

From right to left this represents the 
charge, and from left to right the discharge. 

By measuring the electromotive force 
(e.m.f.) of different oxids of lead and hy- 
drats of lead on lead against a zinc elec¬ 
trode and comparing with a charged posi¬ 
tive plate it was shown that the charged 
positive plate is the peroxid of lead and 
not some other oxid or hydrat. 

The tabulated results being: 

Pb, PboO 





—Zn 0.42 volt 
—Zn 0,46 volt 
—Zn 0.75 volt 
—Zn 0.96 volt 
—Zn 0.41 volt 

A charged plate has a potential of 2.4 
volts, showing that lead peroxide is the 
compound that exists on the positive plate. 

Kolilraiisch and Heim showed by measur¬ 
ing the specific gravity of the acid on 
charge and discharge that the production 
of sulfate on each plate was proportional 
to the quantity of electricity that had been 
past thru the cell; the density changing ex- 
actly f» proportion. A calculation of the 


change in specific gravity by means of 
equation 7 agrees \\ith tliat found. The 
calculation is as follows: The uncharged 

battery contained 3350 cubic centimeters of 
acid of 1.115 sp. gr. corresponding to 16.32 
per cent acid. The total solution therefore 
wcichcd 3735 grams, and contained 610 
grams of acid, and 3125 grams of water. 
After charging with 50 ampere-hours, ac¬ 
cording to equation 7, the amount of water 

Fig. 1 . Curve Showing Change In Density of 
Acid With Charge and Discharge. 

that disappeared was 33.6 grams, and the 
amount of sulfuric acid formed was 183 
grams. The solution therefore contained 
after charging, 3091 grams of water and 
793 grams of sulfuric acid. The total 
weight was therefore 3884 gpms, and the 
amount of sulfuric acid contained was 20.42 
per cent., corresponding to a density of 
1.146. The observed density being 1.147. 

It is quite evident that since the acid be¬ 
comes more dilute on discharging a lead 
battery, the electromotive force must de¬ 
crease with decreasing concentration. The 
table given below, shows the relation be¬ 
tween the concentration of the acid and 
the electromotive force, from direct 


Density of 

Per Cent 


H 2 SO 4 


at 15 Deg. C. 
















It will be noticed that the electroinotive- 
force of the lead storage batter\% with the 
concentration of acid ordinarily used, has 
the unusually high value for a battery of 
over two volts. Sulfuric acid, if elec- 
troRzed between platinum electrodes, gives 
a weak evolution of gas at 1.7 volts and at 
1.9 a strong evolution. If lead sulfate were 
spread on platinum, it would therefore not 
be possible to reduce it to lead and oxidize 
it to peroxid, for the potential required 
could not be reached. On lead, however, 
the over-voltage is so great that the gas 
evolution does not take place below 2.3 
volts, which is greater than the voltage 
needed to change the sulfate in lead on one 
electrode and peroxid on the other. If it 
were not for this high over-voltage on lead, 
the lead storage battery would be an im¬ 

The temperature coefficient of the lead 
storage battery for the concentration of 
acid used is positive, but on decreasing the 
concentration of acid the temperature co- 
cfiicicnt falls to zero and then becomes 
negative. The curve (No. 2) represents the 
results of experiments in which the tem¬ 
perature coefficient was determined between 
0 deg. and 24 deg. C. The temperature 
coefficient is constant in value between 10 
and 71 deg. C, The heavy line in the plot 
gives the e.xperimcntal results. 

The mechanism of the reactions taking 
place in the lead storage battery has been 
{Continued on page 422) 



October, 1917 

This department will award the following monthly prizes: First Prize, $3.00; Second Prize, $2,00; Third Prize, $1,00. 

The purpose of this department is to stimulate experimenters towards accomplishing new things with old apparatus or old material, 
and for the most useful, practical and original idea submitted to the Editors of this department, a monthly series of prizes will be awarded. 
For the best idea submitted a prize of $3.00 is awarded; for the second best idea a $2.00 prize, and for the third best prize of $1.00. The article 
need not be very elaborate, and rough sketches are sufficient. We will make the mechanical drawings. Use only one side of sheet. Make 
sketches on separate sheets. 



1 give herewith a description of a “col¬ 
lar-button” switch, which I am contribut¬ 
ing to the “How-To-Make-It” Department. 

Somebody's Been Reading Faithfully Page 
330 of the September “E. E." Instead of an 
Electrical Stunt with Old Shoe Nails, How¬ 
ever, We Are Presented with the “Collar- 
Button" Switch, for Which We Are All Duly 

This switch can easily be made with a 
collar-button and a small strip of brass. 
By simply putting the head of the collar 
button down, the switch is “on.” This 
small switch can be used where an}' bat¬ 
tery switch is needed and can be quickly 
and easily made. (Bugdom extends its 
sincere thanks, Albert!—Editor.) 

Contributed bv 



The device described and illustrated 
herewith is a convenient means of changing 
the polarity of a pair of wires, of reversing 
small motors, etc. 

It consists of a wooden base upon which 
are mounted six binding-posts and a pair of 
two-point switches, so connected b}' a hard- 
rubber strip as to move both the switches 
at the same time. The manner of reversing 
the polarity at once becomes evident by re¬ 
ferring to the diagram. Connections from 
the binding-posts are made in grooves on 

A Handy Polarity Keverser Constructed from 
Two Switch Blades, Four Contact Points, 
Some Binding Posts and a Base. 

the under side of the wooden base. 
Contributed by 




Manufacturers of high-resistance tele¬ 
phone receivers are well aware of the ad¬ 
vantages to be gained by tuning the diafram 
of the receiver to the desired note. How¬ 
ever, theirs is a compromise. Nearly every 
radio station emits a tone distinctively its 
own and the manufacturer has to strike 
a mean. Receivers have been developed 
that were adjustable as to the tension 
on the diafram and worked with sat¬ 
isfaction when both diaframs were tuned 
alike. A receiver that can be adjusted in¬ 
stantly to any note within a wide range 
is shown in the attached illustration. It 
is designed particularly for use with some 
form of amplifier that allows of its use 
as a loud-talker, but by using high-resist¬ 
ance windings it will serve in place of the 
regular receivers for nearby or powerful 

To construct this receiver the shell of 
a long t>'pe telephone receiver is required. 
A hole is drilled in the center of the dia¬ 
fram and a short brass bolt inserted. The 
threaded end of tlie bolt is slotted to take 

Here's What You’ve Been Looking For, 
“Bugs"; a Loud Talking Telephone Receiver 
and Amplifier Which May Be Adjusted for 
Different Currents and Circuits. 

a strip of thin iron ^-inch wide and long 
enough to reach the length of the receiver. 
One end of the strip is soldered into the 
bolt on the diafram and the other end of 
the strip is soldered into the head of a 
brass bolt that passes thru the hole in 
the small end of the receiver shell. The 
latter bolt is fitted with washers and a 
nut to adjust the tension on metal strip. 

A hole is cut in the side of the receiver 
shell large enough to pass the magnets as 
shown. If the device is to be used with 
an amplifier the magnets shown have a low 
resistance of about 20 ohms. When used 
in place of the regular receivers they may 
he taken from a thousand ohm telephone 
ringer. The magnets are supported in a 
box and wired to two binding-posts. 

The pole pieces of the magnets should 
come within l/64th of an inch of the iron 
strip. Ill use the apparatus is connected 
in the circuit in the usual manner. The 
thumb nut at the small end of the re¬ 
ceiver is turned till the strip is just taut. 



The accompanying drawing shows a very 
simple pencil rheostat. It is simply a com¬ 
mon “clutch” pencil as sold anywhere for 
ten cents, and no work is necessary to 
convert it into a rheostat—just the con- 

If You Carry a Meta! Magazine Pend! You 
Are a Potential Electrician. Connect a Wire 
to the Case and Lead, and Prestol You Have 
An Adjustable Rheostat. 

nection that is all. To vary the resistance 
it is only necessary to slide lead in or out 
of the pencil case. 

Contributed by G. SCHOENDUVE. 

When the signals come in it is only neces- 
sar>' to turn the nut and adjust the ten¬ 
sion on the strip till it is in resonance 
with the note of the signals, which point 
will be indicated by the loudest tone. 

M'hen high-resistance magnets are used 
and the instrument is connected direct to 
the circuit without an amplifier it will be 
found advisable to use a mica diafram and 
a steel piano wire instead of the metal 
diafram and the iron strip. 

Contributed by THOS. W. BENSON. 


When a window tapper is running for a 
long period, the dry batteries run down, 
causing the tapper to stop. In order that 
it may work again the batteries must be 
disconnected until they regain their full 
strength. Using the method shown here 
the tapper can be used continually without 
a stop. 

To Prevent Paralyzing One Set of Batteries 
When Operating a Window Tapper, Use Two 
Sets Alternately with This Circuit. 

The S.P.D.T. switch blade is in contact 
at “B,” making a circuit. When the power 
is exhausted, it is thrown to “A,’' putting 
a new set of batteries in the circuit; while 
the others at “B” will be recuperating. 

Contributed by FRANK HARAZIM. 

October, 1917 




The illustration is of an electric door 
lock and bell alarm for the front door of 
a home, garage or shop, which is easily 
made and installed in a very short time. 

It consists of a half-inch quartered oak 
board large enough for the initials, which 
are made by driving brass upholsterer’s 
tacks in the board. On the under side of 
board wires are connected to the tacks as 
per diagram and should be soldered to the 
points. An ordinary electric bell and a 
bell-ringing transformer or dry batteries 
are connected according to illustration and 
it is then ready for use. The heavy lines 
indicate the circuit which operates the lock. 
A finger ring or any small piece of metal 
placed in contact with the two tacks on 
F and \V will operate the lock and open 
the door. Anyone tampering with or not 
knowing the secret of the lock will cause 
the bell to ring, as the diagram will show. 
A push button connected to the lock cir¬ 
cuit and located at a convenient point in¬ 
side will be found very handy. A low- 
voltage lamp can also be placed in the cir¬ 
cuit and will serve to light up the entrance. 
This device has given excellent service for 
a long time and is still in fine condition. 

Contributed by JOHN F. WALLACE. 


it would be essential that the supply of 
current is always on the line. If one of 
the fuses (K) should blow out the line 
would be dead, and unless the operator 
was on the scene it might cause serious 

With this apparatus he 
can be in his office and will 
be notified by the bell that 
the line is dead. The ex¬ 
planation of this device is 
as follows: 

The current passes in 
thru the resistance (E) 
which amount depends up¬ 
on the voltage and the cur¬ 
rent in the line; this can 
be easily calculated by 
applying Ohm’s law. The 
current continues to flow 
thru the magnet (E) back 
to the line; thus the cur¬ 
rent passing thru the coil 
will energize it, and will 
hold the armature down. 
In case the voltage goes 
off the line the coil (E) 
ceases to be ma^etized, 
and the armature is pulled 
aw^ay from the coils, by 
spring (H)—(which has 
a tendency to pull the armature away from 
the coils) and a local circuit is made at 

Line Vo/ioge 

When the Line Voltage Falls the Relay 
Closes an Alarm Bell Circuit, the Bell Being 
Placed At Any Point Desired. 

quantity 01 potassium. If a little mercur\ 
be added, and the whole well shaken, it will 
take fire and burn vividly. 

The White and Black Statue: Construct 
a small figure or statue of white paper or 
cardboard, and moisten it with a solution 
of lead aeetat. Expose it to fumes of 
sulfuretted hydrogen, and it will turn black. 

The Kettle that Boils on Ice: Set a small 
water kettle on a piece of ice, now put a 
small amount of liquid carbon dioxid into 
the kettle. The contents will boil violenllv. 

The Blushing Picture: If any plain print 
or drawing be taken (preferably one of a 
young lady> and the face, hands and neck 
be painted with a solution of equal parts 
of water and methylated alcohol, to which 
a few grains of phenolphthalein have been 
added, on subjecting the picture to the in- 
fiuence of ammonia vapor it will “blush" 
most vividly. Contributed by 



It is often necessary to break a circuit 
at relay contact points, where the circuit 
to be broken carries current at 110 volts. 
The arcing is intense when the current is 
much above I ampere. A simple and very 
effective oil switch may be made from ma¬ 
terial which is almost always on hand. 

Secure a brass base from an Edison 
lamp (one may be removed from a lamp 
by heating the glass near the base in a 
Bunsen flame). Drill a hole in the bottom 
of it for a bolt to pass thru. Screw the 
socket onto the end of the armature of a 
telegraph sounder which will serve as the 
relay. Before putting the bolt thru the 
socket, slip a soft rubber or fiber wa^sher 
on to prevent any leaking of oil thru the hole. 

A standard which serves as the rear con¬ 
tact may be made from an ordinary fixture 
crow-foot, a piece of gas pipe and a piece 
of 3/32" brass or steel which is threaded 
to receive an adjusting screw. (See illus¬ 

The writer had a great deal of difficulty 
in securing a suitable oil to kill the are. 
Alter trying sweet oil, linseed oil and ma¬ 
chine oil he tried—glycerin. And it does 
the work. Arcs from breaks carrying 10 
amperes were successfully quenched by 
using glycerin in the cup. 

It may be also of interest to note that 
castor oil is quite as satisfactory' as gly¬ 
cerin, and a lot cheaper too. The cup may 

The Electric Puzzle Lock Shown Acts As Its Own Thief Alarm. 
The Uninitiated Will Invariably Short-Circuit the “Alarm" 
Contact Points Instead of the “Lock” Circuit Contacts. 

Both primary and secondary or storage 
batteries (accumulators) are affected by 
temperature. A battery that gives no 
trouble in an ordinarily warm room shows 
a falling off in the output of current if 
exposed to a very low temperature. This 
is due to the fact that the internal ^ re- 
ristanee decreases as the temperature rises, 
within certain limits. Storage batteries 
have been found to develop a maximum 
efficiency at temperatures approaching 50“ 
C. If the temperature is much above or 
below this figure, the output of current 
falls off. Since the ordinary tempeptures 
of a room at any time of the year is gen¬ 
erally between 12 “ and 20 “ C. it will 
be seen that most storage batteries arc 
not given an opportunity to deliver the 
maximum amount of energy of which they 
are eai)able. 

(Contributed by IT J. GRAY. 


Where an operator can not watch his 
voltage continuously and where a con¬ 
stant voltage is required, the accompanying 
diagram shows how a telegraph instru¬ 
ment can be made into a voltage indicator 
in a few minutes’ time. 

If a motor (J) was operating a flood 
pump or any other apparatus automatically. 

contact (I), which 
in turn is in series 
with a battery and 
bell, as shown. A, 
is a rubber con¬ 
tact to p r e V C n t 
cross - connections. 

Besides this use 
of the indicator it 
can he put to many 
other advantageous 
uses as the opera¬ 
tor secs fit. 

Contr!l)uted by 



Combustion: A 
mixture of potas¬ 
sium chlorat and 
flour at once takes 
fire on being 
touched with a 
drop of sulfuric 

The Spontaneous Comluistion of Tliree he partially filled with mercury with the 

Metals: In a perfectly dry ladle place a oil over the top of it. 

small piece of sodium with an equal (ontril>uled liy Ai^BERT H. BEILER. 



Sjj p/p€ 

or Breaking Heavy Currents the Arc Is Best Broken In Glycerin. The 
atter Is Held in a Cup, Operated by “Sounder” or Other Magnets In 




October, 1917 

Under this heading we publish every’ month 
useful information in Mechanics, Electricity 
and Chemistrj". We shall be pleased, of 
course, to hav'e our readers send us any 
recipes, formulas, wrinkles, new ideas, etc., 
useful to the experimenter, which will be 
duly paid for, upon publication, if acceptable. 


Alabaster. —Use strong soap and water. 

Black Silk. —Brush and wipe it thoroly, 
lay on table with side intended to show, 
up; sponge with hot coffee strained thru 
muslin; w hen partly dr>% iron. 

To Remove Stains ar Grease from Oil 
Paint. —Use bisulfid of carbon, spirits of 
turpentine, or if dry and old, use chloro¬ 
form. These and tar spots can be softened 
with olive oil and lard. 

Stains, Iron Rust, or Ink from Vellum 
or Parchment. —Moisten the spot with a 
solution of oxalic acid. Absorb same quick¬ 
ly by blotting paper or cloth. 

Rtist from Steel. —Take half ounce of 
emery powder wdth one ounce of soap and 
rub well. 

Fruit Spots from Cotton. —Apply cold 
soap, then touch the spot with a hair pencil 
or feather dipped in chlorate of soda, then 
dip immediately in cold w'ater. 

Grease from Silks. —Take a lump of 
magnesia, rub it wet on the spot, let it dry, 
then brush the powder off. 

Iron Rust may be removed from white 
goods by sour milk. 

Scorch Stains from IVhite Linen. —Lay 
in bright sun. 

Mildew. —Moisten the spot with clean 
water; rub on it a thick coating of castile 
soap mixed with chalk scrapings: rub with 
end of finger, then w’ash off. 

Oil Marks on IVall Paper. —Apply paste 
of cold water and pipe cla}', leave it on all 
night, brush off in the morning. 

Paint Spats from Clothing. —Saturate 
with equal parts turpentine and spirits of 

To Cleanse House Paper. —Rub with a 
flannel cloth dipt in oatmeal. 

Black Cloth. —Mix one part of spirits of 
ammonia with three parts of w'arm water, 
rub with sponge or dark cloth, clean with 
water, rub wdth the nap. 

Furniture, for Finger Marks. —Rub with 
a soft rag and sweet oil. 

Chromos. —Go over lightly with a damp 
linen cloth. 

Zinc. —Rub with a piece of cotton cloth 
dipt in kerosene, afterw^ards with a dr>' 

Hands from Vegetable Stoins. —Rub wdth 
a slice of raw’ potato. 

IVindozi^ Glass. —Paint can be removed 
by a strong solution of soda. 

To Clean Titiware. —Common soda ap¬ 
plied with a moistened newspaper and pol¬ 
ished with a dry piece, will make it look 
like new. 


By Aaron Van Citters. 

A number of firms have advertised w'hite 
metal plating outfits, for plating knives, 
forks, spoons, etc., for which they charge 
from ten to tw’ent}* dollars. B 3 '’ tollow’ing 
the instructions ^ven below, you can, with 
the assistance of a blacksmith in making 
the crucible and hood, set up. this outfit 
complete for about two dollars and a half 
or less. 

To make the crucible—Take a piece of 
gas-pipe 4x6 inches, weld a bottom in it, 
and a band around the top from which it 
hangs inside the hood. 

To make the hood—^fakc a flaring cylin¬ 
der of sheet iron, the small end the proper 
size to fit under the ring of crucible; the 
other end about one-fourth larger in di¬ 
ameter, and sufficiently long to hold cru¬ 
cible upright with bottom just clear of 
the stove or gas plate. 

Ta make the IVhite Metal —Pure tin, 
10 lbs., lead 4 ozs., antimony 2 ozs. Melt 
and mi.x thoroly. A better grade is made 
by using 2 ozs. of pure silver in place of 
the antimony. 

Jar No. I (Pickle Solution)^Fov iron 
or steel is composed of muriatic acid only. 

Jar No. 2 (Dip Bath )—Dissolve 2 
pounds refined zinc in 2 quarts fluid hj'dro- 
chloric acid C. P. When dissolved and 
cold, add half a' teacup of clear rain w’ater 
or filtered water. (This is a dangerous 
solution to mix, as it is verj’’ violent w’hen 
the zinc is being consumed, and great care 
should be taken.) 

Jar No. 3 (Chill Bath )—Dissolve 6 ozs. 
di-ammonia carbonate in 3 pints of filtered 
water. Use at a temperature of 120 de¬ 
gress F. 

Jar No. 4 (Pickle Solution )—For Irish 
silver and brass, dissolve 12 ozs. granu¬ 
lated nitratum in 2 quarts of filtered w’ater; 
then add slowly 2 quarts commercial sul¬ 
furic acid. (Note—Unless you are going 
to do a great deal of plating, Jar No. 4 
is unnecessary, as Jar No. 1 answers as 
a pickle solution for all metals. 

Stnpping Solution —Is composed of 1 
pound granulated kali: or potash and 2 
scruples of French rouge; dissolved in 1 
gallon commercial sulfuric acid. 

(The Flux )—Mix thoroly 5 lbs. granu¬ 
lated white ammonia hydrochlorate with 
4 drams French rouge. For convenience 
in using, put a portion in an ordinary tin 
pepper box. 

Directions for Plating —Place the sheet 
iron hood on the stove or‘gas plate, the 
small end up, then set the iron crucible 
previously filled wdth the white metal, in¬ 
side the hood, so edge wdll rest on top 
of same. But little heat is required to 
melt the metal, which forms a thin metal¬ 
lic solution. Care should be taken not 
to get it too hot. If after an article is 
plated it shows a yellowish color, it is be¬ 
cause of too much heat, which should be 
partly turned off. Proceed to plate as 

First, put articles to be plated in Jar 
No. 1 , allowing them to remain ten min¬ 
utes to remove all rust, etc., then rinse 
in clear, cold w'ater. Next take one piece 
at a time and rinse in Jar No. 2 for a 
few' seconds; then immerse the article 
slowK' in the crucible containing the melted 
metal; raise slow’ly up and dowm once or 
twice, sprinkle a little flux on the article, 
letting some of the flux fall on the melted 
metal. Then draw article from crucible 
and immerse slowly into Jar No. 3, which 
hardens the plate, after which rinse in 
clear water and it is finished. 

Knives, forks and spoons should be 
plated, one-half at a time; then the oper¬ 
ation reversed. About one minute is re¬ 
quired to plate a single article. A little 
practise will make you perfectly familiar 
w’ith plating in this manner, and you wdll 
be able to see at a glance w'hen everything 
is perfect. When there is much old plate 
on an article, place stripping solution in a 
crock, heat it, and immerse article therein 
until the old plate is all removed; then 
rinse in clear water, dry with a chamois 
skin, and proceed to plate as above. 

(Special Note)—When much old plate 
is removed by stripping, it pays to reclaim 
the silver, which may be done in the fol¬ 
lowing manner: Add common salt to the 
stripping solution as long as it throw's 
down a precipitate, then pour off the solu¬ 
tion. Wash the precipitate with clear 
W’ater, then add a few small pieces of sheet 
zinc to it and let stand until the preciptate 
turns to a black powder, w’hich wdll take 
several hours. Then wash the powder 
several times in w'arm w'ater, dry betw’een 
sheets of blotting paper, and pick out the 
pieces of zinc. The powder will be pure 
silver which you can melt and run into 


Bottles. —Better to send the unknown 
contents of a bottle dowm the sink than 
risk spoiling a formula with it. Do not 
wait for labels to drop off; give the lot 
an inspection every three or six months, 
and replace any w’hich are becoming illeg¬ 
ible, says the Am. Photog's Weekly. 
Don’t wait till this has happened. 

Labels on Bottles Containing Solu¬ 
tion. —Place the label in such a position 
that you can indicate by an arrow point 
on the label just how' far up in the bottle 
the stock solution comes wdien making up 
a fresh lot. 

Waste Box. —Do not throw spent 
matches, plate-box wrappers, bits of string, 
or anything else (not even cigarette ends) 
on the floor, but in the waste box (a large- 
size biscuit tin is just the size and shape). 
Everything on the floor makes for dust. 

Seconds Pendulum. —A little over a 
yard of fire string, the bob of an old 
clock, a long bit of brass chain. This 
clinks against the rim of a half-pound 
tobacco-box lid every second swung. The 
pendulum hangs from a nail in the w^all. 
The pendulum is forty inches long. 

Cotton-Batting Bottle. — This bottle 
contained caustic potash solution. The 
stopper being fixt resisted "firmly but 
gently” every persuasive invitation to move 
it. It was tapt off at the neck. The 
shoulder of the bottle w'as cut with a file 
scratch and hot wire. The sharp edge 
taken off with a hard pebble. It now’ stands 
on the sink shelf, and holds cotton batting 
w'ith w'hich to sw’ab the surface of a nega¬ 
tive or use as a quick filter. 

Toothbrush Bone Handle. —Filed down 
to make a finger-nail shaped end, which 
acts admirabb' as a plate lifter. 

October, 1917 



Experimental Chemistry 


Seventeenth Lesson 

Ammonia (NIL) and Ammonium IlydroxiJ 
(MI 4 OII) 


T he aqueous solution of ammonia 
gas and sonic of its salts, as am- 
moniuin clilorid, or sal-ammoniac, 
were known to the early alchemists, 
and described by them as “Spirits 
of Hartshorn/' Basil Valentine in the 

Fig. 84. Apparatus Set Up for the Prepara 
tion of Ammonium Hydroxid— NH4OH. 

fifteenth century showed that the gas could 
be made as we make it to-day; narnely, 
from ammonium chlorid (NH4CI). Priest¬ 
ley in 1747 was the first to prepare gaseous 
ammonia, by heating together sal-ammoniac 
(Ammonium chlorid), and lime, and col- 

Flg. 85, Necessary Apparatus for the Col¬ 
lection of Ammonia—NHj—by Upward Dis¬ 

lecting the gas over mercury. He called it 
“Alkaline Air” which was later changed to 
‘‘Volatile Alkali.” 

Berthollet in 1785 showed that it is com¬ 
posed of Nitrogen (N) and Hydrogen 
(H), and Davy in 1800 made the volumet¬ 
ric determination necessary for the symbol. 

Occurrence and Formation: 

Ammonia is found free in small quantity 
only. A very minute quantity is formed in 
combination with carbonic, nitric and 
nitrous acids, during electrical discharges 
in the air, from the hydrogen of water, 
and nitrogen of the air. This often com¬ 
bines with an oxid of nitrogen (formed 
by the same process) to make ammonium 
nitrat (NH4 NO3), and the product is 
finally washed by rain into the earth. 

It is also found as sulfate and chlorid 
near active volcanoes, having been pro¬ 
duced by the hot lava flowing over fertile 
soil containing nitrogen. Ammonia and 
its salts are formed in the distillation of 
many organic substances as bones, and 
other animal tissues and excretions, as well 
as the putrefaction of nitrogenous organic 

Formerly horns, hoofs, and other animal 
products were distilled, and ammonium 
carbonat thus produced neutralized with 
hydrochloric acid, the product after sub¬ 
limation being known as sal-ammoniac 
(ammonium chlorid). At the present time 
coal is used and the supply obtained by a 
similar process. 

Preparation : 

1. Thru the union of its elements by 
means of the silent electric discharge. 

2. Thru the reduction of the various com¬ 
pounds of nitrogen and oxygen or their 

N,0, -f- 5 Ho = 2 NHa. + 2 HoO 

Nitrogen iJio.xtd Hydrogen Ammonia Water 

3. Thru solution of many metals in Nitric 

HNOh + 4 Ho = 3 HoO -fNHa 
(4 Zn -!- 9 HNO 3 = 4 Zn(NOa )2 -f NHs 4 - 3 HoQ) 

4. By the reduction of nitrats or nitrits 
by nascent hydrogen in alkaline solution. 

NaNOo 4- 3 Ho = NaOH + H 2 O 4* NHs 
8A1 4- 5“KOII + 3HNO3 - 2 HoO 4- 8KAIO0 
4 - 3 NH 3 Potassium 


5. Ammonia gas is prepared on a large 
scale by heating together calcium hy¬ 
droxid and ammonium sulfate or chlorid. 

(NH*)oS 04 4- Ca((>H)o = CaS 04 4- 2 NH 3 
4- 2 HoO 

6. For laboratory purposes it is prefer¬ 
able to heat the solutions of ammonia. 

7. The hydroxid is prepared by the ac¬ 
tion of a strong base or one of its salts. 
The chief salts are ammonium chlorid 
(NfBCl) : ammonium nitrat (NIBNOa) ; 
ammonium sulfate ( (NH4)2S04) and am¬ 
monium carbonat ( (NIl4)2C03). By mix¬ 
ing any one of these with cither calcium, 
potassium or sodium hydroxid, and apply¬ 
ing gentle heat, there arc formed am¬ 
monium hydroxid (NlhOH) and ammonia 
(NHs). These reactions come under 
Barthollct’s Um' of gases. Sal-ammoniac 
(NH4CI) and slaked lime (Ca(OH)2), be¬ 
cause of their cheapness, are usually em¬ 

2NH4CI + Ca(OII)s = CaCb 4- 2NH4pn 
Aiunionium Calcium Calcium Ammonium 

Chlorid Hydroxid Chlorid Hydroxid 

(Slaked lime) 

It should be remembered that the hy¬ 
droxid is only the gas combined with water, 
and two substances, ammonium hydroxid 
(NH4OH) and ammonia (NH») are both 
called “ammonia”, but not accurately so. 
Whenever one of them is found the other 
usually exists, as Ammonium hydroxid 
gives off the gas and ojnmonia takes up 

Fig. 86. Simple Apparatus Required In Per¬ 
forming the “Ammonia Fountain" Experi¬ 
ment. It Is Shown Here in Acual Operation. 

When required pure, the gas must be past 
over calcium oxid (quicklime) to remove 
the moisture, and then collected over 

{Continued on page 427) 

Fig. 87. Apparatus for Illustrating Diffusion 
and Absorption of NH3. Left Hand Flask 
Contains NH4OH; Right Hand Flask—Water. 



October, 1917 

Our Amateur Laboratory Contest is open to all readers, whether subscribers or not. The photos are judged for best arrangement and efficiency 
of the apparatus. To increase the interest of this department we make it a rule not to publish photos of apparatus unaccompanied by that of the owner. Dark 
photos preferred to light toned ones. We pay each month $3.00 prize for the best photo. Make your description brief and use only one side of the sheet. 
Address the Editor, “With the Amateurs’* Dept. 

At Last an “Electrical Laboratory'' Photo!!! 

Well, “Radio-bugs,” vou have got to take off your hat to Alark Slabodnik, of Ely, Minnesota, winner of this month’s 
prize, and mark vou, the ONLY prize awarded this month in “With the Amateurs' Department.” Now, why is it that we 
can’t receive more photos from “ELECTRICAL LABORATORY” owners, when there are about a million of you scattered 
thruout the United States at this very moment! A^ you will remember we made all of you a special offer in the September 
number, z’ic., we offered to give not only the $3.00 monthly prize for the best “Electrical Lab.” photo, but 5 (five!!!) addi¬ 
tional prizes of one year’s subscription to this journal, and a copy of the “EXPERIMENTAL ELECTRICITY COURSE” 
for the best five photos submitted, after awarding the first prize. But nary a peep from a blessed mother’s son of you. _ Now 
it is up to you to get busy at once, and photograph that “Electrical Lab.” We mean every word of it, “Bugs”! For if you 
do not. this department is simply going to slide into oblivion. As we have just said, it is strictly up to you whether you 
wish to take a chance on winning the $3.00 cash prize, and also if you wish to throw away the chance of receiving “The 
ELECTRICAL EXPERIMENTER” magazine for one year free of all cost, besides the copy of the /a/£/cc/nct/y 

Course, which is worth $1.00 alone to any electrical student. Address the Editor “With The Amateur’s Prize Contest.” 


Electrical Laboratory of, 1—Mark Slabodnik, Ely, Minn. (Prize Winner); Radio Stations of, 2—G. Eddie Johnson, Toledo, O.; 3 Nicholas L. 
Googin, Jr., Cazenovia, N. Y.; 4—Armin Vogt, Jansen, Nebr,; 5—Steddom Bros., Oklahoma City, Okla.; 6—Warren Benson, Brooklyn, N, Y» 

October. 1917 



That “Perpetual Motion” 

W l*. HA\'K never publislit a prize 
anilest tlial came within miles 
of being such a hilarious success 
as our “Scenic Railroad’' hoax. 
When wc publisht it, we did ii 
more in order to show how young boys are 
often misled, due to incomplete knowledge, 
rather than our exploiting a scientific im¬ 
possibility. In other words, the whole 
thing simply was a joke. 

Imagine then our genuine surprise when 
immediately after publication, hundreds 
upon hundreds, nay 
thousands of letters 
poured in upon us, 
telling us why the 
scheme would not or 
really would work! 

Up to this time of 
writing 2,109 letters 
were received! Imag¬ 
ine such a thing—and 
they still come and 
come, and we have as 
yet to hear from for¬ 
eign countries!! 

The amount of good 
people who took the 
thing really serious is 
little short of astound¬ 
ing. And hundreds 
really imagined it 
worked! Even the 
gentle sex wrote four 

llundreds of letters 
were alike, most of 
their writers consider¬ 
ing “friction” only. 

But the greatest hone of contention was the 
dynamo-motor point. Almost a thousand 
correspondents contended that when feed¬ 
ing the storage battery current hack 
into the dynamo, the latter would reverse 
thus making the car go backward! These 
good people evidently never heard of an 
automatic reversing switch, nor did they 
stop to think that the great Chicago, Mil¬ 
waukee and St. Paul Railroad actually 
works on this principle, where the coast¬ 
ing trains pump energy back into the line. 
Of course, this is not perpetual motion, 
nor anything near it, it is simply efficiency. 

Only one letter. Air. L. J. Bair’s, men¬ 
tioned this fact, hence the award of the 
“first prize” to him. Several other good 
letters are also publisht and prizes were 
awarded to the writers. 

Scores of correspondents turned uncon¬ 
scious humorists, and we are printing a 
few choice samples selected at random. We 
are genuinely sorry that we have not the 
space to publish several hundred more of 

using the rcgencralivc apparatus, no such momen¬ 
tum will be attained <as the speed of the cur will 
he reduced in direct proportion to the amount of 
current generated. 

LlilGH J. BAIR, 

111 West lllih Street, 

Xew York City. 

to “E E” 

Honorable Mention and Subscription 
too Words—Count 'Em 
The air resistance, friction of bearings, brush on 
third rail and magnclic drag on armature reduce 
speed in descending hill so that the momentum of 
car will not ascend a hill equal in height to its 
starting point, consequently in order to have the 
car travel nearly around the ring, each succeeding 

drawn from the storage battery and, owing lo the 
losses in the machinery, more power would be con¬ 
sumed than was gmerated. 


51 East 123d St., 

New York City 

Is He Joshing Us? 

The Scenic Railway idea would be hne but for a 
few obsiruclions. 

The energy loss due to the friction between the 
Hange of the wheels and the rails is hardly worth 
mentioning. The voltage drop in the iron rails is 
small. Some energy is also lost in overcoming the 
air pressure on the front of the car. 

Much energy is wasted in starting and stopping. 

This could be prevent¬ 
ed, however, if the pas¬ 
sengers would jump on 
and off while the car is 
in motion. 

Not counting these few 
hindrances the idea is 
bne and it ought to be 


Saegcrsvillc, Pa, 

lO- COurtr "tM -lO 

In Our “August" Number We Publisht This “Perpetual Motion" Scenic Railway Problem. 
The Large Storage Battery Was Supposed to Supply Current to the Ascending Cars; the 
Descending Cars Pumped "Juice" Back Into the Battery, etc., ad Infinitum. Here Are 
Some of the Answers We Received. The Editor’s Chair Is Still Oscillating From the Shock. 

hill must be less in height. Therefore car will stop 
some distance below its starting point. 

Assuming efficiency of dynamo, storage battery 
and motor 80 per cent each, then about 51 per cent 
of energy lost is returned to it as motive power. 
Therefore, would come nearer performing feat with¬ 
out dynamo attached. 


Honorable Mention and Subscription to “E E" 
The fallacy of the idea may be shown in the 
clearest way by a simple mathematical process. In 
this solution the loss of energy thru friction, dyna¬ 
mo inefficiency and electrical resistance is disre¬ 
garded, altho. of course, this w’ould be great enough 
to make the idea impractical. 

It may be asssunicd that the energy required to 
drive the car from the point B to C would he 
equal to the energy obtained from the car traveling 
from A to B. Let these amounts equal x and x‘. 

Collisions and Wrecks! 

Wow, What a Head¬ 

The “Perpetual Motion 
Device" won’t w'ork be¬ 
cause when the dynamo 
operates as a motor it 
v'ill run the car back¬ 
wards, which would col¬ 
lide with the other cars. 
Also while ascending cars 
arc using current, the 
descending cars arc send¬ 
ing current in the oppo¬ 
site direction to charge 
batteries. Thus there 
would be two electrical 
currents tending to go in 
opposite directions in the 
same conductor, and that 
is impossible, as each 
would tend to stop the 


633 Carlton Street. 

Toledo, Ohio. 

“Closed Circuit”—Bless Its Heart!! 

The Scenic Railway cannot operate perpetually, 
because the dynamo-motor is connected to a closed 
circuit. To operate a circuit of this kind a dynamo 
must have sufficient power applied to it. Thus, 
when descending a hill, the energy required by the 
dynamo checks the speed of the car so that after a 
few descents the car must stop aliog^ethcr. 


714 Moore Street, 
Huntington, Pa. 

K and the electrical 

First Prize and Subscription to "E E" 

As an answer to your Perpetual Motion Scenic 
Railway Puzzle, 1 wish to otter the following for 
your consideration: 

The facts resolve down to the following condi- 
Uons: Wc have a weight mounted at a height^ and 
in falling or rolling from this height, it attains a 
certain amount of kinetic energy in fnot pounds. 
It requires exactly the same amount of energy in 
foot pounds to elevate this weight to the same 
height as is generated by falling. 

From these facts, it is self-evident that were all 
app.aratus and processes of this transfer of energy 
qne hundred percent efficient, the system described 
would be O. K.p but it is also evident that, due 
to wind friction and bearing friction on the cars, 
and copper, iron, windage bearing and brush losses, 
pf the generating apparatus and motor equipment, 
it will be only about 60 per cent efficient at its 
best. This efficiency is attained by the regenerative 
apparatus used on the Chicago, Milwaukee and St. 
Paul R. R. on a three phase electric system over 
the Rocky Mountains. 

The misleading feature of this perpetual motion 
scheme is that, due to the momentum of the car on 
the downward slide, it would reach to a high point 
on the upward grade and requires only a little 
effort to carry it over the top peak, but when 

X ~ . 

Also let the kinetic energy 
energy = E. 

Now in traveling from .4 to B, kinetic energy K 
will be obtained minus the electrical energy used 
to charge the storage batteries, or 
/C —. £ = 4r. 

Now from B 
to Cf the energy 
required will be 
the kinetic K, 
which will carry 
the car to some 
point (P, plus 
t h e electrical, 
from C* to C, or 
K E = x^ 
and since 

K — E 
K E - 

Tv — /: = A' -f £ 
which, of course, is impoisible. 



1 ^ 

^ * 


^ t 





_ 1 


Eureka! It Works! Oil!! (Castor Oil?) 

The reason why this device will not work is this: 
Tho the energy generated by the descending car 
would be sufficient to carry up a similar hill a 
similar car some of the energy is wasted in heat 
by friction. Altho hy oiling this could be reiluccd, 
it could not be eliminated. Then some current 
would be wasted in heating the wires. If there 
were fewer cars or fewer people on the next trip 
it might work. But it would die down in a short 
time unless power were supplied from an outside 


3*^ Hope Street, 
Ridgewood, N. J. 

Quick—Call an Ambulance!! 

The car in going down hill would generate a cur¬ 
rent that would, at the bottom of the incline, tend 
to dri'*** the car back up again, and it would back 
it up a little way, the car only to come lo rest at 
!:ist at the bottom 


920 S. 11 til Street, 
South Bend, Ind. 



E. Morton Avc 


Honorable Mention and Subscription to “E E“ 
In explanation of the inoperativeiicss of the Per¬ 
petual Motion Scenic Railway, described on page 
249 of the August number of your magazine, I 
would state the following: It is well known that a 
dynamo consumes mechanical energy in proportion 
as it produces electrical energy. Therefore, the 
power required to drive the dynamo would so re¬ 
tard the descent of the car on the down-grades that, 
having less momentum, additional power would be 
required lo lift it on the up-grades. This would be 

Everett Has the Right Dope! 

A car would climb lusl as tar up the last pe.ak 
without the addition of a generator and storage bat¬ 
tery plant as with it, since its momentum would be 
impeded by the running of the generator, as by 
the well-known law: The current generated in a 
conductor by its motion in a magnclic field flows in 
such a direction that its magnetic field tends to 
prevent the motion. In other words, the amount of 
energy used up by the running ot the generator 
is greater than that g.aincd hy the motor, the loss 
being due to resistance, friction in the ^r 
and motcr, etc. 


145 Congress Avc., 
Providence, R. 1. 

This Bird Claims It Will Run 40 Seconds!! 

It IS impossible for your “Perpetual Motion 
Scenic Railway” lo work for several reasons: 

Regardless of what height the grades arc upon 
which the cars descend, the dynamo-motor would 

(Continued on page 430) 



October, 1917 


Illuminated Torpedo 
(No. 1,232,671; issued to Alphonse 

This electrically illuminated tor* 
pedo is intended for use by mariners, 
as an aid in discovering the pres* 
ence of enemy craft at night. The 
torpedo may contain explosives if 
desired. To prevent disclosing the 
location of the ship dispatching the 
torpedo, a special electric time switch 
is provided, which does not close 

ment to be able to illuminate the 
road ahead of the horse, and thereby 
prevent shadows being caused by the 
animal from the usual lights on the 
vehicle. When not in use the lamp 
attachment can be removed in part, 
and the remainder of the lamp pro¬ 
vides a neat ornament upon the 
breast collar. 

Fire-Detecting Wire 
(No. 1,235,028; issued to Charles A. 


This invention involves the use of 
a fusible conductor inclosed within 
the walls of a cell or tube in the 
wall of which there is provided an 

the searchlight battery circuit until 
the torpedo has reached a prede¬ 
termined distance away from the 
ship. Also the inventor provides a 
centerboard or keel which is auto¬ 
matically released after the torpedo 
has reached the end of its range, 
and which device helps to keep the 
torpedo in a given course; the in¬ 
ventor thus not relying on the ordi¬ 
nary rudder or plane steering me¬ 
chanism. It is possible to retrieve 
torpedoes of this type after they have 
performed their service. 

Magnetic Shift lor Head-Lights 
(No. 1.233,341; issued to Henry S. 


Electromagnetic shifting device 
for rotating head-lights of an auto 
or other vehicle which involves the 
use of an extremely simple rnotor, 
the head-light being mounted rigidly 
on a central threaded stem, which 
engages a relatively heavy iron nut. 
Normally this nut is sufficiently 

heavy to fall to the bottom of the 
casing, and maintain the head-light 
in a straight ahead position. If 
battery current is past thru the 
electro magnets at the t(m of the 
casing, the iron nut is drawn up¬ 
ward and in so doing, it causes the 
threaded cap just under the magnets 
to rotate, thus, turning the central 
stem on which the nead-light is 

Portable Lamp for Harness 
(No. 1,232,201 ; issued to Carl F. 


A novel use for a battery lamp de¬ 
signed so as to be quickly attached 
to or detached from an ordinary 
harness, the wires carrying the cur¬ 
rent to the lamp being concealed 
within the traces. Battery may he 

placed in the vehicle, and when the 
lamp is to be used a simple plug 
connector or switch can be attached 
to the trace closing the lamp circuit. 
An auxiliary switcm mounted on the 
vehicle seat, may be used if desired. 
The inventor claims by this arrange- 

Fan Deodorizer 

(No. 1,233,039; issued to Bert W. 

This invention provides a simple 
deodorizing attachment which may 
be readily attached to the wire cage 
found on all eletcric fans. The 
patent relates to refrigeration, and 

more especially to air coolers and de¬ 
odorizers which include a fan or 
other means for pumping air into 
contact with water or other liquid 
before it is delivered to the point 
of use. This attachment includes a 
reservoir for water or deodorizing 
liquid, also a moistening surface with 
a fabric sheet hanging in front of 
the fan, and means for delivering 
the liquid as rapidly as may be de¬ 
sired to this surface, so that the air 
from the fan is blown against the 
moistened fabric and cooled or dried 
hy the deodorizer before it reaches 
the point of application. 

Lsfoe/ fppt 

fief urn conduchr 

outlet, so that when the metal be¬ 
comes plastic, it may be forced out¬ 
ward thru this perforation in the 
wall of this cell, and penetrate thru 
the fibrous insulating material sur¬ 
rounding itj and establish the de¬ 
sired electrical connection between 
the inner and outer conductors. 
The fire-detecting wire as devised by 
this inventor comprises an inner 
core of easily fusible metal, a gal¬ 
vanized steel tape of suitable breadth 
to nearly envelop a soft metal core, 
leaving a longitudinal slot, a braided 
insulated wrapping and an exterior 
conductor, formed preferably of a 
galvanized steel tape, helically dis¬ 
posed on the exterior. 

Radio Receiving Circuit 
(No. 1,233,841; issued to Elmer E. 


Radio-telephonic or telegraphic sig¬ 
nals of any characteristic, and par¬ 
ticularly undamped wave signals are 
received and made audible by the 
simple arrangement here shown. 
The patent covers the use of a per- 

Rc^rtng condenser 

Thermionic Amplifying Circuit 
(No. 1,232,879; issued to Peter I. 


This invention relates to the ampli¬ 
fication of small continuous voltages 
or currents, and its purpose is to 
make it possible to detect or measure 
such voltages or currents, which 
might not otherwise be detected. 
Audion type vacuum amplifiers are 
utilized wnich are connected in a 

special circuit as shown. It will be 
observed that current from the bat¬ 
tery 16 divides at the middle point 
of the resistance 15, and flows thru 
the two output circuits. It is also 
apparent that the two halves of re¬ 
sistance 15 \vill be equal and op¬ 
posite, and points C and D \yill 
normally be at the same potential, 
and no current flows thru the gal¬ 
vanometer 20. When key 21 is 
closed, however, the current will flow 
thru the resistance 6, and if the 
direction is such as to bring the 
terminal A to a higher potential 
than the terminal B. the grid‘10 will 
have a higher potential than grid 11. 
This results in the current flowing 
thru output circuit to amplifier 8„, 
being greater than that of amplifier"* 
u. Thus point C will he at a lower 
potential than point D, and current 
will flow thru the galvanometer 20. 

(C), and at the opposite end a m|- 
crophonic transmitter (D). The coil 
may be 6 inches long with an iron 
wire core Vz inch in diameter, 
wound with five layers of No. 23 
B. & S. magnet wire. The me^l 
tube (B) absorbs the brush dis¬ 
charges. The microphonic inter¬ 
rupter (D) acts in unison with the 
spring interrupter (C), but is not 
electrically connected wnth it. 
Terminals (13 and 14) go to the 

Vacuum Bulb Rectifier 
(No. 1,230,004; issued to George S- 

An improvement in vacuum tube 
rectifiers involving the use of an in¬ 
candescent cathode ^ device in the 
manner shown. This idea provides 

iodically changing capacity constant 
in the receiving circuit. A con¬ 
stantly changing condenser driven 
hy a motor is shown in the present 
diagram. It is thus apparent that 
as the revolving condenser plates 
rotate, the capacity of the condenser 
increases to a maximum, and de¬ 
creases to a minimum periodically; 
thus throwing the secondary circuit 
into and out of resonance with the 
aerial circuit, and an audible signal 
of a frequency proportional to the 
speed of rotation oi the condenser 
is produced. No exact tuning is 
necessary with this circuit, aS the 
revolving condenser, within limits, 
finds the exact point of resonance 

Microphonic Buzzer Transmitter 
(No. 1,234,650; issued to John Pat¬ 
rick Ferriter.) 

A buzzer transmitter for the pur¬ 
pose of telegraphing over a wire 
telephone circuit or for use as a 
telegraph transn|itter over a radio 
telephone circuit. 

i' cropt>one inffptr 

a rugged main cathode, and separate 
or auxiliary electrode which oper¬ 
ates in conjunction with such cath¬ 
ode to spring a starting arc which 
heats the cathode to incandescence, 
preliminary to starting the main 
arc. The cathode tip perferably 
consists of tungsten; the space with¬ 
in the bulb should be carefully 
evacuated of all gases and vapors, 
and the envelop is then filled with 
an inert gas, such as hydrogen, 
argon, etc. When the tube is to 
be started, a suitable heating cur¬ 
rent is conveyed to the starting 
electrode 9, from a special winding 
on the transformer as shown. 

Wind-Wheel Electric Generator 
(No. 1,233,232; issued to Albert H. 

A very clever form of wind-wheel 
electric generator in which the 

The apparatus comprises an ac¬ 
tuating coil as shown, which is in¬ 
closed in an open-ended metal tube 
(B) of brass or copper. At one end 
of the coil is a spring interrupter 




wind-wheel itself acts as the rotor 
of an alternating current dynamo. 
The rotating element simply carries 
inductor plates, which are caused 
to move by a series of stator poles, 
which poles carry a series of elec¬ 
tro-magnetic windings. The device 
acts in the same way as an alter¬ 
nating current generator, and also 
serves as its own exciter. The 
terminals of the stator windings 
may he connected with a rectifier 
to change the alternating current 
into a continuous one when so de¬ 

October, 1917 




Under this heading are publiaht electrical or mechanical ideas which 
our clever inventors, for reasons best known to themselves, have as yet 
not patented. We furthermore call attention to our celebrated Phoney 
Patent OHizi for the relief of all suffering daffy inventors in this country 
as well as for the entire universe. 

We are revolutionizing the Patent business and OFFER YOU THREE 
DOLLARS ($3.00) FOR THE BEST PATENT. If you take your Phoney 
Patent to Washington, they charge you $20.00 for the initial fee and then 


you haven't a smell of the Patent yet. After they have allowed the Pat¬ 
ent. you must pay another $20.00 as a final fee. That's $40.00! WE 
PAY YOU $3.00 and grant you a Phoney Patent io the bargain, so you 
save $43.00!! When sending io your Phoney Patent applicatioo, 
be sure that it is as daffy as a lovesick hat. The daffter, the better. 
Simple sketches and a short description will help our staff of Phoney 
Patent examiners to issue a Phoney Patent on your invention in a 



FIRST PRIZE, $3.00: Smokelight. Works on Vacuum Cleaner Principle. Suction Created by Smoking, Operates Air Turbine, Which 
In Turn Energizes Dynamo. The Latter Charges Storage Battery Which Feeds the Current to Electric Lamp. Thus Collisions in 
Dark Are Avoided and Keyholes Are Found Easily. Inventor: F. R. Prey, Somerville, Mass. 

ELECTRIC SAILOMOBOAT: Wind Fills Sails Which Slowly Move Ship. Water Turns Paddles 1, Which Thru Gear 2 Work Dynamo 3, 
the Latter Charging Storage Battery 4. This In Turn Drives High-Speed Motor 5, Which Turns Propeller 6 at 3898 R.P.M. Thus Ship 
Is Driven Forward at 49'/4 Nots an Hour. Inventor: Albert Branson, Logan, Pa. 



October, 1917 

D CLu: 







This department is for the sole benefit of all electrical experimenters. Questions will be answered here for the benefit of all, but only 
matter of sufficient interest will be publisbt. Rules under which questions will be answered: 

1. Only three questions can be submitted to be answered. 

2. Only one side of sheet to be written on; matter must be typewritten or else written In ink, no penciled matter considered. 

3. Sketches, diagrams, etc., must be on separate sheets. Questions addrest to this department cannot be answered by mail free of charge. 

4. If a quick answer Is desired by mail, a nomlnai charge of 25 cents is made for each question. If the questions entail considerable re* 
search work or intricate calculations a special rate will be charged. Correspondents will be informed as to the fee before such questions are 


(842-A.) O. Saterdale, E. Boston, Mass., 

Q. 1. What is the resistance of sea¬ 
water and what current could be transmit¬ 
ted thru 1,000 feet of it? 

A. 1. The resistance of sea water varies 
somewhat of course, but it has an approxi¬ 
mate resistance of 5 ohms per cubic centi¬ 

Your question is very indefinite, as it 
makes all the difference in the world 
whether you wish to compute the amount 
of current which could be transmitted thru 
one thousand feet of sea water in a pipe; 
which would of course be a comparatively 
easy computation; or whether you wish to 
make such a calculation for an open body 
of sea water, such as in a harbor or inlet. 
In this case, the matter would become ver>^ 
involved indeed, and a number of sound¬ 
ings and breadth measurements of the body 
of water would have to be taken, and a 
mean of these values selected, so as to 
obtain the average cross-sectional area of 
the water. The resistance of a cross-sec¬ 
tion of sea water 10 centimeters square 
would only be 1/100 of the resistance of a 
cubic centimeter, etc. The current in 
amperes which could be transmitted thru 
a certain resistance of sea water would be 
given by Ohm’s law or 

C = —. 



(842.) Charles Honeywell, Gloversville, 
N. Y., asks: 

Q. 1. Can you suggest proper size of 
condenser to eliminate sparking at bell cir¬ 
cuit contact shown in diagram? 

A. 1. Concerning the special electrical 
contact which you are experimenting with, 
w'ould advise that without more exact de¬ 
tails as to how you have the special contact 
arranged, we cannot very well advise you 
as to how to overcome the trouble. 

We should think that it would be pos¬ 
sible to make the spring tension acting on 
your contact sufficiently strong so that the 
contact will not be jarred shut by a slight 
mechanical disturbance. 

A condenser will only help you indirectly 
in solving this problem, if you have the 
contact member arranged so delicately that 
the slightest jar will cause it to close. We 
would like to advise you further, but feel 
that it would only be a waste of time to 
discuss matters which we do not quite 
understand for the reasons above stated. 
Your trouble apparently seems to lie in the 
manner of arrangement of the contact. 
Besides the condenser the principle of the 
ihagnetic blow-out could be applied to over¬ 
come the arcing at your contact, but even 
the latter would seem to hardly be of any 
distinct benefit to you, if the design of 
the contact is not properly carried out. 

The principle of the magnetic blast as 

applied to radio ke^'S and other switches 
carr>*ing heavy currents and liable there¬ 
fore to severe arcing, lies in the fact that 

S/fi^er co/?/i:7c/ 

^ -A_ 

Q-34Z @ 

A Simple Yet Difficult Problem. It Is Re¬ 
quired to Break This Circuit With a Mini¬ 
mum of Sparking and the Interrupter is a 
Delicately Mounted One, Easily Vibrating 
With a Slight Jar. 

1 AT $1.00 EACH!!! ■ 

M Now is the time to viake your ^ 
^ Kodak pay for itself in a real praeti- ^ 
^ cal way. IVe are after interesting J 
= photographs of out-of-the~ord inary = 
J electrical, radio and scientific sub- J 
^ jects and are willing to pay $1.00 cash ^ 
^ for every one zve can use. Please g 
H bear in mind that for half-tone re- o 
^ production in a magacine, a photo- J 
^ graph should be particularly sharp ^ 
J and clear. Of course, if a subject ^ 
J happens to interest us particularly J 
g zvell, zve can have the photo retouched, p 
J For the general run of subjects, how- gf 
g ever, it does not pay to go to such ^ 
^ ejvpense. Therefore, please take pains J 
^ to properly focus and e.vpose your g 
g pictures. It often happens that a ^ 
S really mediocre subject well photo- ^ 
graphed zvins approval over an ex- g 
cellent subject poorly photographed. ^ 
^ And dont send us plate or film ‘‘nega- M 
^ tives’*; send unmounted or mounted g 
^ **printsf* preferably a light and a dark ^ 
g one. ^ 

^ As to what to photograph: Well, g 
W: that's hard for us to .ray. We leave ^ 
^ that up to you, and every reader now ^ 
g has the opportunity to become a re- ^ 
g porter of the latest things in the realm ^ 
^ of Electricity, Radio and Science. ^ 
g But, please remember — it's the ‘'odd, g 
^ novel or practical stunts” that we are ^ 
W interested in. Every photo submitted s 
g should be accompanied by a brief de- g 
m scription of 100 to 150 words. Give g 
W the “facts” — don't worry about the M 
J style. We'll attend to that. Enclose ^ 
^ stamps if photos are to he returned ^ 
^ and place a piece of cardboard in the ^ 
= envelope with them to prevent mutila- g 
g tion. Look around your town and M 
= see zvhat you can find that's interest- ^ 

J Address photos to—Editor “Odd g 
m 233 Fulton Street, New York City. m 

f H ll’ll I 

a strong electro-magnet is connected in 
series with the circuit, in most cases. This 
magnet for small circuit breakers, may be 
of about the same size as a telegraph 
sounder electro-magnet, and in any case, 
this series blow'-out magnet should be 
wound with wdre of the same size as that 
used on the primary of the transformer, 
spark coil or other apparatus which the 
key controls. 

It is usual to allow from 800 to 1,000 
circular mils per ampere, in designing such 
blow-out coils, and the electro-magnet 
should be provided with suitable tapered 
pole-pieces with a small air gap between 
them, and so arranged that the break be¬ 
tween the platinum or other contacts of 
the circuit-breaker takes place behveen the 
magnet pole-pieces. In this w'ay the arc 
w ill be blow'U out by the magnetic field. 


(844.) A. Luchs, Jr., Ridgew’ay, Pa., 
asks a number of questions regarding the 
electrolytic production of hydrogen. 

A. 1. With respect to the explosive qual¬ 
ity of hydrogen gas, would say that this 
is an explosive only w'hen mixed with 
oxygen or wdth air, which is the same 

The most efficient way, and the one now' 
used commercially in the largest oxj'gen- 
hydrogen producing plants in the country, 
is that producing hydrogen or oxygen gas 
by the electrolysis of w'ater, which is ac- 
complisht by passing a strong electric cur¬ 
rent thru it. 

The following data is given by one of 
the leading manufacturers of oxygen and 
hydrogen gas. A current of 2 volts and 
600 amperes is used per cell and 4.8 cubic 
feet of oxygen and 9.6 cubic feet of hydro¬ 
gen per hour are produced with this cur¬ 
rent of 1,200 watts. The U. S. Army bal¬ 
loon electroHzers use 1,000 w'att hours to 
produce 71^ cubic feet hydrogen and 5.76 
gallons of water per 1,000 cubic feet of 
hydrogen are required. The electrolytic 
apparatus used for producing these two 
important commercial gases is usually de¬ 
signed so that the two gases are collected 
separately and independently; the hydrogen 
gas being evolved at the negative electrode 
and the oxygen gas at the positive elec¬ 
trode. You w'ill do veo' well to obtain a 
copy of U. S. Patent No. 1,219,966 describ¬ 
ing an improved form of electrolytic gas 
generator as used for the commercial pro¬ 
duction of these products, and w’hich w’e 
can supply at 10 cents. 

With reference to the proper ratio of 
hydrogen gas and air, to make the most 
explosive mixture, we would suggest that 
you try this out by experiment, as it would 
depend to some extent on the quality of 
the air; i.e., it w’ould vary for different 
levels, and an adjustable mixer valve should 
be used in any such work as this, similar 
to the carburetor employed universally on 
all gasoline automobiles. 

October, 1917 




(845) E. E. C-, Ohio, asks whether 

several sizes of wire can be used in t!ie 
same circuit in a satisfactory manner. 

A. 1. W'itli regard to running a 3-phase 
7200-volt line one-half mile, to deliver cur¬ 
rent to a bank of ‘ 3-25 K.V.A. 25-cycle, 
6f)00-volt to 440-volt transformers for 
power load would advise as follows: 

We have not inade any calculations on 
this problem, but assume that you are tak¬ 
ing care of these calculations yourself. 
However, regarding the use of various sizes 
of wire in the transmission line, would 
advise that so long as the smallest size of 
conductor used is not below the minimum 
allowable cross sectional area, in circular 
mils, as computed by the usual A.C. for¬ 
mula for such circuits, then it will not 
matter in the least for all practical pur¬ 
poses, whether you use several different 
sizes of wire in the circuit or not. 

That is if, say. No. 6 B & S conductor 
was given by the usual voltage-drop for¬ 
mula, then so long as any of the pieces of 
wire to be used are not smaller than No. 
6 gage, the circuit will operate satisfacto¬ 
rily. Of course it is the usual case that no 
one would want to use sections of conduc¬ 
tor larger in size than that absolutely re¬ 
quired by the conditions surrounding the 
problem, but of course in your case, there 
is an exception as you state, owing to the 
fact that you have a quantity of various 
sized conductors on hand for the installa¬ 
tion in question. 


(846.) John Davidson, Ohio, asks several 
questions regarding A. C. magnets to be 
used for repelling torpedoes. 

A. 1. We have considered such an elec¬ 
trical device as you describe, and which is 
supposed to repel metallic bodies such as 
those made of steel or iron. 

Considered from a fundamental electri¬ 
cal viewpoint, an ordinary magnet excited 
hy a direct current will not exert any re¬ 
pelling effect on an iron or other body. It 
is possible to create a magnetic repulsion 
effect if powerful alternating current elec¬ 
tro-magnets are used, but this effect exists 
only over a distance of a few inches at the 
most, and several inventors have recently 
proposed that it would be a good idea to 
put a belt of these powerful A.C. electro¬ 
magnets around the waterline of a steam¬ 
ship so as to repel torpedoes and the like. 

While we are on the subject, it is well to 
point out that if this arrangement was car¬ 
ried out that firstly, the cost would be prac¬ 
tically prohibitive, and secondly there would 
be no repulsion effect exerted on the tor¬ 
pedo, which is made of steel, for the reason 
d^at it would not be of the proper shape. 
To produce a repulsion effect between an 
iron core within an a.c. magnet coil and a 
copper or aluminum inductor, the latter 
must be made in a ring form either square 
or round, so that induced currents are set 
up in this ring which will produce within 
the ring an opposing magnetic field, whicli 
reacts with the inducing a.c. field of the 
electro-magnet just mentioned. 


(847.) Roy N. Meier, Wayne, Nebr., 
wishes to know how the size of wire for 
lighting circuits is computed. 

A. 1. One of the simplest and most reli¬ 
able rnles for computing the proper size of 
a conductor to be used for wiring a Iiouse 
for lights, etc., is the modification of Ohm’s 
law which states that the resistance of the 
wire in the circuit (both legs) in ohms should 
equal the volts drop in the circuit, divided 
by the current in amperes in the circuit. 

ncuRm CYCLOPEDH anDPEHi aaflPEHi craoPEm cyclopbIu crooreiii 

I tK 7 ^ ff ■ 

APPLel ;u>mED4 f 




By merely filling in and mailing the coupon below you can get this complete set of the 
Cyclopedia of Applied Electricity on trial. Use these books for seven full days before 
you make up your mind whether or not you want them. If you keep them, you may 
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want them, you may send them back at our expense and you won't be out a penny. 
Remember, we pay the shipping charges both ways. 


These seven splendid volumes contain all the knowledge you need in order to earn big 
money in the electrical field. They are not thin handbooks, but thick, encyclopedia- 
size volumes, handsomely bound in half red morocco leather, gold stamped. Each 
one measures 7 by 10 inches, and is 2 inches thick. 

This big size permits the use of large and comprehensive illustrations, plates, dia¬ 
grams, etc. Over 3,000 cuts are contained in the Cyclopedia’s 3,500 pages. 

The completeness of the Cyclopedia will be a revelation to 
you. Everything electrical is explained in plain, simple 
English—every technical point is made clear. Each volume 
is carefully cross-indexed for instant reference. 

For this sum—an insignificant 
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Society—regular price $12.00—will be included with all or¬ 
ders for a limited time. The advice of an entire corps of 
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for a whole year FREE! * 

50c a Week 

Read These Subject* 
Elements of Electricity— 
Electrical Measurement* 
—Underwriters' Require¬ 
ments—Theory, CaJcula- 
Uon, Design and Con- 
Btructlon of Generators 
and Motors — Dynamo- 
Electric Machinery— 
Lighting Machinery— 
P n w e r Transmission— 
Electric Railways—Power 
StaUons — Switchboards 
and Switching—Stortga 
Batteries—Applied Elec¬ 
tro-Chemistry — Electric 
Eleraters—Electric Weld¬ 
ing and HeaUng—W«ra 
and Wireless Telegraph. 

* American Technical Society 
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by mentioning 

The Electrical Experimenter’ 

xvhen writing to advertisers. 



October, 1917 

MescoTelegraphPractice Set 

For Learning Telegraph Codes 

The Practice Set comprises a regular tele¬ 
graph key, without circuit breaker, a special 
high pilch bu 2 zer, one cell Red Seal Dry 
Battery, and four feet of green silk covered 
flexible cord. 

The key and buzzer are mounted on a 
highly bnished wood base, and three nickel 
plated binding posts are so connected that 
the set may he used for five different pur¬ 

For the beginner, the set is of exceptional 
value, for it may be used for individual code 
practice or for operation of a two party line, 
which is an excellent method of quickly 
learning the code. After the beginner has 
mastered the code, the set may he used in 
his wireless outfit for setting the detector 
in adjustment, and also the key may he used 
to control the spark coil. 

Recommended for schools, as it gives ex¬ 
cellent service for class instruction in code 
work. Full directions w’ilh each set. 

The main object of the set is to enable the 
beginner to master the telegraph codes. The 
buzzer emits a sound similar in pitch and 
tone to that heard in wireless receivers. 

Every beginner needs one of these sets, 
and as it is the equivalent of five different 
sets, the price is very low. 

List No. Price 

342. Telegraph Practice Set, with Bat¬ 
tery and Cord.S2.70 

344. Telegraph Practice Set only, no 

battery or Cord. 2.55 

Send for Our New Edition of our 
Catalog W28 Ready about Oct. 1st 

It is pocket size, contains 248 papes. with over 1.000 
illustrations and describes In plain, clear language 
all about Bells. Push Buttons. Batteries. Telephone 
and Telegraph Material, Electric Toys, Burglar and 
Fire Alarm Contrivances. Electric Call Bells. Electric 
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Electrically Heated Apparatus. Battery Connectors, 
Switches. Battery Gauges. Wireless Telegraph In¬ 
struments, Ignition Supplies, etc. 

Send for the Catalog Now 

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Supply Co., Inc. 

New York: Chicago: ST. LOUIS: 

17 Park Place 114 S. 5th Ave. 1106 Pins St. 

San Francisco Office: 604 MIssIod SU 

Electric Row Boat Motor 

Makeyour Row Boat 
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Buy a Jewel Detachable 
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Simple, noiseless 
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.Attaches to aoy 
Row Boat and 
runs on two bIx 
volt Batteries. This is our 5th 
successful year. 


Look Inside your storage battery through the 
pateoted open window. See condition of 
plates and height of electrolyte. If you need a 
new automobile starting Battery buy a Jewel 
and save money. 6-60 Si^clal S8.50. 

Motorcycle Electric Lighting Syatem 
Tho Jewel Generator Motorcycle Storage Battery and 
complete lighting system Is In great demand. Aireau 

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Stromberg - Carlson Telephone Mfg. 

Rochestar, N. Y» 


It is usual to allow about 3 volts drop 
from the main panel board to the lamps. 

In making the final selection of the 
proper size of wire to be used for light and 
power circuits reference should be made to 
the Fire Underwriters’ rules and tables, 
and if the}' specify a slightly larger con¬ 
ductor than the one given by the above for¬ 
mula, then that is the one that should be 
used of course. 

With reference to the size of fuses to 
be used on the main panel board, these 
should be a multiple of the fuses in the 
branch circuits. For example if a panel 
board supplies four branch blocks, each 
fused at 5 amperes, then the panel board 
should be fused at 4 times 5, or 20 amperes, 

substance (H-S) is present in the liquid, 
and can be obtained by evaporation. (This 
is not, however, the case with HCl.) The 
solution of the gas will, however, give cer¬ 
tain chemical reactions, as, turning litmus, 
and when deposited on a silver coin, will 
produce a black stain of silver sulfid. 


(850.) E. W. Cleave, Oakland, Calif., 
wants to know if an A.C. motor can be 
built in which the rotor will oscillate back 
and forth instead of rotating. 

A. 1. Concerning oscillating squirrel- 
cage A.C. motor, we must say to the best 
of our knowledge, there is no method of 
winding such a motor so as to cause the 
rotor to oscillate back and forth thru say, 

Connections of a One-Step Amplifier and Audion Detector Arranged to be Quickly Switched 
In For Undamped Waves Up to 10,000 Meters or Damped (Spark) Signals Under 4,000 Me¬ 
ters Wave Length. 


(848.) Leroy F. Bremmer, Fort Dodge, 
Iowa, wants to know: 

Q. 1. What is the wave length of an 
aerial 80 feet long, 4 wires, 55 and 38 feet 
high, with lead-in 100 feet long. 

A. I. The wave length of your antenna 
is 350 meters. 

Q, 2. Please show diagram of connec¬ 
tions of a one-step amplifier which can be 
changed from a 10,(XX) meter undamped 
wave set to a 4,0(X) meter spark set by 
switches. Please show all necessary in¬ 
struments in hookup. 

A. 2. Diagram herewith shows connec¬ 
tions of the necessary instruments. The 
double-throw, double-pole switch is em¬ 
ployed for changing from the 10,000 meter 
coupler to the 4,000 meter coupler. In re¬ 
ceiving spark stations it is essential that the 
grid loading coil is short-circuited by 
means of the switch as shown. To receive 
spark station the D. P. D. T. switch is 
thrown to the left and for undamped wave 
it is placed to the right. 



(849.) S. Lenkin. Washington, D. C., 
wants to know if hydrogen sulfid (HaS) in 
water is a physical or a chemical solution, 
and why. 

A. 1. Hydrogen sulfid in water is a phys¬ 
ical solution. When the gas is past into 
the water there is no evidence of any effer¬ 
vescence or of any precipitat forming (un¬ 
less lead is present in the water which will 
cause the H-S to precipitat the lead as an 
insoluble sulfid). This oneration is sorne- 
i^imes called a simple solution, the origi¬ 

nal ]E4th of a revolution as you suggest. 

We would suggest that you take up this 
matter with the Engineering Department 
of the General Electric Co., Schenectady, 
X. Y., as we have an idea, if we recollect 
correctly, that that concern have a special 
alternating current apparatus, which oper¬ 
ates on a principle somewhat like the one. 
you outline. 


(851.) B. P. B., Chicago, Ill., asks about 
constructing a large spark coil. 

A. I. It is often the case, as you suggest 
that the efficiency, and therefore the length, 
of spark produced by a given induction coil 
will be intensified by substituting a vulcan¬ 
ized fiber, or a hard rubber tube for a paste¬ 
board one, if that is the kind of tube now 
separating the primary' and secondary coils 
in your apparatus. 

Some makers have used to very good 
advantage a glass tube, the point at issue 
being to have the very' best insulation possi¬ 
ble between the primary and secondary, 
owing to the vep" high voltages induced in 
the secondary winding, which will of course 
always attempt to jump the shortest possi¬ 
ble path or gap, such as around the ends 
of the primaiy' insulating tube into the iron 

For this reason in designing large induc¬ 
tion coils, above the 2-inch spark size, it is 
invariably the practise to so proportion the 
secondary winding that it shall not come all 
the way to the end of the primary insulat¬ 
ing tube, but a considerable distance from 

You are correct in your statement accom¬ 
panied by diagram (fig. 1) relative to the 
connection between various secondary sec¬ 
tions, but this is the older and practically 

You benefit by mentioning **The Electrical Experimenter'* when zvriting to advertisers. 

October, 19)7 



obsolete manner of making these connec¬ 
tions, and most always leads to dissatis¬ 
faction at an early date, for the reason that 
there is a very high potential always exist- 

Old and New Method of Arranging Spark 
Coll Secondary Sections. In Method of Fig. 
1, the Full Potential of Each ‘‘Pie’* Tends to 
Jump Between the Lead and the Winding. 

ing between tlie top of one section or “pie/’ 
and the down-coming lead wire from the 
adjacent “pie.” It is the best and modern 
practise to connect first two inside leads 
together and then two outside leads, etc., 
etc., reversing every other *‘pie” of course 
as it is placed in position over the primary 
insulating tube. The Editor has generally 
found it most convenient and practical to 
secure the primary element with its insulat¬ 
ing tube in place in a vertical position by 
means of wooden blocks, etc. This could 
easily be arranged, and a few blocks may 
be used if necessary to form a sufficiently 
high base at the point where the first “pie” 
will come. All leads should be soldered, 
using a non-corrosive flux. You will find 
a number of excellent books on this sub¬ 
ject illustrated in our “Book Catalog.” 


(852.) Cecil Mathers, Miami, Fla., de¬ 
sires a hook-up for a buzzer system to 
work on lighting circuits. 

A. I. VVe give you herewith diagram of 
connections for two buzzers, batteries and 
keys to he used with ground return and 
electric light or other circuit, for the pur¬ 
pose of transmitting telegraphic signals 
over a one mile range. 

Both telephone receivers (of the usual 
75-ohm type) should be connected to the 
same line wire; i.e., both of them should 
be connected to either the positive or the 
negative line wire. If you experience any 
trouble due to a grounded system, a small 
fixt condenser should be connected in series 
with the telephone receiver at each station. 

Simple Buzzer Telegraph for Use on Light¬ 
ing or Power Circuits. 

The use of electricity for lighting is rap¬ 
idly increasing in Japan, even in the homes 
of the poorest classes in the cities. 



in an Imporlant trained capacity. Several thou¬ 
sand operators are needed for Army and 
Navy Service, our new merchant 
marine and air fleet. 

d'he licensed Em¬ 
ployment Department 
finds temporary day employment 
for those who must earn while learning. 


Marcy Ave., near Broadway, Brooklyn, N. Y. 

13 minutes to New York City Hall 


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writing or manifolding. 

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^EI^MORSE and wireless-—J 


in half the usual time, at trifling cost, with the 
wonderful Automatic Transmitter, THE OMNIGRAPH. 
Sends unlimited Morse or Continental messages, at 
any speed, just as an expert operator would. 

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39L Cortlandt St. New York 

an Behind the 

is equally as important today as the Man behind the 
gun, as well as the Man in the trench. 

The Government and Merchant Marine need thousands of 
1 RAINED operators now, the demand far exceeding the sup¬ 
ply. Men are needed urgently for the Naval Reserve, Naval 
Militia, and Signal Corps, etc., etc. 

Pick your rating before you are drafted. 

.Special short code courses, Day or Evening for those desiring 
to join any branch of Radio for Government Service. Fall classes 
both Day and Evening start Oct. Isl. Send in your enrollment 
today. Students from all over the country. 

The Eastern Radio Institute is endorsed by the United 
States Gove rnment and Marconi Co. 

Send for free booklet 



'eastern Radio Institute, 

899B Boylston St., Boston. 

Please send to address below your 64-page book- 
cl, giving full information about your school. 

You bettefit by *'Thc Electrical Experimenter*' tvheu reriliuj? /<.> uii: ertisers. 



October, 1917 

Wire l ess Ta ught Bv Mail 

Vou Alay L,earn "Theory, Code and L,aws of Radio 
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Send stamp for catalog giving facts. Resident classes 
open Oct. 2nd. 

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(Cofitinued from page 367) 

the first officer of one of the large British 
merchant ships has invented a simple and 
very effective “zig-zag control board,” which 
is herewith illustrated. It consists of a 
board about two or three feet square, carry¬ 
ing in its center a clock, and on each side 
of the clock a series of alternate green and 
red cards and glow lamps, each card and 
lamp corresponding to the starboard and 
port courses on which the ship is being navi¬ 
gated at any given time. Above the clock, 
extending across the head of the board, is 
plotted a zig-zag course which it will take 
the ship one hour to cover. 

In the accompanying chart (top) the 
straight line represents the true course 
which, in this case, is, let us say, due north. 
The ship commences her zig-zag course 
at, say, 2 o’clock, at which hour the helm 
is thrown over and the ship’s course is 
altered 30 degrees to port of the true course. 
[The original conception of this zig-zag'* 
control board Zi^as limited to automoticolly 
warning the helmsman every time the rud¬ 
der was to be thrown over. The helms¬ 
man then set the electrical clock contact to 
ring after the next leg of the course had 
been completed, thus introducing manual 
control, which may or may not be a de¬ 
sirable feature. The editors have given this 
device considerable thought and suggest a 
full automatic electrical control of the rud¬ 
der during such *'z\g-zag" runs, leaving of 
course the manual control ahvays operative 
in the event that the course inight hove to 
be suddenly changed or when the automatic 
control might fail.] She continues on this 
course until seven and one-half minutes 
past 2 o’clock, when the minute-hand of 
the clock makes electrical contact with a 
bell which rings loudly, announcing that the 
time has come to change course again. 
(In the original scheme; in the revised 
plan shown in the diagram herewith the 
contact closed by the clock hand causes the 
proper relay to function, running the “port” 
or “starboard” rudder motor for a prede¬ 
termined time, sufficient to pull the rudder 
over sufficiently to start the new course.) 
The helm is now thrown over, and the ship 
is put on a course 45 degrees to starboard 
of the true course. This course is main¬ 
tained for ten minutes, when another elec¬ 
trical contact is made, the bell rings, and 
the ship is turned the necessary number of 
degrees to port until she is on a northern 
course, parallel with her true course. 

There are seven changes of course dur¬ 
ing the hour, at the end of which, the ship 
is back again on her true course. In this 
particular zig-zag a 12-knot ship loses two 
knots of distance in one hour, which rep¬ 
resents a loss of about fifty miles in the 
twenty-four hours; but it is better, surely, 
to lose fifty miles of distance than to lose 
the ship. 

The course herewith shown is a purely 
suppositious one. The navigator can plot 
any course he may desire in a few minutes’ 
time, and having done that, he has merely 
to shift the electrical contacts from hole to 
hole around the periphery' of the clock, in 
accordance with the zig-zag as plotted. 

The explanation given so far will un- 
doubtedy make clear the action of the “elec¬ 
trical zig-zag” course apparatus. Let us 
now consider one change of the course right 
straight thru to see just what happens. 

Suppose the “zig-zag” course is suddenly 
decided upon. The navigating officer 
throws in the proper switches to permit 
the automatic helmsman to take control of 
the ship’s rudder. The clock may be turned 

benefit by mentioning “The Electrical Experimenter'' tvhen uriting to odz-ertisers. 

October. 1917 



so tliat the hour hand with its attached con¬ 
tact is just on the hour. The first stationary 
contact is thus livened up, causing the rud¬ 
der motor to function, and the ship to take 
its first lap on the “zig-zag" course or 30 
to port. In order that the helm motor shall 
run just long enough to throw the rudder 


{ Continued from page 389; 
with the November issue we are going to 
print a monthly list of names of those 
young men who think sufficiently of their 
services to Uncle Sam as radio oper¬ 

This list will be termed ; 


At the end of this article you will find 
a blank to be signed by you. Pill it out at 
once and mail it today. There are no 
charges, no expenses. 

Sign the blank, showing that you are a 
good citizen and that yon are prepared to 
do your "bit” for your country. We pledge 
ourselves to publish every name sent in to 
us—even tho we have to run ten solid pages 
of names a month. 

You may never be called for service, but 
in the years to come you will look with 
satisfaction and pride upon the ''Radio Rail 
of Honor" containing your name, in mute 
testimony of your genuine patriotism. 

Now amateurs, all together : LONG LIVE 

to the proper course angle, the stationary 
clock contact could be made a certain length | 
or else a dash-pot time switch can be used j 
in the circuit to cut off the motor after the ! 
proper time has elapsed. 

But this is not all of the problem by any 
means. We can’t leave the helm thrown 
over, say 30^ to port, indefinitely, or. the 
vessel would turn a complete circle. We 
will have to use either an automatic time 
relay to close the opposite motor circuit 
and rectify the rudder to a position parallel 
with the ship’s keel, or better yet, rig up a 
special gyroscopic compass so that when 
the ship has turned and lined up on its 
new course, the compass will actuate a 
relay controlling the opposite helm motor 
and pull the rudder to its central position. 
The gyroscopic compass is rugged enough 
to stand this work, but it would not be 
necessary to fit any rubbing contacts to it. 

A Tesla relay would do tlie work, the relay 
current passing thru a spark, or the proper 
contacts could be closed by an inducti^ 
mechanism. The plans here shown include 
tell-tale lamp signals, which indicate the. 
course the ship is changing to. and also 
two distinct “zig-zag” course charts, each . 
good for one hour’s sailing. One course 
is the exact converse of the other, i. c.. the 
first lap of lYz minutes on the left-hand 
chart is run at 30® port; the corresponding 
lap on the right-hand chart is run at 30® 


Application for Membership in the 
Radio League of America 

THE UNDERSIGNED, a Radio Amateur, am the owner of a Wireless 
jl Station described in full in this application. My station has been in use 

since.. and I herewith desire to 

apply for membership in the RADIO LEAGUE OF AMERICA. I will abide 
by all the rules of the LEAGUE, and I particularly pledge my services as a 
Radio operator, or for Signal Corps duty to the United States Government 
when called upon. 

1 understand that this blank with my signature will be sent to the United 
States Government officials at Washington, who will make a record of my name. 

Witnesses to signature: Name... 

. City. 


. Date.191 

Description^ofl My Station and Apparatus 

Sending .. . . ... .... 


I can send approximately.words per minute. 

I can receive approximately.words per minute. 

Aly age is.years. 




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The electrical industries offer wonderful 
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The discovery and development of new 
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The International Correspondence Schools 
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Explain, wllhout obh^tlng me, how 1 can qualify for 
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October, 1917 









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{Continued from page 370) 
of the cable, and this of course is but a 
few ounces. Even the sudden jerk after 
releasing the bomb is not imparted to the 
vire—the reel takes it nearly all. 

Now, the observer thru his trench peri¬ 
scope watches the flight of the homb. His 
one hand rests on the switch which is con- 
nected to a thirty- or forty-volt storage 
battery, while the bomb-cable connects wdth 
the switch and the battery^ also. By merely 
throwing the switch, the man at the peri¬ 
scope can set off the distant bomb at the 
proper moment. WTiat this proper moment 
is depends of course upon circumstances as 
.veil as the will of the operator. 

And now we come to the point showing 
where this device is superior to the present 
homb. Suppose during a dark night we 
brow several hundred of these bombs in 
‘no man’s land’' (the strip of land between 
lur own and the enemy’s trench). They 
•nay rest peacefully here for days or months 
well hidden by plants or dirt. The fine 
ables running toward our own trench can 
hardly be seen. The enemy therefore is un¬ 
aware of the hidden bombs. It goes with- 
)ut saying that all the cables are connected 
^o one central point under supervision of 
me or more operators. If now the enemy 
wishes to raid our trench we can set off 
the entire string of bombs right under his 
feet, as he advances toward us. Such tac¬ 
tics are sure to demoralize the bravest 
troops, and the second advancing column 
will hesitate, not knowing if there is not 
mother set of bombs, which may go off at 
iny^ second. 

Of course, the electrically fired bomb 
would probably be used mostly to “bomb” 
•^he enemy’s trenches, exploding it after its 
^e«icent into the trench. And after the 
enemy becomes acquainted with this devilish 
device, no one will be fool enough to pick 
up such a bomb with an idea to hurl it back 
at the sender. For the sender, thru his 
periscope, would see it before it was two 
»eet above the enemy’s trench, when he 
■vould explode it of course, thereby almost 
■ertainly killing the man who attempted to 
hrow it back. 

Also, suppose that due to faulty throwing 
»he bomb does not reach the enemy trench. 
Is the bomb thereby' lost as is the case with 
ts present brethren? Indeed not! For we 
•ran pull it back by means of the cable, and 
throw it once more! 

Now let us turn from the murderous 
to the more humane. Instead of filling 
our bomb with a high explosive, let us fill 
it with chloroform. Our Fig. 2 illustrates 
such a bomb. It is composed of two hemis¬ 
pheres separated by a soft gasket. After 
artly' filling the bomb with chloroform, 
he remaining air is pumped out, thus leav- 
ng a vacuum. This will cause the hemis¬ 
pheres (working on the famous “Magde¬ 
burg Hemispheres” principle) to hold to- 
b^ether as if riveted. The two ends of the 
•lectric cable go to a fusible ping in the 
vail of the bomb which when melted by a 
’eated platinum wire allows either air or 
•hloroform to leave the bomb. Or other¬ 
wise a minute electrically fired charee of 
explosive will separate the two hemispheres, 
praying the trench with chloroform. If a 
uflicient number of such bombs are thrown 
nto a trench, the occupants will promptly 
'‘11 to sleen for some time to come. No, 
this idea is not half so ridiculous as it 
seems, and we may see it tried yet. 

if tlie “powers that be” do not approve 
f the chloroform bombs, they' may replace 
he narcotic with oil. In this way the en- 
ire trench of the enemy can be set on fire 
hen setting off the bombs. 

Probably quite a few more ideas will 
^^crrref^t themselves when the electrically' 
fired homb is tried out in actual warfare. 

You benefit tv tnentionino “The Electrical Ex p crimen ter “ when writing to advertisers. 

October, 1917 




(Co)iiitiucd from page 387) 
structors in the following subjects: 

Magnetism and Electricity. 

Alternating Currents. 

A. C. and D. C» Recording Instruments. 

Primary and secondary batteries. 

Motors, motor gcjierators and controlling 

Gas and oil engines. 

Primary and secondary circuits. 

Oscillating circuits. 

Transmitting and receiving sets. 

Naval service radio sets and operation. 

Wave meters and measurements. 

Radio regulations and fleet work. 

Instruction is also given in drill work, 
thereby fitting the radio operator for his 
future duties as petty officer. 

During the period of training, men will 
receive, in addition to their regular pay, 
an allowance of $1.25 per. day with which 
to subsist themselves. 

Upon being called to active service each 
man will receive a uniform gratuity of 

Upon completion of three months’ active 
service men may be e.xamined, and if found 
competent, will be confirmed in their rat¬ 
ing. After such confirmation in addition 
to their regular pay, they will receive an 
annual retainer pay, equal to two months’ 
pay of the corresponding rate in the Navy, 
same to be paid quarterly. 

Enrollment in the U. S. Naval Reserve 
Force is for a period of four years, but 
in times of peace, a man enrolled may be 
discharged upon application to the proper 

Now, fellow “Bugs”, here is an excel¬ 
lent chance to serve your country, at the 
same time enabling you to broaden your 
education, build up your physique, come in 
contact with real men doing real things, 
save money, get good wholesome food to 
eat, and free medical attention when you 
are sick. 

A chance to secure advancement in the 
Radio Profession, an invaluable experi¬ 
ence acquired thru coming in contact with 
up-to-date methods and most modern equip¬ 

On top of all tliis you secure an honor¬ 
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splendid reference at all times in civilian 

So its up to you. Radio Amateurs, and 
those desiring further information should 
present themselves to, or communicate with 
the Enrolling Officer, Building No. 13, Navy 
Yard, Brooklyn, New York. 


{Conihnted from page 381) 
noid, “F”. At “G”, at the upper end of 
the wooden lever “B”, is attached a cord 
which is led across and over the pulley 
“1” to the scale pan and weight “K”. With 
“A” just at the level of the pole and in¬ 
side the solenoid, this solenoid, with the 
battery which I used, will draw 15.8 grams 
two centimeters out of perpendicular. In¬ 
side, four centimeters from the pole, it will 
draw 25.8 grams—the additional weight be¬ 
ing placed at “K”—the same distance; an 
increase of power of si.vty-ihree percent. 
At seven centimeters within the solenoid 
it will draw 22.5 grams; an increase from 
the poles of forty-four percent. At the 
center of the solenoid the power varies 
but little from that at the poles. (This 
will be explained later.) If^ it were pos¬ 
sible to investigate the interior field after 
the insertion of an iron core, it would 
probably be found that the point of great¬ 
est lateral (outward) attraction is near the 
center of the magnet. 

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October, 1917 


are constantly writing me 
for new ideas protected by OWEN PATENTS. 
Send for my free literature and read their 

FRFF t finest patent books published! 73 

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Mschanical, Electrical & Chemical experts 



It is now possible to map completely the 
exterior and interior ‘'lines” or currents of 
a magnetic field; a thing never heretofore 
truthfully done. Those produced hereto¬ 
fore have been merely guesswork. Fig. 6 
shows such a mapt field. A,A, is the point 
of greatest compression. This point would 
also be the point of the greatest interior 
lateral attraction if it were not for the 
fact of the conflicting currents from the 
poles meeting at this point. B,B, on both 
sides of the magnet is the neutral line, or 
line of repulsion, the point of the outward 
flowing currents, corresponding to the 
greatest internal pressure. E,E. are the 
points of greatest relative lateral attrac¬ 
tion on the interior of the solenoid. The 
several lines C,C, are the reverse curve 
lines on the side of the magnet and the 
lines D,D, are the slightly eiirved or 
straight lines entering the magnet near the 
poles. In all of these the arrows indicate 
the direction in which the iron tends to 
move and consequently the direction of 
the force or current. It must be borne 
in mind that all of these lines have an¬ 
other motion, that is— a spiral motion, as 
has been shown, and that while the spiral 
lines or currents meet in the center of the 
magnet, the rotation of the spiral is con¬ 
tinuously in the same direction thruout 
the len^h of the magnetic field. 

These experiments, including the pro¬ 
duction of Magneto-graphs by means of a 
magnet, prove unquestionably the following 
negative facts: 

The “lines of force” in a magnetic field 
are not “lines of tension,” “mere lines of 
direction,” or “imaginary lines of direction 
like the lines of latitude and longitude on 
the earth.” It will be noted ^ that these 
expressions are quoted from high and ac¬ 
cepted authority. 

That the lines of force in a magnetic 
field 'are not continuous from the North to 
the South pole, that they do not “exist” 
from the North pole to the South pole, 

and that they do not “emerge” from the 
North pole, or that so far as the lines 
about the North pole are concerned they 
do not “pass to” or “enter” the South pole. 

The same experiments seem to prove be¬ 
yond controversy the following positive 

Currents surround and enter magnets 
and solenoids and make up the field of 
force surrounding them, and their effects 
are due to these currents. The word “cur¬ 
rents” is here used and will be continued 
to be used for the present without refer¬ 
ence to the matter which composes them: 
for, of course, currents must be composed 
of matter. This is done advisedly, and in 
due time the nature of the matter will 
be conclusively proven. There can be no 
question but that these are currents. A 
child seeing straws moving about will at 
once tell you that there is wind—currents 
—and indicate its direction. This is in con¬ 
formity with every known fact of physics 
as shown in liquids and gases. The fact 
is doubly confirmed by the Magneto-graphs. 
No one except a person seeking some mys¬ 
tic or mysterious cause instead of the plain 
and simple laws of nature, would question 
this or assert otherwise. Especially is this 
true when, as here, the motions are so 
many and so various, so complicated. No 
“line of force”, “line of direction”, “ten¬ 
sion”, or other mj'thical cause can account 
for the results shown in these experiments 
and especially for the production of Mag¬ 

The action of the electro-magnet, the 
permanent magnet, and the solenoid are 
exactly the same, their effects are the same, 
and are produced in the same manner, 
and they are governed by the same laws. 

These currents do not emerge from 
either pole of the magnet. They enter 
at the poles and at the sides of the magnet. 
They emerge from the center of the mag¬ 
net, to some extent at least, and if they 
do not cause a point of actual repulsion, 
they form a line of neutrality in the^ center 
of the magnetic field and from this neu¬ 
tral zone, as well as from other surround¬ 
ing points, they move toward the sides and 
poles of the magnet. Beginning at this 
neutral zone they move in opposite direc¬ 

Currents entering the poles of the mag¬ 
net meet at the center, or near the center. 

Currents, both inside and outside the 
magnet, while they move toward the center, 
are spiral and the motion is continuous, 
in the same direction, thruout the mag¬ 
netic field. The motion of these spiral 
currents is such that, viewed from above, 
the rotation is counter-clockwise over the 
North pole and clock-wise over the South 

The action of the magnet is not due to 
molecular arrangement. Molecular ar¬ 
rangement could in no wise produce the 
spiral motion nor affect a photographic 
plate. If the action of the magnet were 
due to molecular arrangement, there would 
be no attraction at the sides of the mag¬ 
net near the poles for the reason that, 
theoreticall}', the molecules in the ‘body of 
the magnet neutralize each other and there 
would be no attraction. Moreover, when 
the iron core is removed the action con¬ 
tinues, being only less in degree, due to 
the magnetic conductivity of the iron, and 
there are no molecules to arrange. 

Next will be taken up the nature and 
cause of these currents, the “field of force” 
or the magnetic field about a eharged wire, 
and the logical accounting for the forma¬ 
tion of a magnet and the logical explana¬ 
tion of the several phenomena of magne¬ 
tism. This will include Magneto-graphs 
produced by a charged zvire. 









History will repeat itself in the preseDt War. The greatest victories will 
be won, pot through overpoweriag uumbers. but through tho surprises 
wrought hy inveutioo. LiXo and property will be saved for the Nations by 
invoDtioDS. Tlia Government is ready to experiment with and carefully 
consider any inventions which will aid in wnming and ending the War 
The Special War Bulletin just off the press will give you a good idea of 
what is needed. We will send it to you free of charge. l>ocated in Wash- [ 
ingtoD, we are in close touch with tlie proper Government Officials who 
; should be approached with inventions for use in War time, and we will | 
’ .advise you fully how the disclosure should be sent. 

Our cooperation with an inventor is. First, to help him establish his 
rights before sending a sketch, drawing or model to any attorney; Second, 

In give a frank opinion whether It will pay to patent his idea, based upon 
our extensive knowiedge of the patent laws, manufacturers* wants and 
facilities: Third, to obtain for him on reasonable terms, a patent that abso¬ 
lutely protects; and. Fourth, advise and assist him in making the invention 
a source of profit by outright sale, territorial grants, obtaining royalty, or 
the Independent manufacture of the invention. 

.\11 matters aro held strictly confidential, and personal services are as¬ 
sured by our Service Guarantee Contract. References; 2nd National Bank. I- 
Washington. D. C ; .Tohn P. Both Packing Co,, (incinnati. Ohio; Home . H 
Savings Bank. Washington, D. (\ ; DuskU Mop Co., Paducah. Ken. ' 
Before disclosing the invention to anyone, sign, witness and a ** 
deposit in our fireproof safe, the form "Evidence of Conception** y 

and establish your rights. A completed sample form in our ^ 

book shows you clearly how to protect your hivention. All 
nre free. Just ask for them on a post card or simply iiiaU 
<-oupou below. 





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Send me free bonk. ‘•Inventions-Patenting and Promot¬ 
ing/' Special War Bulletin, and blank form "Evldeuce of 

Name . I« 


i'on benefit by mentioning ‘*Thc Electricot Experimenter** when writing to advertisers. 

October, 1917 



Edited by H. GERNSBACK 

In this Department we publish such matter as is of interest to inventors and 
particularly to those who are in doubt as to certain Patent Phases. Regular inquiries 
addrest to “Patent Advice“ cannot be answered by mail free of charge. Such inquiries 
are publisht here for the benefit of all readers. If the idea is thought to be of im¬ 
portance, we make it a rule not to divulge details, in order to protect the inventor as 
far as it is possible to do so. 

Should advice be desired by mail a nominal charge of $1.00 is made for each 
question. Sketches and descriptions must be clear and explicit. Only one side of 
sheet should be written on. 


Send Skf(th or Model of Toui loTeolioa for 
Free Opinion as to Palenlabilily 

C‘« t fi icate of Patenlabil 
is Eviticnce of C i>nceiHion 
your ijivcntioii and may 

f >ur 



('redi* System enabl 
file your api^lication for Pat 
.am! proceed without delay. Ev 
case rcceive<i personal attention 
nnc or both members nf ihe ft 
pB*en*» we wxnire ndverti'^nl our 
pen*® in /■’opiiiaf' itfa(|<xnr<i 

Write today foi Free copy of lOl-paje book 
''Howto Obtain a Patent and What to InrenC' 


Talhert & Parker, Palenl Lavt 7 ers, 
4287 Talbert Bldg., Washington, D.C. 


n 01 f m 
hrm r 



(172.) Harry Abrams of New York, N. 
V., thinks he has a new means of producing 
electricity by means of ordinary sunlight. 
The idea is to use apparatus similar to 
the Crookes radiometer. By placing these 
Crookes devices in a certain electrical field, 
he has observed that electrical current can 
be generated. He wants to know if this 
idea is practical and also patentable. 

A. We have strong doubts as to the 
practicability of an idea of this kind. It 
seems that the power that can be obtained 
from each one of these radiometers would 
be so infinitesimally small, that it really 
could not be termed power; but at best 
would only be faint impulses. We doubt 
if the idea has any commercial possibili¬ 


(173.) Frank C. Stanton of San Fran¬ 
cisco, Cal., has submitted to us an elaborate 
illustration of a gyroscopic motor car, 
showing an automobile designed to run on 
two wheels, one behind the other. He 
wishes to know if he can obtain a patent 
on this device without litigation. 

A. Brennan of England has experi¬ 
mented with a car of this kind, having it 
run over a small, thin cable. We doubt 
if you can obtain a patent that would be 
of any value to you, in ^view of the fact 
that not alone Brennan, but also other 
workers as well have worked along these 
same lines for quite some time past. Our 
correspondent also submits illustration for 
a field wireless set which can be carried 
complete by one man, and he wishes to 
know if the idea is feasible and practical. 

Nothing new is shown in the illustration 
or description, and while the disposition 
does show several novel points, we doubt 
very much if the novelty is sufficient to 
warrant a patent. 

Our correspondent wants to know if one 
has to be a subscriber to The Electrical 
Experimenter in order to contribute to any 
of the various departments. 

Anyone can contribute to any of the 
departments of The Electrical Experi¬ 
menter, and one need not be a subscriber 
in order to send any contributions or 
participate in any of the prize contests 
which we conduct from time to time. 


(174.) Paul William Dorst of New Al¬ 
bany, Ind., submits to us an automatic step 
to be attached to hollow steel flag-poles, 
the idea being tliat the steps are folded 
back ordinarily, so that when climbing the 
pole one step after the other is released 
automatically as soon as one of the steps 
is deprest. 

A. This is a capital idea, and we have 
not seen anything quite like it, and are cer¬ 
tain that it can be patented. We also think 
that there should be a good field for a 

device of this kind, particularly for steel 
flag-poles on tall buildings. 


(175.) H. S. Moody of Edmonton, Alta., 
has an idea to make a small condenser in 
a certain manner by using certain dry 
mounting tissues, etc. Several other means 
are shown to hold metal foils which are 
secured by melting the tissue. He wishes 
to know if an idea of this kind is patent- 

A. Without making a thoro search in 
the patent^ office, we are unable to tell 
whether this idea is of sufficient originality 
to warrant patenting. We would advise to 
have a patent attorney make search with 
a view to ascertaining what has been done 
in the same field before. The idea seems 
quite clever. 


upon electrical *p- 
pUuicea are In de¬ 
mand : manufacturers 
are writing for patenta 
secured through me. 
Send sketch or model for adrice; I aaalat you market 
your ioventioD. Prompt penonal service. Booklet and 
advice free. 

J R If FI I Y 740 0. Woodward Bid?. 




Books and Advice Free 

If you waol to sell your pateol.take It out through my 

WATSON E. COLEMAN, Patent Lawyer 

624 F. Street, N. W. Washington. D. C- 



Ktlenl Firm 
* Hie World 


Before sending your invention to any attorney or 
manufacturer or disclosing your invention, write 
for onr free blank form PROOF OF OONC EITION 
in order to protect your invention and secure your 
rights. This should be signed and witnessed and re¬ 
turned to us, together with a model or sketch and de¬ 
scription of your invention, and we will give a FREE 
OPINION as to the patentability of the inveulioo. If we 
report the invention patentable we will furnish a Certificate 
OoirT^i A Patentability. 

OilLi/IL This Certificate of Patentability, together with our blank form 
y-v c ET e n Proof of Conception will protect the Inventor and serve as proof _ 

n r t Iv Invention until the case can he filed In the U. S. Patent Victor J. Evans. 

OBTAINING ASSISTANCETOR INVENTORS—Our certificate is of great as¬ 
sistance to inventors who require financial aid to obtain patents 


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10 any address. Send for these books—the finest publications ever issued for free distribution. 


Our Illustrated eighty-page Guide Book la a Book Contains a valuable list of Invfnlloni wanted and 

of reference for inventors and contains 100 mechan¬ 
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to invent for profit. 

suggestions concerning profitable fields of inventions; 
also information regarding prizes offered for Inven. 
tlon» amounting to ONE IMILLION DOLLARS 


Contains requests from manufacnirers, mail order houses and rronmters for 
patent.s secured by us and suggestions a.s to New Ideas they wish to i)urchase. 
We place our clients in touch with capital free of charge We have recently 
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Shows the value of Trada-Marka and information regard¬ 
ing unfair competition 

We advertise Our Clients’ Inventions Free in a list of Sunday news¬ 
papers, m inanufacturer.s’ journals and in World's Prugros .‘Sample 
Copy Frt*e. We save you time and money in securing i atenta. After 
Uie paieiu Is grautod wo assist you to sell your patent. 





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Main Offices; 779 Ninth Street, N.W., Washington, D. C. 

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C O. 

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You benefit by mentioning '^The Electrical Experimenter** when noting to advertisers. 



October, 1917 

1 was Terr much pleased with the aeat and 
compact looks of the "RADIOTONE." I have 
not seen one buzzer that can beat it for twice 
or THREE TIMES THE TRICE. I use it for 
hnding tlie sensitive part of the mineral in my 
cryslal delecter and for learning to receive mes¬ 
sages when connected with one or more receivers, 
and a telegraph key to break the circuiL I also 
wish to say that I think that any one who in¬ 
vests t)0c in a ••RADIOTOXE*' will he better 
pleased with the results in the short as well as 
Jong run than any other buzzer that costs twice 
the price. 

I'RIVATE T. TE RE^n•BL. 4tli Co.. C. A. C. 

U. S. ^UtMY. Ft. Rosecrans, Calif. 

I wish to say that your "RADIOTO>^'' Buz¬ 
zer works better than I ever thought it would, 
and 1 don't think there is a BETTER BUZZER 
tLN THE aL\RKET. It also gives a very classy 
appearance to any’ wireless outfit. It cannot he 
praised loo highly. 


13 Ten Broeck SL, Albany. N. Y. 

I have given your “RAl UmTONE" Buzzer a 
thoro test and find it to give \ ERY GOOD SAT¬ 
ISFACTION. Also that 1 am very much pleased 
with it and that it comes up to my expectations. 
1 would, recommend it to all leazners as a very 
good Buzzer. In case I have any more orders 
I will extend them to you. 


U. S. S. UT-VH. Box E. care of T. M., X. Y. 

I wish to say^ that your “R-VDIOTOXE" Buz¬ 
zer i.s the only* test bnzzer that I have seen in 
which I can find XO fault whatever. I re¬ 
ceived it in good condition and it is that war 
IT SEVER.iL FEET. I am using it on a code 
practicing set. It has the best tone of any 
buzzer that I have seen 


Care of .T. n Tate Electric Co. 

IIS Main St,, Bedford, Va. 

I have given the "R.XDIOTOXTl" Buzzer 
which I have received from the E. I Co, a 
thorn test and find it satisfactory in all re- 
specl.s. 1 also used otlier buzzers. Tmt the 
■ R.MnOTOXiy IS the best TII.VT 1 HAVE 
TIONS. The other goods that 1 received are also 


Muir. Pa. 

T arn very pleased to say that I am satisfied 
wifli the re.sults obtained from the "RVOlo- 
TO\'E“ Bn-zer It rives a reaPv WONDER- 

Lavallette. X*. J. 


231 Fulton Street New York City 


The “RADIOTONE” Buzzer which the E. L Co. sent me some 
time ago has been thoroly tested nut In my Laboratory, and I 
am very pleased to give you my opinion concerning Its per* 

The tone and freguency of the Instrument Is TRULY A MOST 
WONDERFUL and perfect reproduction of a MUSICAL WIRE¬ 
LESS NOTE and when used In connection with a wireless re¬ 
ceiver it would be most difficult to distinguish Its rich tone from 
that of a real wireless station with FIVE HUNDRED CYCLES 
In the primary circuit. One of the most commendable teatures 
that tha buzzer possesses Is that of being capable ot standing up 
under continuous service WITHOUT THE ANNOYING ‘‘STICK¬ 
ING” effect that has been so characteristic of other buzzers that 
I have had occasion to test. In conclusion 1 can say that both 
In performance and appearance the ‘‘RAOIOTONE*’ Is truly a 
YATES. 815 Niagara Ave„ Niagara Falls. N. Y. 

I have thoroly tested your •‘R.\D10T0X"E” 
Buzzer, which I received a few days ago, ami 
find that it is very* efficient in all respects, Ii 
is all that you claim it to be. The tone is so 
soft that it cannot be heard imless tlie ear is 
placed a few inches froai the Instrument. This 
makes it very desirable for testing detectors. I 
FOR LEARNING THE CODE, since the sig¬ 
nals soimd just like a high power wireless sta¬ 
tion. Everyone who has a wireless station or 
who wishes to learn the code should have a 

S27-Ilth Ave.. N,, Minneapolis, Mina. 

I received my •'RADIOTOXE*' Buzzer a few 
days ago. and have tried it out in a number of 
waj’S. It is exactly like you describe it. and one 
of the biggest advantages of it is that the sound 
right in the receivers, it is by far the best buz¬ 
zer I have seen on the market. It has also a 
very heantiful appearence. and has one of the 
any buzzer that I have yet come across. Tiiank- 
ing you again for your wonderful buzzer, 1 am. 
Yours very truly. 

f)00. Harrison St,, Lynchburg. Va. 


Your '•RADIOTONE” Ruzzer certainly came 
up to all my expwtations. Its tone is exactly 
like that heard in a rejgular wireless phone. It 
Is not alVected by high altitude nor damp 
weather. It is as beautiful an instrument as one 
could wish to see. IT IS SILENT. That is 
the most important of all in the work for which 
I use it. 11 produces a clearer and higher- 
pilcbed lone on less current than a buzzer of 
any other make that I have tried. IT HAS 
instantly to the application of current since I 
have had it. I wish you and the E. I. Co. 
every success and I will do everything in mv 
power to help you as von are a PROMPT AND 

r .M. McBURNEY. 

Fort Bayard. N. Mex. 

No, HK 1800 

The ‘‘Electro’’ Radiotone 


The RADIOTOXE is X*OT a mere test buzzer, 
it is inlinitely more. Mr. H. Gernsbaek who de- 
siKiied this instrument labored incessantly to 
produce an instrument which would imitate the 
sound of a IukIi power Wireless station as heard 
in a set of phones. This actually been 
achieved in the KADIOTOX'E. This instrument 
gives a wonderful hiph pitched MUSICAL NOTE 
in the receivers, impossible to obtain with the 
ordinary test buzzer. The RADIOTOXE is built 
along entirely new lines; it is NOT an ordinary 
[bnzzer, recnnstructed in some manner. The 
I RADIOTOXE has a single fine steel reed vihrat- 
inj; at a remarkably high speed, adjusted to its 
most efficient frequency at the factory. Hard 
silver contacts are used to make tiie instrumeut 
last practically forever. 

Yes, the RADIOTOXE is SILENT. In fact, 
it is so silent that you must place your ear on 
lop of it to hear its beautiful musical note. 

You will be astounded at the wonderfully clear, 
500 cycle note, sounding sharply in your re¬ 
ceivers. when operated on one dry cell. To learn 
the codes, there is absolutely nothing like it. 
With the radiotone, a key and one dry cell and 
AXY telephone, a fine learner's set is had. Two 
or more such sets in series will afford no end of 
pleasure for intercommunication work. Particu¬ 
larly now that we cannot use our Wireless sets, 
the Radiotone is already in wonderful demand. 
■VH tlie interesting things as described with our 
CODOPHONE (sec our big ad on page 353, 
this issue), can he performed with the Radio- 
tone, a key, a dry cell and a phone. 

Radiotone as described.each 

I received your "RADIOTONE” on June 20lh, 
and tested it thoroly. and found it has the 
All -Lmateurs should purchase one of these 
*'RADIOTONES" if possible, and do self-prac- 
tise during the war. I hope all Amateurs, who 
purchase one of these "R.VDIOTONES” will find 
it as great a help to them as I have. 

Yours truly. GEO. T.INAKA, 

AMATElTt 6 ATQ. San Francisco. Cal. 

After testing the •'RADIOTONE*' I am 
pleased to say that it is the best toned buzzer 
on the market. The main thing is that IT 
DOES NOT STICK as so many others do. even 
among the high priced buzzers, when prac¬ 
tising. I am using it with Omnigraph trans¬ 
mitter. 2 M.F. Condenser. 75 Ohm phone and 
small resistance shunt across phone. With the 
aid of battery rheostat and shunt resistance, I 

S06 S. Mtlton Ave., Baltimore, Md. 

I am entirely satisfied with the "R.VDIO- 
TONF:” Buzzer which 1 bought from you. It 
works fine, being BETTER THAN 1 EXPECTED 
didn’t think that it would be verj’ good at 
the low price, but it is all right. It appeals 
to Tue mostly because of ITS QUICK RE¬ 
SPONSE to the opening and cln.sing of the 
key. .JOHN B. MOORE. 

Delaware Co,, DownsvilJe. 

I am (Me.ased to say that after testing it out 
in a student's buzzer set. it comes up to my 
best e.xpectatioiis. H. D. STRAUGHN. 

Ripley, Okla. 

Am in possession of one of your "R.XDIO- 
TO.VF;** test buzzers and wish to say that 1 
could not have expected a more silent iostru- 
ment, as well as the EXACT TO.NE OF A 

, S. W. DE.LRING, 

R.2, Covington, Tenn. 

Tt gives me great pleasure to recommend your 
"R.VDIO'rO.NE" lest buzzer. 1 find it very 
sensitive and responsive. .\LW.\YS E.MITTIXG 
tlie best feature of all is ITS SOUXD-PROOF 

94 Gladstone Ave., St. Thomas. Ont. 

I wish to say that I have given your '*R.\D10- 
TONE*' Ituzzer a thorough testing and find it 
stands up heantffully under the conditions. Con¬ 
nected to a 75 ohm phone and a No. IftOlO 
Junior Fixed Condenser per diagram in your 
catalogue, it makes an ideal practise set. the 
note of which can H.VRDIA' BE DISTIN- 

R R. .No. 1. Indian River, Ontario. Can. 


Shipping Weight I lb Don't forget postage, 


I Imve used vour *'R.\PIOTONE'' Buzzer, 
and find it THE BEST EVER USED. I find 
it very useful for a layman to learn the code 
quickly. I would recommend it to any one 
interested in wireless. 


1722 Putnam Ave., Brooklyn. N. Y. 

T have had the opportunity of making prac¬ 
tical tests with one of your **R.LDIOTONH** 
HU7.ZERS. and 1 feel justified in making the 
following stnleinonts concerning it: 

1. 11 Is handsome in appearance. 

2. It is practically noiseless in operation. 

3. It gives a clear note of ( ON'ST.LNT FRE¬ 


4. It is equal in performance to other buzze*>s 



I h.nve been perfectly satisfied with the 
“RADIOTONE” and I will be glad to recooi- 
incnd it to anyone. E. K. SNYTIER, 

717 Lake Boulevard. St. Joseph, Mich. 

I. Co,, 231 Fultorv St., New York City, N. Y, 

On your absolute guarantee that .vour ’'R.tDIOTONE'' works exactly as de¬ 
scribed by you. I I'nclose herewith PO ccnls plus . ceiits for 

postage for une Instrument. You guarantee to rcfuml llPs amount to me If 1 
arn not entirely plo.ised. providing I return the "U.tDlOTONE” within 3 daVs 
after its receipt. VKS 

I also eneb'se NO fi cents postage for your 2(b)-pQgu Electrical Cyclo¬ 
pedia. wltli 600 llluslrations, and .7(10 in.strumeni>. etc. 

Name . 

Address ... 

10-17 riiy . 

* Fig. 1. 

t An a radio min- 
H era! tenter. 

I " Fig. 2. 

With ohm 
^hone and horn 
for practicing 

■ code. 

„ Fig. 3. 

• For intercom¬ 
Works aevrrsl 
- mires on 2 dry 
ra cells. 

Yon benefit by tncHttoning *"The Electrical Experimenter” u'hen writing to advertisers. 

October, 1917 




(Continued from page 373) 
Sinusoidal Machines 

One of the most radical new develop¬ 

ments in electrical therapeutics was shown 
in the form of a Morse Sinusoidal Wave 
Generator. The machine delivers a current 
of 21,000 alternations or 42,000 impulses 
per minute and is designed on what is 
knoNvn as the Kennclly design, the prin¬ 
ciple being a circular layer of spools com¬ 
posed of two separate coils, an inner one 
with eight layers of fine wire, and an outer 
one of two layers of coarse wire, the inner 
coil being connected in a series and consti¬ 
tuting a secondary coil, while the outer 
coil, also connected in a series, forms the 
primary coil of tlie apparatus. A direct 
current is supplied to the primary coil and 
to the armature, which is composed of 
laminated iron. When the armature is 
made to revolve the primary coils, having 
a current circulating thru them, mag¬ 
netizes the field magnets. The magnetic 
lines of force thus produced remain sta¬ 
tionary in the field as long as the armature 
is stationary, but as soon as the armature 
rotates the lines of force shift from one 
side of the magnetic field to the other and 
cut the current in the wires of the sec¬ 
ondary coil, first one side and then the 

Cathode. Air Cooling Vanes Are Placed on 
the Anode. 

other, which produces a Sinusoidal current 
in the secondary coil. 

In the apparatus shown, Fig. 3, the pri¬ 
mary coil and secondary coil are conical in 

shape, one moving within the other, this . 
being done by a set of cams, the shape of ' 
the cam regiilaling the type of wave which 
will be sent into the patient’s circuit, and a 
separate rheostat controls the strength of - 
this current. ] 

Llghc 'Hierapy I 

For the treatment of skin I a quartz mercury arc 
lanif) was shown which gave ^ 
off very powerful radiations, ! 
the radiations being so intense i 
that ihc darkest kind of tinted 
glasses were loaned to the ob¬ 
server before he was allowed 
to l(»ok at the light. From a 
lamp of this kind a typical case 
of sunburn could be produced 
in a few minutes time. (See 
Fig. 4.) 


A valuable Anesthetizing 
Outfit was shown (see Fig. 5), 
operated l)y a small electric 
motor of special design for use 
in operations of the month 
and head. 

An interesting Recording Instrument 
was shown for obtaining the tem¬ 
perature within the stomach known as 
iutrogastric temperature, valuable in 
checking up the gastric response to stimu¬ 
lus, showing the action of different foods, 
both hot and cold, practically in degrees 
upon the scale of the instrument. 

For the man with a microscope there 
were several new devices, such as a special 
light for illuminating the stage of a micro¬ 
scope, and one exhibit showed an electri¬ 
cally heated warm stage for the microscope 
for use in examining different bacteria and j 
micro-organisms which only remain alive 
in warm temperatures (blood heat). 

An Electric Incubator for use in connec¬ 
tion with a microscope was exhibited, which 
can also be used in connection with the 
development of special animal organisms 
and bacteria so that they can be cultivated 
directly under the microscope. 


(Continued from page 383) • I 

it for the protection of their soldiers and j 
horses campaigning at this time in the i 
colonics of Toncken, Asia, and as it had 
protected the head against the violent ac¬ 
tion of the ultra violet rays it was quite 

At this time England also tried this pro- i 
tection against the ultra violet rays and as I 
an experiment, an under officer of the Eng¬ 
lish army was completely clothed in gar¬ 
ments which had been previously treated 
to withstand the ultra violet rays. It was ■ 
found that he was able to stay in the sun 
of midsummer for hours, without feeling 
any disturbance or inconv’enience in any 
way. Upon this and other experiments the 
English Government adopted this method 
for the protection of their Indian troops 
against the ravages of tropical sunlight. 


Fifteen United States Marines have been 
added to the detail which has been guard¬ 
ing the wireless station at Sa>wille. There 
are now sixty-five men from the Marine 
Corps at the station and it is said that 
about twenty-five more will arrive shortly 
to augment the force. Ensign W'. R. Smith, 
U. S. X. R., is in command. 

Tlie entire acreage belonging to the At¬ 
lantic Communication Company, which is in 
charge of tlic plant, is being cleaned up. 
Much of its area was wooded and afforded 

Fig. 3. The Latest Pattern Sinusoidal Generator Which 
Yields Currents of Any Desired Wave Form. Special 
Cams as Shown Below, Control This Factor and Can be 
Interchanged Instantly. 

r.uiCt n M >Uel <,/ fhia f'urtiMt 
tary Tractor Mfd in thr ( .s. Army 

Build A 

Model War Aeroplane! 

IVii raayl With **n>KAL** Acrtirate Sr«l« i>r«wlni;a and 
Instrurtionii you can build «3-fuol Mtxb'l Aeroplane that look* 
hkr a re*l one and that will n*e frota tbe erround by lu <n*a 
fly 50 IfW feet. It • yreataummer •port, and you 
ran learn a lot about Acroplanca and how they lly. Send for 


the UrawinKA and InairueUona for thi 

Curtiss Military Tractor 
Bleriot Monoplane 

Niraport MoDoplace cach 

Taube M onoplane for * i. 75 > 

*‘IDKAL‘’ Aeroplane Conatruebon Outfita, 
eont^ninjr all part* and material needed to 
build these Aerapkanea. are aold by l^eadiny 
Tov. Sportiny Gooda and D4manment Store*. 
Ask your dealer for ‘'IDEAL ’ Aeroplane 
Construction Oulfita. 

Send 5c For This Catalogue 

Tell* about Model Aeroplanes and what you 
peed to build them with. 4>i payea of useful 
Information—send 6 cent* for it nybt away, 

76*^2 West Broadway, New York 

you want to bolld. 

Wrigbl Bfpbne 
Csrtiss HydropUoe 
Callus FlyiBj Boat 
Cedi Peofi Racer 



Driver Agents Wanted 

Drive ftnd demonstrate the Bush Car. Pay for It outer 

voor commisaianaooaaiea. My bhl^ 

..... mentaare DrOfnot. 

bark. 1918 roodela 

Write at once for 
my 4.'$-pair e cata¬ 
log and all pmrtic- 
olars. Address J. 

_ _ H. Booh. Brea. 

Detco lenltlon-Clecl. Ste. & Lte. I>«pt. 1041 » 

SeSU mOIUU CU31PA>Y. Baab Teaple* CtUca^D, ininQla 


For shop, factor>% 
garage and home 
—many high class 
tools attractively priced in our Odds and 
Ends pa7nphlet which is mailed free on re¬ 
quest by 

Montgomery & Co., Inc., 105 Fulton St., N. Y. Gty 

Feldman “Geyser” 
Electric Water Heater 

Instantaneous Hot Water 


1514 Times Bldg. New York City 

I—Edison Says:— 

**t hove watched the prog- 
re s a of the International 
Correspondence School* 
almost from the begiooing. 
To me their rapid gromth U 
easily understood because I 
realize the practical Vo 1 u e 
that is bock of it ond know 
something, too, of the suc¬ 
cess attained by many om- 
bitious mco who hove taken 
I. C. S. courses.” 

Edison knows what stuff men are made of 
who use iheir spare hours to train themselves 
for the biizirer jobs ahead. And he knows 
what the International Correspondence 
Schools will do for the man with the grit to 
say, 'T will.” ' 

All men who have made their mark in the 
world improved their spare lime. Didn’t 
Edison himself stay up half the nitjht to read 
every cet-at-able book on electricity? You, 
too, can possess power, money and happiness 
if you'll only make the start. With I. C. S. 
help the way is easy. 

Put it up to us. without payincor promisinu 
—just mark and mail the coupon and find out 

_ . TCAR OUT Hcne — WWH 


Bxpluin fully about your 
Hi l^rlrlraJ I nclurrrlnc 
llt-ebanlral I nirlurrrlnc 
[^Mechanical Drolling 
] Civil Engineering 

!S1alln»iar» |■.t<tri***‘rrl»g 

.Mining Engineering 
.\rchitcctu re 
Xrrbllprtural Uratllnc 

SCHCOLS, Boi 5 3 5 8, Scranton, Pa. 

Course in the subject marked X: 

3 ^ ilM I KTI^IXI 
, Bookkeeping 
1 Civil Service 
JKt. Mall 



I'pu benefit by mentioning '*The Electrieal Ext'crimenter*' uhen xiriting to advertisers. 



October, 1917 




For Boys 



» 6 ^ 

For producing current for in¬ 
ductance coils, re-charging 
storage batteries, elec¬ 
troplating and hun¬ 
dreds of other uses. 

Well constructed 
ally smooth running 
and highly efficient. A 
good, strong, durable 

lasist oo your dealer shnwiog you the KNAPP lioc 
—KNAPP goods are best. If your dealer cannot 
supply you, order direct. Send for FREE illustrated 
catalogue showing a complete line of Electrical 
Moto'’! and Novelties ranging in orice from,10c up. 


.523 West Slat.Street, N. Y. City 


Some Stetes b&ve been. T^iee enougn to insist upon a 
medical examlnaUon of the two cootracting parties to a 
marriage before a Ucease is i&sue<L Through the adop' 
tloQ of B law whereby the phyeically unfit were barred 
from marriage in every State in the Uoioo. there would 
indeed be a relatively amaU percentage of the popula- 
tioQ that would measure up to the standard. 

doomed to go through life alone, without the joys that 
go hand in band with a loving wife and healthy chU- 
drenf Our first duty is to posterity. We are not put 
here by an aU-wlse Providence merely to live out our 
Uvea, and then go out lihe a snufied candle. We are 
entrusted with the sacred duty of perpetuating the race. 
LIKE BEGETS LIKE: A man who is torn and rack^ 
by Physical ailments and excesses of 
aU kinds wiU some day see these tr&ita 
in bla children. Oo the other hand 
the stroQg, virile man. who jealously 
safeguards his body and his health, 
wlU some day revd in the algbt of 
offspring that are a picture of joyous, 
bubbling health. 

The sweetest, purest, dearest girl in 
the whole world whom you would call 
wife. Is your body clean? Do you 
realize the terrible conseQueoces of 
the follies that are wrecking your 
body? Bemeniber then that STRONG. 
FORTISM will restore to you the vi¬ 
tality of MANHOOD. 

I have prepared a little book, “Intelligence 
'? and Health Culture,'* which read by everyone aafficiently Inter* 
ested m themselves to wish for the beat in 
life. It points the way to better health, a 
^aner. happier life, and a splendid physiqae. 
Three 2;CenI stamps will pay for mailing the 
book. Send for it NOW. 

U0NU SlRO.'lGfORI, Ussier sf Physical Collore 

276 Park Building Newark, N. J. 

a Monti 

^ The master- 
piece of watch 

\\ ed to the eecond, positions, tem- 
^perature and isochronism. En¬ 
cased at factory into your choice 
^of the expuisite oew watch cases, 

21 jewel 

2!?^ Watch sent oo simple request, 

the same price even the wholesale jeweler must pay 

Write Today for Free Watch Book 

See handsome color illustrations of all the newest 
designs in watches that you have to choose from. 
Your name and addt^ on a postcard is enough. 
Get this offer while it lasts. Write today. ^ 

Jorlingt£n Warch C^^ 19lh & MarshairBN. Chiaco 



Of This 

Built by & boy from Junior parts fur- 
Dlshed by us. Any boy can build this 
car. Parts very cheap. Send 28 
cents for blue prints and price liat 
of parts showing how to build this 
speedy litUe car. 


After working for many months to per¬ 
fect a new type of mine, electrically con¬ 
trolled by means of a powerful wireless 
apparatus located at a distance from the 
mine itself, a device which would enable 
one submarine to destroy another, it was 
learned recently that Dr. J. B. Whitehead, 
of the Johns Hopkins University, had 
brought his labors to a successful termina¬ 

While Doctor Whitehead refuses to com¬ 
ment on this new invention, it is learned 
that by means of a powerful electric bat¬ 
tery the new style of mine can be directed 
upon whatever course its operator may de¬ 
sire and can be exploded by simply press¬ 
ing a button, the wireless waves being em¬ 
ployed both in directing it and in its 

The advantage that such a mine will have 
over the ordinary torpedo used by the sub- 
rnarine is the impossibility of failure to 
either miss the target or its non-explosion 
after the target is struck. By this method 
Doctor W hitehead has solved the problem 
of destroying submarines by submarines. 
In connection with this is a report that an 
instrument has been perfected to locate 
positions and distances of the submarine to 

be attacked. --- 


{Continued from page 372) 

The invention of this new slow speed 
design at once eliminates the gear troubles 
which all others who have attempted to 
utilize wind-power to drive d^'namos have 
had to empio}*. It also makes it possible 
to effect, by magnetic leakage in the ma¬ 
chine itself, its own regulation, and elimi¬ 
nating the use of auxiliary apparatus. 

A boy sixteen years old can turn a 
crank fitted on to the wind-motor axle, 
when the machine is on the ground, and 
generate sufficient current to magnetize the 
dynamo fields and to light to full brilliancy 
three 16-candle-power lights for a period of 
twenty minutes at a time. 

The axles, differential gearing and bear¬ 
ings are contained in a hollow steel hous¬ 
ing, the same as a motor car rear axle, and 
this housing is pumped full of gear grease. 
Several machines are on record that have 
not been re-greased for two years at a time. 

The drawing shows that the automatic 
cut-out and cut-in for the battery is a 
mechanical ball governor, but this cut-out 
has been substituted by an electro-magnetic 
cut-out and cut-in. The electro-magnetic 
cut-out simplified the plant and is located 
on the switch-board. W^ith an average 
wind pressure of ten miles per hour for 
ten hours per day the larger plant has in 
practise charged a 25 volt battery with 90 
A.H. per days, and has maintained a daily 
discharge for 8 months of 75 A.H. per day. 



MaUed upoQ receipt of 8c in atAmpa 
or coin which may be deducted on 
first dollar purchase. Catalog con- 
taine 160 pages of wireless iDstru- 
ments end 140 pages of electrical 
supplies. No bigger or better values 
are obistnable elsewhere. We have 
a complete stock of everything listed 
In this catalog. Wireless orders 
prompUy filled. 

230*232 Superior St. Toledo. Ohio 


The Marconi station at Bandoeng, East 
Indies, has succeeded in establishing com¬ 
munication with America, Madrid and Ber¬ 
lin, according to The Batavia Nieuwsblad. 
Presumably this refers only to the reception 
of messages sent out from those parts of 
the world. Experiments are being made at 
Bandoeng with a view to the ultimate estab¬ 
lishment of regular wireless communication 
with the mother country, Holland, and a 
300 horsepower motor has enabled the oper¬ 
ators to secure the promising result re¬ 


{Continued from page 371) 
ing trick of the electrical conjurer known 
as “The Human Dynamo." The lecturer's 
assistant lights a candle from a stream of 
water. The experiment is easily performed 
by taking the high-frequency current up 
thru the legs. A piece of wire here and 
there often helps out the lecturer and pre¬ 
vents him from getting unpleasant shocks. 
If the current is of sufficiently high fre¬ 
quency no trouble will be experienced in 
passing it right thru the body. But—don't 
try letting the current jump to or from the 
skin or you will rapidly lose your sang 
froid. Arrange matters so that the cur¬ 
rent jumps to or from a piece of metal 
in some way. And your conscience need 
not trouble you, either, for the audience is 
not being humbugged. The current actually 
does pass //in< your body, just the same. 
It's simply a case of knowing how to handle 
the current. 

The three lower illustrations are of Mr. 
Ford in a few more of his electrical roles. 
At the left he lights fire balls by high-fre¬ 
quency current past thru his body. (The 
lecturer stands on a metal plate covered 
with a rug, the plate being connected to 
a high-frequency coil. A metal insole 
should be worn, making contact with a 
spiked nail in the heel of the shoe, which 
thus ensures a good large area contact be¬ 
tween the charged plate and the lecturer’s 
body.) The center photo shows the lec¬ 
turer actually lighting up a bank of lamps 
thru his body. This experiment always 
attract undivided attention from any audi¬ 
ence, large or small. It really is a re¬ 
markable demonstration, involving in many 
cases the transmission of possibly 500,(X)0 
volts and several amperes of current thru 
the body; and 1/10 of an ampere of low- 
frequency alternating current past thru 
the heart is said to invariably prove fatal. 
In the final photo at the right we see Mr. 
Ford bidding us good-night, and like all 
good souls, he lights his candle and pre¬ 
pares to retire. But he lights the candle 
by a spark shooting forth from his tongue. 
And just to make it interesting we are go¬ 
ing to let our electrically inclined reader 
find out for himself how this trick is done. 


{Continued from page 401) 
explained with the help of the osmotic 
theory by Le Blanc. The difficulty in ap¬ 
plying this theory to the lead storage bat¬ 
tery is to know what are the ions in the 
case of the lead peroxid plate. According 
to Le Blanc’s theory, the lead peroxid, 
having a definite, tho slight solubility, dis¬ 
solves in the dilute sulfuric acid and then 
reacts with water according to the follow¬ 
ing equation;— 

(8) PbOs-f 2 H 2 O = Pb -f 40H 

Lead Water Lead Hydroxvd 
Peroxid Radical 

i’oM benefit by tnentioninff **The Electrical Experimenter'* when writing to advertisers. 

October, 1917 



During the discharge the tetravalent lead 
ions give up two charges of electricity and 
combine with the SO4 ions to form lead 
sulfate. The tetravalent lead ions are re¬ 
placed, as they are used up, by the solution 
of more lead peroxid. There is no loss 
in free energy in this solution and reactions 
with water, for both of these reactions 
take place at equilibrium concentrations. 
The spongy lead electrode is similar to the 
zinc in a Danielles cell. It goes in solu¬ 
tion as a lead ion, but is precipitated on the 
lead plate because of the low solubility of 
lead sulfate. The hydrogen ions of the 
sulfaturic acid combine with the hydroxyl 
ions of the equation last given, to form 
water. The equation representing the re¬ 
actions that take place subsequent to the 
reaction of the last equation given, for the 
entire battery are accordingly;— 




Pb — 

Pb -f 

SO 4 = 

2 PbS 04 






4 UH 


4- 4 H 


4 H 2 O 






On the charge the reverse of the above 
reactions take place. Both the positive and 
negative plates are covered with lead sul¬ 
fate, and the sulfuric acid surrounding the 
plates must also be saturated witli lead 
sulfate. On the negative plate the lead 
ions are deposited as spong>' lead, and on 
the positive plate the bivalent lead ions are 
oxidized to tetravalent lead. The solution 
and electrolysis are represented by the 

-f- + — 

(11) 2 PbS 04 solid - Pb -f 2 SO 4 
Lead Sulfate Lead Sulfate 


-r ”4“ 

(12) 2Pb = Pb -f Pb 

The tetravalent ions then react with the 

hydroxyl ions according to the following 
equation :— 

j--h _ 

(13) PbUa -f 2HuO = Pb -f 4 OH 
taken in the reverse direction:— 

(14) 211^0 4 OH 4 11 


4- “T 

(15) Pb -f 4 on IV).. 2 H 4 ..O 

The hydrogen ions corresponding to the 
hydroxyl ions and the sulfate ions from 
equation 11, unite to form sulfuric acid;— 

4 " = 

(16) 4II -h 2 SO 4 = 2 H 2 SO* 

Hydrogen Sulfate Sulfuric 

Radical Acid 

The sum of equations 8, 9 and 10, and 
of the equations II, to 16 will be found to 
result in equation 7. In support of Le 
Blanc's theory it may be stated that 
tetravalent lead ions do exist, and tliey are 
therefore probably capable of forming by 
the electrolysis of lead sulfate solutions. 
Liebenow's theory differs from Le Blanc’s 

in Science? 

Then you will find ail of th« latcU . 
and famous Mr»>ndfr4 and stunt» fully j 
lIlustrattHl In /.d'Iwion’i» pi». book | 

• KXrKUlMK.NTS, " I'pd. A i 

uealth of Information that you want 1 
and cannot llnd clnewhere. »uch 
'Tltra • violet Itjys," "Hiith Fre* 
qucncy." '‘.Mecltanic*.'' *’Wlrclc % 
plcKled .Mines.*' and "Are Weldinit" 
aUo "How tn KstablHh Your {labora¬ 
tory and Make Successful Experl- 
menls"; only tl '»0. 

Watchlnc WIreteas Procress? 

Then now la the trolden time to act „ 

a copy of 2 72 pp book "EXPERI- ^ 

You do not fiee«l a set In operation because j 
^ tills plain Enifllsh book shows you all aboul I 

pi iUnlnir, uavelpneths. resonance, audion oscillators, I 
jjele.. so you understand. All modem equipment Is J 
g Klven locethcr ssith new material on wifeless tele -1 
^ phony, aniplltlers, evpcrlments requlrinc no aerial.] 

: and 

list of U. s. Radio Patents. Jl.50 Ppi | 
Experimenter’s Library S2.8S I 

Both of above books handeonsoly boand In GoM* S 
eovera, 6M fonnerljr f3,B0, thlsj 

month only Pp<J. Batman booka *re abao-J 

lutely Knaranteed. You arr auro to be aalianed. j 
Order Now. P. EDELMAN. Pubtlsher 
ia02 Hacue Ave., St. Paul. Minn. 

Give Your Boys and Girls [hey’'w oIfdemand 

from you could they but know the dangers which confront them. 

Before they obtain wrong and incomplete impressions from sources outside the 
home, give them the proper viewpoint by placing in their hands 

The Mysteries 

Four widely commended volumes by 
They tell with proper delicacy and restraint, 
ycl .simply and plainly, the story of the mystery 
nf life; and impart with powerful subtlety an 
abhorrence of all that tends toward even the 
sllglUest lowering of the highest sex ideals. 

Warmly recommanded by Judge Ben B. liindsey of 
Denver; Edward Bok. of the Ladies' Home Journal; 
Rev. C. H. Parkhursl, New York; Rev. Francla E 

SawU l2mo. CloUt. Price 75e , 

of Life Series 


Clark, Pres. United Society for Christian Endeavor; 
Charles W. Eliot, ei-Presldeni of Harvard; and many 
other eminent authorities. 

Four Volumes: What a Father Should Tell His 
Lima Boy; WTiat a Father Should TeU Hla Son; WTiat 
a Mother Should Tall Her Little Girl; What a Mother 
Should Tall Her Daughter. 

Place them In the hands of yotir children and they 
will reap a lasting benefit. 

)er vohme. All Four for $2,50. 

Dept* 933 Fulton St., N. Y. C* 


W'hile the government will not permit the 
use of wireless telegraph and telephone 
e(][uipment at present except under its super¬ 
vision, the Public Service Company of 
Northern Illinois is investigating the prac¬ 
ticability of using radio-telephones for load 
dispatching so that some development can 
be made along this line when conditions 
will permit. Two radio-telephone sets suit¬ 
able for communication between sections 
150 miles apart have been purchased and 
are being tested with the co-operation of 
the United States Navy Department. If 
the units prove satisfactory on test, and the 
indications are that thej^ will, one unit will 
probably^ be installed in the s^-stem oper¬ 
ator’s office, which is in the new Toliet (Ill.) 
generating station, and the other will be 
placed in the company’s generating station 
at Blue Island, Ill. It will be possible to 
use the instruments in these locations to 
facilitate load dispatching in emergencies 
that may be occasioned by failure of the 
company's private metallic-circuit line. If 
the units prove practicable in these loca¬ 
tions, their use will probably be extended to 
other important switching ccnlcrs. Tlie 
use of the radio-telephone rather than the 
wireless telegraph was favored by the en¬ 
gineering department of the Public Service 
Company of Northern Illinois because the 
instrument can be used without a knowl¬ 
edge of the Continental Morse code and be¬ 
cause it is possible to transmit messages 
with greater speed by telephone than by 

CLIPPING 8,950,368,000,000 HAIRS ON 

Talking about horse hairs, about how 

many hairs do you figure our 
equine friend possesses? Well, 
there is said to be 32,458,000 horses 
in the U. S. A., and also that each 
horse has an average of 8,950.- 
368,000,000 hairs. Therefore the 
number of hairs on these horses 
totals up to 290.421,544.544,000,- 

All of which brings us to the 
problem of clipping these 32 mil¬ 
lion odd horses. The electric way 
has proven to be the best and 
quickest one, the time required 
for clipping a full-grown horse 
averaging 17 minutes 354 seconds. 

In the clipping machine pictured, 
the motor is a vertical type, 

H. P., equipt with ball thrust bear¬ 
ings. The flexible shafting is the 
hardened steel unit type, 8 feet 
long, encased in a servicabic and 
neat cover. It is noiseless and the 
clipping heads are interchange¬ 
able. Can be attached to electric 
light socket. Tlie advantages of a 
vertical type motor over the old 
portable motor are manifold 
viz.: Out of the way of the op¬ 
erator. No moving of motor. 
Greater compass in working. 
Takes up considerably less space, 
and when thru can be hung up 
out of the way. Of course the 
machine can clip other hair be¬ 
sides horse hair. Our illustration 
shows what tlie W’all street broker 
would term “sliearing the lamb.” 



October, 1917 

War Conditions Demand 

CPI men with training. Prepare 

HImCLw I KIwA\L> service in military or 

industrial life. Of 193 alu- 
denu In class of 1917, about one-third are already in the 
Engineer Corps and two-thirds are speeding production. in 
rfectncal Industries. Having trained over 2000 young men 
m the j^t 24 years In the fundamentals of Applied Elec- 
tnaty. The Bliss Electrical School, with Its well-equipped 
shops and laboratories. Is peculiarl>- Qualified to give a 
condensed course In Electrical 


including Mathemetica, Strain and Gac En. 
jrines. Mechanical Drawing, Shop Work and 
TheoreUcoI and I'ractical Elecd icit>-. m all 
branches. Students actnaliy construct dyna- 
moa, iBatall wiring and test efficiency of 
electrical tnachinery. Coorse, with diploma. 


-Hk c. young men with limited time. 

Z£tb ) ear opena Sept, 2bth. Catalogue on reqttest, 

260 Takoma Avenue, Washington, D. C, 

Big Powerful 

Made of finest tungsten mag¬ 
net steel, absolutely permanent. 
Length 5 Inches. IJfts about 
3 pounds. Educational, useful 
and enables you to perform end¬ 
less tests. e:speriment$ and make 
other magnets. Nothing better 
made. Sent parcel post Jl.OO 

We also have a number of 
Holtzer-Cabot Hand Generators 
which we will dispose of at bar¬ 
gain prices. Give up to about 
100 volts, alternating current. 
You can make direct if desired. 
SlricUy high grade, fully up to 
^H-C standards. WTule they 
last. $3.00 each. 

Watson Electric Co. 


will «dd. subtract, moltlply. divide, 
solve problems involving even and un¬ 
even ronu and powers. It will also 
give the Logarithms of numbers and 
the Sines, Cosines. Tangeuta and Co- 
tangenta of ell angles. 

Its operation is very simple and with 
this instrument one can quickly solve 
any matheiratical problem. This slide 
rule is made of wood and metal and it 
is adapted for shop work as well ae 
office use. 

Size 3 t-4 X 3 l>4iD. Price, with 
Instructions. 75c. Your money back 
if you are not satisfied. GILSON 
SLIDE RULE CO.. Niles. Mich. 


Perfected Gasoline Engines—1 and 
1 )^ h.p.—for Farm and Shop use. Price 
$19.50 and up. Also 


We ship on irial. Send for Booklet end Special Offer 
Sieverkropp Engine Co., 1401 t9lh Street 
Racine, Wis. Star Ur for Ford Cars 

Convert Your Bicycle Into 
a Motorcycle 

Motor fits aoy wheel. Best, 
most reliable. Best hill climber. More 
STEFFEVS Id use than all others. A fine 
motor for running amall Dynamos. Lathes aod 
amaU shops. Motors only as low as $16.95 

Steffey Mfg. Co., 5025 W. Brown St., Phila, P*. 



and BICY'CLES at cut nrh 
Singles aod twins $25 to $] 
I New Mo tore yc le Tires 
Automobile Tires $3. B 

_ . Motorcycle Belts $5. Carb 

hand Bicycles IS. Tandems ItS. New Blades sTpactory^J^efT^ 
Denlnger. The PHee Cntter. Rnoheater. New Tc 

Learn Watchwork, Jewelrywork an 

EncrraVinP ^ trade commanding a good s: 
. ^ , 5* ar^% and your services are always 

demand. Address HOROLOGICAL Departmer 
Bradley Institute. Peoria, Ill., for our latest catab 

only as to the action of the peroxid elec¬ 
trode. According to this theory the lead 
pero.xid goes into solution as doubly 
charged lead peroxid ions, so that the 
peroxid plate is to be considered a re¬ 
versible electrode with respect to the per¬ 
oxid ions. On diseharge, the peroxid 
passes into the solution surrounding the 
pero.xid plate, which is already saturated 
with respect to these ions. They then re¬ 
act with the hydrogen ions of the acid as 


(17) PbO? -f 4 H = Fb 4- 2 H 2 O 

The lead ions then combine with the sul¬ 
fate ions to form solid lead sulfate:-— 

4—h — 

(18) Pb 4- SO 4 = PbS 04 solid 

During charge, just the reverse reactions 
take place. The lead peroxide ions are de¬ 
posited on the positive plate, and are re¬ 
placed as they are used up by the solution 
of the sulfate from the electrode and its 

++ + 

(19) Pb 4- 2HoO = PbOa 4- 4 H 

The work obtainable from a storage bat¬ 
tery depends on its capacity and the electro¬ 
motive-force measured at its poles while the 
current is flowing. If V is the voltage on 
charging, E is the open circuit electromotive 
force, I is tlie charging current, and R is 
the resistance of the battery, then 

(20) V := E -f IR and on discharge, 

(21) = E 4 - IR 

{To be coneluded) 


{Continued from page 386) 
perpendicular to the mirror and E 3 C pro¬ 
longed ; the image of B will be found on the 
straight line E,B, prolonged perpendicular 
to tile mirror and along the line EsD. 
These lines may be marked on the paper 
after sighting ' along a ruler or other 
straight-edge. If now these lines are pro¬ 
longed-after removing the mirror, the in¬ 
tersection of .-\.F and E 3 C will be the point 
A* the image of A, and the intersection of 
BC and E 3 D the point B' the image of B. 
fdght from A going along the direction AF 
is reflected back and appears to come from 
\*. Light from A going in the direction 
AC is reflected along CEs making the angle 
of incidence equal to the angle of reflection. 

In a similar manner light from B appears 
to come from B^ and light from each of the 
points in between A and B appears to come 
from definite points in between A^ and B' 
tlius forming the complete image of AB. 
If the distances AF and A'F are measured, 
they will be found equal. The same holds 
true for BC and B'C and for any other set 
of corresponding points. In short, we have 
learned that EACH POINT OF AN 

The question is often asked, “If a person 
runs toward a mirror, how fast does he ap¬ 
proach his image?” The answer of course 
is, he approaches tiiicc as fast as he Is run¬ 
ning. The image is just as far behind as 
the person is in front and hence if the per¬ 
son approaclies a certain distance, the image 
approaches an equal distance, or the image 
and person are nearer by twice the distance 
that the person approached. It can be shown 
that a mirror must l>e at least half as tall as 
a person in order that the person may sec 
his whole image. This is left as an ex¬ 
ercise to the reader to try, and the author 
will gladly look over any solutions that may 
be sent to him. 

EXPERIMENT AS. A very simple ex¬ 
periment can be performed which will il¬ 
lustrate the manner in which many of the 

magician’s tricks are performed. Let M 
represent an ordinary milk bottle filled with 
water, GG a piece of smooth polished glass 
(the window after the pane has been well 
cleaned will do), C is a candle, and AB a 
board or other opaque object to screen the 
lighted candle. W'hen the eye is at E, the 
observer cannot see the candle C, because it 
is screened by AB. Light from the candle 
however on striking the points P to Q is 
reflected according to our previouslv dis¬ 
cus! law. and appears to come from inside 
the bottle. Hence we see the image of the 
candle in the bottle, and not seeing the 
candle itself we are mystified to find that 
a candle may buni in zvater. Obviously, with 
large pieces of plate glass and by use of 
trap doors and strong light a person under 
the stage may be made to appear on the 
stage. When the magician shoots his gun 
at the image or ghost it disappears (lights 
were turned off underneath the stage). 
Also men may walk thru other rnen, men 
and women may change places in cages, 
heads without the rest of the human body 
may be made to appear, etc., etc. 

EXPERIMENT 49. A piece of apparatus 
can be easily made as in Fig. 39-A, the 
working of which depends solely on the law 
of reflection, but which seems complicated 
to the person ignorant of Physics. M and 
yV are small mirrors or pieces of rnirror 
placed at angles of 45 degrees in their re¬ 
spective corners. Mirrors should each 
have a hole bored thru them or else be cut 
and have openings near their centers. If 
now an object is placed at B and the hand 
or a brick or other screen at A, the object 
will be seen by the eye at E, since light from 
the object B is reflected by mirror ^f^ to 
Ml and from Mi to M 3 and thence from Ms 
to M' and from M^ to the eye. If now the 
screen be removed from A and an opaque 
object placed in the tube at S, the light from 
B will pass thru the holes in the M* mirrors 
and to the eye at E so that the object will 
be seen in either case. Care must be taken 
not to have screens in place at A and S at 
the same time for then there is no path 
thru which the light may pass from B to E. 

This same principle of reflection is made 
use of in the modern submarine boat. .-X 
long tube AB (see Fig. 39-B) witli joints 
CA and BD extending in opposite directions. 
Small mirrors are placed at A and B, mak¬ 
ing angles of 45 degrees. Light from a 
distant ship is reflected by mirror A to 
mirror B and the image is seen. 

EXPERIMENT 50? When light passes 
from air to water or some other liquid it 
is bent. This phenomenon is called re¬ 
fraction. This retraction can be shown to 
he due to the retarding of the speed of light 
when passing thru a medium more dense 
than air. If a spoon or a pencil is placed 
ill a tumbler partly filled with water (see 
Fig. 40-A), it will appear bent. Place a coin 
in a bowl and step back from it until you 
just 7niss seeing the coin. If water is poured 
into the bowl carefully by someone without 
disturbing the coin and you stay in your 
original position you will find that you sud¬ 
denly see the coin. The explanation is re¬ 
fraction. While the coin is at A before the 
water is in the bowl, the observ er will see it 
if his eye is along the line ABD and hence 
if the eye is at E the coin will not be seen. 
However when water is poured into the 
1 ^ 0 wl, light from A is bent along the broken 
line ABE and the coin is seen and appears 
to be at C. since the eye is accustomed to 
consider light to reach it thru a straight 
line path. 

At this point it may be well to consider 
briefly what the present theory of light is, 
or rather to give the reader a start so that 
he may later read up intelligently on the 
subject. Like sound, light is considered to 
be a wave motion. The theory was first 
formulated by Huygens, the great Dutch 

) ou benefit by mentioning *'The Electrical Experimenter'* when writing to advertisers. 

October. 1917 



IMiysicist, in 1629-1695. The theory met 
with opposition on two groinids and even 
the great Newton died witlioiit accepting the 
theory which is universally accepted today. 
First, light travels thru vacua, and the better 
llie vacuum the greater the speed, whereas 
sound does not travel thru vacua at all. 
Hence, if light is really a wave motion it is 
thought to be a motion ot some medium 
which fills all space, hut does not retard th? 
motion of the stars and planets. I'.jood 
serials stop at tense moments like this, so 
we will stop here and say “continued in our 
next issue.”] 


(Continued from page 396) 

When you have your arbors all done 
and wheels mounted, the hardest job is 
locating the bearing-holes in your plates, 
so that your gears will run neither too 
tight nor too loose. I made an adjustable 
frame (Fig. 9), in which the wheels could 
be set; and when they were running just 
right, I scratched the distance on the plates 
with the sharpened ends of the arbors. 
Screw the two plates Hat togetlier, and drill 
them both at llie same time. These holes 
lia\ c to be center-punched and drilled with 
all the care you’ve got in your system, as 
a wonderfully small error will make your 
gears work as hard as getting Johnny home 
at supper-time. 

That’s all. Look like a good deal of 
work? Well, perhaps it is. It’s a great 
pity you can’t buy these wheel-works ready 
made. A movement like Fig. 6 (just the 
plates and wheels, I mean, without the es¬ 
capement) would be very simple and cheap 
for a clock-manufacturer to produce. iMa}'- 
be, if there was enough call for ’em, the 
supply houses advertising in the “E. E.” 
would have some made up. Why don't 
you send the "Ed.” a postal saj ing you arc 
interested^ and if enough postals came in, 
perhaps the Co.’s will get excited and think 
they see some business. The wheel-work 
is mainly a nuisance; and with that off 
his mind, a long-suffering “Bug" would be 

free to put his main effort into the pendu¬ 
lum and otiicr mechanisms. There are 
several principles, such as torsion and scale- 
spring oscillation, working more or less 
ill time-keeping intervals, that you want 
to try, but you don't feel like going to 
the trouble of making up wheel-work for 
each one. 

I want to say right here, tliat in this 
clock game it's "no fairs” designing a 
mechanism to run on an electric-light cur¬ 
rent. ’fbe first rule is, it must run on 
one dry-cell, and tlie end to aim at is hav¬ 
ing the cell dry up on you before the 
clock takes all its electrical output. You’ll 
find that’s hitching your wagon to a star- 

Oh, just to round out the article—as 
to clock hands—you can make them, of 
course, but they're very cheap and it doesn't 
pay to try. The dial 3 '^ou can make all 
right. Make it of zinc—wood is too apt 
to warp and stop your hands. W rinkle: 
Put a coat of shellac on your zinc before 
you paint it, otherwise your paint will peel 
off when very dry. Lay out your figures 
and circles on paper first, and transfer them 
to the painted surface with carbon paper. 
If, like me, you haven't an artistic hand, 
you can put in the figures with India ink 
and a ruling pen. You can buy excellent 
engraved paper dials up to 11 inches di¬ 
ameter, but unfortunately that isn’t quite 
big enough for a really szvell looking tall 

Fig. 10 is a detail sketch of a tall clock 
case. The design is copied from a very 
old clock, and is simple and i)leasing and 
easy to make. Use stock. For the arch 
over tlie dial, select a nice colored picture 
and stick it on with shellac. 

Final wrinkle: Harden up your heart 
like—like agate against all married sis¬ 
ters, aunts, friends of the family, and such 
like fry, for if you begin producing clocks, 
they’ll beg ’em from you faster than you 
can make ’em. You don’t have any dif¬ 
ficulty in extorting admiration as in the 
case of your more mysterious rinktums; 
they go into fits over ’em, and contemplate 
larceny' on you. 

{Cont'uiucd on page 427) 

Radio “De Luxe” Crystal Set 

For Commercial, Navy and Army Ooerators 

“increase your efflclency*' It the watchword at the 
present time. 

Here la a very efficient outfit which every Eadlo Op¬ 
erator should have on Ida table or carry In ble pocket. 
It mr “The right thing In the rlghl place, and the 
rlghl place for the right thing." 

.No more bunttni; arouod for that piece of crystal 
when the slcnals are not coming in strongly, no more 
soiled and broken crystals laying around In drawer's 

Our Radio “De Luxe" Crystal Set not only obvi¬ 
ates this, hut Uie high minerals furoiebed with 
the outfit will prove a boon fur every operator. 

The outfit consists of a water- and dust-proof, air¬ 
tight box of special constructloD. as per Illustration. 
Tlie hnx can be carried ea.nlly Id tbe pocket on account 
of its fiat and neat abape. 

It contains: 

One piece of tested Radloclte. 

tJne piece of tested tlulena. 

One piece of tested Sllicoo. 

Furthermore, one IS Karat Gold Catwhisker and two 
phosphor bronze catwhiskers of different shapes. 

It is not necessary for us to Indulge here upon the 
merits of our "Padloclte" t’rvstal. as it is in universal 
use today in all well e<iui|i(iod Radio Stations; we 
will, however, add a few words uf explanation conreni- 
Ing the quality ot the two other minerals which we fur¬ 
nish with oiir set: 

We use only Galena of the best and purest grade, 
especially selected cubic crystals, carefully tested and 
ultra sensitive. 

Our Silicon is fuse<l material, imported by us from 
England, and we have a good sized stock of same al- 
wavs on hand. Every piece is selected and tested, tbe 
same as our (lalena and Radiooite. — Our tested 
Minerals should ho handled only with pincers, never 
with hare fingers. We recommend strongly the use of 
the (Jold Catwhisker with our "Radiocite. “ It Is 
especially invaluable on hoard ships, as the gold can't 
rust and nn oxidation can set in between the point of 
the catwhisker aiul tJie nuneral. 

Order one of our Radio “De Luxe" Crystal Sets 

Prico of the outfit as described above. S2.00. 

Shipping weight, 1 lb. 

Add sufficient postage to Insure prompt shipment. 


233 Fulton Street New York City 


DO YOU WANT FROM $S,000 TO $20,000 A YEAR? 

Of course you do. Well here la YOUR OPPORTUNITY to gel It. ami at Ibe same lime to become a TR.AIN'ED man. One with a PRt)- 
FESSION. A person who Is looked up to and whose opinion is respected. A man who cao secure a position ANA'AVUERE. at salaries 
ranging from $5,000 upwards. Our Courses are the REGULAR COLLEGE COURSES and will fit you to hold ANY kind of a position .aNV 

WHERE. Our Course is compiled by some of the best known ProfoMirs In .America. Professors 
In Rutgers Cellege, Clark College. The University of London. England, etc., have all helped to 
make this Course the BEST and the MOST THOROUGH. THROUGHOUT, .and when yuu finish 
your complete Course, we grant you a Diploma in I’heimstrv. 

These Courses would cost you over $2,500 in cost of tuition, board, room, clothes and wash¬ 
ing for a four year Course in .VNT' State University, and many linu-s mure In some of Uie Large 
1‘olleges. (.»ur Courses are tbe same in every way. and will fit you to hold .ANY position that 
an.v graduate of ANY College or University could fill. Every Course Is a UKRStl.N.AL Course, 
and not simply a few sheets ot paper. You get your lessons from time to time, and reiiiru to 
U3 your answers for correction. Our Courses ronlaiii HU.NDRED.s of Expcriiiients. to make the 
student get a perfect understanding of his studies atid to thoroughly GROUND and F AMILIAR¬ 
IZE himself with Ills work. 

NO SPECI.AU EDUC.ATION NEEDED to study these Course-s. as we thoroughly ground you In 
algebra by our simple method, and by iho u.^e of simple oxpenments. lead you gradually through 
Plivsics, and on into the bnlaiuv of our Chemical t'onrsc. .A.NVONK KR<»M 15 Sk.ARS UI*- 


Tliore Is hardly a largo Maniifaotunng firm in the Cmiiilry that lines mu lunplov a Chemist, 
and they ore looking aroutul trying to fliml .MORE Chemists, but the .supply ts F.AR SHORT of Uie 
demand. Fees as high ns SIS.500 have been paid to expert chemists for juct one single analysis. 

Wo give the regular Collogo Courses in the fnllnwliig: PHYSICS. INORtUANIC .AND OR- 
SOAP. CEMENT. <HLS. ETC . ARSOLUTELV FREE, while thev would take from to 
six years of your time, and liurulrtHls of dollars of your money to take up. Here is your 
I’banco to become a Professional Man, a Trained 

.Alan, wliogo services are .ALAA'.A^'S IN DEMAND ■ ■■§ mm 

Here Is YOUR Opportiiiiltv. AVill vou grab It? 



1 LilV V/VIAIK of buying on outfit contnining 

44 expensive rlM*micnls. incliiiting Mercury, Iodine, Phosphorus. 
:n etc., unit th« apparntus listed beh*w fur only five doUnrs, nor to 
lion having your name enrolled with ihe Z. C. L. Service Dept. 
Our Master Outfit contnins. rhemieids. Pieces ttlass Tubing. Uenl; I I lecc i.lnss 
Tubing. Bent; 1 Erlinmyer Style Wash BoltV. I Frienmyer Siyte tlMk. I Oronper. 10 
Sheets Imported Filter Paper, fi Test Tubes. I Delivery Tube with t nrk, ! Ounce 
kAinnet, 1 TesI Tube Holder. 1 Conical Engraved .Scale Measuring (tlnss. I ( hemical 
Measure, 1 M-Cenl Insiruclitui Book. cunUiining 100 Kxpenments, 


lAC A I FRQf ® great opportuiil'v 

* for you. Get our unique prnp- 
osUlnn 111 a field full of possibilities, A few ler- 
rltoricii still opoD. Wrtto today. 

Zenilh Chemical Laboratories, Duluth, Minn. 

Ouluth, Minn. 

Without obligation to me, send me at once 
I'afalog describing all vni^ 
ch* mica I outfits ranging from $125 to $3850 

J-.5U0 1H* HthK » ollegp ( htmisiry Course. 
Namo . 

You bt'vefit by mentioning "The Electrical FxterimcutcY* tt/icn Tfi ifiin; L' a ii crtiscrs. 



October, 1917 

^i,; I" 

■'111 1 










The ‘^Electro^^ Codophone 

(Patents Pending) 

Xow that we are for the time being, deprived of using our 
Radio outfits, it behooves us as good Americans to become 
proficient in learning the Wireless as well as Telegraph 
Codes. Operators who know the Code are. and will be. in 
ever rising demand. The Army and Xavy need’ thousands 
of operators right now. 

So far the Government has not been able to obtain any 
way near all the operators it requires. Xot alone does the 
Federal Government call for thousands and thousands of 
operators for the army and navy, but nearly all of our many 
slates require operators for tbe 
militia. Here is llie great opportun¬ 
ity of a life time for you. 

Would you rather fight in the 
trenches, or punch the key behind 
the lines? Either way you benefit 
your country. Which do you prefer? 

And it i.s SO easy to become an oper¬ 
ator. You do not necessarily require 
a teacher, nor do you have to go to 
a school to learn. 30 days of intel¬ 
ligent .study will make you proficient. 

Can you qualify XOW? Are you 
proficient? Can you send and receive 
when your country calls you? 


(Patents Pending) ! 

which we present herewith is thej 
outcome of several months of intense 
study and experimentation of our 
•Mr. H. Gernsback. It supersedes our 
former Radiotone Codegraph, which 
comprised a Radiotone silent Buzzer, 
a loud talking telephone receiver and 
a key. As in all of his work 31 r. Gernsback strives for simplicity. So 
he combined the three above mentioned instruments with one stroke into 
ONE single instrument. He combined the Radiotone Buzzer and the loud 
talking receiver into a single unit, not only mechanically, hut electrically 
as well. This involves an entirely new principle, never before attempted, 
and on which basic patents are now pending. 

What this remarkable instrument is and does. 

The “Electro" Codophone is positively tbe only instrument made that 
will imitate a 500 cycle note exactly as heard in a Wireless receiver, so 

closely and so wonderfully clear, that Radio operators gasp in astonish¬ 
ment when they first hear it. And you need no receivers over the ears to 
hear the imitation singing spark, which sounds for all the world like a 
high-pitched distant powerful Radio Station. No, the loud-talking receiver 
equipped with a born, talks so loud that you can hear the sound all over 
the room, even if there is a lot of other noise. 

THAT’S NOT ALL. By lessening or tightening the receiver cap, a tone 
from the lowest, softest quality, up to tbe loudest and highest >creaming 
sound can be had in a few seconds. 

FURTHERMORE, this jack-of-all-trades marvel, can be changed in¬ 
stantly into our famous silent Radiolone test buzzer, simply by replacing 
the metal diaphragm with a felt disc, which we furnish with every instru¬ 

FOR INTERCOMMUNICATION. Using two dry cells for each in^tru- 
meot. two Codophones when connected with one wire and return ground, 
can be used fur intercommunication between two houses one-half mile 
apart. Any one station can call lije other, no switches, no other appliances 
required. No call bell either, the loud-talking phone takes care of thi.s. 

AS AN ARMY TYPE BUZZER. Last, but not least, two Codophones 
with two 75 olim receivers can be used to converse over miles of fine (X'o. 

3»i B S Wire), so that no one 
can see the wire. Or you caji use a 
long metallic fence and the ground, 
or you cao communicate over your 
no volt line up to several miles, us¬ 
ing no wires, only the ground. 

Full directions how to do all this 
furnished with each instrument. 

One outfit alone replaces the old- 
fashioned learner’s telegraph set, 
consisting of key and sounder, which 
is all right to learn the telegraph 
code but not the wireless codes. 

The “Electro" Codophone is a 
handsome, well made instrument, 
fool proof, and built for bard work. 
Contacts are of hard silver inch 
in diameter, that will outlast the in¬ 
strument. Base and bousing is of 
metal throughout, horo and key 
lever nickel plated and buffed. Three 
new style metal binding posts are 

There is also a neat code chart and 
full directions enabling any intelli¬ 
gent young man or girl to learn the codes within 30 days, practising one- 
half hour a day. 

Sizes: 69i x 3 x Shipping weight. 4 lbs. 

The "Electro" Codophone as described, complete 

Money refunded if instrument is not as represented or does not come up 
fully to expectation. 

Ready for delivery Aug. 25th. There will be an enormous demand for 
this new marvel—place your order now. All orders filled in rotation. 
Better order two instruments today. • 

$ 1.35 


As usual we lead—others follow. Now the Spinthari¬ 
scope. first to be introduced to the American public by 
us. The Spinthariscope was originated by the famous 
English Radium expert, .^ir William Crookes. Everyone 
knows that Radium gives off a tremendous amount of 
energy which goes on for several thousand years, with 
imdiminished force. 


telescoping into the other. The top tube has a powerful 
lens. The bottom contains the zinc-sulfide screen and 
a minute quantity of REAL RADIUM, too small to do 
any harm. The instrument can only be used in the 
dark. After the top tube with the leas has been ad¬ 
justed to the right focus, we observe a vividly illumi¬ 
nated green background, glowing in a soft light. As 
the eve becomes accustomed to it. we begin to see the 
ELECTRONIC BOMBARDMENT of the Alpha rays from 
the Radium. It looks exactly like tiny fireflies flashing 
off and on in the dark night. The more we look the 
better we see the miniature fireworks. We are now in 
tlie presence of the most marvelous substance man ever 
knew, RADIUM and its iincanny forces—Radium, which 
some day will turn the world upside down. 

The Spinthariscope up to now sold from $10.00 up¬ 
wards, but by greatly simplifying it the cost has been brought down by 
us to such a DoniiDal figure, that no one can afford to be without this 
most important and marvelous instrument. « 

Y'ou owe it to yourself to own one. It is small enough to be put into your vest-pocket, and interesting enough to show it to all of your friends. 
It will continue to operate after you are dead 2500 years! We guarantee the instrument to be genuine and to contain a minute quantity of real 
Radium salts. “Electro” Spinthariscope, in neat box and directions for use, described^... . $ 1.00 

Radium gives off a number of rays of which the 
Alpha rays are known chiefly for their great power. 

These electric rays are invisible to the naked eye. the 
same as are X-rays. But if we lake a small amouot of 
Radium and place it in front of a zinc-suJflde screen, 
the latter lights up. If the radium speck is arranged 
suitably the .Vlpha rays will bombard the zinc sulfide 
with a veritable hail of electrons and the screen begins 
to scintillate like Fourth of July fireworks. 

This is the principle of the Spinthariscope, wliich we present lierewith. 
It is a little instrument made of two neatly nickeled metal tubes, one 



We have spent considerable time to com¬ 
bine jusi sucb a practical outfit and pre¬ 
sent it berewiUi to our friends. 

The outfit is complete as per illuslration 
and consists of: 

1 Stand, made of well quartered oak. 
varnished three times, so as to he add proof 
and grooved on top and bottom, so that it 
will not warp in getting wet. Size 5^* 
inches high by 11^ inches loug. 

such as test-tube holders, tripods to support 
relori.s. etc. We furuisU a blue print with 
the outfit, showing how to make all these 
wire articles. 

Now this whole outfit as described Cl OC 

costs you only . 

Postage extra. Shipping weight. 4 lbs. 
Order one today, even if you don't need 
it DOW. 

2 inches. Uses wood alcohol and is In- “The Livesl Catalog in America” ■ 

tn tho o-rru^rlminiilv»- " = 

valuable to the experimenter. Besides be¬ 
ing used to heat test-tubes contents as per 
illuslration. it can be used to bend glass 
rods and tubings, to solder wire, etc. 

1 Glass Filter Funnel. This funnel Is 
made of heavy glass that will not break 
easily. It fits accurately io the hole on lop 
of the Filter stand and Is provided with a 
thick rim on the outlet, so that a rubber 
hose can be attached to it. without slipping 

1 Glass Rod, to be tised in stirring and 

10 Test Tubes, made from the best im¬ 
ported glass. A new feature of some of 
the test tubes is that they have a flat bot¬ 
tom aod therefore can be placed on aiiv 
table if desired, needing no special stand. 

1 Roll of Copper Clad Steel Wire. This 
^vire is to be used to make a iiuniher of use¬ 
ful articles as sbo\Tn in the illustration. 

Our big, new electrical cyclopedia X’o. 18 
is waiting for you. Positively Uie most com¬ 
plete Wireless and electrical catalog in print 
today. 200 Big Pages. 600 illustrations. 500 
instruments and apparatus, etc. Bic “Trea¬ 
tise on Wireless Telegraphy.” 20 FREE 
coui»ons for our lb*0-page FREE Wireless 
Uourse in 20 lessons. FREE Cyclo- ^ 
pedia No. 18 measures TxoU"- HI 
Weight H lb. Beautiful stiff covers. 

Now before you turn this page write 
your name and address on margin be¬ 
low, cut or tear out. enclose 6 cts. 
stamps to c<iver mail charges, and the 
Cjciopedla Is yours by return mail. 


231 Fulton Street, New York City 


ELECTRO IMPORTING CO., 231 Fulton St., N. Y, 



You benefit by mentioning “The Electrical Exf'erimenter” when writing to adicrtisers. 

October, 1917 




{Continued from page 425) 

Wy this time, you’re either got the craze, 
or arc deatlily sick of clocks. If the form¬ 
er, I could give you a little spiel on un¬ 
usual forms of movement, striking-mech¬ 
anisms, and other daffy dope, but 1 got to 
be coaxed that is, you mail the Editor a 
nut nr something to show youVe crazy and 
not bored, because I don't ^Yant him to 
load lip his ^^ag, with the kind of stuff 
that you skip when you come to it. I’m 
a modest and retiring guy—what's that?— 
Yes 1 am, too, and 1 can prove it in court 
if T have to. Now, is everybody happy? 


(Continued from page 399) 

by the tiny black spots on the rod where 
the lacquer had been burnt. 

Yes indeed, trouble shooting is '‘Sport," 

There are possibly more chances for 
ridiculous situations and strange mistakes 
in the installing end of tlic game. Trouble 
is oftimes encountered in properly ground¬ 
ing the 'phone. One subscriber has to 
water his ground rod every day or so to 
keep the 'phone working properly. Re¬ 
minds me of the chap that wanted to 
ground on a coal bucket. He even offered 
to allow enough slack so the lady of the 
house could bring coal out of the cellar. 

And streaks of^ luck, let me tell you 
about a certain incident that caps them all. 
On a certain job it was necessary to drill 
a hole thru the floor to pass a pair of 
wires. Going down the cellar he starter! 
to drill up. After sinking the drill some 
six inches he began to wonder how thick 
the blamed floor was. He went upstairs 

and lookt for the hole but none was in 

He then returned to the brace and sunk 
it another three inches before he decided 
to check up his measurements. After a 
little trouble he located the place where 
the hole was coming thru. Where, you 
ask ? 

Up a Piano Leg! 

And plumb in the center. A quarter 
inch cither way would have broken thru 
the veneer. 


{Continued from page 405) 

On a large scale it is made mostly from 
the ammoniacal liquor of the hydraulic 
main of gas houses, which results from the 
destructive distillation of soft coal. This 
liquor contains dissolved (NID-S; (NH 4)2 
CO 3 ; etc., and when treated witli hydro¬ 
chloric acid, nitric acid or sulfuric acid, it 
gives the salts NH 4 CI, etc., and from these 
salts "liquor ammonia" is obtained. Great 
quantities of the gas are formed in the pre¬ 
paration of coke in the iron regions. 

Properties : 

Physical: 1 . Ammonia (NHa) is a color¬ 
less gas, possessing a pungent and char- 
acterisitc odor and acrid taste. 

2. It is very easily soluble in water, with 
which it combines to form the hydroxid, 
which in turn gives off the gas at all tem¬ 

3. Ammonia can be liquefied and when in 
that state it is colorless. The liquid boils 
at -40 deg. 

4. It solidifies at about -80 deg. 

5. Its own evaporation may produce cold 
enough to freeze water, hence the making 
of artificial ice. 

6 . Charcoal rapidly absorbes ammonia 
which may be shown by introducing a piece 
of charcoal into a tube of the gas over 

Chemical : 

1. It is not ordinarily a combustible gas 
or supporter, but if mixed with a small 
quantity of oxygen combustion readily 
takes place on the application of a flame, 
with the formation of w^ater, nitrogen, and 
nitric acid. 

2. Like other bases, it combines with acids 
forming salts. 

3. It gives a strong alkaline reaction. 

4. NHa partially dissociates into its ele¬ 
ments at 500 deg., as may be shown by 
passing it thru a red-hot tube. 

5. The two elements do not combine 
under ordinar\* conditions. 

6 . It is decomposed at red heat or by 
the electric spark into nitrogen and hydro¬ 
gen ; when past over heated sodium, potas¬ 
sium, or magnesium, the nitrogen combines 
w’ith the metal, forming a nitrid, and hydro¬ 
gen escapes: 

3 Mg -f 2 NHa = Mg, N. + 3 Ih 
W'hen treated with an excess of chloriti 
or iodin, a salt of ammonia results, w'hich 
in turn is decomposed by the halogen, yield¬ 
ing very explosive compounds, as nitrogen 
chlorid (NCL) or nitrogen iodid (NHL 
or NL). 

Dkti ci io.\ : 

( 1 ) .\mnionta and its solution (the hy¬ 
droxid) are very easily detected by the 
characteristic odor. (2) In smaller quan¬ 
tities by bringing over the suspected solu¬ 
tion a piece of moistened red litmus paper, 
which it turns blue. (3) A still more 
delicate test is the reaction with fumes of 
hydrochloric acid. A rod or piece of paper 
moistened with the diluted acid is brought 
(Contintn'd on page 429 


FREE TRIAL Use as You Pay. Only 
$2.50 a month until the low total price of 
$48.80 is paid and the machine is yours. 

This is absolutely the most generous 

lypewrller otter ever made. Do not rent a 
machine uhen you can pay $2,50 a month 
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{Conliniicd from page 427) 

into contact with some of the gas, or over 
some of the warm solution, when im¬ 
mediately dense bluish-white fumes of am¬ 
monium clilorid are formed. (4) When 
combined witli acids, ammonia is detected 
by first liberating it from its combination 
with an alkali like potassium or sodium hy- 
droxid, and then applying one of the above 
tests for the gas; or the solution may be 
aeidified with hydrochloric acid and solu¬ 
tion of platinic acid added, when a yellow 
precipitat of ammonio-platinic chlorid, will 
slowly separate in minute crystals. (5) 
Xessfer's Reagent produces a broxen pre¬ 
cipitate with ammonium compounds, or if 
in very dilute solution a broxen or yelloxo 
color. Kessler’s reagent is made b^' adding 
to a solution of mercuric chlorid (corro¬ 
sive sublimate) a solution of potassium 
iodid until the precipitate at first formed is 
nearly all redissolved. Solution of potas¬ 
sium hydroxid is then added to strongly 
alkaline reaction and the liquid allowed to 
settle until it becomes clear, when it is de¬ 
canted from any sediment. 

Uses : 

Ammonia is widely used in medicine and 
pharmacy, in making dyestuffs, in calico 
printing, and in refrigerating operations. 
Its compounds serve to furnish nitrogen, 
which is essential to the growth of both 
vegetable and animal life: hence the use 
of ammonia in fertilizers for the soil. The 
three elements necessary to be restored to 
the soil for the raising of crops are nitro¬ 
gen, phosphorous, and potassium. Com¬ 
pounds of these three elements with otliers 
are made into fertilizers by manufacturers. 
Ammonium compounds, with some iiitrats, 
furnish the nitrogen on which all higher 
animals depend for tlie nitrogenous ma¬ 
terial foods. 

The value of ammonia water as a cleans¬ 
ing agent is due to its ability to dissolve 
grease. Its basic properties also give it a in the laboratory, whenever a volatile 
alkali is desirable. Large quantities of 
ammonia are used in the manufacture of 
soJiiDn carbonot bN' the Soh^ay process. 

Ammonia is very e.xtensively used for 
making artificial ice and for large refrig¬ 
erating and cold storage plants. When a 
gas is liquefied, heat is liberated, and when 
the liquid returns to the gaseous state, heat 
is absorbed. The process consists of al¬ 
ternately liquefying ammonia and then 
vaporizing it. The ammonia gas is first 
obtained from very strong ammonium h}*- 
droxid, and by a compressor pump, and is 
forced as a gas into pipes, called condens¬ 
ers, upon which cold water is permitted to 
pass, which together with the compression, 
makes liquid ammonia, which then passes 
thru a valve, called the expansion valve, 
into a series of pipes. 

Tliese pipes are immersed in a strong 
brine of Calcium chlorid solution (Sodium 
chlorid not being so good). As the liquid 
ammonia goes thru the expansion valve 
and into the tubes it again vaporizes, and 
in the process withdraws heat from the 
brine, cooling it to -20 degs. or over, thus 
making a freezing mixture of the brine, in 
which tubes of pure water are immersed 
and the water frozen. The gas KHa then 
passes back to the pump, where it is used 
again, the process being continuous. 

E.xperiment No. 93: 

ACade from Ammonium Chlorid and 
Calcium Hydroxid. 

Connect a plain Florence flask (125 or 
250 cc.) having a two-hole stopper with a 
thistle and delivery tube (tlic delivery tube 
in the Florence tlask should just pass thru 
the stopper, (but the tliistle tube should be 

immersed beneath the solution), to an 8- 
ounce bottle, this being fitted with a three- 
hole stopi)cr. In the second hole a plain 
piece of glass tubing is inserted so that it 
l)rojects over tlie stoi)per and beneath the 
litpiid. The tliird hole is to accommodate a 
second delivery tube which leads to the 
second 8-ounce bottle which has no stop¬ 
per. Fig. 84 depicts tliis apparatus. Both 
8 -ouncc buttles should be about one-fourth 
full of water. ‘I'he delivery tube from the 
first to second bottle should i)ass below the 
surface of the Ikpiid. 

I’lit about 10 grams of ammonium chlorid 
(KH4CI) on a piece of paper, and on an¬ 
other about 8 grams of calcium hydroxid 
(Ca (OH)j), recently ^laked lime being the 
best. Pour these successively into the tlask, 
add 20 or 25 cc. of water, and mix tlic 
contents by rotating the tlask: See wliethcr 
any odor comes from it. 'I'licn set the 
flask on an iron tripod or ring stand, with 
asbestos or iron gauze, make connections, 
and apply heat for fifteen minutes. If there 
is a tendency to froth up and run overj 
take away the lamp, and, if need be, pour 
a little water thru the thistle tube. In case 
the frothing should extend into the tubes 
or bottles, clean them out and begin again. 
Observe fully all phenomena in the flask 
and try to find an explanation. 

W’hen ready to stop the action remove 
the lamp, take out the stopper, and apply 
these tests in rapid succession to the gas 
iii the flask. The}" must be made wdiile 
generation is progressing. (a) Apply a 
piece of both red and blue litmus to the gas 
and notice which one is discolored, and con¬ 
clude what this would indicate, (b) Ap¬ 
ply a lighted splint to the gas, in order to 
test for the combustibility of the gas. (c) 
Test the odor, (d) Test with hydrochloric 
acid by pouring two or three cc. of the 
acid into a dish and dipping a folded paper 
into it; or the test may be made by bring¬ 
ing the dish to tlie mouth of the flask or 
with a tuft of cotton. Dense bluish-w'hite 
(ammonium chlorid) fumes will appear, the 
same being a test for free ammonia. Let 
the flask cool a few minutes after taking 
away the lamp, then pour in water from a 
test tube, shake the contents, and pour 
them into a sink. Any adherent substance 
may be removed from the flask by using a 
little hydrochloric acid. Save the liquid 
in the first bottle for further tests. 

Experiment No. 94: 

Properties.—The positive radical or ion 
of an ammonium salt is NH*; the negative 
one OH. The best test for the positive 
(NIL) part is to mix a little of tlie 
powder to he tested with a equal amount of 
slaked lime (Ca(OH) 2 ), heat the mixture 
and obtain ammonia, in case it is an am¬ 
monium salt. A simple test can often be 
made by rubbing in the palm of the hand a 
pinch of each substance, moistened, and 
noting the odor. The tests for the nega¬ 
tive radical or ion, in addition to the one 
with litmus, consists in making insoluble 
hydroxids as given below. 

Experiment No. 95: 

Action on Ferrotf.? Sulfate.—‘Take a small 
crystal of ferro«j sulfate (FeSO*), dis¬ 
solve in 10 cc. of water l)y boiling (it may 
first be pulverized in a mortar, if desired), 
then filter the solution and add to the fil- 
trat a little of the ammonium hydroxid 
(the liquid in the first bottle of the first 
experiment of this paper). 

Note the color and state of the product. 
Also note if there is a precipitate. See 
whether a solution of sodium hydroxid 
(NaOH) would give the same result as the 
fcrro »5 sulfate solution. Try also tlie 
action of potassium hydroxid (KOII) in 



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Experiment Xo. 96: 

The Ammonia Fountain. Ammonia Gas 
(XHa). Tests and Properties.—\ arioiis 
tests were applied to the gas ammonia in 
experiment No. 93, The simplest one is the 
odor test, which is very characteristic of 
this gas. Its action on litmus, and inertness 
to the combustion test, do not distinguish 
it from other substances. The litmus test 
is a test for the base OH. 

To show its action on water, collect a 
bottle full of it by upward displacement by 
use of the apparatus shown in Fig. 85, either 
from a generator or by boiling about 20 cc. 
of strong ammonium hydroxid. The lat¬ 
ter will give the purer and stronger gas. 
Have the delivery tube from the generator 
reach close to the top of the inverted bot¬ 
tle. Close the mouth of the bottle with a 
one-Iiole stopper carrying a glass tube, as 
soon as it is filled with gas (which is made 
apparent when the odor is observed around 
the bottle), and at once thrust the out¬ 
side end of the glass tube into a dish or 
l>eaker of water, having the bottle in an 
inverted position till action takes place. 
(Fig. 86 illustrates the apparatus for use 
for the Ammonia Fountain). As the name 
implies, the ammonia will absorb the water 
from the beaker, thereb}’ drawing it up into 
the bottle with such force that a miniature 
fountain will be formed. L^nless the am¬ 
monia is unmixed with much air the ex¬ 
periment will not be a success. By having 
a few drops of red litmus solution in tlic 
water in the dish or beaker into which the 
tube is thrust, a double test may be made. 
Observe any color phenomena when the 
litmus is introduced into the beaker. 

The reader may have heard or read of 
reversible reactions and never stopt to 
inquire as to their meaning. This experi¬ 
ment is an excellent illustration of a re¬ 
versible reaction. A reversible reaction is 
one in which tlie factors become the pro¬ 
ducts and the products the factors. Heat¬ 
ing ammonium hydroxid (XH4OH) gives 
W'ater (H2O) and Ammonia (XH3). Re¬ 
verse the experiment by passing Ammonia 
(XH3) into water and you have ammo¬ 
nium hydroxid (NILOH). Thus the re¬ 
action goes either wa}', according to the 
conditions, or may go both ways till 
equilibrium is established. 

Experiment XM. 97: 

Diffusion and Absorption.—Take two 
small flasks (125 cc.) each carrying a one- 
hole stopper, and connect them b}' means 
of short glass tubes, connected with a rub¬ 
ber stopper, as shown in Fig. 87. Into one 
pour 30 or 40 cc. of water and into the 
other the same volume of ammonium hy¬ 
droxid. The tubes should not pass below 
the surface of the liquid, as we are to 
deal with a gas. Allow them to stand in 
this manner for a week or so, then test 
the liquid, both with litmus and Xessler's 
Reagent, in the bottle which at first con¬ 
tained the water only. Observe any re¬ 
sults. This would show that the ammonia 
(XHs) from the hydroxid (XH 40 H) 
past over the tube and again formed an 
ammonia solution with the water which 
^^as in t^e flask. 


{Continued from page 407) 

onl\ run forty seconds or so at each descending. 

Consequently, the dynamo would not have enouRh 
time to charge the batteries, regardless of the num¬ 
ber of cars or how often they run. 

Also the continual charging and discharging of 
the batteries at such minute intervals, would not 
give them sufficient time to charge properly, and 
consequently the cars would not run three minutes, 
much less for years as was suggested. 


Stamford, Conn. 

Let’s Nickleplate the "Superstructure”!! 

In the first place you must think ot the super¬ 
structure upon which the track is laid. Without 
paint and proper care it would soon rot. The cars 
also would need attention. 

Altho the cars charge the storage batteries when 
going down grade, they would use up a great deal 
more current going up. At which rate the current 
would soon he used up. The distilled water in the 
storage batteries would vaporaie, alter which the 
’’bats ’ would not work. 

The fric.ion wheel, third-rail contact shoe and 
belt would also wear out, after a.l of wnich the 
device would stop going, 


Blue Ridge Summit, Pa. 

To "Rub” Or Not to "Rub,” That’s the 

In charging the cells receive a positive and 
negative charge. Then when the car goes uphill 
the batteries should discharge, but in discharging 
the batteries change poles. This would tend to 
make the car go backwards on the hill, so that the 
batteries would hinder more than help. The dy¬ 
namo is not perfect, for it can never cut the lines 
of force of all its poles and, consequently, can 
never generate enough power to be 100 per cent 
perfect. Friction (which is always present), in 
rubbing places would make the car stop. 


642 Susque Avenue, 

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Ob Carl, How Could You Be So Cruel in 100 

This device can impossibly keep going for years, 
due to the fact that no storage battery ever built 
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electrolyte thereby decreasing the efficiency of the 
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their woBc faithfully. Another thing is that stor¬ 
age batteries must he charged at an even rate of 
current, and in this case it would not be. Also 
the cars, while descending, would be going so fast 
as to overload the dynamo, thereby possibly burning 
out its armature, 


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October, 1917 



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Subscribers experiencing trouble in dealing with any advertiser should notify the publisher very promptly. 



. )m 

CASH PAID for a set of Bound Volumes be* 
lotigitiR to I. C. S. Electric Engineering Course 
(.Part Two). II. Walton, Amtgart, Ontario, Can. 

WAXTED—Vour old Wireless Apparatus. I 
also have a $50 W ireless Set to trade for a u'otor- 
cycle. Enclose stamp. Lawrence Johnston, I'air- 
tield, Illinois. 

FOR SALE—15,000 meter coupler, 3,500 meter 
receiving set, two 3,000 ohm headsets, two 20 ohm 
telegraph sets, telephone transmitter. Write for 
photo and description. F. B. Dadisman, Inde¬ 
pendence, West \’^a. 

HAVE—Xew Western Electric table fan ($25). 
Want typewriter ami wireless goods. Mack Sim¬ 
mons, \’an Alstyne, Texas. 

FOR SALE CHEAl^—One new Power’s 6-.A Mo¬ 
tion Picture Outfit, used four weeks. Would con¬ 
sider an immediate cash offer. Austin Miller, 
Erwin, Term. 

FOR EXCHANGE—$40.00 worth wireless and 
electrical apparatus. Would like 8 x 10 view cam 
era or other photographic goods. W’rite for list of 
apparatus and say what you have. K. R. Sipple, 
160 W'hitney PI., Buffalo, X^. W 

(LAfXS--D. C. 500 \\ I 2 H. P. S.andard Dynamo, 
$24.50. Robbins 1-16 H.P. 500 V. new enclosed 
motor, $8.75. Both fine for radiotelephones. Smith 
motorwheel, $27.25. Tubular audion, $4. Mignon 
Receiving Set, $4.90. P. Edelman, 1802 Hague, 
St. Paul, Minn. 

FOR SALE—Electron Relay and cabinet com¬ 
plete, $10. New Electron Relay, $4. 1 K. \V 

Glass Plate Transmitting Condenser, $3. 5 H P. 

motor starling bo-\, $4. Ralph Lcftler, Tiffin, Ohio. 

FOR SALE—N^cw 3 speed bicycle practically 
new; 2 speed Hub; new' Camera and 5x7 enlarger, 
developer and printing set. No. 4 Erector: 1 
Transformer; 2 motors. Send for description. 
Clair Miller, W'ilmington, Ohio. 

FOR SALE—2,500 Meter Loose Coupler; un¬ 
mounted 43 plate \’artable; unmounted Detector; 
Brandcs 2,000 ohm Phones; Spark Coil; Jove 

Key. Express.age extra. W'alter J. Schneider, 
R. R. 2, Mason Rd., Hamilton, Ohio. 

ABOUT 1,000 copies specifications and drawings 
for all U. S. Radio-communication patents from 
beginning to <late; will sacrifice complete collection 
for $55. P. Edelman, 1802 Hague, St. Paul, Mum. 

W’AX'TED—An Amco or Tesla Tr.insformer. 
Have apparatus to trade. W'rite for my list. Robt. 
Fairchild, Minden Mines, Mo. 

W’ANTED—One H.P. Gas Engine, Redemotor 
preferred, good condition, cash. Sell—Harley twin, 
run four thousatul miles, thirteen model, i.incty 
dollars, ready to ride, bargain. Write me. H. I*. 
Rea, Carrollton, Mo. 

FOR SALE—15,000 meter Navy Type Loose 
Coupler, $10; 200 ohm Phones, $5; Galena and 
Electrolytic Detectors; Sp.irk Coil, 75c.; 

Shocker, 50c., and $3.50 Telegraph Set, $1. Har¬ 
old Hammer, 3225 23rd Ave., So.. Minneapolis. 

FOR SALE—Hudson Audion Amplifier Bulb, 
new, $500; Spark Coils, $1.25; large Accurate 
\'oltammeter, $2; also chemicals. All answered. 
J. C*. Swimmer, 19U4 Park PI., Brooklyn, N. V. 

WILL .SEI.iL OR TRADE—Complete set Cyclo¬ 
pedia of Applied Electricity in A 1 condition. R. 
O. Miles, Wyanet, Ill. 

WANTED “150 ohm relay, Yibroplex, Omni¬ 
graph, key, sounder, Audion, 15,000 meter coupler, 
small coupler, storage battery, high tension con¬ 
denser, rotary gap, ground switch, rheostat. Cash 
or trade. Write quick, giving best price, to tieo. 
Rozum, Mitchell, S. D. 

WANTED—For cash or trade, an Edison Phono¬ 
graph with records. Give condition, terms, etc. 
Frederick Towns, Winchester St., Ke«ne, X'. IL 

FOR SALE—$25 Erector Set complete in A-1 
condition, used once, $20. A. E. La France, 40 
Ely Street, Holyoke, Mass. 



^ Do you realize that these “Scientific Ex- 
= change Columns” are the World’s most re- 
= nowned “Swap” market? “THE ELEC- 
m TRICAL E.XPERIMENTER” prints 79.800 
^ copies of this issue; that means that at 
^ least 160,000 readers see this page and 
M probably a great many more. Our readers 
g who advertise here seldom advertise the 
= same thing tw-ice—usually within five days 
after the issue is out the advertised article 
has been sold, or swapped. The many testi¬ 
monials which we print here from time to 
time are ample proof of the almost miracul¬ 
ous pulling power of three columns. ^ 

Look around in your attic or workshop ^ 
and you will find dozens of long forgotten ^ 
articles, useless to you now, but very use- g 
ful to someone else. At a ridiculously low g 
cost you can either sell or swap such articles, g 
And remember this fact: The U. S. Postal g 
Laws protect you. No one can “do” or g 
cheat you. Of 3,410 “ads” published in g 
these columns during the past five years, = 
only twelve complaints were reported to us, ^ 
and each and every one was adjusted to ^ 
the full satisfaction of the complainant. m 

It matters not if you Imve old books or g 
magazines, a kodak, electrical or chemical ^ 
g apparatus, scientific instruments, bicycles, ^ 
s typewriters, moving picture machines, air g 
^ rifles, watches, structural toys, etc., etc. ^ 
s All these and countless others can he speed- ^ 
^ ily disposed of here. Try it and be con- ^ 
g vinced. g 

FOR .SALE—I C8 Electrical Engineering 
('ourse, 9 Vol. in goods condition. Cost $UUL 
Tlie best offer takes tlitin. fieo. Fehrcnhack, 76 
Hancock A\e., Jersey City*, N. J. 

FOR .sale—W irelr-is Sending and Receiving 
Apjmratus. Large m.arblc switchboard, miscel¬ 
laneous other electrical apparatus, hooks, chemicals. 
Want vacuum and X r.-iy tubes .\C and IK' meters. 
Ralph Hatcher, 131 Hyland, Ames, Iowa. ■ 

FOR .SALE—$50.00 buys $200.00 complete, 
good as new, Edison Moving Picture ^Iachine. 
135 feet of movie picture iTlin tor toy moving ma¬ 
chine. $1.25, .^0 foreign coins, $2.00. Herman 
D.avitl, 711 South Kedzie Ave., Chic.ago, HI. ^ 

.A SX*AP Owing to dissolution. $40 takes one 
Edison Motion Picture Machine, good order. En¬ 
terprise P. ^ X'. Co., Kewanee, Ill. 

SVMPHOXV PfIOXOGRAPH with about $25 
worth new \'ictor and Columb.a records, all good, 
$16. P. Edelman, 1802 Hague, St. Paul, Minn. 

FOR SALE-“Electric Therapeutic Apparatus 
Machine. Second-hand, in good condition, used by 
physicians for rheumatism and circulation. Will 
sell at a very reasonable price. John Ferguson, 
113 West 63rd St., Xew )'ork City: home, 364 
West 57tb St. 

\\'AXTED—Copy of book “Michael Faraday, His 
Life and Work’’ by Sylvanus Thompson. Also an 
^hmeter of the Roller-Smith type or a Wheatstone 
liridge; must be in first-class conditmn, and include 
galvanometer. II. \V. Secor, c o Elkctrical Ex- 
peri me.s’ter, 233 Fulton St., New York City. 

no lens or rheostat; automatic stcropticon, carries 
eighteen slides, uses motor; nineteen sets colored 
song slides; good make snare drum; cash or trade. 
High-tone rotary $9; Murdock oscillation $2.75. 
Want reliable wireless goods. New $7.50 Racine 
A. 1\. Utility Motor, $ 6 . 50 . \'erner Hicks, Marion, 

Motorcycle, in excellent condition, 2-speed, 2- 
cylinder, 9 II P., cost $275. Full equipment, tires 
almost new. Will sell cheap. Laverne Bushncll, 
Hanover, X. H. 

6 Typewriter. $14; $8 Drafting Set, $5; Set of 
“lIa^^kin’s Electrical (iuides,” $S. W'rite for list 
of other electrical and mechanical hooks. Want 
cash or good camera, or what have you? P. Plat- 
zer, 119 E. Grand Ave., Chicago, Ill. 

FOR SALE—Tligh-graile, second hand wireless 
app.aratus for sale at a bargain price. Write for 
list and information. Eldred Hall, Solvay, X. V. 

LARGE W'lRELESS receiving set wuh aerial, 
$12. Robert Bowers, c o F. White, Great Xcck, 
X. V. 

I'irelesv instruments or sell. Deiiecke. 1539 Ave. 
A., Xew York. 

EXCH.VXGE—Bicycle, toy transformer, and 
electric train for Hraiuies Superior Phones, llO 
volts a.c. motor or gas engine. Frank Low, Jr., 
193 S. Pine St., Pauls N'alley, (Oklahoma. 

SELL OR EXCHANGE New .VA Kodak, $36 
Meccano, 4-<>0 Storage. Send f »r list. W'ant 
Th ^r*hirson and other apparatus. Huff. 91.s Camp¬ 
bell St., Williamsport. Pa. 

SMALL screw cuttiiig lathe, 3 speed I.aihe and a 
Bolev .atcbm.aker's lathe for sale or exchange. 
Ralph C. Morse, P. th Box 14 7, Foxboro, Mass. 

FOR SALE —$50 set Harvard Classics, 51 bonks, 
new. $30; also 15” sp.ark coil without condensers. 
If interested write, will send piioto of coil and 
open bids. .\ny for less than $49 ignored. Harry' 
J. Frenz, 740 I'ranklin Ave., W'ilkinsburg, Pa. 

BARGAINS—6,000 meter XavT Type Coupler, 
$4.50. All kinds of wireless apparatus, all new. 
Write. W'alter Johnson, Salem, Nebr. 



October, 1917 

Opportunity Exchange 

V"OU will probably 6nd more opportunities and real bargains in these columns than anywhere else in the country. Most good things in 
* life are bard to find and worth going after—these little ads illustrate that point; you alone will be the real loser if you don’t take the 
time to scan through these columns. 

Advertisements in this section 4c. a word for each insertion. Count 7 words per line. 

Name and address must be included at the above rate. Cash should accompany all classified advertisements unless placed by an accredited 
advertising agency. 

Ten per cent, discount for 6 issues, 20 per cent, discount for 12 issues from above rate. Objectionable or misleading advertisements not 

.\dvertisenients for the November issue should reach us not later than September 25th. 


EXPERIMENTER PUBLISHING CO., INC., 233 Fulton Street, New York, N. Y. 


AERIAL AtiE. America's only illustrated week¬ 
ly, presents the latest dev'elopments in aeronau¬ 
tics throughout the world. Up to the minute 
technical information concerning aero-engines, 
planes, accessories and patents. Complete model 
news and instruction. Trial subscription six 
months, twenty-six issues, one dollar. Sample copy 
10c. Aerial Age, 280 Madison Ave., New York 
City, N. V. 


.WCTIONEERS make from $10 to $50 a day. 
Free catalog. Missouri Auction School, Kansas 



.\mateur Photographer’s Weekly; illustrated; week¬ 
ly prize competitions: print criticisms; many unique 
features; $1.50 per year; three months’ trial sub¬ 
scription 25c.; Abel Publishing Company, 401 
Caxton Bldg.. Cleveland, Ohio. _ 


Mind Reading. You can astonish everybody. Only 
20c for this book if you send now. H. Union Book 
Co., Palatine, 111. 

BOOKS—Scientific and wireless supplied. Let 
us know what you want and we will quote you. 
Experimenter Pub. Co., 233 Fulton St., New 
York City. _ 


MENTER will preserve your copies for all time. 
Price, 50c. Postage on 3 lbs. is extra. Send for 
one today. Experimenter Publishing Co., 233 Ful- 
ton St., New York City._ 

BOOKS. Due to fire in our stock rooms, a great 
many of our books were water stained, but not 
otherwise damaged. Rather than dispose of them 
to dealers we prefer to give our readers the bene¬ 
fit. Look at this list! Our celebrated Wireless 
Course, 160 pages. 400 illustrations; Experimental 
Electricity Covirse, 160 pages, 350 illustrations; How 
to Make Wireless Sending Instruments, These 
three books for $1.00 prepaid. Regular selling 
price of these three hooks is $2.50. We guarantee 
you will be satisfied. Experimenter Publishing Co., 
Inc., 233 Fulton St., New York City. 

OLD E.E. BACK NUMBERS—We have some 
valuable old E.E. hack numbers ou band as per. 
list below: 



.price each $.20 

Jan. ... 

. price each $.25 

April . . 
May . . . 

Feb. . .. 

(1 II tt 

March .. 

” “ “ 

June .. 

H ♦» ■* 

April . . 
May . .. 

. “ “ “ 

July ... 

M *1 i* 

,« It « 


M M i* 

June ... 

II II tt 

Sept. .., 

tl 14 

July .. . 

II 11 It 

Oct. . .. 

t . n 

August . 

“ “ “ 

Nov. .. 

. * ** ** 

Sept. ... 

11 •! tt 

Dec. .. 

. * ** ** 


It it tt 


Nov. ... 

It 11 tt 

Jan. . .. 

. ” ” .15 

Dec. . . . 

tt 11 tt 

Feh. . . 
March . 


April . 
M^ay . .. 

It <1 II 

Jan. . .. 

■ t" \\ ‘^Pt 


June .. 
July ... 

«t tt <t 

We can fill orders at once upon receipt of your 
remittance and if you have not these numbers al¬ 
ready now is your chance to get them as they 
probably will be snapped up very quickly. Ex¬ 
perimenter Publishing Co., 233 Fulton St., New 
York City. 


BUILD .a money-making business of 
your own. \Ve will instruct yon to manufacture 
articles that sell rapidly. We will teach you how 
to make Silver-Plating Powner, Liquid Court-Plas¬ 
ter. Straw-Hat Bleach, Rc-Silveriiig Mirrors. Dress¬ 
ing and Polish for tan shoes, Luminous and Oilcloth 
Paints, Toothpaste for Collapsible Tubes, Soap- 
Btihhle Liquid. .Ml these formulas with instruc¬ 
tions. only 50c. Sidney Specialty Co., 233 S. Fulton 
St., New York City. 


URANYL CHLORID (Radio-Active) pure, 
oz., 75c; Uranyl Bromid (Radio-Active) pure, *4 
oz., 90c; Uranyl Oxid (Radio-Active) pure, J4 oz., 
85c; Uranium Metal fused (Radio-Active) I gram, 
$2. The above are guaranteed genuine. Robert 
j. Haiichett. Nestor, (^ak__ 

.STOP playing. Experiment systematically with 

real chemicals and apparatus. Six cents brings 
catalogue. Clarence Appel, Mathews Avenue, 
Knoxville, Pittsburgh, Pa. 


or over, wanted by Government for excellent clerical 
positions, $100 month. Steady work. _ Short hours. 
Life appointment. Common education sufficient. 
Write immediately for free list of positions now 
obtainable. Franklin Institute, Dept. G-27, Roches¬ 
ter, N. Y. 

Gentlemen: | 

lichen it comes to results th$ **E.E*‘ 
is all broke out zvith it. Rec'd an ^ 
anszver with the same mail that I got | 
the magazine on. M 

Yours truly, J 

Bernard Brown. M 

BE A DRAFTSMAN—Big pay; tremendous 
demand. Study at home; complete course; draw¬ 
ing instruments FREE. Our students tilling good 
positions as Draftsmen and Chief Draftsmen with 
Government and private concerns. We help you 
secure position when qualified. Columbia School 
of Drafting, 25 McLachlen Bldg., Washington, 
D. C. 


ELECTRICIAN and Armature Winders. Send 
$1,50 for 16 blue prints of motor windings, 10 A. C. 
Single, two and three phase and 6 D. C. Or, 20 
A. C., 6 D. C. and 6 rotary converter drawings, 
$2.25. Winding made easy. Superior Electric 
Co., Pittsburgh, Pa. Lock Box 1372. _ 

MINE R A L S—T wo cents brings catalogue. 

Clarence Appel, Mathews Avenue, Knoxville, 
Pittsburgh, Pa. 


We have a sm.ill supply of Tennis Rackets, made 
by one of the largest firms in the country, on hand 
which we will close out at the following prices: 
No. 2375—Extra best Tennis Racket, $5 grade, air 
dried ash, popular long oval form, concave walnut 
wedge, superior quality of gut; each, $2.75. 

No. 2377—First grade Tennis Racket, second 
growth ash. walnut and maple throat, very good 
grade of gut; handle of cedar with leather cap; a 
$3.25 grade; each $1.85. 

No. 2.376—Medium grade Tennis Racket made of 
the same stock as No. 2377 except the gut. A per¬ 
fect $2.25 grade. Ideal for beginners. Each $1.35. 
Shipping weight of each size two pounds. Send 
for one today. Our stock is limited and policy is: 
“First Come, First Served.” Don’t forget to in- 
cliifle money for postage, or we ship express collect. 
The Electro Importing Co., 233 Fulton St., New 
York City. 


SEND for circular. 12 in. Semi-quick Change 
Gear, Screw Cutting Lathe. Compound Rest, Power 
Cross Feed. Complete $200. Western Machinery 
Co., Cincinnati, (Dhio. 

CASTINGS for “Machine-shop” Bench Lathe, 
6 in. swing C. to C. Complete set only, $7. Louis 
E. Schwab, 3708 Brooklyn, Cleveland, Ohio. i 


IDEAS WANTED—Manufacturers are writing 
for patents nrocured through me. Four books 
with list hunareds of inventions wanted sent free. 
I help you market your invention. Advice Free. 
R. B. Ow’en, 130 Owen Bldg., Washington, D. C. 

PATENTS—R. Morgan Elliott & Co., Patent 
Attorneys, Mechanical, Electrical ancl Chemical 
Experts. 716-724 Woodward Bldg., Washington, D.('. 

PATENTS—Without advance attorney’s fees. 
Not due until patent allowed. Send sketch for 
free report. Books free. Frank Fuller, Wash¬ 
ington, D. C. 

PATENTS w’orth while. No free booklets, no 
premiums, no trading stamps—nothing but good 
service. Samuel Herrick, Master of Patent Laws, 
Washington, D. C. 


facture them for profit. Drawings, instructions 
etc.. Twenty-five Cfents. Satisfaction guaranteed 
Circular free. Associated Phonograph Co., Dept 
E, Cincinnati. 


MO\MN(; PK'TURE FILT^IS three feet long 
10c each or 50 ft. for 50c. Larger quantities at 
rate of Ic per foot. L. £. Adams, Lewiston, Me. 

CUT PRICE developing, printing and enlarging 
for films, film packs, and plates. Send stamp for 
price list. X.L. Photo Co., 24 Franconia St., 
Worcester. Mass._ 

WE HA\’E a limited number of beautiful art 
pictures r-f the following famous electrical men on 
nand. Nikola Tesla, Thomas A. Edison, Guglielmo 
Marconi, C!harles P. Steinmetz and Reginald A. 
Fessenden. These make a handsome decoration 
for any laboratory or workshop and should be 
prominently displayed. Price tor five, prepaid, 
25c. Experimenter Pub. Co., 233 Fulton St., New 


STAMPS—75, all different, free. Postage, 2c. 
Mention paper. Quaker Stamp Co., Toledo. Ohio. 

to applicants for our approvals. Postage, 2c. 
W’rite for premiums. 

300 Different.30c. 

100 Different. 5c. 

Universal Stamp Co.,< Mt. Clemens, Mich. 


LESS, also STATION AGENCY, taught quickly. 
TREMENDOUS DEMAND—much greater than 
BKi SALARIES — recently raised. IDE.^L 
WORKING CONDITIONS—short hours, vaca¬ 
tions with pav. sick and death benefits, etc.—pre¬ 
greatly desired by Railways and Western Union. 
Tuition reason.ible. Cheap living expenses—can 
be earned. Oldest and largest school established 
43 years. Endorsed by railway. Western Union 
and Marconi Telegraph Officials. Large illustrated 
catalogues free. Correspondence courses also. 
Write today. ENROLL IMMEDIATELY. Dodge’s 
Institute, Lone .St., Valparaiso, Indiana. 


TYPEWRITERS, all makes factory rebuilt by 
famous “Young Process.” As good as new. look 
like new, wear like new, guaranteed like new. 
Our big business permits lowest cash prices. $10 
and up. Also, machines rented—or sold on time. 
X’o matter what your needs are we can best serve 
voti. Write and see now. Young Typewriter Co., 
Dept. 362, Chicago. 

Succeed Throulh Electricity 

This interesting story 
^hows vou the wav to 

Read These Testimonials 

"Any Electrician. Oneratinsr 
Engineer,or Student who wants 
to do hia own construction or 
further advance himself in the 
Electrical hold should have a 
set of these hooka ’’ 

John Kelley 
116 Union St., Newark. 0» 

*' For the_ man not fretting a 
collese training’ and even in 
that case, 1 can aincerely a'ay I 
do not believe there is a better 
eet of books in the market to¬ 
day." Lloyd D. Huffman 
Dayton, O. 

" We consider Hawkins Elec¬ 
trical Guides the moat compact 
and complete aet of electrical 
references in the market." 
Noggle Electrig Works 
Monterey, CaJ. 

" Hawkins surely knowa the 
srt of condensing inforroa- 
tioD." Elbridge F. Ball 
Buckland, Coon. 

This is the Electrical age. 
Electricity now controls more 
trades, directs more men, offers 
more opportunities than any 
other power that man has yet 
discovered. Through exact 
knowledge of Electricity you 
will advance in salary and 

Hawkins Electrical Guides 

Will Show You How 

These books are the standard works on Elec¬ 
trical Science. They are a complete and up-to-date course 
in Electrical Engineering, presenting the information in a 
way you cHn use it. Only Sl.OU per volume and owners of the eet 
say there are no better electrical books published at any price. 

Specially Arranged for 
Home Study and Reference bo°u 

flexible Mack buckram with gold edges. Fkasy to read and handle. 
You tan carry each single volume about with you until you 
havt- ma.<l« red the subject it foniains. Written in the fomi of 
question.^ you would ask and the answers to them—in plain, 
practical, everyday language, complete, concise, authentic and 
to the point. Over 3200 pages and more than 4,000 illustrations. 


1 00 

A Number 

1 00 

A Month 

Shipped to You FREE 

■ ■ „ .. . COUF 

Theo. Audel & Co. 
72 Fifth Ave.p N. Y. 

Ple.ase send me for 
F R H 1C examin tion 
11 I w k i n s Klecirical 


Send no money. Examine the books first. Decide for yourself that they 
are the most complete library of Electricity ever published and that you can- - 

not afford to be without them. Every book is complete in itself, but the complete set is 
the best bargain. The last volumes are just coming off the press. 

Accept this unusual offer now — (;,id fs (Trice $1.00 each). 

■ ayiTlCJIla today. Each page—every illus- 

tration will convince you of the big value i agree to .semi you $ each 

we are offering. See the books first, 
then decide. If you decide to keep 
them you can make settlement at . 

only $1.00 monthly until paid for. Signature 



Mafrnetism—InHuction—Experiment'^ — Dynamofi 
—Elfciric Machinery—Motors—Arnn.Ttures—Arm¬ 
ature Windings—Instailinir of Dynamos—Paectri- 
^ c Mnstrumi'nt Testing — Practical Managrement 
?ir and .Motors—Distribution Syatems— 

\\ irinji—WirinK DiaKrama—SiRn Flashers—Stor* 
"P*; Batteries-I’rinciplesof Alternating Currents 
and Alternators—Altematin;? Current Motors— 
DiK ( urrent Systems—Circuit Breakers—Meaaur- 
mif lnatrumenL*<—Switch Boards—Wiring—Power 
S^tions — Installing —Telephone— Teleirraph— 
Wir-elcsa-Bells—Lighting—kailwavs. Also many 
Modem Practical Applications of Electriciti* and 
Heady Rcfcretjce Index of Uio lOouJoabers* 

irionth until p:iid. 

72 Fifth Ave. 

Business Address. 

Residenco . 

Reference .. . fkt. E.E. 

You benefit by mentioning "'Jlic Lieetricat Lxf'erimenter „ 

i f r .>i »s. 

Bud Morriss 

Chief Instructor 

American School of Aviation 

This well-kmnvn aviatur 
IHTvf)nalI\ .miiih the i>rog- 
n of cacli slinU nt. He 
.'i^^iNted by a fli''tingiiishcd 
StatT of Xeroiiauiicai Fngi- 
1 <‘i r>, Xviators and Aero- 
j lane Alanniacinrers. "I lie<e 
t' en give yon i)iact'cal. 
r i L' h t down-to-tlie-minnte 
^\( rking knowledge of the 
er\ 1 igix ''l mi T t. 

witi • raw II 

•’r « l^'-.rt \> 

,* ith •111 ii-»! 

A t at 

If >011 read the newspapers you know the facts. Right 
now new Aeroplane factories are being built everywliere. By Spring 
they will be ready and looking for thousands of trained men who know and under¬ 
stand Practical Aeronautics and the ^Mechanics of ^Aviation. Here is your chance. 

Aviation is the young man's profession—tlie richest held 
of opportunity ever opened to “live wires.*’ Are you one? 

Then write, quick, for full information. Send the coupon 

War has given to .iz'iafiott only its start. The return of 
peace will see this ama/ing new industry rivalling the rai)i(l 
growth of the anlomohile bu.^lness, with bigger opportuni- 
•Ts for the ph^neers, tlie men wlio get in XOW and are 
ready nevt Spring to step into one of the thousands of big 
I>a\ing positions. X'ou can do it. 

Learn in a Few Months M^ii 

No matter who you are, where you live, 
or wiiat yoi-r age. if yon can read and write l-'nglisli. 
>‘'U can quickly and easily master this wonderful Ccnirse in 
Practical Aeronautics. Lessons are written in simple, non¬ 
technical easy-to-understand language, and illustrated willi 
diagrams and blue prints. You are under tbe personal <li- 
rectioii of i)ractical aviators and aeronautical exi)erts 
tbroughoiit tile entire Course. Positively the most PRAC- 
'I IC.\L. most iiUerestiiig and fascinating Course of home 
lutly instruction ever prepared. 



Prepare NOW 
for One of These 


Aeronautical Engineer 

$lnO lo $300 per week. 
Aeronautical Instructor 

$f)0 to $150 per week. 
Aeronautical Contractor 

Enormous Pruth.-i. 
Aeroplane Repairman 

$fjO to $75 per week. 
Aeroplane Mechanic 

$40 to $b0 per w cek 
Aeroplane Inspector 

$50 to $75 i>er week. 
Aeroplane Salesman 

$5000 per ye.vr and up 
Aeroplane Assembler 

$40 to $^5 per work. 
Aeroplane Builder 

5135 to 53 



TIktc'.s nol a moment to lose. Send thi' 

c<'npon—<r a postal today—thi? minute—for full 

].. • til •!].• r;« .a* lUt ll i< great Soh m 1, it? faculty of famous ^ 
avi.ii. rs and its remarkulde tra iiing Co rse. X\’e PROVE 
ib.'tt v\e can t^uickly It >ou for any branch of the .Ava- 0 
I I Industry y - i to enirr. I.rl us tell you 
al loit t'<• \M n i* rf'd .SPECIAL OFFVIR we ar<- n< w 0 
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Money Back Guarantee 


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refund rvrrv rrt t p. id f,.r tu f n if \i u arc n« t satlstle I on con jilc- 

American School of Aviation 

431 So. Dearborn St. 

^ Dept. 803A, Chicago, III. 

Without nny obligations on my part, 
please scn<l me full particular? of 
your in Practical .\cronautics 
iiiul your Siiecial LIMH IvD OtYer. 




431 So. Dearborn St., 

Dept, 803A