THE ELECTRICAL EXPERIMENTER June, 1917 AVIATION81 PRACTICAL AERONAUTICS by MAIL Earn $50 to $500 a Week!

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JEJUNE, 1917 IS CENTS

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THE ELECTRICAL EXPERIMENTER June, 1917 AVIATION81 PRACTICAL AERONAUTICS BY MAIL Earn $50 to $500 a Week!

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Electrical Experimenter 233 FULTON STREET, NEW YORK I- -l.i liy hxpcrinu-nU-r I'll l.lishing Company, Inc. III. l,.-rn rer;) 233 Fulton Street. Vol. V Whole No. 50 CONTENTS FOR JUNE, 1917 No. 2

I TJX', I UK RO( ENEMY. .From O ER WIRELESS STATION WINS PRIZE LOVING CUP ., painting by George W.,11 ELECTOR CROSSING SIGNAL OPERATED BY TRAIN'S THE NAVAL RADIO OPERATOR—WHAT THE Ui !.' NAVJ

WHISTLE By George Wall oil) I VDIO MEN ing CHANCES FOR ELECTRICIANS IN THE NAVY RADIO OUTFIT BUILT BY GERMAN SPY" TALKING MOTION PICTURES VIA WIRELESS B By Worth MacKnigbt 112 ELEi rRICITY AND WATER TO Kl'N OUR AUTOS 1111. HOW A ID Win OF RADIo APPARATUS NO. 4 SPARK SHOOTING WITH ELECTRICITY Bv Hugu Gernsback 113 THE (LOCK ( RAZE CTRICITY'S AID TO WOMEN' THE INFLUENCE Bv Thomas Reed 114 OF LIGHT UPON THE V : i.NT At T POTEN- POWERFUL HYDRO-ELECTRK SALVAGE APPARATUS TO TIAL OF RAISE SUNKEN SHIPS.. By H. W'inrield Secor, Assoc. A.I.E.E. SELENIUM AND OF CUPROUS OXID "« ELECTRO-DEPOSITED MIRRORS NOW USED FOR PHOTO HIGH FREQUENCY AXd" • APPALS 'zxVAJsiKslr"^ i 1 1 1 1 WORK 97 117 "JOE'S EXPERIMENT"—An electrical story by C. M. Adams 100 THE PROBLEM OF USING THE ENERGY H^liU&IGHT*!"? ELECTRICITY AND LIFE By Dr. Frederick Fineh Strong 104 3 118 EXPERIMENTAL PHYSICS—LESSON 5, "HYDROSTATICS EXPERIMENTAL CHEMISTRY-THIRTEENTH 'less, In™"'' Bv John Furia. A.B , F.K.S. J. MA. 106 By Albert W. Wilsdun 123

Silencing America's Wireless

S all our readers are aware the United of the President's Executive order, the more we become States Government, thru the Navy Depart- convinced that the closing of every amateur station, or ment, has issued orders thruout the land to even commercial stations, was remote from President cause the immediate dismantling of all radio Wilson's mind when he issued his order. stations, In conformity to the

large = , whether Radio Act of 1912, the or small, com- President in time of war, mercial or amateur, send- EXECUTIVE may authorize any depart- ing or receiving. All ORDER ment of the Government ordered aerials have heen THEREAS the Senate and House of Representatives of the to close all radio stations. dismantled and apparatus W' L'nited States of America, in Congress assembled, have But the President's order packed away. declared that a state of war exists between the United States and the Imperial German Government; and of April 6, was not to the This action came as a Whereas it is necessary to operate certain radio stations Department of Commerce, great surprise to all pa- for radio communication by the Government and to close other which in the past con- radio stations not triotic amateurs, who for so operated, to insure the proper conduct of trolled the war the nation's radio years past had been en- against the Imperial German Government and the successful termination thereof affairs, but to the Navy couraged by the Govern- Now, therefore, it is ordered by virtue of authority vested Department. Why? Be- ment and who were cer- in me by the Act to Regulate Radio Communication, approved cause the President, it tain that in time of war August 13, 1912, that such radio stations within the jurisdic- tion of the L'nited States seems to us, had only the they would be allowed to as are required for Naval Communi- cations shall be taken over by the Government of the United radio communications of "do their bit" with their States and used and controlled by it. to the exclusion of any the Navy in mind. If, other control or use; and, outfits for the country. furthermore, that all radio stations therefore, the Navy De- That the Government not necessary to the Government of the L'nited States for Naval Communications may be closed for radio communication. partment had caused the should silence all sending The enforcement of this order is hereby delegated to the closing of all radio sta- outfits was eminently Secretary of the Navy, who is authorized and directed to take tions, particularly sending such action in the premises as to him proper, and we have as yet may appear necessary. stations along our sea This order shall take effect from to hear the first complaint and after this date. borders, such action would The White House, on that score. But why (Signed) Woodrow Wilson. 6 April, 1917. have seemed perfectly log- the receiving outfits should ical. But why the Navy he dismantled by the Navy Department should wish Department is very puz- I - •••» to close stations a thousand zling indeed. miles removed from the President Wilson's Executive Order is based upon sea borders, seems to us very puzzling. Furthermore, the Radio Act of 1912, which act however, mentions why all college radio stations, and those belonging to nothing about closing receiving stations during the time radio apparatus manufacturers as well, should be dis- of war. That purely receiving stations were considered mantled seems far fetched. Then there are cases like harmless by the framers of the law, is best proved by the one of the Lackawanna Railroad, which is one of the the fact that such stations do not require to be licensed pioneer railroads in the United States to use wireless as do all sending stations. in Moreover, President Wil- for train dispatching. Is it wise to dismantle such sta- sons's Executive Order of April 6, no mention is made tions on which the safety of passengers depends? of receiving stations. Indeed, the following passage We certainly have no quarrel with the Navy Depart- strikes us as very significant: ment quite the contrary. wish to help, " ; We but we sin- and furthermore that all Radio Stations not nec- cerely do hope that its officials will soon find a way to essary to the Government of the United States for Natal Com- munications may be closed for radio communication. modify its recent suet ping order. The italics are ours. Particularly the one word MAY. There are, indeed, eno ^igns already. Cer- In the same paragraph the President uses the command tain commercial stations on the Pacific Coast have re-

SI I \I.I„ while the word may does not implj thai every cently resumed operation, and it is to be hoped that radio station should be taken over by the Navy Depart- amateurs will be allowed to operate their receivinf UEmsmmmmment. Indeed, the longer we study the third paragraph tions, at a not too distant future. H. GERNSBACK. THE ELECTRICAL EXPERIMENTER is puhUahl on the IMS of MCh month -ii 233 ire paid for on publication, a si>eclal rate is paid for novel experiments: Fulton Street, New York There are 12 numbers per year. Subscription price is $1.50 a good photographs accompanying them are highly desirable.

( s ud possessions Canada and foreign countries $2.00 i year D S coin a* well as V. a stamps accepted (rm foreign coins oi in s each. TITE ELECTRICAL EXPERIMENTER Monthly Entered as second-class matter at A sarnplo copy will t>e sent gratis on reQUi CI t lers should be to the N'-w York Posl office, under A<- of March 3. ' drawn order of THE EXPERIMENTER PUBLISHING CO.. INC If right WIT, bj B P Co I New York, The contents of this address notify us promptly, In order thai copies ere nol miscarried or losl A green magazine are copyrighted and must not be reproduced without giving full credit to the wrapper Indicate* expiration. No copies sent after expiration. publication.

mmunlostlofu and contributions to this Journal should be addr.-st to: Editor, Stat.s THE ELECTRICAL EXPERIMENTER, 233 Pulton Sti ri Unaccepted con- Till" ELECTRICAL EXPERIMENTER Is tor sale at all newsstands in the United 1 tributions cannot he relumed unless full return postage has been Included a 1. 1, accepted and Canada; also at Bnotano'S. 37 Avenue de 'Opera. Paris. 83 84 THE ELECTRICAL EXPERIMENTER June, 1917

Now Is the Time to Rebuild Your Set and Install that Supersensitive Receiving Apparatus Owing to the present war conditions we can supply the Highest Grade Apparatus at very low prices

Receiving Sets Amplifying Coils from Detectors $9.10 to $910.00 Panel Sets Amplifiers and Cabinet Sets Oscillating Cabinets Vacum Tubes Complete

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( Oscillating- Audion) Generator of absolutely undamped oscillations of any frequency. Permits Radio Telephone speech surpassing in clearness that over any wire. For 1 Laboratory and Research Work has a field utterly unfilled. Patents issued and pending. ^^^^^^^^* -MANUFACTURED BY- 1 3 DEFOREST RADIO TELEPHONE VC4 PRICE TYPE EJ2—PRICE, $32.00 AND TELEGRAPH COMPANY TYPE — $20.00 VARIABLE CONDENSER NEW AUDION AMPLIFIER FOR NEW YORK CITY INCREASING STRENGTH OF RE- This Condenser is similar to our commercial type but is en- CEIVED SIGNALS 25 TIMES. Office and Factory Cable Address: closed in an oak cabinet. It has 35 semi-circular aluminum It is not a detector in any form. 1391 SEDGWICK AVE. RADIOTEL, N. Y. plates. The maximum capacity is approximately .0025 M. F.

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H. GERN5B&CK editor H. W. 5ZZUR A550Z\mE editor

Vol. V. Whole No. 50 June, 1917 Number 2

Electric Crossing Signal Operated by Train's Whistle By GEORGE WALL

VORK genius has developed tlit- sensitive reed relay, the latter closes such as a slow-moving dash-pot attached ANEWa clever idea for automatically the proper circuits to a powerful electric 1" id' sensitive relay, so that the relay sounding tlic alarm at railroad siren installed at the top of the signal could not open the siren and lamp circuits crossing, and whereby the alarm tower at the railroad crossinu. as shown for a period of a minute or so; thus mak- is controlled and actuated by the in the accompanying illustration and dia- ing certain that the signal will sound until whistle of the approaching train itself. gram of the elemental circuits. For night the train has past the crossing. The idea The accompanying illustration shows how requirements, the alarm may consist of the is, all in all. quite novel and possesses the inventor proposes to mount a number electric siren and a powerful beam of light, many other possibilities. of large size horns along tin- crossing- both of which are projected out of the The microphone has proven its worth in approaches, each horn being fitted with a nal horn. The siren is enabled to project many difficult roles in industrial as well super-sensitive electrical microphone, such its sound out into the horn past the incan- as military and naval operations. The sol-

Instead of Having the Gateman Sound the Alarm at Railroad Crossings This Inventor Proposes That Sensitive Microphones be Erected Along the Crossing Approaches, the Sound of the Locomotive's Whistle Causing Them to Actuate a Relay Device Connected to an Automatic Crossing Signal.

sensitive as used in the well-known Dictagraph. descent lamp, as the latter is mounted on diers in Europe have found the listening When the train whistle sounds for the a perforated disc, thus allowing the sound microphone of extreme value in sappers as they picked and sing these microphones, scattered along waves to pass by it. The alarm tower may to enemy below the listeners. Again .i distance of several hundred feet on either carry two or more of these combined elec- shoveled a mine enabled to accurately side of it, pick up the sounds and are tric siren and lamp signals, and. as he- the French have been off caused to control a sensitive relay device comes evident, the operation of the device locate and "spot" an enemy submarine as shore suitably disposing two or more operating on the tuned-reed principle. The is extremely efficient ; the alarm ceases by the coast relay will thus respond with maximum effi- soon as the train lias past the crossing. specially tuned microphones along ciency to a certain whistle tone, as the There are. of course, several details at a known distance apart. Then by a simple computation on a clever \ ibrating reed armature fitted to it is which aia not shown in the accompanying triangulation

- selected to vibrate sympathetically with tin- view, which would be necessary in carry- slide rule, the distance at which the dominant note of the locomotive whistle. ing out and applying the plan here pro- marine happened to be. is readily found. When the approaching train's whistle has posed. For one thing there would have and a fast patrol scout will be waiting thus actuated the microphone and in turn to be some form of time-element device her when she arrives at the surface. —

86 THE ELECTRICAL EXPERIMENTER June, 1917 Chances for Electricians in the Navy consequently the training and experience The U. S. Navy now tors in use for ventilating blowers, ammu- received in their operation and main- offers excellent chances nition hoists and conveyors, gun-pointing tenance are of exceptional value to the to ambitious young men equipments, turret-turning machinery, and who have a desire to various other purposes. These motors are electrician or radio operator in after life. proper operation and care of urn a trade and supplied thru special control apparatus from Since the dynamos, all the varied electrical apparatus is essen- arn it right. The na- turbogenerators, engine-driven tial efficiency of the it is the val electrician has un- motor-generators, etc. The lighting equip- to the Navy, equaled opportunities ment includes incandescent and arc lamps, practise to send all new recruits for this for attaining an ex- searchlights of the highest powers, special branch of the service to either of the two ceedingly broad and signal lamps, etc. Communication appara- Navy Electrical Schools at the navy substantial elec- yards at Brooklyn, X. Y., and Mare trical knowledge, Island (San Francisco), Cal. These covering dyna- schools provide instruction in two mos and mo- classes, general electrical work and length of the tors, wiring of all kinds, special and radiotelegraph}-. The standard signaling systems, telephone full course for both classes is eight systems, radio apparatus, and a host months. Men specially proficient in thru this in of other things with which the aver- the work pass period age "land-lubber" may never become shorter time, depending on the knowl- thoroly familiar. U. S. naval elec- edge and skill they- show. All stu- either recruits tricians never need to fear that they _ dents, or men from can not land a job after their service J the general service, may enter these schools at any time. In addition to in the navy is finished. Naval service offers many induce- the practical instruction imparted at ments to ambitious and spirited the electrical and other naval trade schools and training stations, the young men. Xot only does it provide men opportunities for free travel in many receive thruout their service aboard nearby and distant waters with ship and elsewhere both academic and practical training to enable them to changing scenes, but it furnishes excellent training of high value in civil demonstrate their abilitv and to ad-

Another View of the Electrical School Uncle Sam's Naval Men Receiving at Mare Island, Calif.. Class Receiving Training in the Operation of Electric Instruction in Electrical Appliances, Generators in the Navy School at Including Electric Searchlights. Mare Island, Calif.

pursuits at the conclusion of enlist- vance in their chosen vocation. ment. It also furnishes steady, In order that a recruit may en- healthful work, free board of a list for the electrical branch, he must wholesome nature, free lodging and have a knowledge of either general clothing, and in addition provides electricity, or be an operator of the pay, even during the period of train- Morse telegraph code or have suffi- ing, that can be practically all set cient foundation in radiotelegraph}- to aside for saving. The United States be competent to keep up with the Electricians Navy pays its enlisted men better class at the school. (gen- than any other national navy and eral) must know the names and uses in most lines more than the men of the various parts of the dynamo could save and in some cases even and dynamo-driving engines and more than they would receive in must be familiar with the ordinary of similar pursuits in civil life. Above types of switchboards and methods for both classes all this it enables the men to render wiring. Applicants the highest patriotic service open to must be able to write legibly, must the citizens of any nation, that of understand elementary arithmetic and defending the security of their coun- must be between the ages of 18 and citizens try in the first line of defense. 25. All applicants must be of the United States, either native The many uses of electricity aboard Top: —View in Navy School, New York, Class in Interior ship and in the naval stations have Communication and Ship Control Apparatus. Below: or fullv naturalized. Testing Dynamos and Motors. require- been steadily increasing. It is used Recruits meeting these not only for lighting and power ments are immediately transferred to of in- service, but also for communication and tii* consists chiefly of telephones and radio- the electrical school, where the course signaling, and even for cooking and bak- telegraphic sets. Machinery and apparatus struction comprises machine-shop work, ing. There are a multitude of electric mo- in use in the Navy are of the highest types, (Continued on pituc 142) June, 1917 THE ELECTRICAL EXPERIMENTER 87 Talking Motion Pictures Via Wireless

of us have no doubt wit- diated thru a ground wire leading to metal a corresponding record of their voices on MANY exhibition of talking plates (and points if necessary) on the the steel nessed an mo\ ing wire of the telegra- motion pictures, and numerous heels of the actors, as shown, and also phone, which has been explained in detail patents have been taken out on thru a miniature antenna comprising a in previous issue.-, of this journal. some very elaborate schemes in- series of tin-foil leaves which are Mini In brief, the telcgraphone operates

truded to improve the efficiency of the ap- in the clothing in the manner indicated in i the principle that if a moving steel paratus involved in recording and repro- the accompanying illustration. The i. wire is past by the pole of an electro- ducing the voice, as well as the figures of apparatus is carried in the clothing, and magnet thru which electrical voice curr ' photoplay productions. the weight of each part distributed in the are circulating, then there will be local

bi i I Ine of the most novel ideas devised to- manner possible. As will be noted magnetisations set up in the steel wire ward accomplishing tin purpose is out- the batteries are placed somewhat differ- corresponding to the voice fluctuations. If lined in a recent patent awarded to Wil- ently in the case of a lady, as compared then we afterward pass this steel wire liam B. Vansize, of Brooklyn, N. Y. The to a man. under another electro-magnet, the coil of

accompanying illustration by our artist I .mi fat . ee thai whenever tl which is connected to a telephone receiver, shows how the inventor proposes to utilize tors speak, that they will be radiating wire- we can then hear the voice reproduced. and apply the art of radio communication less telephone Currents, and these are in- The great problem confronting all in- to the recording and reproduction of talk- tercepted or picked up by a larger radio ventors who take up talking motion pic- ing motion pictures. In the first place, the antenna erected back of or just above the ture work is to accurately and practically studio stage is fitted with a metal floor, scenic settings of the studio stage in synchronize the motion picture voice with such as one covered with tin or sheet iron. manner illustrated. The stage antenna is the voice of the actor. This is the most

The One Great Problem in "Talking" Motion Pictures Lies in the Difficulty of Simultaneously Recording the Voice and the Scene. A New Method of Accomplishing This End Is Illustrated Here. Each Actor Carries a Radio-Telephone Transmitter on His Person. His Wire- less Love and Other Speeches Are Intercepted by a Stage Antenna. Connected to a Radio Receiving Set. This Set Is Connected to a Telegraphone Joined Mechanically to the Motion Picture Camera. Thus Synchronism Between Voice and Picture Is Established.

This may be painted so as to give the connected up thru suitable tuning coils, important problem, and by means of this effect of tile or carpet, and may have a with an oscillation or vacuum bulb de- wireless telephonic arrangement, as pro- few rugs scattered about to give an artis- vice, which is used in this case as a de- posed by Mr. Vansize, it seems that it tic stage setting. The small insert illus- tector and amplifier of the received radio- should become a simple matter to readily tration shows how the inventor proposes telephonic currents. accomplish the purpose intended, viz., to to have each actor actually personify "a Now we have the actor's voice radi: record and reproduce faithfully a talking walking wireless station." In brief, each by wireless from his own person, thence motion picture, and one in which the ac- ir carries a complete wireless transmit- propagated thru space by etheric waves, tors' lips will not be moving about ten ting system on his person. When the ac- and finally, we have them coming in thru seconds after the voice is heard or vice tor speaks, the voice waves affect a super- the receiving circuit of the stationary radio versa. sensitive microphone hidden inside the coat detector. The secondary or auditory cir- In practise a number of loud-speak- or in the bodice, in the ease of a woman. cuit of the detector and amplifier is con- ing ti are scattered about the mov- This microphone is connected to some nected with the recording electro-mauncts ing picture theatre, and as the operator form of miniature wireless transmitting ap- of a Poulsen telegraphone, mounted in- cranks his machine, the telegraphone wire pal, itus, such as an Oscillion or vacuum tact on the motion picture camera which is unreeled at exactly the same speed. The bulb generator of radio currents. The vo is recording the scene photographically. impulses from the recorded telegraphone

fluctuations are cause. 1 to var\ the cur- Thus, as the photographer turns the handle wire now are used to operate the loud rent developed by the Oscillion. and these on the motion picture camera, he not only talkers about the house, with the result fluctuating, high freqtiencj oscillations cor- records the physical movements of the ac- that the audience sees and hears the ac- responding of course to the \oiee, are ra- tors, but simultaneously he also obtains tors in a truly remarkable manner. —

88 THE ELECTRICAL EXPERIMENTER June, 1917 Electricity and Water to Run Our Autos GASOLIKE forms the nucleus of close arrangement of the positively and load. The motor develops 45 h.p. on an power in practically all automobile negatively charged electrodes, the gas gen- average at this speed, and under full load, engines of the present day, and eration is both rapid and efficient. with a well worked in motor. The suction many inventors and chemists have As before mentioned the oxygen is liber- displacement per revolution is 244/2 equals expended considerable energy and ated by suitable automatic valves, and the 112 cubic inches; equals .0648 cubic feet. money in an effort to find a satisfactory hydrogen is retained and past thru a mixing Then at 3,000 revolutions per minute and substitute for this all-important commodity, valve, similar to the usual carburetor used assuming 100 per cent volumetric efficiency, which has been rapidly and constantly in- on all gasoline engines and which can be the number of cubic feet drawn into the creasing in cost. One of the latest attempts controlled from the driver's seat, follow- motor per minute is 3,000 times .0648, or in this direction is that of Mr. Ernest E. ing the standard practise in motor-car equip- 194.5, and 60 times 194.5, or 11,670, is the Punches, who hails from Detroit, Michi- ment. A suitable quantity of air is taken number of cubic feet drawn into the motor, gan. in thru the mixing valve, and which, when of mixture each hour, running at maximum "Give me a suitable tank containing a set combined with the proper quantity of hy- speed and under full load. of plates submerged in water and a source drogen, forms a highly explosive gaseous The gasoline entering into that mixture of electric current, and I will drive your compound. When this is fed into the en- is 7 per cent by weight, and the amount by

MIXER CONTROL INT/IKE MM/FOLD TO Cn /AIDER

DYNAMO,

A Detroit Genius Claims to Have Solved the "Gasoline Substitute" Problem for Automobiles. He Utilizes a Very Simple Electrical Phenom- enon—That of "Electrolysis" or the Decomposition of Water by the Passage of An Electric Current Thru It. The Hydrogen Gas Evolved Is Mixed With Air and Past Into the Engine Cylinders. The Inventor States That It Is More Economical Than Gasoline Because of the Higher Explosive Value of the Hydrogen-Air Mixture. automobile engine without any gasoline gine cylinders and ignited by an electric volume will not depart far from the 7 per whatsoever at reduced cost," says this san- spark, it produces a force many times more cent, as there is no great difference between guine inventor. powerful than that obtained when gasoline the weight of air and gasoline vapor. So, The secret of this remarkable invention vapor is used. Some of the hydrogen gas in face of the fact that an explosion of lies in the fact that if an electric current produced by the electrolytic cell (decompo- hydrogen in a pure state, when mixed with is past between two plates submerged in sition of water) is stored in a suitable tank air, is a thousand times as powerful, as is water, it decomposes the water, evolv- under pressure, which makes it available the same per cent of gasoline vapor and 10 ing two gases, oxygen and hydrogen ; the for starting the car and emergency. The air, we shall be way above in figuring a oxygen accruing from this process is liber- entire combination unit fits the carburetor per cent mixture of hydrogen gas with air. ated, while the hydrogen is collected and side of the engine and is supported by the As 10 per cent of 11,670 is 1,167, the number « hen suitably mixed with a proper amount former manifold holding means and also of cubic feet of hydrogen, we must generate of air, it forms a highly explosive mixture by the frame of the auto chassis. It has in an hour. Bearing in mind that there are when ignited in the automobile engine cylin- been found by Mr. Punches from trial and 1,257.52 cubic feet of hydrogen in a cubic der. also by calculation, that the hydrogen gas- foot of water, and that 1,728 watts will de- The accompanying illustration shows how generating outfit here described, and which compose the cubic foot of water in an hour, the proposed water-electric gas-generating it is proposed to substitute for gasoline, will and also that 746 into 1,728 goes about 2J4 plant would be fitted to a motor-car, the require up to 5 per cent of the horse-power times, it is apparent that we will generate special dynamo together with the decom- developed by the engine, this 5 per cent of 90.52 cubic feet of gas per hour more than posing chamber and gas storage tank being the total engine horse-power being used to the Chalmers motor can use at maximum placed with the engine under the same bon- drive the decomposing current dynamo. speed, and under full load, taking less than net. The small Unipolar type dynamo is There are 1,257.52 cubic feet of hydrogen 5 per cent of the 45 h.p. to drive the decom- connected bj suitable gears or driving gas in one cubic foot of water, the gas at posing current generator. The inventor has chain to the timing gear on the crank shaft atmospheric pressure, zero degree Centi- demonstrated his invention before the entire of the engine, and supplies ;f low voltage grade, and it will require 1,728 watts of engineering staff of the Tecla Electrical direct current. This current is past thru electricity to decompose a cubic foot of Laboratory of Detroit, Michigan. the electrolytic cell shown in the illustra- w ater in one hour. Compare this with the When it is understood that gasoline is of hydrogen tion, alternate plates being charged po i following data, obtained from a Chalmers simply a mechanical mixture tively and negatively. The plates are pre- Motor Car Company engineer: and carbon gases and impurities, it will be ferably perforated so as to promote circula- The maximum revolutions of the Chal- -ecu that a mixture of pure hydrogen gas tion in the gas-generating cell, and by the mers motor is 3,000 per minute under full {Continued on page 145) ^ -

June, 1917 THE ELECTRICAL EXPERIMENTER 89

OPTICAL DEVICE THAT RIVALS GOVERNMENT TAKES OVER Todd, at TELESCOPE IN STUDYING Washintrton. will have charge of HEAVENS. MARCONI STATIONS. stations operated by the government. En- THE rollments will be made by commands of An optical device, which is said to rival The TJ. S. Government has availed it- naval districts. it not surpass the telescope in revealing self of the offer of the Marconi Wireless the mysteries of the heavenly bodies was exhibited at a recent meeting of the Amer- ican Society of Mechanical Engineers in New York. The invention was exhibited

by I >r. John A. Brashear, the grand old man of American astronomy, of Pittsburgh. "This instrument is called a diffracting

d I >. .< tor Brashear, as he what looked like a rectangular

• piei 1 about 2 bj 4 inches ! >n

thai 1 colors under the electrii limits. "< )n the plane surface of this pol ished plate, made accurate to one-tenth of a lieht ua\e, ..r within ofte-forty-fivi thou sandth of an inch, are ruled mure than

00 hues between which there is i greater error than one-two-millionth of an inch. "With this delicate piece of apparatus, made possible, first by rigorous scientific

trch ; second, by the skill of the artisan; third, by a knowledge of a vi us care to avoid temperature changes, and, fourth, by the accuracy of the mi

1 1 iphj sii ist has been able to tell the composition, temperature and dis- " tance of the -tar- REVIVING THE CHAIN SHOT TO DESTROY RADIO AND OTHER AERIAL WIRES. An American inventor has recently proposed that the military and naval authori- To Counteract the Poisonous Gas Fumes Blown Toward European Trench Rescuers Who ties revive a relic of warfare which was in Are Called Upon to Go Forth and Carry Prostrate Soldiers From Have Their Positions. They vogue many years ago—this is nothing Guarded Themselves Against Being Overcome by a Novel Telephone Appliance At- tached than the generally well-known chain to the Gas Defying Equipment. thot. In our grandfathers' and great-grandfathers' day it was considered quite a Telegraph Company of America, placing EUROPEAN SOLDIERS USE GAS nifty idea to tie one or more cannon balls its staff and stations at its service and has MASKS FITTED WITH TELE- together with an iron chain —thus, the name taken over for the period of the war not PHONES. chain shut. The accompanying illustration only the Marconi stations but all other ra- The accompanying illustration shows in shows a clever form of split projectile dio stations for military purposes. The a marked manner one of the peculiar and composed of three or more pieces divided eligible operators will be enrolled in the particularly effective scientific det in the manner shown, so that means. government service. Stations not required by brought out by the great European war. of a time fuse or other arrangement, these will be closed. The trans-Pacific stations Needless to say this war of all wars has pieces would fly thru the air as a solid will continue handling commercial traffic, developed hundreds, even thousands, of i projectile, and at the critical moment would but under government supervision. No inventions of every conceivable character. explode and describe a path of consider- ship traffic will be permitted on the At- First the Germans invented the gas ap- able width thru the atmosphere, and lantic and Gulf Coasts and the Great Lakes prov- paratus by which they attempt to overcome ing, it would seem, of decided excepting for the government, it will efficiency but their enemies in the trenches with clouds of noxious fumes, and here we have the answer to this challenge in the form of a gas mask or helmets, which are worn by the members of the trench rescue brigade, who are called upon to go forth ami carry prostrate soldiers from their positions where they may have fallen between the trenches, when overcome by the gas cloud. Each gas helmet and mask is fitted with a novel and specially designed telephone outfit, properly connected to a trailing wire leading back to the trench. so that the rescuers are able to telephone for aid without removing their helmet apparatus. GOVERNMENT RADIO BILL GOES OVER. House leaders at Washington have decided definitely not to pass at this session the administration bill for permanent Gov- ernment dictatorship over wireless app; tus, unless the President specifically requests it. It was learned that the House Mer- chant Marine Committee believes the Pn dent already has power enough over r A New War Invention Is a Split "Chain Shell" That Automatically Explodes at a Given stations to prevent their use in time of Range. It Should Prove Particularly Valuable In Destroying Radio Antennae and Other war. Wire Structures. The principal feature of the bill is its in destroying radio antennae, and all other continue for the present on the Pacific. ision for eventual Government owner- ted «ue structures such a- telegraph Trans-Atlantic traffic via Glace Bay will ship of radio companies. This feature is and telephone wires, power transmission not be disturbed. The Director of Naval not considered by the committee to circuits, et cetera. Communications, Lieutenant Commander strictly war legislation. ,

90 THE ELECTRICAL EXPERIMENTER June, 1917 Shooting With Electricity By H. Gernsback

ago, when the New York liquid fire is sprayed upon the enemy, be- lines) there is a 10-H.P. gas engine driv- YEARSCity elevated lines changed from ing a parallel to the writer's scheme. While ing a 5- to 8-H.P. Alternating Current steam to electricity, one of the ele- shooting flames over a distance of 50 feet Generator. The latter is connected to a vated trains caught fire. An alarm or more has not proven a wonderful suc- step-up transformer delivering from 10,000 was promptly turned in and in due cess, nevertheless the idea seems to have to 15,000 volts. A thin but extremely well time the firemen were on the spot. The some merits. And if the Germans can shoot insulated cable connects with the nozzle stream from the high-pressure hose was flames at us, why can't we return the com- carried by the soldier. This cable is con- played on the cars, and to prevent the fire pliment by shooting electricity at them? nected to one side of the transformer: from reaching the wooden structure on One is as easv as the other, with a few the other pole is grounded to earth. If which the rails rested, as now the stream hits an well as the wooden foot ^^^^^^^^^ —^^——-—-— enemy soldier (who is not path, one of the firemen of insulated from the necessity directed his IJAVE you ever stopt to consider that a fireman does not dare to let ground), the high-tension stream on the third rail. *• ^ a stream of water from a nozzle strike an electric wire, carrying current passing thru the ********** stream of highly conduc- any appreciable potential, say a thousand volts or more, as he may be The stars are not in- tive acid, runs thru the electrocuted. Proverbially speaking, it is a poor rule that will not work tended to indicate what man's body and thence happened and what that both ways. Hence we have the unique proposal by Mr. H. Gernsback, thru the earth, back to the transformer. In this case poor fireman saw ; rather that we charge the enemy with highly electrified streams of acidulated he probably will be elec- they are meant to illustrate water under high pressure. This unusual invention is not intended as a how long he remained un- trocuted or else knocked substitute for guns, but to supplement them. It represents one answer conscious. As a matter of senseless by the powerful fact the man was almost to the German's "Flammen Werfer"—Liquid fire. current. Even standing on electrocuted. Since that a piece of dry wood or a ~~~ — fight -^ — stone will not help him, time firemen do not ~^ elevated fires unless they for the acid running - are assured that the power has been turned points in favor of the latter , it would seem. down from his uniform will turn the wood off. Briefly, the idea is as follows : Strapt to or the stone into an excellent conductor Xow, the N. V. Elevated Lines only carry a soldier's back is a lead-lined metal tank and the enemy will almost certainly be ren- 500 volts direct current, but this pressure carrying a solution of diluted sulfuric acid dered unconscious. Probably the most effi- is sufficient to pass from the third rail of about 1200° specific gravity. (A solution cient way of utilizing the new scheme will line, then to the water of the fire hose, of chlorid of zinc or even ordinary salt be found in directing the charged stream and from there into the metallic nozzle water could be used.) By turning a knob at a machine gun. The second the stream held by the fireman. Altho ordinary hy- on the outside of the tank a small quan- hits the metallic portion of the gun, the drant water is a poor conductor, a 500-volt tity of zinc or iron filings is thrown into operators will be knocked unconscious or current nevertheless finds but little trouble the acid and immediately hydrogen gas is will even be killed. It is also understood in passing thru the stream of water and evolved, causing considerable pressure in- that the entire electrocuting outfit, gaso- thence thru the body of the fireman, with side of the tank. This causes the acid line engine, dynamo, transformer, acid tank

-jr

The Germans Invented "Liauid Fire" With Which to Destroy the Enemy. Mere is «n American invention—onooung me enemy »»" Pressure StreamV Charged to An Electric Potential of 15.000 Volts. Trench Gasoline Engine. Electric Plants Piercing High Acid Water P.-bber Shoes and Transferers Supply'the Necessary Power. The Nozzles Are Heavily Insulated and the Soldiers Wear Heavy As Well As Gloves and Masks.

all the rest of the equipment could be the result that he is knocked unconscious. to be forced out thru the hose attached and placed in an armored car. In that case, If the stream had been sea (salt) water, to the tank and from the hose the acid the operators would not be exposed to ma- there remains little doubt but that the man passes thru the long nozzle carried by the chine gun fire. would have been electrocuted instantly. soldier. The acid leaves in a fine stream, When used by the soldier, however, it this principle the writer has based less than a quarter of an inch in diameter, Upon is self-evident that his equipment must be witli fairly calm atmosphere, it should his idea of shooting electricity at an enemy, and a such that he himself will not be electro- feet. most pur- impracticable as the scheme sounds at first carry from 75 to 100 For cuted. To that effect he wears a special thought. Many murderous ideas, of course, poses, 50 feet however, will probably be "high-tension" rubber shoe, capable of with- have been advanced for trench warfare, found sufficient. standing 20,000 volts.* Then too he uses the German Flammen Werfer, whereby Now, back in the trench (or behind the "high-tension" rubber gloves, and in addi- June, 1917 THE ELECTRICAL EXPERIMENTER 91 The Best Way to Aid the President Hy HOWARD II. <;i<()SS, President Universal Military Training League

military policy which will Thej are emergen, he has while the unpatriotic rejoice in secret in AFIXTprotect tlir nation and said, 'flu, universal military training plan pportunity to remain safe and sound her manhood is the spei ial ni ed i, supplem< m, u - i<, the I ' esidenl ei at home, pile up money and have a good It ill oi the hour. Each pas ing da; em , tsures. goes further and v, time. i,,: l,t , r. i-. till demonstrati - this. This League While la- doing Such a false premium upon patriotism

,11. in universal he can do safely to pilot the ship of state t only disgraceful in a national mili- 1 its sponsors believe that military training lies the na tary program, but it i tion's chief hope. Thej there- cidedly uneconomical and ful. In nine cases out fore urge two things : of ten the slackers are able- First and foremost : Stand behind President Wilson in bodied, and under proper tutelage would a 1 everj way. 1 fe is beat ing a m tremendous burden. Assist soldiers, while the patri w fellows who rush to the colors him in all emergencj measures, whether financial, mili- are the sort who are needed tarj or ec >mic. most to man the commercial Second: Use every influ- and financial craft of the na- ence to impress upon our tion. The best brains will go Senators and Representatives into the ranks a- privates and i at in Congress that emergency leave the sluggards home nation's af- measures now pending < onduct the will not soke our military fairs. This is fundamentally needs except temporarily. bad in a democracy. They may carry the country Selective conscription n o along for the present, but doubt may be necessary at they will not do for the fu- times, but it never will be ture. The most democratic popular. Universal military program as a fixt military training, on the other hand. policy for the United States is, thru its very universality, It is that of universal compul- plain, simple democracy. SOry military training. It says that all having the bless- in.:- of our in stitutions treats all alike, makes use of What Military Training Does For a Man. Compare the Two Recruits young men before they reach on the Left With the Two Erect Figures on the Right. They Are the should, in time of need, con- After Being Trained for Five the age where their earning 'Same Men. Photographed Before and tribute their aid to defending Months in the U. S. Army. capacity is high and when these institutions. It saj s, untrained they are yet unmarried, and further, that the gives them six months' intensive military thru the eddies just ahead, I ask all patri- soldier is so much "cannon fodder of trained lad return- training. Then it sends them hack to work. otic citizens not only to strengthen his arm that the chances the These trained youth will form the backbone in this effort, but to aid the nation as a ing home in health from war are about of a great, democratic citizen army. This whole in supplementing the President's la- three times greater than the untrained boy's. training. is the only definite, simple and patriotic plan bors by the establishment of universal Therefore, in universal military that will make America safe and ready. military and naval training. the secret of our general military and naval I earnestly hope that every American The benefits resulting from such a demo- needs for today, tomorrow and All Time will stand by President Wilson and the cratic plan for raising an army in emer- is found. Government officials who, with the Presi- gencies cannot be over-estimated. The last The Universal Military Training League dent, are hearing a gigantic responsibility. few weeks have shown how weak and makes special appeal to the people of the their Congressmen to 1 have just returned from the national futile other devices have been. The vol- country to write capital and I know and sense in a measure unteer system is unfair, and because it is back President Wilson in all his emer- the weight that is taxing our silent and so thousands of young men who are as gency measures and to eradicate forever conservative Chief Executive. It would he patriotic and loyal as the best in the land the doubt, uncertainty and weaknesses of shameful to see his plans for meeting this will not offer their services. They have present muddled military policy by es- crisis defeated. Therefore, as should all come to realize that the strong, highest tablishing in law a fixt plan for universal, service. citizens, I bespeak general co-operation types of manhood go forward while the compulsory military training and with President Wilson in these mighty cowards and slackers only too gladly stay Stand by your President and strengthen

works. at home. The best blood goes to the front vour nation !

lion to this the nozzle is heavily insulated several minutes. On the other hand, the AUXILIARY SIGNAL CORPS from his hands by means of a special in- high-tension current kills either outright, UP-TO-DATE. sulator, as grafically shown on our trout or otherwise puts the enemy out of the Perhaps the finest single auxiliary sig- by army has been r. The tank of course must be well fighting for the time being, with little nal corps possest any insulated by soft rubber pads from the back ha'' after effects. The acid, plus elec- given to the United States by the Amer- of the operator. Thus equipt he is in little tricity, does not cause horrible burning ican Telephone and Telegraph Company. danger of being shocked hy the current. wounds or burned off limbs as does the \l,,ut 500 engineers already have been In order to prevent the wind from driv- liquid flame. -elected and some of them have been difference- ing his own acid spray against the opcr As with all war-schemes, the wise ones •.worn into army service. The pay their salaries alor's face, he is also equipt with a soft will now ask the usual question : What between government and rubber mask, as illustrated on our front happens, if the enemy. too uses the elec- with the telephone companies will be paid cover and on opposite page. tto, ni ing apparatus? by the latter. From a humanitarian standpoint, the In answer tin writer asks another ques- The corps will be made up of general to,' plant traffic engineers to plan, set up scheme is far ahead of the < lerman flame tion: What happens, if the enemj and shooter; sulfuric acid of 1250° does not uses liquid flames, or if the enemy too and operate telephone, telegraph and wireless If the regular force of the blind, nor does it destroy animal t, uses machine guns? plants. proves to be too small, men also unless it remains in contact with it for a army long on the skin, but will be provided to assist in the wireless period. Sprayed This shoe ":is described ,,n page 24, May, 1017, slightly itching results after a lapse of is,',.- ,.t lln work.

obtain Electricai DATE OF ISSUE.—As many of onr readers ha;-,- recently become unduly agitated as to when they could The the month in EXPERIMENTER, we wish to state that the newsstands have the journal on sale between the fifteenth and the eighteenth of should he in the eastern part oj the United States and about the twentieth of the month west of the Mississippi Rircr. Our subscribers that are not handled with the same dispatch by the possession of the,,- copies at these dati r. Kindly hear in mind, however, publications patient and do not send us complaints as to non-arrival Post Office as a letter. For this reason delays are frequent, therefore kindly be ol your copy before the twenty-fifth oj the month. 92 THE ELECTRICAL EXPERIMENTER June, 1917

Electricity Is Aid io Women.

Remember the Fellow Who Told the Walter the V u 1 6 Back-Breaking ?«i. ^ i " ,0 Polish Waxed Floors? This Steak Was Too Rare? Said the Walter— "We ow Accomplished In a Short Time and In a Highly rm i . .. Give That Steak tmclent Manner, Shown Cook by Electricity." "Well. by the Electric Motor Floor-Polisher E-Z Another Shock." Said the Patron. 93 June, 1917 THE ELECTRICAL EXPERIMENTER Electricity's Place In Business ELECTRICITY SPELLS EFFI- APPLYING PSYCHOLOGY WITH measures, President Wilson has appointed BOSS THE ELECTRIC "PSYCHOMETER." a number of prominent engineers in the CIENCY TO THE country to positions in the army. The latest device for testing speed and OF TO-DAY. will quality of human thought is the "Psychom- One of the appointments which meet reached a very important Efficiency has which is industry where the manu- role in modern an electrical appa- desire obtain the facturer manifests a to ratus now being his plant with a mini- maximum output of used in San Fran- other words Efficiency. mum input— in — cisco, where it is Various schemes have been promulgated being applied to in the direction of increasing efficiency in accurately measure machinery and it was found that the best the degree of means which the manufacturer can em- alertness in em- of ploj to determine the efficient output ployees in industrial his plant is to note the actual productive establishments, a s of power of the individual output each well a s general machine and employee. Schemes were in- mental alertness in troduced for this purpose, but the defects all vocations. encountered in them were numerous and The Psychom- to be abandoned for most of which had eter is operated by the purpose for which they were made. either alternating The distinct need of an instrument for or direct current increasing the efficiency in productive plants and may be at- grew more and more urgent, which caused tached to the base- a number of prominent engineers to study board electric light this rapidly growing problem. This work socket. The clock- finally led to the development of an instru- work attachments ment called the Productograph, herewith and electrical con- illustrated and which has proved the solu- nections are oper- tion to this absorbing problem. The intro- ated by pressing a simple telegraph key which is con-

nected with the Photo from Press Illustrating S- baseboard plug. Prof. Munsterberg Claimed to Be Able to Select the "Best" Ship All Psychology. The instrument is Captains, Locomotive Engineers, Aviators, Etc.— by the "Psychometer" Being Used to Test the Mental built in a grip and Here We See Alertness of San Francisco Factory Employees. The World Do Move. mav be easily carried around. The readings are made by with the most hearty approval of the elec- is that of an electric light, which is mounted on the trical engineering profession side of the small suit case. The instru- Paul M. Lincoln, Commercial Engineer of Electric Mfg. Com- ment is an accurate gage of memory and the Westinghouse & measures speed and quality of thought pany, as Captain of the Engineer's Corps to the fifth of a second, besides charting in the U. S. Army. alertness and ability to react quickly in Announcement has just been made of mechanical work and emergency situations. this appointment together with a number of other prominent engineers. If the machine stops for any reason, the Mr. Lincoln graduated from Ohio State indication on the paper shows this and University in 1892, and has for 24 years immediately gives the owner visual indi- been associated with the Westinghouse cation of the fact. In addition to this Electric & Mfg. Company. He is a Past equipment, an electro-magnetic counter President of the American Institute of is connected to the same circuit, which in- The Business End of the Electric "Producto- dicates the number of graph"—the Instrument that Keeps Tally on operations made by the the Dally Output of Each Worker in Shops this and Factories. machine. Thus, if instrument is attached to a printing press, it duction of this instrument was made pos- will indicate exactly sible by the application of electricity. the number of printed The first illustration shows the complete sheets that the machine instrument which is stationed in the man- has made during a cer- office. It con- ager's or superintendent's tain p e r i od . Each sists of a drum upon which a sheet of needle has its corre- specially prepared paper is placed. Over sponding counting in- this paper there are ten recording needle strument and both are arms, wdiich are actuated by electro-mag- connected to a single

nets ; these are located within the cabinet. switch. This particu- Each needle is directed over the proper lar instrument here- section of the paper and each needle is with shown is adapt- electrically connected to a single machine, able for ten machines. of which the productive efficiency is to be The second photo- found. The sections of the paper are longi- graph shows the adopt- tudinally divided into 24 equal parts cor- ion of this device in responding to 24 hours. Each division is a clothing establish- subdivided into minutes. The cylinder is ment, where it is used rotated by means of an electric motor con- for checking up the nected to a standard clock, operating a number of coats made series of electrical contacts. Normally, by each operative, when the needle arms are not acted on by the electro-magnet, which is connected PROMINENT to a special switch attached to the ma- ELECTRICAL EN- Here We See a Portable "Productograph." Connected to Each chine the record of which is to be obtained, GINEER BECOMES Machine It Enables the Young Lady in the Foreground to Readily ARMV lUTAWm/\i\l. a straight line is made and every time AKIVIY Keep an Exact Record of Each Employee's Output. Appreciating the im- the machine is in operation it causes the , Electrical Engineers, and lias always taken switch to close the electrical circuit period- portance of securing active interest in the work of this as- ically, which operates the needle arm and the ability and training of the engineers of an this in turn traces a curve on the paper. the country for use in national defense sociation. ; ! -!

94 THE ELECTRICAL EXPERIMENTER 1917

SOUND RELEASES TOY DOG block of wood, the dimensions of which AN ELECTRIC SELF-WAVING FROM ITS KENNEL. are those of the interior of the metal case. FLAG. The lower part of the lever B, should A very interesting toy has recently been One of the most talked of features at touch lightly the metal surface of the case introduced in the toy market and which the Electric Railway Convention at Atlan- A, at point C. Of course this must be is herewith illustrated. A similar toy was within the case. The complete circuit- described in our June, 1916, issue, but the breaker is placed behind the electro-mag- present one is of a simpler construction. net frame, as noted in the assembled ap- The "Wireless Pup," as it is called, is paratus (center). Two sheets of metal are fastened to the base to form a sound col- lector. The connections of the toy "pup" is very

simple, and is made as follows : One terminal from the electro-magnet is linked with the metal case of the circuit-breaker. The lever of the latter is terminated in a small flashlight battery and the opposite side of the battery is connected to the second lead from the magnet. When the "pup" is pushed into the kennel and against the tension of the spring disc, it is held by the energized electro-magnet. Then by making a sound such as by blowing a whistle, the cir-

c u i t - breaker will be spurred up, thus opening m om en - tarily the circuit which releases the spring disc, bouncing Mr. "Fido" out of the kennel.

A trap drum- mer has discovered that Two Views of New "Wireless Pup" That Springs Out electric lights of His Kennel at the Sound of a Whistle, the Voice, or i n s t a 1 1 ed in- the Clap of the Hands. side his drums keep the mois- shown in Fig. 1 ; this shows the dog stand- ture out and makes the drumheads tight. ing outside of his kennel. sensitive The This Flag Always Waves, Whether There Is circuit-breaker and other apparatus are all St. Patrick's Cathedral of Norwich, a Breeze or Not. A Motor-driven Blower Pumps a Strong Draft of Air Up Thru the placed within the kennel. This interesting Conn., is lighted with six electric projec- Hollow Mast, Which Accounts for the Mys- and most amusing toy was originated and tor units, which bring out the chancel arch terious Effect Obtained. perfected by Mr. Christian Berger, a promi- and altar in beautiful relief. nent physicist who has devoted most of tic City, N. was a waving flag which his attention to developing scientific toys. J., fluttered from a 27-foot flagstaff in front The operation of this toy depends upon of the General Electric Company's booth the opening of a delicate circuit-breaker puttong! inside the spacious convention hall. Not a by sounding a whistle or by the produc- "Speakin" o' buttons," said Zeke, Uncle breath of air wr as stirring, yet the flag tion of any other sound. This circuit- Shifting his quid to the other cheek, stood out on the pole as if a thirty-mile breaker is connected in series with a bat- "Speakin" o' buttons, I want to say, gale was blowing. The flag pole was of tery and electro-magnet, which acts There's upon the beatenest kind, down New York ordinary dimension and there was nothing a flat metallic disc. This disc or plate is way visible to betray the source of the breeze. so arranged that when it is released in by 'Twaz one o' them big hotels, by jing, The base of the pole was surrounded with the electro-magnet, it will strike the dog, That melts your dollars like snow in spring, banked palms. It was only when visitors pushing him out of the kennel. The elec- That I see them buttons, along the wall, got very close to it that the scarcely audible

trical circuit is only made when the flat Right in a bunch ; mebbee six in all. hum of a motor gave a clue to the source disc is prest against the core of the mag- 'Twas gittin' too dark to see outdoors, of the breeze. net, which holds the same to itself until An' I got to foolin' with them because The whole device is really quite simple the circuit-breaker is excited by sound There wuzn't else fer much me to do, in construction and easily explained, for the waxes. i When , Jiminy crick t — flagpole is metal tube electric ( a and an A detail photograph showing the various "«- ets before I _ O I knew, blower at the base shoots a strong current parts used in making up this toy is given l thought I .--^^. ^ Z. had sot of air thru the flagstaff. The air escapes at Fig. 2. The holding electro-magnet is _ "> ^ -\ tne house afire, thru perforations in the top of the flagpole / ,N seen at the left and consists of a core / '. I 't \, And yelled as loud as and imparts a waving motion to the flag. 54-inch in length and '.(-inch in diameter; \ \ ^ our old town crier, two insulated end pieces are placed on Till the folks came PROCESS FOR DRAWING LAMP each end and the coil is wound with No. runnin', licketty cut FILAMENTS. 30 B. & S. enameled wire. The complete I told them what wuz magnet is mounted on an iron frame, as the matter, but A process for cold-drawn metallic fila- shown. The small projection on top of They didn't do nothin' ments has recently been patented by Mr. the magnet is used to strengthen the mag- but laffe an' joke, K. Nishimoto, of Tokyo. Forming at first netic pull of the electro-magnet. The re- 'Bout that dad blamed a consolidated stick of mixture of tung- lease or discharge disc is fastened to this button I tried to sten and a small proportion of thorium, frame in such a way as to permit the poke, an alloy is obtained by uniformly heating disc to spring forward when released by Then they showed me the mixture at a sintering temperature and the electro-magnet. The complete arrange- just how it worked, then gradually keeping its temperature at is ment then mounted on a wooden I an' gee dull red heat. The consolidated stick is The sound operated circuit-breaker is 'Twas the cutest thing I ever see. then subjected to repeated hammering or seen on the right. This consists of a Why, it made a blaze like a bonfire done! rolling until it becomes so ductile that it rectangular metal box A. in which the sen- They said 'twuz invented by Eddy's son; may be hammered into bars, rolled into sitive parts are placed. The horizontal I don't know just who Ed is, but say, sheets or drawn thru dies into wires, much lever I'. is made from a Xo. 18 bare wire, His son is the feller that gits my pay!" like the metals which are commonly treated bent as shown; tin- ends are pivoted on a By Pauline Frances Camp. in this manner at ordinary temperature. "

June, 1917 THE ELECTRICAL EXPERIMENTER 95

Powerful Hydro - Electric Salvage Apparatus to Raise Sunken Ships By II. Winfield Secor, Assoc. A. I. E. E. POSSIBLY more than one enterpris- the position where they are to be used, the they will exert a tremendous lifting power ing inventor of to-day has conjec- engineers then proceed to fill the base mem- of thousands of tons. After these cylin- tured on the problem of raising ber with water causing it to sink. As it ders have gone up a suitable distance the some, if not all, of the hundreds of does so, the upright cylinder naturally as- are caught by the stationary vertical torpedoed steamers which lie scat- sumes a vertical position, and moreover the member and the ship is thus held while the tered along the European coast in compara- base member obtains a very powerful hold floating cylinders re-fill and take a new

t li«? tively shallow water, not t" mention on the bed of the ocean or harbor by "sand- bite ; the same operation is then repeated to many .sunken ships lying within the coast suction," besides the heavy water pressure the surface. boundaries of our own country. It is not bearing down on its outer surface. A num- Mr. Linquist intends building these cylin-

:: that we hear of a sunken ship being ber of strong cables are let down in the ders, not of steel but of narrow strips of floated and brought wood several inches into dry-dock for thick, or steel may the reason that the be used in certain cost of performing cases. The wood such an engineering strips are tongued feat is generally and grooved and prohibitive, and caulked and are held also in many in- in shape by steel stances, the prob- bands. The pressure lem of raising the of the water on the sunken vessel at all outside of the cylin- has practically been ders will in conse- d solution. quence tend to al- Now comes an ways tighten them, American inventor, as becomes evident. dt" Swedish birth, The inventor has one Mr. Carl Lin- broached and dem- quist of New York, onstrated by n and formerly of the of models, his Swedish Xavy, who unique idea to a has devised a re- large number of markable new sea-going men, in- scheme for raising cluding commander^ sunken ships of no of salvage squad- matter what size, as rons, and also to a long as they do not number of naval lie in too great a men, and has re- depth of water, and ceived unqualified which idea he in- recommenda- tends commercializ- tions from these ing at an early date. men, who should be It goes without qualified to judge as saying that if Mr. to the efficiency or After the War There Will Be Thousands of Vessels Lying on the Oceans' Beds. If Only a Linquist's idea, as inefficiency of such Fraction of These Can Be Floated and Repaired, Think What It Will Mean to Commerce. outlined herewith, A New Invention Intended to Accomplish This Purpose Is Illustrated Here and Involves a device if anyone proves feasible and the Use of Two or More Powerful Cylinders Which, as They Are Emptied of Water and could. Xot only is More and More Buoyant, Finally Exert Sufficient Upward Pull on the Cables to Made this idea consid- successful, that he Lift the Vessel. of will find plenty of erable promise and work for several years to come. water, and with the aid of an operator in- utilification in salvaging sunken vessels in The inventor's idea involves the use of side the inner pontoon who directs the times of peace, but it possesses according two or more telescopic cylinders or cham- w ork, these cables are swept under the hull to Mr. Linquist. several valuable naval fea- bers as shown in the accompanying illustra- of the sunken vessel. When all of the tures. For one thing he has suggested that tion, which are attached thru massive uni- cables have been properly placed, the en- one of these hydrostatic units would prove versal joints at their bases to the large gineers are ready to begin operations for very efficacious in the role of a "Submarine horizontal submerging chambers or "feet" raising the wreck. Here is where the re- Base," the outfit being anchored several which rest on the bed of the ocean or lake. markable genius of Mr. Linquist comes into hundred miles from shore stations if de- In the first place, it is of course paramount play, for he does not attempt to raise the sirable. Also they would serve as a resting that the exact location of the sunken vessel ship by means of steam or any other form place for the crew. be known. Having this information, the of engine. He has called upon Dame Na- The inner cylinder would have a large salvage expedition sets out from the near- ture herself to furnish the wherewithal to capacity for the storage of oil and gaso- est port with the necessary number of these raise any ship, no matter what the size. In line for submarines, and in the event of large collapsible cylinders with their at- brief, what he does is this:— being sighted by a hostile war vessel, the tached base members (or "Forts" as their The upper telescopic and movable cylin- upper cylinder and super-structure could be inventor calls them). The vertical cylinders rising within the vertical floating submerged so as to be invisible, and the in- ders shown lie horizontally, and as do also chambers and guides, they are allowed to ventor claims that no force, even the ocean the base members, which are made to float, fill with water from the ocean itself, and itself, cannot budge his suction foot mem- and the vertical and horizontal sections as will be seen these will then sink to any ber an inch, once it has got its grip on the double up like a jack-knife, permitting the required depth. When they have submerged bed of the ocean by natural "sand-suction. several units of this equipment to be towed until their upper structure is just above the and besides most of the floating membei by tug boats to the scene of the wreck water, the valves are closed, and by means lies in calm water, the action of the w. The present plans of the inventor con- of powerful electric pumps ( in case the not reaching very deep. A means is pro- sider that salvage operations may be suc- operations take place a considerable dis- m led for releasing this all-powerful grip cessfully carried on for any <\/v vessel in tance from shore, gasoline engine-driven upon the ocean-bed when it becomes depths of water up to three hundred feet, pumps are available"), the water within the sirable to move the unit to some other lo- and where nec( ssary four to eight or even movable upper cylinders is rapidly pumped in. U. S. Naval Officers have I is required ably imprest with this idea. more of 1 1 it- raising cylinders are emplo out. But a moment's reflection placing an equal number of them on each to at once see that these upper cylinders In closing, it is interesting to note that side of the sunken ship. will naturally become steadilj more and another valuable possibility of this device Supposing that several units of the sal- more buoyant, and providing they are built is that of releasing stranded vessels which vage euuinment are ready and floated to of the proper size for the work in hand. (Continued on pit tic 144 i

AMONG the hundreds of new devices and appliances publisht monthly in The Electrical Experimenter, there are several, as a 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. 96 THE ELECTRICAL EXPERIMENTER June, 1917

ELECTRICITY NOW ROCKS THE and sawed a slot into it for a distance of a head machines. When desired, however, CRADLE. foot at the other end, this slot passing thru the motor can be removed readily by a hole bored in it of the size of the wood loosening one thumb screw, as it is light and portable. "The hand that rocks the cradle, rules handle on the grinding mechanism, which is two The speed regulator is slipt on the the world"—runs an age old proverb, and, inserted thru the hole and then the brought to- treadle and held by a spring, making the albeit, one that embodies more truth than parts of the connecting rod little bolt. mounting exceedingly simple. The operat- fiction nowadays, perhaps, when we have gether upon it by means of a Only a minute is re- ing chain is attached to the metal frame- quired to trundle the work directly above the controller and little wooden frame pulled taut. to any place in the The regulator is light and substantial. house, one end being The case is made of prest steel and the provided with little principle of operation is entirely new. casters, also shown in When there is no pressure on the treadle the picture. The mo- the circuit is open. With a slight pressure tor can be attached to on the treadle a contact is made and as a any lamp socket by greater pressure is applied the resistance means of a flexible is cut out turn by turn. By varying the attachment cord, and pressure, one stitch, or several hundred in this circuit near stitches a minute can be taken. There are one of the binding approximately 100 steps in the controller, posts on the motor giving a corresponding number of speeds. Mr. Joleen has in- When folding up the machine it is only serted a small push- necessary to loosen the belt, disconnect the button switch for plug, and swing the motor around under starting and stopping the head. Felt pads underneath the base the motor. When the prevent the motor from scratching the fin- carriage is set on its ish of the machine. little track the con- The motor itself is out of the way when necting rod can be in- operating. This leaves both sides of the stantaneously con- machine table clear so that the operator nected by simply lay- can use this space for sewing material. ing it on the bar so The outfit, which is compact and light, that the slot engages consists of a small motor which operates the latter, and the ap- on either alternating or direct current, paratus is ready to mounted on a nickel-plated base, a speed work. Who will be regulator with operating chain and ten feet A Chicago Genius Has Evolved a Clever C ombination—a Baby Carriage Plus an Electric Motor and Part of a Small Grinder so kind as to invent of cord and plug, and a round leather belt. Reduction Gear. Result— No More Pushing the Baby Carriage an electric bottle The weight, including the speed regulator, Back and Forth. We'll Bet His Wife s a Suffragette! feeder? Next! is only 7 pounds. The cost of operating this motor is so the suffrage party to conjure with. But SEWING MACHINE PLUS MOTOR, small as to be almost negligible. At 10 look to their lau- the "suffs" will have to SAVES LABOR. cents per kilowatt hour, it costs less than rocks rels, for here is an electric motor that one cent an hour or less than it takes to The sewing machine was one of the first the cradle. Yes, and it doesn't object to run the ordinary incandescent lamp. household appliances to be equipt with an twins or triplets. "Come one, come all," is its motto. IS This device not only will rock the cradle THE ELECTRIC TEA KETTLE but will trundle a baby carriage back and HERE. sooth- forth on a little track, with a gentle, The recognized convenience and growing better than the ing motion which may be popularity of heating small quantities of movements. The traditional cradle rocking water by electricity has prompted the de- private use by Mr. device was made for velopment of the electric tea kettle illus- Chicago. Xels Joleen, of trated. little girl required so much Mr. Joleen's The successful operation of an electric that the resourceful of Mrs. Joleen*s time tea kettle depends largely upon the type of the gentle father decided that as long as heating element—method of application of fro the baby carriage pushing to and of heat. etc. The heating element here used to be a sovereign pacifier on all seemed is of the submerged type, located on the provide something occasions, he would bottom of the tea kettle and when in use perform the mechanical work, which would is entirely surrounded by water. Thus all mother free to go about her leaving the heat generated is efficiently utilized. other duties. The tea kettle has a capacity of 2y2 pints, the little Accordingly, Mr. Joleen made is made of drawn copper, spun into shape; frame, shown under the wheels of wooden spout of white metal : has bail handle, sides grinding the carriage : attached thereto a of which are steel, grip made of ebonized wheel designed to be operated by hand, something which he had in the house for

sharpening tools ; and then attached a small Machine Motor Drops motor of the kind which was once used as This Electric Sewing Out of Sight with the Head and Drives Very a sewing machine motor, accomplishing the Efficiently Owing to Its Spring Base connection by means of a belt from a verv Mounting. Small pulley on the axle to the perifery of the grinding wheel. The driving pulley had electric motor! The first motors employed to be made so small that he simply cut a were just the ordinary type, but later de- short section of a broom handle, bored a signs have resulted in the development of hnle thru the center, and fastened it on a motor having necessary speed control for with a small set-screw. The gearing in the use solely on sewing machines, and the effi- grinding wheel mechanism, originally in- ciency and operating features of such tended to speed up the grinding wheel with motors have been greatly improved. reference to the number of revolutions per- The latest and most desirable features formed by the handle, now works just the are to be found in the special motor shown other way to all intents and purposes, as in the accompanying illustration. Electric Tea Ket- the speed of the motor must be reduced to This type can be readily attached to any Here We Have the tle. Hot Water When You Want It the slow circular movement desired. make of stationary or drop-head sewing and Where You Want It Is Now an In order to transmit this motion and at machine, new or old, with the exception of Actual Fact. the same time translate it into a back and a few obsolete models. When not in use convenient forth movement Mr. Joleen then took a the motor, if mounted on a stationary head wood comfortably shaped for small piece of wood about three feet long, machine, can be pushed back out of the pouring. The lid has no hinge to come off knob forms an notched it at one end where it rests over a way and the cover put on, or dropt with —locks on securely. The brace underneath the body of the carriage. the head if used on modern types of drop- integral part of the metal lid. :

June, 1917 THE ELECTRICAL EXPERIMENTER 97 THE PROPERTIES AND COMMER- CIAL APPLICATIONS OF Electro-Deposited Mirrors Now Used for SELENIUM. Photographic Work

By W. F. Alder. splitting the light from a certain voltage, however, is very high and is stept Selenium was discovered by the Swedish IN"source, the problem of dividing the up by a transformer from a value of 156 ntist, Berzelius, in 1817 as a by-product rays in definite portions may strike volts to 5,000 volts. oi the distillation of sulfuric acid from one at first thought as an exceedingly As soon as the current is turned on a imn pyrites. It has an atomic weight of difficult task. In certain kinds of pho- pink glow is noticeable in the jar. Just 79.S specific gravity in its electrical con- tographic and optical work, however, it is above the thin metal cathode, however, ducting form of 4.788, its va- there is a certain dark region which is por sp. gr., at 2,5881'., being called the Crooke's dark space. The action 5.68. of the current causes minute particles of Selenium, like sulfur, with 1 to leave the cathode and to be deposited the glass which is placed which it is isomorphous, ex- on plate ists in different allotropii just at the edge of the Crooke's dark space, forms, three of which are as where the metal is most cohesively depos- follows: is ( 1 ) Amorphous Selenium Fig. 3 (At Left). Jar for Making 11-inch Partly Transparent ied as a finely divided Mirrors. The Cathode Is at the Bottom and Consists of a Thin Sheet of Gold or Platinum- so- brick-red powder, when a iridium Alloy. The Glass Plate to be Coated Is In a lution of selenous acid is pre- Plane Parallel to the Cathode. cipitated by sulfur dioxid gas, Fig. 1 (Below). Arrangement of Apparatus for Electro- or when the acid is reduced by plating Partly Transparent Mirrors in a Vacuum, the suitable agents. Amorphous Smaller Jar Being In Operation. selenium has a sp. gr. of 4.26 and is soluble in carbon disulfide. (2) (a) Semi-colloidal red amorphous Selenium is formed when solutions of dextrose and selenous or selenic acid are gently heated together. At 100"C. it is partially trans- formed into ordinary black Selenium. (bi Colloidal Selenium can be obtained in a blood-red solution by an aqueous solution of the red precipitate obtained by the

reduction of Se 2 . (3) Vitreous Selenium is formed when the amorphous variety is heated to 218 C. and then suddenly cooled when it forms a brittle, black, glassy mass, soluble in carbon disulfide having a sp. gr. of 4.28. All three of the above forms have so high an electrical resistance that they may be regarded as non-conductors. The Selenium as used in the electrical arts belongs to still another modification, viz., the crystalline or metallics state metallic selenium is obtained when the melted vitreous variety is cooled to 210° C., and then maintained at that tempera-

ture for some time. very essential to divide the rays in such a ited. With the current constant it is only gray crystalline modification which The manner that one portion of the light will necessary to record the time of operation : occurs in makes possible the selenium cell go in one direction and the remaining por- the amount of metal deposited can then be two forms, vi7 tion in one or more other directions. Part- easily determined, since it will, according gran- ( 1 ) Round ly transparent mirrors are used for the pur- to Faraday's law, be proportional to the stable ular crystals, pose, and in order that the precise division time and current. 140° an insu- at C, of light may be known beforehand, the In Fig. 2 is shown a set of interesting dark lator in the thickness of the thin layer of metal which curves obtained in a typical run with a sensi- and not very is deposited on a plate of glass to form the tive to changes in mirror must be exactly known. <> intensity. \ y light In Fig. 1 is shown the apparatus devel- \ ^ (2) Which is oped in the research laboratory of one of d \ !> readily formed the leading camera manufacturers for use ji, when the above in making mirrors of different degrees of P - granular form is transparencies employed in certain impor- y^ ft -v :' 200° /- heated to C. In tant photographic experiments. Two in- ^ this form it is a rel- verted glass bell jars are shown, each of ^ < > atively good con- ~~- which is connected to a vacuum-pump sys- A/ ductor. It will, gto tem. By means of this arrangement the air ::- ' /\p however, instantly pressure inside the jars is reduced to a .- respond to succeed- scant millimeter. This is done because in 00 loo *w ing exposures. The a rarefied gas the passage of electricity Mi/ Amps. - Minute general belief, also from the cathode, the terminal at the bot- Fig. 2. Curves Showing Reflecting Power at Degrees Incidence erroneous, seems of each jar, to the anode the upper 45 and Percentage of tom — Metal Deposited Light Transmitted the short- and for to be that terminal, is greatly facilitated. The ca- Platinum-iridium Mirror With Varying Prod- est wave lengths, thode consists of a very thin sheet of metal, ucts of Time and Current. i.e., the violet, are which usually is of gold or an alloy of the ones which have platinum and iridium. A short distance cathode of 70 per cent platinum and 30 the most pro- above this sheet of metal in a plane paral- per cent iridium, measuring 120 millimeters nounced effect upon 120 millimeters l.\ 0.1 millimeter. lel to it ; the glass plate to be coated is by These the conductivity of placed on glass pillars as shown. curves show the reflecting power at 45 Selenium Cell in Vacuum. Selenium, but ex- The larger jar is 16 inches in diameter degrees incidence and the percentage of haustive research and 11 inches high and , is used for coating light transmitted and metal deposited on a has proven that the waves having the great- mirrors 11 inches square. With the air ex unit of area for varying products of cur- est activity for increasing the conductivity hausted the atmospheric pressure on tlii- rent and time. It was found that a mirror have a length of over S.OIH) units. jar (about 15 pounds per square inch) whose transmission was equal to its re- The writer encountered innumerable mounts up to approximately five tons. flection required a deposit of 3.4 milli- difficulties which were, however, overcome The current is measured in thou- grams per square decimeter. in the type of cell illustrated herewith. sandths of an ampere (milliamperes). The Photos court, istmatt Kodak Co. —;

98 THE ELECTRICAL EXPERIMENTER June, iqi;

A New Optical Pyrometer laminated i on cores must be provided for the coils; these are built up of Xo. 22 gage The new pyrometer here shown is a prac- scale pointer is directly attached as seen. iron strips one and a half inches wide by tical, convenient, and at the same time, ac- In this manner the unknown rays are twenty-six inches long, the completed core curate instrument, which can be success- compared with those of known intensity being about half an inch thick. The strips fully used by unskilled workmen. Temper- from the electric lamp. As the accuracy are shellacked before being put together, atures from /(.IOC. upwards are read di- depends upon the constancy of the light and are held by paper insulated rivets in rectly upon clear, open scales. Owing to from the electric lamp, a small ammeter order to prevent the formation of eddy the rapidity with which readings can be and regulating resistance are fitted in the currents in the iron or rivets. After insulating the cores they are wound with two layers each of Xo. 20 D.C.C. magnet wire, coated with shellac or insulating var- nish, wrapt with cotton armature binding tape and then bent to conform somewhat to the curve of the couch surface when sagged by the weight of a patient lying upon it

As part of the equipment a Test Coil is provided. This comprises a built-up iron core similar to the others, but only about three-quarters of an inch square in section. At its center is wound two layers of Xo. 25 D.C.C. magnet wire in a coil about six inches long, the terminals of which are carried to a miniature lamp socket at the end of the core containing a two-and-a-half volt battery lamp. This wand-like contrivance is considered by the patient an indispensable part of the outfit, and is used to determine when the couch is "working."' When brought into the influence of the rapidly alternating, magnetic field surrounding the coils the little lamp is lighted, the dimensions of its coil being such that the core be laid taken, and the ease of sighting upon small box containing the accumulator to ensure may upon the couch in close proximity to the coils beneath without objects, this pyrometer is particularly suit- that whatever the voltage of the battery danger of burning out the bulb. By moving able for research purposes and in many may be, the current passing thru the lamp the test coil away from and around the processes in steel, pottery, glass and other is constant. To ensure that the candle- couch a visible demonstration of the strength works. It has been developed by an Eng- power of the lamp shall remain constant and extent of the magnetic field is af- lish concern. over long periods as the filament ages, pro- forded. The instrument may be regarded as a vision is made for calibrating the instru- photometer, in which, by simply rotating ment from time to time against a stand- To operate the couch the patient merely the eyepiece, a beam of selected monochro- ard anryl-acetate lamp, and thus ascertain- lies down upon it and switches on the cur- matic light from the hot body is adjusted to ing the correct reading of the ammeter rent. Xo physical effect is noticeable be- equal intensity with a beam of similar light when the electric lamp is giving the cor- yond a slight vibration due to the alter- from an incandescent electric lamp. It is rect illumination. This test need only be nating current, the beneficial results ob- not a color-matching instrument, and in made at long intervals and the standard tained being supposedly an effect of the consequence of the simple construction, ac- lamp need not be carried into the factory rapidly alternating magnetic field surround- curate readings can be taken repeatedly by or plant. ing the body. different observers with remarkable con- The pyrometer is supplied fitted with one There appears to be a difference of sistency. The formula, which expresses or more temperature scales of any desired opinion among medical men as to the exact the relationship between the intensity of the range from 700°C. upwards, but the fol- action of this magnetic field upon the hu- radiation of a hot body and its temperature. lowing standard ranges are suggested as man system, but in looking at the subject has been examined both theoretically and suitable for most practical considerations: from the engineer's instead of the physi- practically by many investigators and has single scale instruments, 70O-14O0°C. ; sin- cian's viewpoint, the following theory sug-

give results accu- instruments, 900-2000° C. ; been shown to of great gle scale double gests itself : Do the blood circulatory pas- racy up to the highest temperatures. The scale instruments, 700-1400° C. and 1200- sages, the veins and arteries, or any of the constants of this formula for every instru- 250O°C. ; double scale instruments, 900- ment are individually determined at several 2000°C. and 1400-4000°C. temperatures before calibration. The general arrangement of the instru- ELECTRIC COUCH INDUCES ment is shown in. the figure and includes : The pyrometer, consisting of the optical CURRENTS IN THE BODY. system, the electric lamp, the shield carry- By H. H. Parker ing the temperature scale and pointer ; the The electric couch described in this ar- teak carrying-case with fittings for fixing ticle makes possible a simple application of the pyrometer and standard lamp for check- the commercial alternating current in the

ing ; 4-volt accumulator, ammeter and reg- electro-therapeutical treatment of insomnia, ulating resistance, complete in teak case hardening of the arteries, nervous dis- an adjustable tripod the standard lamp and orders and other similar ailments ; a num- stand. ber of sufferers from such troubles claim The following is a brief explanation of that they have been greatly benefited thru the construction. Behind the enlarged part its use. While the apparatus has been con- in the front of the pyrometer in which is structed: in various forms, the one described fitted the electric lamp, are two holes. has the advantages of simplicity, lightness, Light from the object (such as a furnace) neat appearance and ease of operation, pro- under observation passes thru one, and vision being made for connection to any light from the lamp thru the other. These' lighting circuit carrying alternating current beams of light then pass thru a system of at 110 or 220 volts and any frequency. lenses and prisms, are polarised in differ- The couch itself is an ordinary wicker- Unique Electric Couch Which Passes Power- ent planes and rendered monochromatic. work affair, to the bottom of which are ful, Alternating Magnetic Fields Thru the Body. Finally the two beams of light pass thru fastened a series of coils, wound upon lam- a single ocular. The observer sees an il- inated sheet iron cores. In the one shown it were, luminated circular field divided into two in the illustration eight coils are used, con- organs or other parts, form, as of a trans- semi-circles One semi-circle is filled by an nected in series for 220 volts and in series- the closed secondary circuit induced image of the hot body under observation, parallel in groups of four in series when former, in which currents are field while the other is uniformly illuminated by operating on 110 volts. At a convenient through the action of the magnetic current flowing the electric lamp. The two semi-circles are point at the head of the couch is placed a produced by the alternating brought to an equal intensity of illumina- wall key socket for cord and plug. in the primary winding of the coils beneath tion l'\ turning the eyepiece to which the Owing to the use of alternating current. the couch? J. 1917 THE ELECTRICAL EXPERIMENTER 99

SIR OLIVER JOSEPH LODGE. Prof. June, 1917, Marks His 66th Birth Bell Receives "Civic Forum Medal" For 1917 Anniversary. rhi i shows the pre- service, in re f his invention of Om hi" the most profound scientific sentation of thi "( h ii Forum Medal" for workers and thinkers we have ever had. is 1917, to Dr. Alexander Graham Bell, the The medal was established in 1914 to ex- Sir Oliver Joseph Lodge, who is still an actiw- figure in the field of scientific rc- search, and all of us expect in the near future i" see something even more won-

di i ml than any of his preceding discoveries and inventions. fS Sir Oliver foseph Lodge was horn on fune 1-', 1X51, at Penkull, Staffordshire, England. He received his early education in the Newport Grammar School and later he entered the University of Coll, London, where he specialized in scientific and mathematical research. His scientific trend was noticed by the professors of different universities, and after he had graduated from this institution he was elected as Profes- sor of Physics at the University of Liver- pool. Since 1900 he has been principal of the University of Birmingham, He has had many honors and degrees conferred upon him and is an active mem- hcr of many of the leading scientific institutions. Sir Oliver Lodge was- presented with the honorary degree of Doctor of Science from Oxford, Cambridge, Victoria, Liverpool and others, also that of LL.D. from St. Andrews, Glasgow and Aherlaide. lie was president of the Mathematical and Physical section of the British Association in 1891 and President of the Physical So-

ciety of London. His most important work Copyright by International Film Service. in electro-physical science is that of wire- The Inspiring Moment When Professor Bell, Inventor of the Telephone, Was Presented With the "Civic Forum Medal" at New York, on March 21st. Reading Left to : less telegraphy, in which he has introduced Right— John J. Carty, Union N. Bethell, Dr. John H. Finley, Prof. Bell and Thomas A. Watson, some of the most fundamental steps in Who Made the First Telephone for Prof. Bell. commercializing this fascinating art, and in fact he is called by many the father of inventor of the telephone. Those in the pic- press the sentiment of the American people ture wireless. The Lodge coherer was the first from left to right are : John J. Carty, toward their great living men and women. chief engineer instrument used for successfully receiving of the American Telephone Its purpose is to promote more general ap- radio waves. and Telegraph Company ; Union N. Bethell, preciation of distinguished public service lie president of the York Telephone discovered in 1889 that two metal- New and inspire ambition to emulate such ser- lic surfaces in perfect, Company and senior vice-president of the but not conducting vice. American Telephone and Telegraph Com- The medal this year was awarded to Dr. pany; Dr. John H. Finley, (presenter of the Bell by vote of the members of the National medal) ; Alexander Graham Bell, inventor Council of Seventy, of the telephone, and Thomas A. Watson, representing the whole country, geographically associate of Dr. Bell, maker of the first and so far as pos- telephone instrument and receiver of the sible in all other respects. first telephone message. On the table are The medal was first presented to Maj. the first instruments used by Dr. Bell. Gen. George Washington Goethals, U. S. On March 21, in Carnegie Hall, New A., in 1914 for his work in building the York, Dr. Alexander Graham Bell, was for- Panama Canal. In 1915 it was presented to mally presented with the Civic Forum Thomas A. Edison in recognition of his Medal of honor for distinguished public contributions to electrical inventions.

along wires. He thus came into close the specification deals exclusively with the contact with the researches of Hertz on utilization of electromagnetic waves. This the creation of electromagnetic waves in is the noted Lodge tuning patent which free space, and this work he both expounded is universally employed in all forms of and extended. radio transmitting apparatus today. The His interest in these matters was, how- patent recently expired and became public ever, scientific rather than technical, and property. he himself has admitted that before the Sir Oliver Lodge is a noted author, and matter had received attention from others some of his most important works are it bad not occurred to him to suggest "Elementary Mechanics." "Modern Views the employment of Hertzian waves for of Electricity." "Pioneers of Science." "Sig- practical telegraphic purposes. In the nalling Thru Space Without Wires," "Life

course of his scientific work he had di- and Matter," "Lightning ( onductors and rected much attention to the phenomena Lightning Guards," "Modern Views of Mat- of electrical resonance. Hence, when it ter," "Man and the Universe," and bis latest had been indicated that the chief prac- book. 'Raymond— A Treatise of Life and tical importance of Hertzian waves might Death," which purports to prove that the be in their application to space-telegraphy, author actually received communications Lodge was not slow to apply his knowl- from his dead son. who was killed while edge to this subject. serving with the English army in France. On May 10, 1897, Lodge applied for a Hi-* theory however was received coldly provision patent protection in Great Britain by the scientific world. for improvements in Syntonizing Teleg- raphy Without Line Wires, and in this HOW ELECTRIC VEHICLES Sir Oliver Joseph Lodge, Famous Eng- document he states that the subject of his lish Physicist and Savant. He Is Re- invention was to enable operator to BOOST EFFICIENCY. garded by Many as the Dean of Pres- an ent-Day Scientists. transmit messages across space to any \ New York department store speeds or more of a number of different individ- up the loading of us delivery wagons by contact, were welded together when an elec- uals in various localities, each of whom is running its "electrics" inside of the build- tric discharge past between them, and later provided with a suitably arranged and ing and transporting them to various floors on studied the propagation of electric waves "tuned" receiver. The subject-matter of on large eleval 100 THE ELECTRICAL EXPERIMENTER June, 1917 Joe's Experiment

By C. M. Adams

<« A XD anotheanother thing," Mr. Robertson the mountain-side, Joe Benson paused and as much about the plant as I do," one of the faint unit X'o. f\ checked Pete ; "don't bring that listened to purr of 1, them ejaculated admiringly, after Joe had r\ blind kidkit around here any more, far away down the slope. Ever since the come off victorious in a technical argument. •*- -*- He's jusist in the way, and if he Snake River Power Company had started "Sure he does," Pete retorted. "Don't ^it< hurt the company'll have the the first day's work on this water power think he don't know anything because he damage' t<> pay. What business has a project, Joe had been an interested listener can't see. He'll make his mark—you blind kid got around an electric plant, of everything that went on. Listening had watch." anyhow? You keep him out of here, been his chief avenue of impression, for At first the size of the Snake River understand?" his eyes were useless, and had been project had dazzled Joe. Then with a Pete Foley whirled and surveyed the so for several years. He had heard the realization of the extent of the undertak- nervous, drawn face of his chief lor a rumble of the blasts, and the grit and ing had come, at first as a dream, and resolve, moment, and then flung back hotly : grind of drills and steam shovels as they then a the idea that he, too, would "Look here, that boy's a friend of mine prepared for the big concrete dam which become an electrical man, an electrical en- and a mighty good friend. He's not in held back the water. He had listened and gineer. True, he was blind. But he was your way when he comes around here, and been interested, but mystified, until Pete attending the high school up the valley I'm responsible for his safety. As for Folev. a member of the electrical construe- and in two vears would be ready to enter

"No, you don't. Not me," Pete interrupted, as Mr. Robertson turned to him. "Here's the boy you want to thank. He saved your plant and not me." what business he's got around an electric tion crew, had come to board at his home. the university. Other blind men had done plant, let me tell you that he knows more It was Pete who had answered his Inn^s things equally as wonderful. Why could about electricity right now than some men and U'hys about the plant and its opera- he not enter this field? who are paid big money for what they tion, and during the year which had And what a day this had been, what a are supposed to know. He'll make his elapsed Joe absorbed electrical information wealth of impression and sensation. He mark some of these days when he gets like a dry sponge taking in water. had stood beside the great towering masses into the electrical world, you'll see. And At first he had listened to the conversa- of iron and copper and had felt with his furthermore, he's going to come here when- tion of the men, but had been loath to own sensitive hands the giant castings and ever he wants to, as long as I'm around." take part in it because he felt his own coils of the great generators, while Pete Mr. Robertson's white, haggard face ignorance of their work. However, as explained how they were built and worked. flushed angrily and his lips parted as if to time past, and Pete's daily instructions bore So this April afternoon he went home speak. But he was silent as Pete swung fruit, he began to take a more active part warmly glowing with new- impressions and out of the power house and up the trail to in the talk of the men during the evening. desires. the company's tool shack, Pete Foley was At first they had regarded him as an Pete did not have time to talk after a good electrician, a very go<>d electrician, outsider, whose ignorance of their work supper. He went upstairs for his clothes and men with this particular kind of good- was to be tolerated for politeness sake only. and then disappeared down the slope in were so scarce in these mountains But gradually, as Joe's comments and ques- the company car, on his way to Merwin that it behooved Mr. Robertson to stand tions became more intelligent, they began to complete preparations for the trans- for much from this member of his con- to look to him as an equal—as one of their formers in the sub-station there. And so struction crew. own number professionally. Joe sat on the porch and listened to the Half way up the road to his home on "I'll be hanged if that kid don't know faint hum of the generators below him. — 1

1917 THE ELECTRICAL EXPERIMENTER 101

while lie dreamed of his future. Joe knew that the sixteen thousand volt from school. That night as he sat on the Two days later when Pete returned from current could nol be turned directlj into porch he was still thinking of it, and yet Merwin, Joe was waiting for liim alter the city lines. He knew that burned out had found no ready solution for the dif- supper as the group 01 gathered equipment and electrocuted people would ficult). on the porch. be the result. The voltage bad to be ' "I don't see how they're going to fix "Pete," foe began, "I've been wanting to ered, but how? He wondered about it and that up if those transformers don't come," ask you something since day before yester- tried to think what Mr. Robertson would to Pete. day, but you weren't here to answer it." do, as he sat on the porch and listened ou aren't trying to figure "i .o ahead, but don't go too deep. Re- to the men talking, and far away the faint out a way, are you?" Pete exclaimed. member I'm only an ordinary electrician," hum er house, "Why yes, 1 ought to be able to, or try Pi te warned. limbering up their beam anyhow," Joe protested. "Well," Joe went on, "Let Robertson do that. "on one of those switch- ^^^^^^^^ ;^^^^^^^^ He's paid for worrying," board panels you showed Pet( "turned easily. me the other daj there AST month we publisht a rattling good story—"Eddy Currents" But that did not satisfy was a rheostat, but you 1 The plant by Mr. Adams. We confidently believe that the present tale will below say it L didn't what was him had grown under his appeal to all dyed-in-the-wool electrical readers. You don't require an for. \\ hat does it do, rstep. He had anyhow?" electrical education to become "en rapport" with the author, as he pos- heard every bit of metal "Oh, that's the rheostat sesses that happy faculty of weaving the technical and personal aspects and concrete put into for the exciter's field," place, and he felt in such a way that the moral cannot be mist. The facts related in this as if Pete responded. "'It's the thing were his own. story are human, pertinent every-day affairs. Similar obstacles to those connected in the shunt Then, too, was he not go- winding of the exciter facing invincible Joe Benson, the hero of this narrative, have confronted ing to be a consulting en- field coils. It controls all of us at one time or another. But true "Philosophy" will unlock all gineer some day; would the voltage." doors and surmount the greatest of barriers. not a problem similar to "What docs it do that this be put to him for for?" Joe insisted, going __^__^_ solution? He ought at to the bottom of the mat- least to attempt to solve ter. it now. So he puzzled "\\ ell, here's the idea," Pete explained. Of what use would this power be if ln~ brain over the thing that night and "You see the exciter supplies current to the there were no transformers at Merwin? all the next day, suggesting, rejecting, field of the big alternator. Well, the volt- Without the intervening coils the big ma- scheming and pondering. But by the eve- age of the alternator will depend on the chines would be as useless as if their wind- ning of the twenty-ninth he had not voltage of the exciter, because if the volt- ings were stript from them. He thought reached any solution. age of the exciter changes the strength of of this and tried to answer for himself the He was not the only one who was think- the field will change and affect the alter- question that was puzzling the chief of ing of this problem. The worried, anxious nator's voltage. So if they want to raise construction. face of Mr. Robertson, with its black- or lower the voltage of the big alternator, "What do you suppose Mr. Robertson ringed eyes, glittering with sleeplessness, they just raise or lower the exciter volt- will do?" he asked Pete as the latter started testified too plainly of his own struggle age by putting in more or less resistance upstairs for bed. over the proposition. with this rheostat. Do you understand?" He remained at Portage Falls directing "Oh, yes." Joe replied. "Then by ad- hits of finishing work, while he hoped and justing this field rheostat on the exciter almost prayed for the momentary arrival you can change the voltage of the big IN THAT "JULY" E. E. of the coils so much needed. Hourly he alternator." Are There Currents About a Mag- telephoned to Merwin to see if they had "Exactly," Pete assented. net?—with a number of original pho- arrived. Hourly he hoped that they might Joe sat for some moments, thinking of tos and charts never publisht before, have come, and then grew despairing as he this new addition to his store of electrical —by F. F. Mace. was told they had not. information, while the men about him "Cold Light" or La Lumierc Froidc, On the morning of the thirtieth he went talked lazily. to the as the French call it. The zvork of Merwin with determination of stay- "Robertson's getting grouchy about those Prof. Dussaud. ing there until they came, and hoping transformers. I tell you," one of the men Back to the Days of "Volta"—with against hope that service could be started said a moment later. some extremely interesting photos of on time. "If don't come, the won't / Pete the others they company I olta's original apparatus—by Jacques and stayed behind at be able to get its franchise, and he seems Boyer, our Paris Correspondent. Portage Falls, finishing up fine points of to think it's up to him to get them here." "Ham Jones—Scientist"—a rollick- the work there. The plant was in order, "I know that all right, but he oughtn't ing good electrical story with a live- each great machine ready to send its thou- to treat the rest of us like we were to wire wallop in every line by H. W. sands of kilowatts over the line to Merwin blame." Pete retorted. "He's been a fright Eveleth. to be used for every sort of work, pro- for the last two weeks." The Marvels of Radioactivity by vided the intervening transformers were "What transformers are those?" Joe Jerome S. Marcus. there to step down the deadly high tension asked. Lightning—How to Protect Your- to a safe voltage. Rut at noon a message "The transformers for the Merwin sub- self from It—An article everyone to the Falls reported that no transformers station, the step-down set," Pete informed should read by W. C. Whitman. had arrived. him With illustrations. Pete loafed up the steps of the Benson "Haven't they come yet?" Joe asked in Where the Radio Amateur Fits in home at dinner time. Worry over what surprise. the U. S. Naval Reserve Force by would happen to the company did not in- "No, they've been shipt a week but can't M. B. West. terfere with his appetite, and he was ready be located on the road or anywhere else." A Page of Marvelous X-Ray Skia- for the food awaiting him. "What will he do if they don't come?" graphs, including one of a four- But five minutes after he had sauntered Joe asked in concern. d chicken. leisurely inside, he dashed out, leaped off "I don't know. That's what's bothering raced The t alt illation and Measurement the porch, and down the steep hill- him, I guess," Pete replied. of Inductance — Conclusion by H. side, recklesslj speeding toward the com- The generators at Portage Falls devel- Winfield Secor and Samuel Cohen. pany's tool shack at the bottom. A minute oped current at low voltage which was Besides these and a large num- later he flung open the doors of the build- then past thru a set of transformers which ber of other valuable and interesting id was cranking the little service stept it up to sixteen thousand, five hun- articles, there will appear a liberal nt mobile. Two minutes later and the dred volts, at which tension it was trans- sprinkling of timely summer-time pebbles were flying in a stream from his mitted to Merwin, fifteen miles away over topics of interest to all readers. Don't tire- as he bumped away over the rough the mountains. There it was Stept clown I.. miss the 'July Issue!" It'll be right toward Merwin two thousand, three hundred volts for dis- there waiting for you with a wallop An hour and a half later he stopt Mr. tribution thru the service lines of the city. on every page. Robertson's big high-power roadster before Joe knew this as well as the rest of the the building, while the chief himself sprang men. He also knew now that if the step- oul and dashed down to the power house, down transformers did not arrive, the with Pete closely pursuing him. Snake Kivcr Power Company would be in "Go crazy, if those transformers don't * * * * * * a very awkward position come," Pete replied unconcernedly. It was a varied group which clustered Its franchise required it to supply cur- The next day Joe found himself think- about the switchboard, handsomely drest rent to Merwin on May first. Today was ing of the problem again as he heard the directors, oilers and workmen in overalls, April twenty-seventh. machines purring away on bis way home (Continued on page ISO) 102 THE ELECTRICAL EXPERIMENTER June, iqi7

AN ELECTRIC SEMAPHORE FOR hands or not, as becomes readily apparent. NEW METHOD OF MEASURING AUTOISTS. The Instructograph consists of three FRESSURE OF LIGHT.

The accompanying photograph shows a units : the transmitting unit, the receiving In a paper to the Physical Society. Mr. cleverly designed automobile electric sig- unit and a battery case, and while the pieces Gilbert D. West describes the measurement nal device which has recently been devel- are of light and compact construction, the of the pressure of light by a method re- oped by the well-known civil engineer, Mr. complete installation weighing but six quiring few of the elaborate precautions H. Hartman, of Xew York City. pounds, without batteries, they have been generally necessary in such experiments. designed for the strength and durability The essential feature of the apparatus was necessary for the hard usage they will be a strip of gold leaf suspended in the mid- subjected to in service. dle of a test tube containing air or hydro- The Transmitter consists of a gen at reduced pressure. Radiation from case, of light metal construc- a 32 c.p. carbon filament lamp, impinging tion, about six inches long, three directly on one side of the strip, was suf- inches thick, and an inch wide. ficient to cause a microscopically measure- A series of six double throw able deflection of the end. keys project from one edge, to The pressure of normally incident radi- the right and left of which ex- ation on a perfectly reflecting surface has te nd engraved plates, bearing all been shown by Maxwell others Motorists Will Be Interested In the . and to be Electric Semaphore Signal Here lllus- of the instructions commonlv numerically equal to twice the energy con- ated r ted ec ro -. P y ' us ed in teaching flying. ii; 'A '! M S l o J-L }. the art of tent of the radiation per unit volume, and Magnets, Controlled By a Push Button -r, , i. v. c \ On the Steering Wheel. The Arm l.he keys, which are ot such hence, if this quantity be measured in the Hangs Downward Normally, and Car- size that thev can be easily way described below, a check on the orig- ries a Red Signal Lamp At Its Ex- handledu with giovGlovedea bandsnanas canran inal observations can be made. A mean tremity. The Bull's-eye At the Hub i , Is Also Illuminated. be thrown to either the right or of the results of several successive experi- left, remaining in the position ments with the deflected strips gave a value This, like other inventions of Mr. Hart- placed until released by a touch, when they for the pressure of radiation which only man, is really quite simple in construction fly up to their normal vertical position. The differed from that calculated from the en- and performs its functional duty just as twelve instructions themselves, neatly let- ergy density by a small percentage. The well, or perhaps better, than many existing tered, have been chosen with great ingenu- accuracy and constancy of the final results and more complicated similar devices. The ity and are so placed that actual air work seemed to preclude their being seriously sole purpose of this instrument is to warn cannot necessitate the use of both of the affected by gas action ; but, as gas action an automobilist in which direction the ma- two directions, placed by each of the keys, had to be taken into consideration, the pres- chine ahead of him is going to turn, either at the same time. The case itself can either ent research was undertaken with a view to to right left. or be fastened by the side of the instructor, or its fuller investigation, and if possible to It consists of a mag- complete elimination. netic field having two In measuring the energy magnetizing coils similar density, the initial rate of in design to the field of a rise of temperature of a motor. An armature coil blackened copper plate, is placed in this field, and enclosed in the tube, was its shaft is attached to the measured by means of an signal or semaphore arm. attached copper eureka The field and armature thermo-j unction. Due al- are enclosed in a water- lowance was made for proof metal case which is cooling corrections, and seen on the left. One end the lamp black was as- of the pointer is fitted sumed to absorb 95 per with a red lamp, so as to cent of the incident radi- serve as a danger signal. ation. The cold junction The armature and field was immersed in oil con- coils are connected to a tained in a vacuum flask, storage battery and a sim- and during an experiment ple switch, so that the au- a delicate indicating ther- toist can throw the arm The Electrically Operated "Instructograph" Enables the Tea cher to Flash mometer in the oil only either towards the left or Up the Proper Signals Instantly Before the Pupil-Passenger: which Is Far showed negligible varia- Superior to Twitching the Various Controls. right, whichever the case tions. The calibration of might be. The principle the thermo-j unction was upon which this instrument is based is that set into the instrument board before him, carried out in the usual way, and a num- of the repulsion and attraction of two dif- as found convenient. ber of minor matters received full con- ferent magnets, one stationary (the field), The Receiver is a box approximately sev- sideration. while the movable magnet is the armature. en inches long, five inches wide and slightly When from the measurements thus taken The at its arm normal position points over one inch thick, adapted to fasten on the energy reaching 1 sq. cm. in one second downward, and as soon as the proper cur- the wheel of the front control itself in the rent is past thru the field and armature, front cockpit of a tractor, under the cowl, the pivoted arm turns instantaneously to or in the instrument board. Its cover is Gi " that direction, by virtue of the attraction , perforated by twelve oblong windows, Hi} between a field coil and the armature coil. closed by translucent white celluloid, with Mb Automobilists of to-day whose slogan is no lettering of any kind visible to confuse Safety First will appreciate this very valu- the pupil. When one of the keys of the able device, as it cannot be mistaken owing Transmitter is thrown, the corresponding to the relatively large moving surface called - direction 4 into play. appears on a window in dense s black against an illuminated white back- f -j - AN ELECTRIC INSTRUCTOGRAPH ground. Three of the directions : "Xose k f FOR TEACHING AVIATORS. Down," "Over Banking" and "Over Con- One of the latest Sperry devices for avi- trolling" flash out in black against a red ators, or rather for would-be aviators, is background, clearly indicating the urgency 1 known as the Instructograph and is illus- of the command. An ingenious arrange- trated herewith. It is intended to facili- ment of small' electric light bulbs enables tate the instruction of pupils in the modern this method of communication to possess \ ! two-passenger tractor aeroplane. Prior to the advantage of positively attracting the the advent of this clever device the Pilot- © pupil's attention whenever a word of in- Instructor, occupying the rear seat of the Arrangement of Apparatus for struction is given, it having been found ex- Measuring machine, depended on twitching the various Pressure of Light.—H is Hollow Stopper. E perimentally that the controls, after attracting the attention of his flash of light accom- Is Cover Glass Cemented to Tube. F Con- tains Pith Charcoal. pupil-passenger by kicking panying the change of direction catches his G Is Tube Which May the back of the Be Connected to Gaide Pump. forward seat, for imparting such instruc- subconscious attention. To safeguard tion as was necessary. This crude method against the possibility of a burned out bulb is known, the energy per 1 c.c. can be cal- of communication is preventing the direction being re- very dangerous, as at from culated from a knowledge of the velocity times neither pupil nor instructor know ceived, the circuits are so arranged that a of light. whether the control of the plane is in their second lamp remains lighted. ( ( ontinued on page 'V-') :

June, 1917 THE ELECTRICAL EXPERIMENTER 103 NEW TELEPHONE SIGNAL A UNIQUE ELECTRIC SOLDERING AN AUTOMATIC EXTENSION PATIENCE SAVER. TOOL. REEL FOR DROP LIGHTS. Patience vanishes rapidly while holding A Buffalo concern has 1 ;ntly brought I he automatic extension reel here illus- a line. at- out a form of electric telephone Save your time and new soldering I trated is intended for drop or portable elec- tend tn other important matters while wait- Among these tools is a two-prong iron with tric lamps. It is simple in construction and ing for the party to prongs of solid bar brass with nickel- other resume conver- positive in operation. sation, say the sporis. .rs of the new llold- plated finish. This type of iron is furnished the-call-signal here illustrated. This clever in capacities of ISO watts, 250 watts and 500 watts. All are designed to work on low pressure, from 6 to IS volts, either direct or alternating. This pressure can be obtained from an ordinary lighting or power circuit, either _>5 or 60 cycles by in- terposing a low-voltage transformer, or a storage battery operating at a pressure of 12 volts can be used. Under no circumstances may these irons be used on any voltage over 15. Another type is the two-handle portable soldering outfit. This is composed of a single prong soldering tool attached to one wire of the secondary side of the trans- How Often Do You Feel Like Cussing the former and a solder-feeding tool attached Telephone When Party No. 2 Says "Hold the to the other secondary wire of the trans- Line"? The Answer Is Don't. Place the A Clever Invention in the Form of An Auto- — former. When a storage battery is used Receiver On the Amplifier Here Shown and matic Extension Reel for Portable Electric You Will Hear the Party Answer. the single prong soldering tool is attached Lamps, Which Winds the 30-foot Cord Up to the negative side, and the solder-feeding and Swivels in Any Direction. device will let you know when the speaker tool to the positive side of the latter. is ready. No electrical connection is needed. When soldering with this outfit the sin- It is designed especially for garages, It simply rests alongside of the instrument gle prong point is brought to bear upon blacksmiths, factories, stores, or any busi- the and the receiver is placed on it while line object to be soldered, and the solder- ness requiring an extension light. This is held open. feeding tool is brought to bear upon the reel is equipt with 30 feet of lamp cord, spot where soldering is needed. The in- easily secured by fastening the arms of the HOW STUDENTS STUDY WAVE stant the circuit is closed the heat point swivel joint to ceiling or beam, as shown. MOTION. glows with a white heat, and the solder is This swivel joint enables one to walk in When the college "Prof.' tries to drum held until the work is done. The current any direction with the lamp. It has an the principles of wave mo- automatic lock ingeniously tion into his pupils' crani- arranged to lock and hold ums, he has available to- the lamp any distance from day the mechanical wave the reel. A slight pull for- reproduction machine here ward unlocks the ratchet illustrated. The small white and the reel revolves, wind- discs form into various ing the cord back as you lines representing curves or advance toward the reel waves of certain kinds, de- with lamp in hand. pending on how the apparatus is operated. This re- A HANDY ELECTRIC markable model was in- DRINK MIXER. vented by Dr. Charles The soda clerk used to Forbes of Columbia Uni- cuss (inwardly) merrily versity. With this appara- whenever a patron called tus the formation and for a drink that required a propagation of the three fancy mixture—a chocolate general classes of wave milk shake for instance. motions may be demon- Wherefore and hence we strated, namely have in our midst the elec- Water or Surface Waves, tric drink mixer that never in which the elliptical mo- tires—no matter if you had tion of the particles of a thirst like an Arabian water, the advancing of camel. the crest tending to form The electric drink mixer breakers, the recession of Several Styjes ofa Unique Electric Soldering Iron That Operates On Low is mounted on a swii Voltage A.C. or D.C. Closing the Circuit Causes the Points to Heat Up, bracket. When the machine the trough tending to form When the Solder Is Applied. the undertow are exhibited. is pushed back and removed Sound Waves, or waves of condensation ceases to flow as soon as the heating point from the glass it takes the position indi- and rarefaction, in which the amplitude is taken from the work. This outfit is cated by the dotted lines. Throwing back of vibration may be changed by lowering made in ISO- and 300-watt capacities and the disc support. The lowering of the is designed for use on direct or alternat- distant end of the support will also repre- ing currents up to 12 volts pressure. sent the decrease in the loudness of sound. Hther Waves, or transverse vibrations, rep- sented. Comparison of Phases. The apparatus admits of a ready comparison of similar phases in the three systems of wave motions, a very desirable feature not possest by any other form of wave machine. By means of the covers resting upon the framework of the apparatus any one or two of the wave systems may be hidden from view, thus leaving the remainder for special examination when desired. The front of the apparatus exhibits the conversion of rotary into direct and lateral reciprocating rectilinear motions, (hi the back, the action of the crank handle, the rod connect- By This Oscillating Pendulum Means of ing the individual cranks, and the opera- Cabinet It Becomes a Sinecure for the "Prof.'' You for Fancy Drink at the tion of double parallel rule mechani- When Ask a to Inculcate His Pupils with the Funda- the Soda Fountain the Dispenser Now Places the mentals of Various Wave Motions. cal motion, first used in this apparatus, are Glass Under An Electric Drink Mixer. clearly exhibited. Its large size is espe- resenting the production of light, heat and cially advantageous, since the wave forms the bracket operates a switch which breaks electric waves. The progressive undula- can be clearly seen across a large lecture the circuit. The swinging down of the tions of a vibrating cord are also repre- room. bracket automaticallv closes the circuit. 104 THE ELECTRICAL EXPERIMENTER June, 1917

Electricity and Life The Uses of High-Frequency Currents in Medical and Lecture Work By FREDERICK FINCH STRONG, M. D. Lecturer on Electro-therapeutics, Tufts Medical School, Boston

(Third Article) ductance coil being adjusted to balance the at the top, and 14 inches high. It is a phenomena of high-frequency different capacities added to the resonator difficult matter to insulate this small coil THEcurrents otter us a fascinating rield terminal. as the turns of the winding are very close from which to select experiments for This little resonator is made by winding together ; it can be done, however, by the puhlic lecture demonstration. In his 600 turns of Xo. 30 triple cotton covered use of from six to eight coats of Armalac. lectures on "The Realms Beyond the wire upon a shellacked paper cone, 12 The primary coil is a ring, 18 inches in turns Senses," the author has used high-fre- inches in diameter at the bottom, 5 inches diameter, formed of five concentric of thin copper ribbon 1 inch wide. The exciting apparatus is the same as that described in the last paper in connection with

the large resonator, except that a ] 2 KAY. transformer is used instead of the heavy 1 K.YY. (See Fig. 2.) The writer also employs a standard Clapp-Eastham Y± K.W. Tesla coil excited by the same apparatus (see Fig. 3). Con- nected with two parallel upright wires the spark from this coil will run up and repeatedly reform again at the bottom, producing a very spectacular effect (Fig.

Another brilliant experiment can be performed with two large glass flasks (ordinary carafes or water-bottles will do). One is filled with water containing a few- drops of fluorescein solution— (a coal tar dye ) —the other with water to which a small amount of bi-sulfate of quinine has been

added : the bottles or flasks are placed about six inches apart and a wire from the Tesla coil terminal inserted into the solution in each. The current passes down thru the water and- the arc takes place between the glass walls of the two flasks. The ultra-violet rays from the discharge cause the water in the flasks to become luminous—the quinine solution with a pale blue light, the fluorescein with a beautiful apple-green. The discharge apparently passes directly thru the glass walls of the flask; in reality, of course, the current passes by induction rather than conduction, Hardening of the Arteries—Most Dreaded of Ailments in Later Life— Is Successfully Treated the flasks acting as condensers in series. Thru Which High-frequency Currents Surge at a By Placing the Patient Within a Wire Cage, (See Fig. 5.) Frequency of 600,000 Cycles Per Second: D'Arsonval's Method. quency phenomena to demonstrate the existence of force and matter beyond the range of human perception. In "The Sci- ence of the New Age" he has employed similar means in calling attention to the fact that the investigators of to-day are leaving the crude matter of earth and are dealing more and more with Etherie I —and with matter of a super-gaseous nature. The scientist of the future will have to provide himself with instruments far more delicate than anything hitherto dreamed of or else he will develop super- normal powers of perception by the mani- festation of faculties already latent in the human organism. For the traveling lecturer who wishes to employ high-frequency currents in his work, the large resonator described in the last issue of The Elixtrical Experi- MENTES may prove somewhat cumbrous and difficult of transportation. Those who wish a lighter, more compact apparatus may use the small resonator shown in Fig. 1.

It is quite small, yet it sends out stream- ers two feet in length, and may be operated

by a j j K.W. "wireless" (step-up) transformer. With this little apparatus beautiful luminous effects may be obtained — as. for example, by connecting the terminals with a tin-foil star glued to a sheet of

glass : with a suspended umbrella (opened) : with a long wire running out over the lecture hall, etc. r-m JaeqoBi Bovm "Effleuve" Brush (or Spray) Tre; Has Proven Highly Effi- For each of these experiments different The or High-frequency cacious In the Treatment of Nervousness (Nerve and Brain E xhaustion) —"N eurasthenia." tuning will be necessary— the series in- American Electro-therapeutists Find It Very Valuable. 1

June, 1917 THE ELECTRICAL EXPERIMENTER 105

The Use of High-Frequency Currents in the This method—employed by the writer for By careful tuning a beautiful effect may Treatment of Disease. years enable, n- to obtain the wonderful be obtained. (lose examination of this

High-frequency currents an ployed by vitali ing i feet of the high-frequency cur- will show it to be literally an physicians in four principal ways, rents on the whole body simultaneously, electric "brush", formed of thousands of adapted t<> the treatment of

1 conditions. These are:

1. "Tola" treatment w i t li vacuum electrodes ("\ iolet- ray treatment"). 2. "Effleuve" or high-frequency spray. ) ' 3. ' I ' A r s o n v a 1 autO- condensation." 4. "Diathermic" 1. The method most frequently employed applies the Testa c u r r e n t thru glass (vacuum) electrodes for the relief of local pain or inflammation. The little muscular pumps around the veins the "vaso-motor system," which keep the blood circulating by withdrawing it from the capil- laries and sending it hack to the heart—act more vigorously in tissues over which the vacuum electrode is applied. In this manner waste products which cause rheumatism and gout are dissolved and washed away ami fresh blood and white corpuscles are brought to in- FIGA fected parts, thus aiding nature in destroying disease-producing germs and their poisonous products. |The Accompanying Il- In most of the smaller high- lustrations Show Some frequency machines for phy- of the Spectacular Elec- sicians' use, but one Tesla tric Spark Discharges

terminal is provided ; a coil of vl/ Obtained From the 1 -> BS the resonator type being con- ' High-Frequency Appa- nected to the glass electrode I ratus Used by Dr. | by a flexible wire. The effects Strong In His Lecture are largely local, but the meth- and Electrotherapeutical

od is of value in relieving pain, Work. The "Ladder of I swelling and congestion. The Sparks" in Figs. 3 and writer has always advocated 4, Is easily Produced, the bipolar method, even for the Tesla Spark Simply | treating purely local conditions. Jumping the Gap Be- m The best results will be ob- tween Two V e r t i c a 1

Copper or Iron Wires. I tained from the use of a Tesla 1 outfit of the type described in last month's Electrical Experimenter. The patient is to be connected to one terminal of with the local effects from the vacuum distinct, delicate, purple threads. Upon the Tesla coil by means of a metal electrode electrode. each of these hair-like paths of light countless millions of ions (electrically-active held in both hands (a piece of thin nickeled For the past few years the writer has pipe will answer, 1 foot long l'j inches atoms), are being shot from the electrode and been in the habit of connecting the Tesla diam.). In this the current is to the patient at a speed of over 60,000 in way dif- coil with an Auto-condensation pad (as miles per second: the treated surface is used in the "D'Arsonval" and "Diathermic" therefore being submitted to a literal bom- methods). This is formed of two plates bardment by countless microscopic proof Bakelite, J-s-inch thick, hinged to fit the jectiles which are thrown out in periodic seat and back of an ordinary chair. To showers from the electrode, once for each the back of each plate is cemented a sheet cycle of the oscillating current. Two ef- of tin or copper foil, covered with leather- fects are produced—one due to the pene- ette. Suitable flexible conductors connect tration of the tissues by oione-forminp these metal plates with each other and ions: the second to the rhythmic or peri with the Tesla terminal. This folding pad impart of the discharge Upon the nerve may be used in both "Tesla" and "D'Arson- endings in the skin and superficial tissues. val" treatment, and is quite as efficient for The writer hopes ultimately to produce an ordinary use as the cumbrous and expen- apparatus of a frequency exactly synchro- sive condenser chair or couch. nous with the rale of vibration of the "Tesla treatment a from 2. For the Effleuve" i rv nerves; an "effleuve" such brass bell electrode is used. This can be a coil would produce a harmless and effi- made from a common brass oil can. the cient local anaesthesia so thai operations tlat bottom being removed and the result- could be performed without the use of ing hollow hemisphere being mounted on ether or cocain. The effects obtained from insulating handle: the occur- an discharge the "effleuve" as now used are stimulating ring from the sharp edge of the brass. The Startling Experiment With Two Glass Water and vitalizing to a marked degree. The patient is seated on the Bakelite pad. which Bottles Connected to Tesla Coil. The Spark nerve endings of the skin may be regarded Jumps Between the Glass Surfaces and is connected to the Tesla coil. The oppo- Solutions Within the Bottles. as sensitive antennae of a complicated ra- Illuminates site terminal is attached to the brass bell dio-system, and any intense sustained vibra- electrode and a sufficient number of turns tion to which tin- apparatus is attuned will fused thru the entire body. The vacuum of the inductance coil are placed in series be transmitted by them to the receiving electrode, connected with the opposite Tesla with the Tesla primary to give a full, station. The effect therefore, is not merely terminal is applied to the skin over the smooth "effleuve" or purple brush dis- as well. Tuber- affected part for from five to twenty min- charge, when the electrode is held from superficial but systemic (Cont'mucd on page 1?2) utes, a very short spark-gap being used. four to eight inches from the patient : —

106 THE ELECTRICAL EXPERIMENTER June, 1917 Experimental Physics By JOHN J. FURIA, A. B., M. A. Instructor In Physics and Science Master. Riverdale Country School possible the elec- not raise the water this distance, and the HYDROSTATICS. it is direct current. If of platinum. A and B siphon would nut operate. LESSON FIVE. trodes should be an test tubes held in the hand after being EXPERIMENT 27—Recently an auto- is plentiful, and we are ATER so inverted full of water and are placed over matic siphon has been put on the market, use so- much of it, accustomed to the electrodes. Immediately, and with a and it can be very easily constructed. Fig. us ever stop to that very few of rapidity dependent upon the strength of the 22 shows the automatic siphon in the act great part it plays w think what a battery used, bubbles will form at the elec- of starting. It should be noticed that the It is without in our daily lives. trodes and rise to the top of the test tubes. tube is filled alternately with bubbles of air indispensable sub- doubt an absolutely These bubbles are the result of the decom- and water. This condition prevails only position of the water into its constituents. We notice that in one tube the bubbles form more rapidly and that there is always about twice as much gas in that test tube as in the other. Call that test tube "B." After the test tubes have been filled with the gases, raise them carefully without tip- ping. Insert a glowing match-stick in "A." It is found to burn brightly. This we remember was the test for Oxygen. If a Hatrie is applied to "B" a slight explosion results, which is the test for Hydrogen. Thus we see that water is composed of two parts Hydrogen to one part Oxygen. EXPERIMENT 26— (Fig. 21)— Illus- A Small Battery and a Couple of Test Tubes Apparatus With Which the Principle of the or Bottles, Together with Connecting Wires, trating the principle of the siphon. A Submarine Can Be Demonstrated. The Small Will Serve to Clearly Show How the Electric and B are vessels at different levels, A Vial 2, Can Be Made to Perform Many Won- Current Decomposes Water. derful Tricks Pushing on Dlafram being higher than B. The vessels are con- By Down 1, or Squeezing Bottle 3 in "B". nected by a piece of tubing; bb' indicates 1 stance. We drink it—we clean ourselves the top of the tubing and aa the level of upon starting and shortly after, the water and our belongings in it—our crops depend of the water in vessel A. d, the level comes out solidly. Fig. 23, shows a home upon it—ourselves and the fruits of our level of the end of the tubing. indicates the automatic siphon and all those inter- continent to made toil are transported from one is placed in position as indi- If the tube ested should make one. 6, is a piece of another by means of it practically every — lamp chimney about 3 inches long. 5, is manufacturing industry makes use of it. a piece of glass tubing about $4 inch in Finally and most important, we swim in diameter stuck thru a rubber stopper 2. it. What would be the use of living if we is some more of the same kind of tubing had no Palm Beach or "the old swimming 4, past thru the stopper 3. The height h, hole in the creek"? We naturally ask what should be about a foot and a half. 1, is is water anyhow? One could never guess a small hole drilled thru the lamp chim- the answer. Water is y.othing more than ney 6. 5 and 4, should be about 54 of an the result of the combining of two gases inch apart. As soon as our auto-siphon Oxygen and Hydrogen. Oxygen, we re- is placed in a liquid it begins to operate constituent of the atmo- member, is the WITHOUT OUR FILLING IT FIRST. sphere necessary to life. Hydrogen is the Thus we see that one made entirely of gas which burned with a pale blue flame glass, as are the commercial ones, is very in the lesson on "Gases." (See March and convenient in transferring poisonous liquids April issues of this journal.) The follow- and acids, as we need not touch the liquid ing experiment can be easily performed at all. There is nothing mysterious about successfully siphon and it is easily explained. When EXPERIMENT 25— (See Fig. 20) — this Siphon. Details the bulb is immersed in the liquid, the C is a jar nearly full of water to which Two Forms of Automatic for Constructing the One on the Right Are liquid rushes in at 1 and at the lower end a few drops of sulfuric acid have been Herein. Given of tube S. The liquid rushing in at 1 added. (The sulfuric acid is added to tends to compress the air in chamber 6. make the water a better conductor of elec- cated in the figure, and A contains water The liquid rushing in at 5 streams up past tricity. Water alone is not a good con- 1 4. the outgoing (or any liquid) at a level aa , nothing the gap and thru Hence ductor of electricity, i.e., is more or less happens. If, however, the tube is filled air takes with it some liquid, and, as noted of an insulator, just as glass is.) D rep- with before it is placed in position, before, we see alternately passing thru the resents lead wires from a battery of at water the water begins to flow from A down if to B. The siphon will also act if the tube is placed in position, and if one sucks

at the lower end ; for this is equivalent to Spring sca/e filling the tube with water. The explana- , In erst body tion of the action is as follows : The up- m ward pressure in the short arm of the tube, is due to the atmospheric pressure (discust in the last two lessons). In the tube ab, this pressure is equal to the atmospheric pressure minus the downward pres-

sure due to . the weight of the column of water ab. The upward pressure of the tube at b' is the atmospheric pressure minus the downward pressure due to the weight of the column of water b'd. The force tending to drive the liquid from A to B is greater than that tending to drive it It is greater by the amount from B to A. Proving the "Law of Buoyancy," i. e., That equal to the difference in the weight of Objects Weigh Less In Water Than In Air. the columns ab and b'd and hence corre- Demonstration and Controlling Factors of sponds to the weight of the column a'd. tube bubbles of air and water. As there the Hydrostatic "Siphon". A Simple and 1 Evidently if d, were at the level aa , the is less and less air left in 6, larger and Effective Method of Emptying Tanks and larger of the liquid pass with Even Reservoirs When Occasion Requires It. siphon would not operate; and if above quantities 1 small bubbles of air intervening, until aa , it would operate in the other direction. least six dry cells in series, or from a If the column ab (for water) were greater finally the air being all gone, the liquid storage cell or from the house current if than 32 feet the atmospheric pressure could (Continued on page 152) .

June, 1917 THE ELECTRICAL EXPERIMENTER 107 ^ RADIO LEAGUE HONORARY MEMBERS CAPT. WH.G BULLARD. U. S.N. NIKOLA TESLA ^AMERICA PROF REGINALD FESSENDEN. DR LEE DE FOREST.

//. Gcryxsback, Manager W. H. Kirwan, Master of Radio Relays

Denver Wireless Station Wins Prize Loving Cup By W. H. KIRWAN (9XE), Master Radio Relays, Radio League of America.

a Denver hoy goes the honor of win- issued some years ago to Captain Smith; in the photograph of the equipment. TOning the trophy cup for the hest Ama- however, the station really belongs to. and There are three towers to Station 9ZF. teur Wireless Station in the United was made by, Mr. Doig, as explained above. one of them being 90' high and the other States. This cup was donated by 9XE to \ record of messages handled at 9ZF two 75' high. One aerial has six Xo. 12 the most efficient and hest equipt amateur from January 13th to March 18th, 1917, aluminum wires, 150" long, and the other wireless station in the United States. shows that 251 messages were received and aerial has four stranded aluminum cables We intended to call in a committee to sent. A number of them were transcon- with 7 strands of Xo. 14 in each cable, and decide upon the merits of the hest amateur tinental messages from coast to coast. is 200' long. Both of these aerials are stations in the country, hut station 9ZF in Station 9ZF held a very strategic position connected L type. Denver was so far ahead of all other ama- in the Washington's Birthday Relay of This station has been working regularly teurs in sending, receiving, and efficiency, February 24th, 1917, and without the as- with amateur stations on both the Atlantic that it would have been a waste of time sistance of this station it would not have and Pacific coasts. Working with 6EA in and energy to have consulted anyone at all. been possible to have sent the message Los Angeles, Cal., has been a continuous This station, 9ZF, is known to every thru from coast to coast, nor for the re- past performance, and recently this station progressive amateur in the United States, turn message to have been brought back. has worked directly with 2PM in Xew and is one of the star stations of the Colo- We believe that nearly all of the stations York City. We claim that this is truly rado Wireless Association, and of which thrtiout the United States can well pattern wonderful work for an amateur station, you have all read in a previous issue of their installations, as far as general ar- and we do not think that there will be

The Trophy Cup for the Best "Amateur Wireless Station" In the United States Has Been Awarded to Station 9ZF, operated by Messrs. E. F. Doig (at Right) and W. H. Smith (Left), of Denver, Colorado. this magazine. The winner is Mr. E. F. rangement and efficiency is concerned, after any question whatever but that Station 9ZF Doig, of No. 848 South Emerson Street, Station 9ZF. Another point in favor of is well entitled to the prize. Denver, Colo. Mr. Doig made nearly all 9ZF was the fact that, while this station Since holding the Washington's Birthday his apparatus himself, and has been assist- was affiliated with nearly every Radio Club Relay, which you will all remember was ed by Mr. W. H. Smith of the Y. M. C. A. and organization extant, the owners never held in the interest of preparedness, with Radio Club and the Colorado Wireless refused a message, nor did they feel that instructions to all sending stations to in- Association. Mr. Doig was for four years Station 9ZF was too proud to work with terest all wireless amateurs in the United Master Signal Electrician in the Signal anyone. States Radio Coast Reserve. Station 9ZF Corps of the Colorado National Guard. He In the receiving cabinet is a large loose worked the hardest for recruits oi any sta- now holds a special receiving and sending coupler for reception of long wave stations tion in the United States. license from the United States Govern- like WG. GW, SI.. OUI and POZ. as well We have radio clubs in the United States ment. His equipment, altho not as large as the Government arc stations. A smaller of minor importance, which seem to think as the Government station, is very com- receiving cabinet is used for the shorter that they were the only ones that had a plete, as you can clearly see from the wave stations, including the commercial divine riyht to exist, who have not, with photograph. coast and sub-stations on the spark sys- all their membership, done as much good Mr. W. H. Smith, also well known for tem. There is also a short wave regenera- work in enlisting the amateurs under the his skill as an operator, is associated with tive receiver, wdiich is used in working with Navy Department for coast reserve work Mr. Doig and has worked on his night shift the amateur stations. This cabinet also as Station 9ZF. at this station. Mr. Doig is also secretary contains an amplifier which can be used All of the stations have been closed by T of the Colorado Wireless Association and in connection with each of the other sets. the X avy Department, on account of the Air. Smith is the chief operator. This There is not much to tell about the Rotary war, for the period of war. and we believe station will hold this cup for one year, Quenched Gap, as the cut shows just what it will be some little time before all of us and if they win it again in 1918 it will it is, and there are not very many ama- are working again. In order that your belong to this station absolutely. teurs but what have had the chance to read interest will not lag in wireless work, and The cup has been properly engraved and about this outfit. for the benefit of the many amateurs who you will see a picture in this magazine The 1 k.w. outfit which is used mostly, have enlisted thruout the country and are shortly of the cup holding a prominent radiates from 12 to 14 amperes on a wave now assigned to the various warships, we place in the Laboratory of Mr. Doig. The length of 425 meters, and the oscillation will continue these write-ups each month, Government Call Book gives Station 9ZF transformer is made with edgewise wound with something of interest to them, and as belonging to Captain Smith of the Colo- copper strip, a type with which you are something to remind them of home and rado National Guard, hut the license was all familiar, and which is clearly shown ( Continued on page 143) 108 THE ELECTRICAL EXPERIMENTER une, 1917

Notice to All Radio Readers

radio readers arc undoubtedly atvare, the U. S. Government has decided that all Amateur Wireless Stations, whether licensed or unlicensed, or equipt for receiving or transmitting, shall be elosed.

This is a very important consideration, especially ' to those who are readers of THE ELECTRICAL EXPERIMENTER. for the reason that we desire to continue to publish valuable articles in the wireless art from time to time, and which max treat on both transmitting and receiving apparatus. In the first place, there are a great many students among our readers who will demand and expect a continuation of the usual class of Radio subjects, which we have publisht in the past four years, and secondly, there will be hundreds and even thousands of new radio pupils in the -carious naval iiud civilian schools thruout the country, who will be benefited by up-to-date wireless articles treating on both the transmitting as well as receiving equipment. Therefore, and in view of the foregoing explanation, zee feel sure that every reader will thoroly understand that altlw articles on transmitting, as well as receiving, apparatus may appear from time to time in these columns, he is not permitted to connect up any radio apparatus whatsoever to any form of aerial.—The Editors.

ti i II nut i milium i mi m

SCHOOLS are established at the Navy radio telegraphy may be enlisted as lands- centage and square root. Testimonials as Yards at New York and San Fran- men for Radio Electrician. The applicant to the good character and skill of the cisco for the purpose of furnishing must be able to take dictation at the speed applicant as an operator must be presented Radio Electricians for the fleet of twenty-five words per minute and pass either from a former employer or from from the enlisted personnel of the the principal of a school where the appli- Navy. After the required sea serv- cant has been a student of radio or teleg- ice has been performed such electricians raphy. The applicant must be able to are transferred to shore duty at Naval receive about twenty words a minute. Radio stations and other places. In addition to the above, men holding The electrical branch of the schools is commercial radio licenses and who pass an divided into two parts. One branch for additional examination at the Electrical general electricians and the other for radio / School, Navy Yard, New York, or Mare (wireless). Applicants capable of passing Island, Cal., may be enlisted as electricians

Future Naval Radio Men Learning How to Operating Room of Radio Class at the Navy Measure Length and Frequency of Etheric School, Brooklyn, New York. Waves. third class (radio). In both cases, whether the examination are enlisted as landsman enlisted as landsmen for electrician or elec- for electrician feither general or radio) trician third class (radio), the regular and are detailed for a course at the Elec- course at the school follows. The oppor- trical School. The pay of landsman for tunity for advancement in the Naval Radio electrician is $17.60 per month while under Service is at present exceptionally good instruction and in addition he is furnished and is worthy of consideration by every with a complete outfit of uniform, board, commercial telegraph and radio operator. lodging, text hooks, tools, and materials The pay of electricians both general and with which to work. The length of the Radio is as follows : Electricians third Electricians course is about eight months. Upon com- class, §33 per month ; second first pletion of the course at the school the class, $44 per month ; Electricians men who are qualified are given the rating class, $55 per month; Chief Electricians of electrician third class (radio). In both (acting appointment), $66 per month, and courses the following subjects are covered: Chief Electricians (permanent appoint- electricity, magnetism, machine shop work, ment ), $77 per month. This pay is in- k. w. alternating currents, dynamos, motors, and Top:— Naval Radio Operator Handling 2 Transmitter. creased with each enlistment. batteries. It also embraces the principles is ad- Below: —One of the Up-to-Rate Radio Sets The present policy in the fleet to management of radio stations and in- and Which U. S. Naval Operators Learn to Handle vance electricians third class (radio) to stallations. The general course covers the electricians second class at the end of a application of electricity to shipboard appli- a creditable examination in spelling and year if their proficiency mark is at least ances. penmanship. Electricians third class (radio) serve Competent operators of the Morse code The problems in arithmetic include mul- 3.2. (Continued on opposite page) or men with a sufficient foundation in tiplication, division, simple proportion, per- 109 June, 1917 THE ELECTRICAL EXPERIMENTER

aerial is controlled by an armature H, NEW RADIO TRANSMITTER FOR high tension glass i and in- net. U. S. "MOSQUITO" FLEET. ductance. A transfer switch is also pro- permitting the receiving and the The accompanyini photograph shows a vided for connected rly -tarted. This bre; operated from transmitting instruments to be complete radio transmitter to of at any time de ired This is shown in tit at I, is due thi

the upper right hand corner. A hot wire the an i rmits a large thru coil, con- neti r is also furnished, and this is current the in the upper center of the panel. arc The three plugs at the botton is shunted with the usual type of o namely, the primary for several pui he left hand one is . circuit. P.V.C., oscillation trans hich in- ill iyed for conni i i\ ing in- of an struments with the ductance is controlled by means of the connects the key with the primary of the h on the left oi the transmitting condenser coil and battery, and the right-hand plug \ variable high-tension in cabinet and links the stor ry with the s is aKo mounted the same multi- source. The plug at the upper left hand its capacity is varied by i a indicated on the front. corner is used for connecting the power ple-point switch, ordinary carbon microphone is linked source with the test buzzer of the I An circuit oi set. A set of binding posts are furnished in the ground for connecting the aerial and ground with the oscillation transformer, as shown in 'I iphone is the set, and these are seen at the uppi r the wiring diagram. t the part of the panel, each being fitted with ioni d on a mo\ able 1 on the proper name-plate. i of the cabinet. During some recent tests, the outfit has The receiving equipment is inclosed in consists of a proven to be very efficient. the lower compartment and standard 1 coupled receiver, with a in metal THE JAPANESE T. Y. K. eti ir. This is placed a RADIOPHONE SYSTEM. housing equipt with a metal di i of the case. Adjusting the Among the early distinguished workers on the left crystal is performed by a vertical rod pro- in radiophony we find that Messrs. W'ichi truding from the top cover. Two variable condensers are used and these are mounted on top, while the coupling of the primary and secondary is varied by turning the front knob. A change-over switch is supplied for connecting the receiving and transmitting instruments whenever desired, and the control handle for the same is seen at rear, left-hand corner of the lower cabinet. The primary switch is mounted on the left. Excellent results were obtained with this system, and a number of sets have been installed in several Japanese land and boat One of the Latest Designs of Ex- tremely Compact and Light Weight Radio Outfits Intended for "Mos- quito" Fleet Service. a current derived from a storage battery. It was designed for supplying the mosquito fleet with an efficient low power transmitting outfit. The Simple Connections Used in the Japanese "T. Y. K." Radiophone This outfit was developed by A. B. Cole, System. a New York radio engineer. It consists of a quenched spark gap of the open air Torikata, E. Yokoyama and M. Kitamura type which is mounted on the panel. The of Japan have done very notable work sparking surface consists of two large spe- in this direction, and the system which cial alloyed discs. The gap is excited by they have evolved is a radio frequency a spark coil of unique design; this is placed spark system of unique design, which we behind the panel, its interrupter, which is herewith describe in detail. _ of the independent type, being stationed on The complete equipment is shown in the front of the panel and visible on the the photograph and resembles very much center right. The oscillating circuit con- an ordinary standard "wall telephone." sists of the usual arrangements; namely, a The transmitting apparatus outside the generator is enclosed within the top on the large vessels and Electricians sec- cabinet, while the bottom one contains ond class are sent in charge of the installa- the receiving instruments and aerial con- tion on destroyers and gunboats. Men who trol switch. The direct current rotary have sen ed two years at sea. in radii >. converter is seen standing on the floor. and who have advanced to second class It runs on a 110-volt direct current source, are eligible for shore duty. The pay and and delivers 500 volts D. C. for the arc. allowances and retired pay of the Navy, tective resistances and choke coil are- and the fact that all men gel shore duty, used, and these are mounted on a sepa- makes the Naval Radio Service more at- rate base; they are seen below the in- tractive than that of tin- commercial ser- strument proper. vices. A comparison of tin- two pays and The transmitting equipment consists oi allowances in the Naval Radio and Com a specially constructed arc. its electrodes menial Radio favors the former. consisting of iron and brass. Tin- dis- The physical and moral qualifications re- tance between the stationary and movable quired for entrance to the Naval Service electrodes are automatically controlled apply in all respects to these branches. If by means of an electro-magnel so ar- The Japanese "T. Y. K." Wireless Phone the recruit is unable to complete the course ranged as to adjust the arc terminals in System Is One of the Simplest and Most Devised. It Greatly Re- the School he- order to keep the oscillatory condition Efficient Ever of instruction at Electrical sembles the Familiar "Wall" Type Tele- cause of incompetency or inaptitude he will operative. This arc is operated in the phone. In- transferred, if he desires, to such rating open air and the same is mounted on top mile in the general service as he is qualified to of the transmitting cabinet. Its connec- stations. The I Fficiency in watts per is remarkably high. Also fill or he will he discharged from the^vTavy tions are made thru the control electro- of talking range for inaptitude. magnets of the equilibrator, as indicated in the design of the complete equipment is (Continued <"i page 1531 the wiring diagram. The movable elec- marked bj distinctive simplicity. — .

110 THE ELECTRICAL EXPERIMENTER June, 1917

Remarkable Radio Outfit Built By After the police were satisfied of the na- German Spy ture of the equipment in the box they asked \\ ax to operate it. LITTLE Mack box of mystery, by Arthur Woods, Police Commissioner, He fingered several parts of the mechanism for a moment or seized recently by the police in the looked at the contrivance that it was recog- two and finally succeeded in causing a short belief that it was nothing more nized as a genuine and extremely effective circuit, which effectually put the whole thing A than a modern adaptation of a time portable wireless outfit. out of commission. The damage, however, worn contrivance for swindling un- The box is about two and a half feet can be repaired easily. sophisticated persons out of their savings, square. It is covered with black enamel and In the examination of the police has silver handles and Wax drew from him the statement that •__>- m^^mm brass hinges and he came to this country from Germany in June, |^^A clasp It must have 1914. cost at least $800, ac- Bkl He denied he had served in the cording to the esti- German army, asserting he rejected for mate of experts. was military service because he had fcij^J As soon Ser- a weak heart. Dr. Baker and Dr. Hamilton, geant Pierce recog- police sur- geons, were called in to examine the pris- nized the use to which oner. pronounced the queer arrange- They him an almost perfect physical ment might be put specimen and said there was no indication that he the outfit was rigged ever had suffered from heart disease. up, its batteries were Considerable interest was set in motion, and in manifested by the police a moment the hissing and federal investigators in sounds and sputtering papers and letters found in Wax's posses- and flashing sparks sion. They declared some were written in that attend the opera- code. All of them were in duplicate. One of the papers, tion of a wireless out- according to the police, was a draft for $12,000 and another for fit were in evidence. was 2,300 marks. The latter was drawn on the Wax persisted, de- Deutsche Bank, of Berlin. It declared spite the effectiveness was by the police that received of this demonstra- Wax some of these papers thru the office of the tion, in his assertion German Consul in this city several weeks ago. The U. S. Government that the batteries, money, the police said they learned, and Police Experts tiny dynamo and in- was sent to by relatives in Were Much Sur- tricate coils were Wax Germany, who the prisoner declared were both prised to Find That placed in the box by wealthy and influential there. the Cabinet Here him to make the ap- Shown, Which Was paratus "look pretty." Recently Seized Eventually he said he ELECTRICITY REDUCES FIRE with Max Wax, a intended to use them HAZARD. German Spy, Was to give color to a mo- One-fourth of all the fires occurring in Capable of Receiv- tion picture scenario Waterbury, Conn., for a year might have ing Secret Radio he intended to write. been avoided by the use of electricity, Messages from Persistent question- according to the report of Fire Chief Germany. ing, however, drew Heitman. from Wax, according to the police state- A NEW VACUUM CURRENT GAGE was revealed as a clever wireless telegraph ment, the admission that he, having bought FOR RADIO. outfit, capable of receiving messages from the materials, the box and its outfit were put Herewith we present the as far away as Berlin. together for him by a seaman on board one vacuum ampere gage, a new Marconi device. Police and government experts who ex- of the interned German ships lying at Ho- demand for a small, sensitive, amined the mechanism in the box declared boken. He refused to reveal the identity The ro- bust instrument suitable for use equally it to be as perfect in construction as an> of the man, asserting he knew him only as on alternating and continuous current cir- they ever had seen. It is (or was) the "Frank" and had met him only a few times. cuits is not new, and inventors have property of Max Hans Ludwig Wax. a When the examination of Wax had pro- made many attempts to satisfy it. German citizen, and graduate of the Uni- ceeded that far L. R. Krum, chief radio The instrument is designed primarily versity of Berlin. Wax, as soon as he officer of the federal government for the as a current gage to indicate the found the police had learned the real nature New York district, arrived at Police Head- maximum condition of syntony in wireless circuits, of the intricate contents of the box. as- quarters. He examined the machinery con- and be as a substitute for sumed an air of stolid indifference, denied tained in the box carefully and then verified may employed a thermo-junction and galvanometer com- he knew the box could be of service either Sergeant Pierce's declaration that it was a bination in the measurement in sending or receiving telegraph messages wireless outfit of great strength. He agreed of wave or that he knew anything of telegraphy, and with Sergeant Pierce that the apparatus lengths and decrement. The principle in-

: ted that apparently useless bits of par- was easily capable of receiving messages aphernalia contained in the box had been from as far away as Berlin. Both experts, tlair Spring Support placed there by him merely to make the however, declared the apparatus probably vance "look pretty." could not be used to send a message much Then, the police say. Wax informed pros- farther than one hundred miles. pective dupes that the little black box con- Despite the readiness with which Mr. tained machinery devised by German scien- Krum and the police wireless operators tists for reproducing American banknotes were able to set the wireless outfit in mo- and currency hills. It be would place a one- tion, many contrivances in the box were a thousand dollar bill in the "press" inside the mystery to them. It appeared as if there box the contrivance would print ten dupli- were three sets of batteries, where only one filaments cates of that bill. It then was the duty of was necessary. The operators exprcst the the "loyal" German, the police say they belief, however, that any one of the three

< were informed. 1 > pass the spurious notes battery sets might have been connected with off for American gold, so that eventually the rest of the apparatus, so that, even if this country would be flooded with counter- two batteries failed, there still would be feit notes and persons loyal to Germany power to keep the contrivance in operation. would he in possession of most of this The only incomplete thing about the out- country's . fit was that the police were unable to find a By Placing the Delicate Moving Parts of Just after Wax was arrested the police sending key and a transformer, both of This High Frequency Current Gage in an learned that he had left the box in a ma- which would be necessary if the machine Evacuated Bulb the Action is Made More Stable and Reliable. It Can Be Used with chine shop in Xew York City. The police were be used for sending wireless mes- to a Wave Meter to Measure the "Decre- finally located the box in a trunk which sages. Wax. however, is described by per- ment." they sai

rotation of which is controlled by a spring if a Murdock variable conden "THE CRUISE"—A RADIO STORY. acting against the tension of the filaments. Audion and variomi By MARGARET L. CAMPBELL. \\ hen a current passes thru the filaments, With thi- sel I hear the calls of KP1I: Early in August, 1916, I transferred my heating them and causing them to elongate, kl'A: XIV; NPE and of course all Ama- wireless set from my radio station to my the arm takes up a new position and the teurs in this vicinity. angular displacement as indicated on the At the present „, „ ,..,_._ »•_, T „„! ,,„;.,„ Mlss Margaret L. Campbell, of Rock- urement of the current. time 1 am using port , Mass., Has Long Been a Radio The movement is enclosed in a glas-. bulb Only a spark coil Enthusiast and Has Operated the Ap- paratus on Frequent Trips exhausted of air. The sensitiveness is thus -mrl drv cells for Shown Made on Her Father's Yacht. She greatly increased, and the movement pro- transmitting but H as Achieved a Distinct Success with tected against damage and preserved from have a 1 kilowatt Her Station, Having Become Thoroly Conversant with All Radio Matters. dust or corrosion. set nearly com- m The drawing shows quite clearly the con- plete. struction of the little instrument, which is 1 thank you in made up in such a way as to resemble an advance for the electric lamp. In one form the bulb is interest you have attached to a brass cap with projecting taken. Wirelessly pins identical with that used on standard yours, Winifred English lamp bulbs, and the size of the Dow, Tacoma, instrument can be gaged by noticing this \\ ask in the drawing. feature There are lots The variation in zero which is character- of worse jobs istic of hot wire instruments in general is than that of Ra- negligible in this of instrument, and type dio operator For the natural damping renders the move- Uncle Sam. Be- ii" m especially dead-heat. sides, he pays The instrument, suitably calibrated, may you while learn- als,. used as a low reading volt-meter or be ing. Why not in- ammeter, or as shunted ammeter. a The quire about it? normal resistance of the commercial type Both women and of vacuum instrument is approximately 12 men are eligible. ohms. Enclosing the working parts in a vacuum MRS. CANDLER AN ABLE RADIO father's new sixty foot yacht, the Wa- has enabled the makers to place on the OPERATOR. hama. She is a flush deck cruiser with market an instrument which should prove Mrs. Candler of St. Marys, Ohio. says. all modern improvements and powered of great general utility on account of the "I surely am very much interested in wire- with a large four-cycle gasoline engine. fact that, at a reasonable cost, it is pos- less and not only interested but have been She also has two masts about thirty-five sible to provide the means of measuring operating our set ever since it has been feet apart, which I used to support my direct and alternating currents of the or- in existence. I now hold a first grade com- aerial. There is a large cabin, ten by twelve der of .01 amp., without sacrificing any mercial license. The first photo of our set feet in size, in which I installed my trans- robustness of construction. The small size was sent you last year by '9XE' and ap- mitting and receiving apparatus, which con- makes it a matter of no particular diffi- peared in the Experimenter in connection sists of a two inch spark coil, two Leyden culty to insert the instrument in a circuit with the report of the Washington's Birlli- jars, helix, spark gap and key. Also, two where no previous provision has been made variable condensers, loose coupler, tuning There Is an Opportunity for a measuring Now instrument. for All Radio Women. One coil, loading inductance, Ferron, galena and With a wave meter using the new vacu- of the Best Qualified Opera- silicon detectors mounted upon a movable tors Is Mrs. um gage the wave-length of the primary Chas. Candler, cabinet. of St. Marys, Ohio. circuit of a l'.-kw. set can quite easily be One of the interesting cruises made last read when the wave meter is held with the summer was with a company of Marine plane of its inductance coils parallel to Boy Scouts of which my father is the that of the primary of the oscillation trans- commander. We sailed along the coast former at a distance of two to three feet. of Massachusetts Bay, visiting vari- The noise of the spark, which often hin- ous harbors and spending several days ders the reading of a wave meter by means in Marblehead harbor during the fes- of a crystal and telephones, in the case of tivities of "Marblehead Week," when the vacuum gage gives no trouble, as the the great racing events of that notable variable condenser has simply to he rotated yachting center are held. until the pointer of the gage gives the The harbor was filled with yachts of all maximum reading. In this way circuits types and age, from the majestic steam can be tuned rapidly as well as accurately. yacht of the millionaire to the small sailing dory of some aspiring youth. I was sur- MISS WINIFRED DOW A RADIO prised to find ho these boats were ENTHUSIAST. equipt with wireless apparatus, also how with find picture of my radio ex- ii-\v of them so equipt appeared to be using perimental outfit. My receivin their apparatus or even listening in. I held ci on with some interested day Relay in the May. 1916, issue. This amateurs on shore. Mar our station (8NH) again to inent part in the Presidential Relay, being We did not send or receive any "S.O.S." a pri/c winner. We have been subscrib- calls, but did have occasion to render timely ers to the Fi.ectrical ExrERi.MEXTER for assistance to a motor boat whose engine more than a year.'' had broken down out at sea and towed her to a place of safety before a severe PHILADELPHIA'S NEW RADIO thunder storm broke upon us. STATION WILL SEND THREE- FOURTHS WAY AROUND I might say that I detected little differ- WORLD. ence in the workings of my apparatus the boat as compared with the ritliniin.u \ work on construction of one same on land.

. station- in of the mosl i ireless I found set the world has begun at the Philadelphia my to be of the greatest service in the evening the Navy Yard, according to an official an- when crew gath- nouncement m construc- the time signals and the of the dav. tion of a hangar which will house eight news

i is battle hj droaii planes alsi under w aj . The new wireless station will have a sending radius of approximately three- WIRELESS TELEGRAPHY ON BRITISH SHIPS. i i i oi the distanci an mnd making possible direct communication with By an Order in Council, issued on July Among the Girls "Radio" Has Now Become the Philippines insular possessions 2S iast, every British ship of 3,000 tons a Promising Vocation. At Least Miss Wini- of the United States. The aerial structure gross or upwards is required fred Dow, of Tacoma. Wash., Seems to to have a Think So. will be more than 700 feet high. wireless installation. 112 THE ELECTRICAL EXPERIMENTER June, 1917 The Marconi Type "106" Tuner By WORTH MacKXIGHT "106'' THE receiver consists of a type The switches marked Transformer Pri- aerial is connected to one terminal of the tuner and a crystal detector. This mary are for the purpose of varying the inductance, so that by varying the trans- receiver consists of a variable induct- amount of inductance in the aeriai circuit. former primary, a greater or less amount of ance primary circuit. One end of this The switch marked i'nits varies the induc- inductance can be inserted between the inductance is connected to the antenna thru tance in one-turn steps. The switch marked aerial and ground. This either increases or decreases the natural period of the primary or aerial circuit. It is necessary, therefore, to make these adjustments to bring the circuit in tune with the received signals. If the wave length of the received signal is shorter than that of the aerial circuit, it is necessary" to insert the primary condenser in the circuit. This has the effect of shorten- ing the time period of this circuit. The secondary circuit consists of a variable condenser marked Secondary Condenser, and a variable inductance marked Trans- former Secondary. By varying either the transformer secondary switch or the secondary condenser, this circuit can be tuned to the wave length of the incoming signals. It is also possible to vary the ratio of capacity to inductance, while maintaining the same wave length adjustment. It is often found to advantage to vary this ratio. The handle marked Coupling is for the purpose of varying the inductive relation of the primary circuit and the secondary circuit. After these circuits have been tuned to the incoming signals, the coupling should be varied until a maxi- Front View of the "Marconi' Type 106 Radio Receiving Cabinet. Radio Students mum response is found. The handle Will Find It Beneficial to Study It Thoroly. the antenna switch. The other end of the inductance is connected to the ground thru Pofent Sec Prim a variable condenser, which can be short- circuited or thrown into circuit at will. The secondary circuit is so constructed that its inductance may be varied, and also its inductive relation with the primary circuit can be changed. A variable condenser is provided, which permits a variation of wave length and also the variation of the ratio capacity to the inductance, while maintaining the same wave length. A battery and potentiometer is provided which permits controlling the current thru the detector. A pair of head telephones is used for receiving the signals. A buzzer is supplied which permits the local excitation of this receiver, so as to determine its condition of sensi- fort* tiveness. A battery furnishes current for both the detector and buzzer. c ^ Fig. 1 is a front view of the type "106" Fig 2 tuner and shows the exact position of the different switches and parts for its opera- Front View of "Marconi' Type 106 Radio Receiving Cabinet, Equipt with Mineral tion. Detector and Loose Coupler.

Tens varies this marked Potentiometer varies the current inductance in ten- thru the crystal detector. The detector is turn steps. The situated between the coupling and conden- Primary Conden- ser handles. A switch marked Battery is ser, when in zero provided, so that the crystal may be used position, has a either with or without the battery. A buz- minimum capacity. zer is mounted on the front of the panel If this condenser and is operated with a button marked Test. is turned beyond Terminals are provided to connect to the

the 180 degree battery : they are marked Battery. Two mark, it automati- terminals are provided for connecting in cally short-circuits the telephone receivers, and are marked itself, so that the Telephones. aerial circuit will The internal as well as the external con- have no series ca- nections of this receiver are shown in Fig. pacity in it. The 3. Fig. 2 is a back view of the panel. terminal marked This hook-up is of interest to all radio is connect- Aerial amateurs and students who expect some ed to the antenn;. day to become commercial operators. switch. The terminal marked \mong other things, note that the buzzer test is linked up with the aerial-ground cir- Ground is connect- cuit inductively a two coil transformer. ed to the ground. by in When this primary Xote how the secondary coil is moved pinion circuit is connect- and out of the primary" by a rack and ed to the aerial and arrangement, giving great precision to the circuit coupling adjustments as well as rotary con- Hook-Up for Complete "Marconi" Type 106 Receiving Set, Showing ground the

Inductively Coupled Test Buzzer. is as follows : The trol. June, 1917 THE ELECTRICAL EXPERIMENTER 113 The How and Why of Radio Apparatus

NO. 4—SPARK GAPS. However, we can increase the amount of any indefinite time, it is best with such From time to time we will describe one current passing thru the gap without in - non-synchronous rotary gaps, to provide a particular instrument used in cither tin- ra- • i' asing the length of the spark, by simply stationary electrode "A," in the form of a dio transmitting or receiving set, explain- increasing the size of the condenser, and segment, having a pitch equal to the dis- ing just how it works, and why. II e have the most efficient circuit for a given amount tance between two of the rotary electrode received so many requests /rum new read- of power, is that in which there is a mod- points.

ers asking for such explanations, that we erate spark length with a large condenser. I or synchronous rotary gaps, driven by a have decided to publish this mailer til serial When the condenser has been fully synchronous A.C. motor or by mounting ft 'i ni. In the course of scleral issues all of charged, tin spark gap breaks down, and the the disc on the same shaft with the motor- the principal transmitting and receiving ap- gap becomes tilled with metallic vapor, and iie in the best types of

I I tonus paratus wtll have been i ovei ed. he subjei tor the time being a high frequency commercial radio transmitting sets, the fixt are. Joe the Join Hi paper is the SPARK (JAP. alternating-current The conductivity electro. [i i| be any larger than a of the spark is due to tin presence of me- [le electrode point on the rotary disc.

spark gap forms one of the tallic vapor in the gap. After the discharge < 'iie of the most efficient spark gaps used Till",most important parts of any os- ceases, and it" tins metallic vapor is not very successfully by commercial stations cillatory circuit, and this proves quickly removed from the gap, the insula- and also by numerous amateurs, is the particularlj so in radio transmit- tion will in consequence be very low at quenched gap illustrated at Fig. 3. This

ting circuits, where everything the time that the condensi i is passing thru gap, which is very well known to-day, is must be designed to realize the utmost ef- its next charging period, which of course designed on several important basic prin- ficiency. This means careful and scientific occurs in a small fraction of a second, usu- ciples. The foremost of these desidera- design at every turn, and it takes into con- ally. tum s is that each gap shall be preferably sideration such important topics as the It is therefore paramount that we re- not over 1/100 of an inch in length, and proper dissipa- moreover, that tion of the heat the gap shall be line electrodes produced in the SparA gap absolutely air- proper Further, gap; the Cooling /ones Threaded /n tight. arrangement o i not over 1,000 to the gap to give , SparAgap 1,200 volts should the desired tone, be applied to and a number of each individual other vital points. gap, and for high- The part plaj ed er voltage a suit- by the spark gap able number of in an oscillatory these short gaps circuit is to allow are placed in se- the condenser in ries, as shown in this circuit to the illustration charge to the re- Fig. 2 herewith ; two quired voltage, gaps being adap- and then to break Rotary plafe ted to 2,000 volts down and permit — three gaps to the charge stored 3,000 volts, etc. Airtight casing in the condenser, The action o f surge Adjustable this gap has been to back Cooling f/anges and forth across 1 To A&G. I bo/i beanngs described at some Grooves the gap in the length in a semi- form of sparks, technical manner until all of its Cooling by Mr. Charles energy is dissi- l/ones R. Ballantine in pated. For sev- aiim mm the March, 1917, eral reasons the InsuI. coupling issue of The ideal spark gap Electrical would be one Mo/ors/iaf/ ExPERIMEXTF.R. which would in- Fix-t plate oos' sph gap Briefly, the action sulate perfectly, oi Mico ring Cost or turned plates of the gap is or be non - eon- Fig 4 based upon the ducting during Fig 3 fact that a small the time when l«] quantity of air the condenser is trapt between was being Various Styles of Radio Spark Gaps Which Have Been Found Efficient for Different Types of the spark sur- Sets. The Rotary Quenched Gap, Fig. 4, Is One of the Best for Small and Medium Power Sets charged, and con- Operating on Low Frequency Circuits. faces separated ducting perfectly, by a mica ring of while the condenser was discharging. move this vapor completely as soon as pos- proper thickness. After the first few sparks The nearer these requirements are ful- sible after the discharges of the condenser have past the oxygen in the trapt air is filled in any spark gap, the more efficient have ceased. This has been attempted in burned up, resulting in a partial vacuum in will this piece of apparatus perform its various ways in the past, such as by pro- the gap. This conduces to the rapid function. While the discharge is passing, viding spark gaps having large cooling quenching thereafter of the spark dis- the resistance of the gap depends upon vanes attached to the spark electrodes, as charges, due to the condenser, and gives two factors : the resistance increasing in Kig. 1, and also by causing one or both rise to a very ideal set of conditions for markedly with the length of the spark, of the spark gap electrodes to rapidly ro- the entire radio transmitting circuit. This and decreasing rapidly with the oscillatory tate, so as to constantly refresh the air in is because the oscillations in the spark gap- current, amounting with a half-inch gap the gap. This latter condition, which is condenser circuit are cut off after the first to several hundred ohms when a fraction usually met by arranging a number of few beats or sparks, but the oscillations in- of an ampere passes, and but a small frac- small spark electrodes on a rotary disc at- duced in the aerial-ground circuit are left tion of an ohm when say sixty amperes tached to the shaft of a motor, or to the free to oscillate for a longer period. This flow across the gap. If the spark length shaft of a motor-generator in the case of prevents the reaction of free oscillations in is above one-half inch, the resistance with synchronous spark gaps, the spark being the spark gap circuit upon the aerial or the same oscillatory current flowing, can caused to jump thru the air between the secondary circuit —a condition which is in- be taken as approximately proportional to constantly moving electrodes, and one or variably found in ordinary radio transmit- the spark length. However, in a condens- more fixt electrodes mounted on the base ters fitted with a plain fixt spark gap, and er circuit, the quantity of electricity is of the spark gap. a condition which mitigates seriously stored up in the condenser, and in conse- Fig. 2 shows a non-synchronous type of against the best efficiency of such an equip- quence, the amount of oscillatory current spark gap in which the speed of the rotat- ment. The quenched spark gap usually increases with the spark length. Hence, ing disc bears no definite relation to the consists of a number of these small gaps we find two conditions working against frequency of the alternating-current in the as above described, which are placed in a each other, as regards the influence of the transformer or spark coil. As a spark is suitable frame so that considerable me- 1 spark length on the spark resistance. apt to occur, or want to occur, at most Continued on pane 153 I : —

114 THE ELECTRICAL EXPERIMENTER June, 1917 C2N5TRVJQT5R W11 11 11 11 r— —ii—ii— —ii—ii— —ii— n ii -it—it—ii—it—ii inn

The Clock Craze By Thomas Reed

cooped up in a flat, late years, over in his grave at that libel, for one of handed over the kale with a feeling which BEINGI've had to give up experimenting. his excellent hrass clocks ought to go for if magnified a few diameters would have Mine's a tine flat, as flats go—all 100 years, and only be talking baby-talk been enthusiasm. modern conveniences, two kinds of then. 1 knew what ailed it all right; it was Everybody (including myself) expected cold water as the fellow says, and a so full of my contact-springs, wires, mag- it would be not over two weeks at the out- fire-escape with a sparrow's nest on it nets and other junk, that its regular works side before I had the clock rigged up and even a little safe let into the wall, big had become discouraged. But that was a secret between me and the clock, and there were good reasons why the secret was safe with me. Anyhow, when the clock took to stopping, something had to be done, and done quick, because mother would figure wrong with her Saturday baking, and Mrs. Skil- lings would get her hot pies out on the window-sill first, which was an awful catastrophe to mother, and made her feel as peevish as the Standard Oil does when a Confoc+s competitor sells a quart or so of gasoline right under its nose. I had pondered a little on electric clocks, and as I say they looked easy, so I made

Armafare the family a proposition ; for half the price of a new clock I would turn the old one into an electric clock that would go 4gote post all the time without winding. Father liked the idea because his back got twisted climb- ing up on a chair to wind the thing, and any clock at all looked good to mother provided it was a going institution. I said this one you couldn't stop if you wanted -

to ; and it would be so accurate that Mrs. Skillings would he running over to ask humbly what the really correct time was. This is known as promoters' language, and is powerful. It clinched the deal. Father F/g.5 m jn ng.i L®

Fig. 1. Attempt No. 1 in Electric Clock Finally the Electric Clock Problem Settled Research as Tried Out by the Author— Did Down to a Resurrection of Hipp's Famous It Work? Read the Accompanying Text if Pendulum. But Oh! that "Agate" Post IX? You Think So, Bugs. Likewise Zowie. enough to hold most of the Wirt's diamond tiaras if you pack 'em tight. Yes, it has was after Mrs. Skillings' goat with it. I all the conveniences tint one, and that's the took the old clock to pieces for the last only one worth having—a workshop. time, pulled out a few superfluous wheels The nearest I can get to it now is read- and springs, and inserted a pawl and rating the good old Electrical Experimenter. chet-wheel where they would do the most When she blows in. I sop her up from good. Then I started gaily on the electric front cover to hack—every word. Adver- pendulum that was to drive it. I wished tisements and all. Well, I'll say so; and afterward I'd made the pendulum first. I'm not' the only one that does it, eh, It was a grand pendulum I made—a sec- Bugs ? onds-pendulum of the due length of 39.1 One place 1 always stop and smile, and inches, with wooden rod and a tine heavy that's the heading "How-to-Make-It De- bob. I was so cocksure that I polished up

partment.'" I guess my department is the all parts as I went along. But when it "How-A"o/-to-Make-It.'' Usually every- was done, it wouldn't work. thing I started went wrong the hrst time; There were two or three main reasons but the finding out why it wouldn't work, why. To begin with, it was hung on pi and making it over till it would, wasn't the like a telegraph key: and the heavy bob

worst fun in the world. In fact. I think set up so much friction there that it would it was the lK--t. No fun simply copying. have taken about a kilowatt to drive it. When it came to the electric clock, Of course it should have been hung on a though, that nearly heat me. There's a suspension spring, which lets the pendu- thing that look^ easy, and isn't: yet it's lum oscillate while supporting its weight simple enough once you're wised up. without friction. Bonehead play number I was sort of forced into the clock craze. one. see, our kitchen clock was the Well, I discarded my pivots tho I You on Attempt No. 2. in Electric Clock Design. — blink. Father didn't Maine it—good old This Arrangement "Worked Too Well." But hated to. they looked so pretty—and with clock, he said, it had served him faithfully the Magnet's Successive Pulls on the Pendu- my pendulum swinging easily from a lum Accumulated till it Banged Against the I her But nix. twenty-five years, and was worn out. Worn Magnet Like Jess Willard Administering a ng, looked to see go. liet out nothing! I'll old Jerome turned K. O. I strong magnet, clean contacts, and —

June, 1917 THE ELECTRICAL EXPERIMENTER 115

all tlmi. but nothing doing. Could any- oter. My stockholders, ignor- fascinating of i lo< ks ai d if so, I thing be wrong with my arrai have many valuable "wrinkle-" which I Answer, oui, oui. oring for quick returns on their investment. should be delighted to share with you.

Vim see I had ii rigged as in Fig. 1. in this mm nl fall naturally Only, avoid my experience, and don't make following tin- idea of tin- electric lull. into sarcasm. 'I "Oh, you were a business proposition of it at first. C-U-L, When tin- pendulum swung over far enough sure as anything when you were in make contact, the magnet gave a vigor- and now you admit you ous pull; Imt unfortunately iv checked tin didn't know what you were doing. Of NEW RESISTANCE MATERIALS.

' ' > uu're right on A Xew York concern is now marketing track it this P/of/nt/m ccm/ocf fh/r> 6er/nao the of tungsten and rib- .w\ Peodt//um - t i in e pooh, i h ! bon and plate form. This development

I [a\ e it all reail makes these metals suitable for new uses morrow > ^L^E. morning at ipens to them a much wider field breakfast, I su] of usefulness than has heretofore existed. Well, a fool and his The tungsten and molybdenum ribbon is " money all that being made in widths of about \\ in. encouraging stuff. I (6.3S mm.) and in lengths of several Coooecftog w/res Brass tr/gger know just how to this 1 yards. In shape the ribbons ought to bat &magnet treat impatient inves- to be ideal material for the manufacture tors now ; but at that of heaters of various descriptions and suit- time the situation, able for high temperatures, the manu- found sfee/ 6/vd coming on top of my facturer points out. The United States beof syff/i/ oog/e defeat at the hands of i inmeiit has already placed an order oofc/rea'at'faa Nature, got my goat, for plates of these metals for spark gaps F,g4 I'm to and ashamed on wireless outfits to be used on its Jlm- M say I declared bank- quito hi' it. Finally I Contrived a Substitute for that "Agate" Post on the ruptcy and quit. Clock Pendulum, Relates the Author, and Decided that the Thing Father bought a new to do Was to "Substitute." Steel Proved Excellent—but I Guess KINKS FOR THE DRAFTSMAN. a Piece of Cheese Would kitchen clock, and is- Have Sufficed. The first "kink" shown is a new section- sued a manifesto liner. There are a great number of appli- pendulum just as much as it pulled it, and (having got an inkling of what ailed its ances on the market for this purpose, but the result was nil. The slow, free-swing- predecessor) that if I monkeyed with its the one described will do the same work ing pendulum acted differently from the insides to the 100th part of a monk, he as the most expensive device, its advantage rapid, springy hell-hammer. would monkey with my outside ; and, in the being simplicity. The two weeks were already up, and vigorous language of the day, I was not It consists of a sheet of celluloid cut as mother was beginning to peeve, because to forget it. shown. The parts shown in black are cut mi anwhile Mrs. Skillings bad put it over I knew why a prophet is without honor away with a sharp knife, leaving a kind of her again on the pies; so I hid my chagrin in his own country. Believe me, my home grid. To use this section-liner place its under what I hoped looked like a confident reputation as a budding scientific and busi- base close to the Tee-square and place the smile and attacked the problem anew. ness man was badly damaged ; to be more pen or pencil into the opening and draw The next attempt is shown in Fig. 2. I exact, it looked like the place where a 42 a section-line, following the outline of the made a flapping contact, metal on one side cm. shell has recently landed. But the grid. Without moving either Tee-square and insulating mica on the other. This clock craze had struck in : and oblivious or section-liner, place pen into the next slot arrangement worked well, if of everything, in cloistered seclusion too you get be- and so on. me. The magnet gave a nice pull, and on hind the barn I pondered upon Hipp and The two corners "X" and "Y" are cut the back-stroke it let all as per inten- his exasperating agate. go, away to the angle of threads used and these tion. But now the pulls accumulated till T pondered long before, in a burst of may come in handy when drawing bolts, the pendulum ended against the the by banging enlightenment, great truth of Bugdom etc. magnet like Jess Willard administering a burst material, upon me—use some other The second "kink" will save those drafts- This pendulum thing began to if it isn't all K-O. seem even as good, anything at men that are on repetition work much time decidedly not as easy as it used. for a starter. Couldn't I use steel, brass and trouble. It consists of the following: to have it at all even ? it would last long to try it Anyhow, go was some enough Draw all those bolts, nuts, washers, fit- consolation \!1 that was It needed now Was anyhow. makes me laugh now, my great tings, vie., that are used over and over

to the discovery : that some arrangement cut current off but do you know some- again in numerous sizes on a sheet of as soon as the pendulum had all the im- times the getting rid of a fixt idea is the tracing cloth and ink it in. Be sure to pulse it needed, and switch it on again hardest part of an undertaking? Why, 1 mark, in the case of nuts and bolt-hi when more was required. Now I began to could have used pewter, paper, I guess from where you strike the radii: see point appreciate Hipp's pendulum, described in even cheese if you took it near the rind. "M"; point "X" shows the height of the the text-hooks. In Hipp's device (Fig. 3) Don't let anyone discourage you. Bugs, bj bolt head arc. the electric contact is made by means of specifying costly and unusual materials. As most offices use transparent draw

i notched post attached to the pendulum, The inventor's describing his rinktum the which normally pushes past a little swing- way it looks after he's got it all babied ing trigger attached to the contact-spring. up in its final Easter dress; but just for \s the pendulum loses its amplitude, there a trial you don't need the platinum, Bake- comes a moment when the notch in the lite, Empire cloth, ami "S.C." wire —no, sir, post just catches the trigger, and then when you'll find all you really require in the it starts the other way the trigger is good old junk-box as usual. Me, I grew raised and the contact made, the magnet so independent finally in the matter of ma- is energized, and gives the pendulum a terials that 1 hardly recognized more than push. The notch now brushes by the trig- two kinds—conductors anil insula!' > ger again, until the narrowing swings allow So, having got the agate out of my head it is — to catch once more, and the process "solid agate" I guess my old bean was repeated. As the battery runs down, the I used steel fur the post ami liru-s for the push is weaker and the contact has to be trigger; and as to durability, let me tell made oftener; but the mechanism does this you that after nearly twenty years i\se I automatically until the battery is exhausted. Can't with the naked eye detect any v.

Hipp's rinktum looked effective, if one Oh, yes, I made the clock, hut 1 had a could only make it; but being a clock- long hunt for something on Hipp's prin- maker, old Hipp had specified agate as the ciple in a form which the amateur work- material for his notched post Agate, he shop might turn out. After mans trials 1 A Celluloid Section Liner for Draftsmen and a Scheme for Quickly Drawing Nuts or says, just like that: "Take a piece of agate, evolved the form shown in Fig. 4; and I Bolt-Heads of Any Size. Mm know, and put a notch in it." Oh, make you free of my invention. Bugs, boil-

The only agate I had ever beard of ing someone will be interested enough to cloth, the standard sheet can easily be slipt was an agate marble; and it didn't look make himself an electric clock. There's under if. outlines traced exactly like easj stuff to make anything of, lots of enjoyment in listening to it- sedate thru. In the case of many hundred holts, Four weeks had now gone by, and the tick-tock as it breaks up infinite time into etc.. required, say in details of holts for family had lost all their peevishness; that, the small units we need to make our good pipe lines, etc., the saving of time will be is, they had exchanged it for black looks ,.i bad u i of. Maybe, now that the war .mil a much neater drawing and language not calculated to please. 1 will del. ,n- us from wireless work for a will be the result.

' was reaping the usual reward of the san- while, you'll feel inclined i" take up this Contributi C. V i iYD. :

u6 THE ELECTRICAL EXPERIMENTER June, 1917 The Influence of Light upon the Contact Potential of Selenium and of Cuprous Oxid By. E. H. KENNARD and E. O. DIETERICH Department of Physics (University of Minnesota) into a tube and showed the resistance of crystal- nated, the concentration of free electrons ducd vacuum change in a THE sensitive would be increased, and one should expect characteristic lines of helium. When line selenium and other light into the darker very old sample of radium bromid was substances, such as stibnite, cuprous diffusion of these electrons portions, leaving the part illuminated more oxid, etc., under the action of light and oth- The negative sign of er agencies, has been explained on the as- positively charged. of the in contact potential, however, at sumption that it is due to a liberation change hypothesis and conducting electrons from the atoms of the once rules out the diffusion theory mentioned above material in question.* In other words, the makes the simple which better change mav be considered as due to a inadequate. An hypothesis If this expla fits the facts is that contained in a theory change in the atom itself. : ot proposed by Professor F. C. Brown nation is correct, then other properties recently University, which as- these substances, which also depend upon of the Iowa State of light consists in inter-atomic forces, should show a varia- sumes that the action of recombination of con- tion from light to dark. The authors in- changing the rate with the selenium atoms, vestigated the influence of illumination up- ducting electrons or. in other words, it decreases the potential on the c tential of selenium and Condenser Method for Measuring Quick electrons in the inter-mole- of cuprous oxid. since this property is one energy of the Changes in the Contact Potential. The Elec- above. cular spaces. trometer, E, Can Be Connected by Means of of those mentioned Suitable Clips, Either to the Gauze, G, the Using, as a check upon each other, two Selenium Plate, Se, or the Copper Plate, C. different methods. Figs. 1 and 2 of deter- POPULAR DISCUSSION ON THE As Shown in the Diagram the Connections Are Such That, by Means of the Poten- mining contact potentials, it was found that PRODUCTION OF HELIUM Fushman. tiometer, P, the Deflection of the Electrom- a change did take place in both substances By Mark eter Which Occurs When Light Falls on the investigation, Janssen upon illumination. In the case of selenium, In a spectroscopic Selenium Plate Thru the Gauze, Can Be something over and Norman Lockyer observed in the at- Made Zero, and the Change in Contact Po- this difference amounted to Are of the sun and many fixt stars, tential Determined. Proper Precautions —0.1 volt, several specimens being exam- mospheres Taken, of Course, to Secure Proper Electro- line which could not be ined. The value, in the dark, of the con- a bright yellow static Screening. that of any known sub- tact potential, relative to clean copper, was associated with substance they gave about —0.4 volt, in the light about —0.5 volt, stance. To this new used, the residue bubble gave the complete more "Helium." Helium was discov- i.e., the selenium surface becomes the name spectra of helium. This experiment 1895 Ramsay and negative on being illuminated. With cup- ered on the earth in by showed that helium was produced by rad- has rous oxid, of which but one specimen ium. Helium is also produced from active been examined thus far, the_ effect is not forms of actinium. This shows also that so great, being about —0.025 volt. helium ought to be a common product of In the case of selenium the effect is very both substances. in- marked, even when light of very low Radium, owing to its property of giv- tensity was used, as can be seen from the ing forth particles, gives forth certain par- curve in Fig. 3, which shows the relation ticles which are called alpha particles. In and between the change in contact potential old radioactive material there is a large lamp voltage. Thus, with a lamp voltage collection of helium which goes to prove of 25 volts (normal 110) the change that the alpha particle is connected with 110 amounts to about 0.035 volts, yet at helium or rather that an alpha particle is illumination volts at which the intensity of a helium atom. An estimate of the rate of Method of Measuring Contact Po- a factor of about 2,000 Ionization has increased by This Method Is Also a Null Method production of helium from radium has 1 tential. is only 3 . over that at 25 volts, the effect as the Diagram Indicates. S Is a Copper been made by Ramsay and Soddy. 1 gram Polonium, the a-Particles times as great. Strip Coated with of radium produces daily 0.499 cu. mm. Which Ionize the Air Above the Sele- recently the most widely accepted from Until nium Se, But Do Not Strike the Selenium helium gas. of sele- theory of the change in resistance Surface. G, as in the Other Method, Is a Investigation seems to show that the the Electrometer. nium with a variation of the intensity of Brass Gauze Connected to alpha particles from actinium and thorium illumination has been that proposed by Pro- are also atoms of helium; therefore we Travers, who obtained it by heating the fessor A. H. Pfund, of Johns Hopkins I m- mav regard these elements as compounds rare mineral Cleveite. Later on, it was versity. According to this theory, the ef- of helium and some unknown element. It found that this element is a companion to fect of light is in the nature of an internal plays an important also discovered in appears that helium of sele- Argon. Lastly, it was photo-electric effect, i.e., the atoms role in the formation of the radioactive the atmosphere. expel electrons, the velocity of which _ helium, like hy- nium of 4.00 and elements. It may be that the Helium has an atomic weight is too low to allow their escape from drogen, plays a part as one of the elemen- monatomic, i.e., that is—the helium mole- is tary elements of which the heavier atoms cule consists of only one atom. At or- are built. temperatures, helium is a colorless dinary the center or 269°C.,__and evap- It is supposed that at gas; "it boils at about by rather in the depths of the earth, where oration at a pressure of 0.15 mm., a tem- the pressure is great and the temperature perature 1.5 above absolute zero was ob- high, radioactive elements are being formed tained. and the deposits of radio-elements now on The fact that this new gaseous element the earth's surface were thrown up from occurred in certain minerals was consid- below ages ago. ered very remarkable. A new light was by the discovery of thrown on this subject CARD INDEXING THE "E.E." radioactivity. Radioactive substances are a little stunt which I thought known to emit spontaneously electrons, or I have of interest to other readers, as particles, as thev are now termed. As might be follows: these particles a're emited the substance small card index that is sold changes into a new and different element: I took a theory for a recipe file /and sold for $1.00 any- this is known as the disintegration as TV read my Electrical Ex- of radioactivitv. In looking for a disin- where, and terimextir each month, I note on the tegration product, the presence of helium Curve Showing Relation Between Light on that may be of fu- helium is found in min- cards all those things the Contact Potential. is noteworthy, for Selenium and to me. in this way erals containing uranium or thorium. ture use hel- \ntenna Switch-Fxp. Jan., 1917. page con- Rutherford and Soddy suggested that interior, hence they produce increased time that I want to make might he a product of disintegration. 658; then at »nv ductivity. The true explanation, however, ium ar- thirty milli- anything, I look at the cards and all for Ramsav and Soddy obtained does not seem to be as simple as this, stack of magazines are listed radium bromid and dissolved it ticles in inv theory, in the regions illumi- grams of on the above there, which/ saves hunting thru a stack of in water. Radium bromid produces hydro- magazines for something you * A more complete discussion of this work is gen and oxygen, so these gases were several doz*i Physical Review for January. cannot find. to-be fo off and there remained a small have seen, but prepared for The Electrical drawn 1917. This article which was intro- Contribute,! by F. C. BROWN. Experimenter." bubble of residue gas, June, 191 7 THE ELECTRICAL EXPERIMENTER 17 High Frequency Apparatus and Experiments By HUBERT A. McILVAIM:

experimenters either do not MANYrealize the vastness of the high frequency field, or think that they __ have not money enough to buy the necessary apparatus. It is the purpose of this article to explain the manner of constructing a few simple instruments, and the method of carrying out si Mile simple experiments. In the first place, a high frequency transformer must he constructed. An Oudin coil will be the best for all-around work, and it may be made in the following simple manner : Procure an ordinary pasteboard mailing tube, about 2' i inches in diameter and 10 inches long, and cover it with a thin coat of white shellac. While this is still wet, wind the tube with line copper wire, spacing the turns far enough apart to ensure proper insulation. (Enough wire may be found in an old telephone ringing magnet. ) Glue this tube upright to a base and fasten three posts on the base. The primary coil may be made of 6 turns of No. 14 copper wire, connected as in the diagram, Fig. 1. A condenser can be made by coating both sides of old photographic plates with tin- foil, and placing tiieni in a cigar box, to hold them in an upright position. A spark gap of most any type will answer. A V/2 inch spark coil should be used. When the above instruments are constructed, they should be connected up as shown in diagram, and the apparatus is ready. When the spark coil is operated, a brush discharge of purple light should appear around the free end of the secondary, uoner end of coil, with sparks about 2 or 3 inches in length. If a piece of metal is held in the hand, a very long spark can be drawn from the secondary wire, without the slightest shock. If, however, the spark Wood dowe//p/n is drawn directly into the hand, a severe sting may result. On the other hand, if a pane of glass is held between the secondary wire and the hand, a spark may be received directly into the hand without pain ; the spark, being dispersed or spread out while passing over the glass. Fig. 2. Manner of Constructing Small "Oudin" Type High Frequency Coil for Carrying on Artificial "Aurora Borealis," If a person insulated from the ground a Series of Interesting Experiments. One of These Is the Which Is Produced with the Aid of an Incandescent Lamp Bulb. Having Its Tip Portion secondary, a grasps the free terminal of the Coated with Tinfoil, and Connected as Shown. match may be lighted from any part of the will light bright- body. A Geissler tube up inside the bulb. Also, if there arc any treat diseases obtain a box which is large ly, when brought near the body. This is loose pieces of filament, these will begin to enough to contain the coil and still leave also a good way in which to treat heart and revolve rapidly about the inside of the bulb enough space (about 4 inches) on each side nervous diseases. If there is any local and will continue to do so for some time to prevent the coil from "grounding." Run object trouble, a grounded metallic should after the current is shut off, and each time the coil wires through the box and leave the be brought near the point to be treated, thus they touch the glass a shower of sparks will free end of the secondary about six inches taking out the induced current at this rly in all directions. long, so as to obtain good radiation sur- point. A by-product of higrh tension electrical face. Place a hose in the top of the box An interesting experiment is to produce stress in the air is ozone. Ozone is merely and another in the lower part of one side. an artificial Aurora Borealis. This may be electrified oxygen. When a high voltage Paraffin the box to prevent leakage, and accomplished with a large electric bulb (a discharge takes place in air or pure oxygen put a small window in one side so that the 100 watt, burned out one will do), covering gas, the atoms of oxygen are "torn apart" coil action may be viewed. Either air or the lower the tip with tin-foil. Insulate the bulb and exist in what is known as a nascent pure oxygen is taken in thru state. In this state each atom combines hose and the ozone is inhaled, or otherwise with one other atom, and the chemical af- applied from the upper hose. In fumiga- colds, finity of these two atoms is such that, as tion, treatment of coughs, pneumonia, uses, besides there is nothing with which they can com- and for many other medical bine, these atoms pull to themselves and oxidation of certain materials, bleaching combine with a third atom of oxygen. flour and cloth, experimenting with its use other commercial uses, Thus it is that a new gas is formed. This in welding and many valuable agent. gas is much denser than oxygen and is ozone is a most many times as active. The smell of ozone Taking the high frequency field as a while for more ex- is very strong and there seems to be a slight whole, it is well worth fre- difference in the smell of ozone produced perimenters to work with it. High properties of both with a static machine and the ozone pro- quency current has the duced with high frequency current. Ozone static and galvanic electricity, besides many Fig. 1. Proper Connections for Small of the above pos- is an excellent "germ killer." as it kills all properties which neither "Oudin" High Frequency Coil Excited by a It will pass over ordinary insulators, Spark Coil or Step-up A. C. Transformer. kinds of disease germs on contact. If it is sess. fre- administered properly, and in time, it will such as glass, almost as easilv as low quency current will pass thru copper. It from the ground and fasten the screw end cure consumption. travels over the surface of a conductor to the secondary wire. Place a strong per- The electric stress about the coil is so and seldom thru it. Its oscillations are manent magnet on each side and start the great, that immense quantities of ozone are In order to {Continued on fagc 154) coil. A beautiful auroral effect will form constantly being generated. —

118 THE ELECTRICAL EXPERIMENTER 1917 The Problem of Using The Energy in Sunlight By Prof. I. Thornton Osmond A RESEARCH PROBLEM AND is but one phase in the focus of a lens, Fresnel Mirrors, one 40x40 cm., the other spherical or cylindrical, all OUTLINED SOLUTION. waves (of a 40x60 cm. ; the latter serving for a Lloyd

i i length are in the same phase at any single mirror, if wanted. 4. Biprism. sul- SUPPOSE all the electrical energy instant. fur. 2p cm. wide, 40 cm. long; small an- used in the world for power, heat Two parts of a complex beam, of a gles 7°, large angle 166°. 5. Polarizers, re- and light to be obtained for nothing. one wave length beam, or of a one wave flecting metal plate, pile of plates, glass or the world would be chan How length and one electric vector beam may be sulfur; fine grating; Fresnel rhomb. 6. Energy in electrical form, of limitless made to traverse the same space by the use The transferring, or receiving, apparatus amount and absolutely free, is fallin of a biprism or a mirror in such a way that described in 7 above (which may not be with a world provided apparatus and appli- the intensity at various places at any in- necessary). 7. Accessory apparatus, as ca- ances for the use of electric energy. But stant has values that vary from zero to pacity, resistance, inductance, and indicat- the world docs not use this constant, ex- four times that of the single beam. ing instruments. haustless flood of free energy; it digs coal 7°. Take a vessel with walls readily tra- Wherever wave length enters into the out of the earth and depends on that for its versed by the solar radiation and that may design of these pieces of apparatus it is power, heat and light. be exhausted to high vacuum if desired, taken as from 0.6cm., to 1.2cm., as being The greatest discovery any experimenter and produce in it an abundant supply of near the lower limit of waves well above is the can seek direct utilization of solar electrons (as by a filament or wire heated the longest heat waves, i.e., waves produc- as the source of power for the energy by a current ) and bring into this vessel ing molecular motion. Greater wave w< rld's work. electrodes to receive the radiant energv lengths, with corresponding changes in de- The following out- sign may be found line of experimental to give better results. research enable j EVACUATEO TUBE may | 10°. Apparatus some so circum- Combined for Ex- stanced that they periments, g i v i n g can make the inves- various kinds of tigations, to make radiation beams.—1. this discovery. In Grating and Lens, or this work I seek to Lenses ; or Lens and obtain energy from CHAT Curved Grating. 2. solar radiation by PLAN SM Grating and Polar- causing it to pro- izer. 3. Grating, duce ordered accel- Polarizer and Lens, eration of electrons or Lenses. 4. Grat- about, and in, a con- ing. Polarizer and electric d u c t o r — Ellipsizer. S. Grat- current. ing, Polarizer, Ellip- Problem: — To Ob- sizer and Lens. 6. tain Electrical Lens and Biprism or Energy "Directly" Lens and Mirror. 7. from Solar Radi- Grating, Lens and ation. Biprism and Mirror. 1°. The solution 8. Grating, Polar- here proposed is izer, Lens and Bi- based on the follow- prism. ing principles : 1. For this work it The solar radiation would be desirable, is electro - magnetic. perhaps necessary, 2. The flow of en- Arrangement of Apparatus as Suggested by Mr. S. Cohen, for Use in Determining to have a complete- the Most Effective Energy Components in "Sunlight." ergy is in the direc- The Various Rays Are Focussed from a Diffraction Grating Into a Vacuum Bulb, and Their Magnitude ly metal (iron) in- tion of propagation, Measured by the Reaction Deflection of an Electro-static Galvanometer Connected closed container of sun to earth. 3. The Across Two Electrodes, Charged As Shown by a High Tension Arc or Other the instruments. If Generator. periodic action, vi- a room of this kind bration, is at right is not available, an angles to the propagation, and is cyclic treated as in 3, 4, 5, 6, and send it thru an iron case 2.4 meter (m.) long 0.5m. wide, variation of two vector magnitudes, elec- external circuit, containing such capacity, 0.8m. high will contain any of the com- tric force and magnetic force. 4. Solar induction, and resistance as may be re- binations of apparatus given above and the radiation produces acceleration in electrons quired, and some form of indicator, as a transferring, or receiving, apparatus. The in its path that have a component of motion galvanometer, telephone, or wave detector. mounting of the combination of apparatus in a certain relation to it. 5. Acceleration (The vessel, vacuum and ionizer may not should permit following the sun or direct- of an electron produces an (opposite) ac- be necessary; possibly the energy of the ing to any point within 90° of it. celeration of surrounding electrons. treated beams can be taken by the elec- electrolytic process of 2°. The experimental solution is rendered trodes without these.) An deoxidation has been patented in the United difficult by the great complexity of the so- 8°. By the various combinations of ap- States by Pascal of London. lar radiation. Take a small area in a plane paratus, in 10-below, using solar radiation, Marino The object to be treated is the cathode in at right angles to the solar beam. At even- produce in the vessel the linear focus, or made an electrolyte containing phosphoric instant there are passing thru this waves of foci, of the different character beams of 3 acid. In ad- millions dition to its normal function of carrying of different lengths and periods, and 4 above; or produce within it the space the current, this acid acts and at every instant they are in millions of variations of intensity of 6 above, with any as a solvent upon rust without attacking the different phases, and the electric and mag- of the kinds of beams named. Try various steel or iron body beneath. It is in this netic vectors in these waves at any instant relations of variously formed electrodes last detail that its chief availability lies, since nitric, sul- are in millions of different directions and to the focus, or foci, and to the regions of furic or hydrochloric acids continually changing at every point different intensity: with various ionizing would not 3°. play such moderation. Finally, A beam of one wave length or period current, as direct, high frequency alter- the phosphoric acid is beneficial in preventing sub- approximately may be obtained by the use nating, or spark discharges of coil or con- sequent further rusting. of a prism or a grating, preferably a grat- denser, and various inductances, resistances The electrolyte is made ing. and capacities in the external, or receiv- by adding ten parts of phosphoric acid to ninety parts 4°. A beam with the electric vector con- ing, circuit —using one or another of the of water, or by fined to one direction may be obtained by indicators named above. adding 105! of the acid to a solution of sodium phosfate. the use of a polarizing mirror or a pile of 9°. Apparatus lor Proposed Experimen- plates; or to two directions, giving elliptic tal Solution.— 1. Lens "f sulfur, paraffin or Due to the advent of the war, we are resultant by an additional mirror or a synthetic resin, cylindrical. 27 cm., chord. particularly desirous of obtaining manu- rhomb. 40 cm. long, 50 cm. focal length : two oth- scripts describing original 5°. and practical A complex beam, a beam of one er-, each 22 cm. chord. 4(1 cm. Ion.:, 50 cm. "Electrical Experiments." We shall wave length, or a beam of one wave length focal length. 2. Grating, plane. 34 ele- continue to publish Radio articles, but and one direction of electric vector, may be ments, b=1.2 a— cm.. 40x41 cm. inside of what we need is snappy "Electrical" concentrated to a small area, circular or frame. Also a curved, cylindrical grating, articles. Be on guard for the enemy linear, in which, at any given instant, there 100 cm. radius, 32 elements, a+b -1.5 cm. 3. Repetition! June, 1917 THE ELECTRICAL EXPERIMENTER 119

This department will award the following monthly prizes: First Prize, $3.00: Second Prize, $2.00: Third Prize, $1.00. Tin' purpose ol this department Is to stimulate experimenters tow ird with .•mil For the most useful practical and original Idea submitted i" thi Editoi ol thif department, a monthlj zes will he i.s tin- bi idi i prize, for third awarded. For the best idea submitted a prize or $3.00 awarded; foi the lecond bi I a $2.00 and $1.00. The article need not l» verj elaborate, and rough sketches are sufficient. We will make the I I drawing I only one Idi of. sheet. Make sketches on separate shi

FIRST PRIZE, S3.00 SECOND PRIZE, $2.00 THIRD PRIZE, $1.00 A NOVEL ELECTRIC CHIME. SIMPLE AUTOMATIC CIRCUIT THE SIMPLEST FLASHLIGHT. Tlie accompanying illustration shows an BREAKER. Mere's the simplest flashlight one can electric which I have used in place The circuit breaker described below is chime make : A flashlight bulb, A, and battery, of an ordinary vibrating bell. giving efficient service on the switchboard in my laboratory. The puces \, B, C and D are brass strips; E, is a soft iron screw with two nuts to fasten/it to the tri; C. F is an electro-magnet wound with No. 12 silk insulated magnet wire. The core of this magnet was obtained from an electric bell. The spring G, and the adjusting screw are used to regulate the instrument. The connections are as shown. The breaker is used on 11(1 volt A.C. or D.C. lighting circuit. When the contact A touches the contact B, it is held there by the trigger C. The magnet F is always magnetized to a certain extent but an overload or short-circuit causes the magnet to attract the armature C, releasing the When the First Gong Strikes, Its Dependent contact breaks the circuit. It Armature Closes the Circuit Thru the Sec- A, which ond Gong Magnet "E", Etc. is to be manually reset. Hats Off to Mr. Peterson— Inventor of the Contributed by ALGIE RIGGS. "Simplest" Electric Flashlight. Can You Beat It? The hell armature sin mid be lengthened and two contact points soldered to the end. and in some cases a strip of brass, B, sold- a button is armature of When pushed the ered to the small battery terminal if it is bell is bell C drawn over, striking the once. not long enough. The lamp bulb is care- The lower contact then strikes N and fully soldered to the longer terminal strip. circuit. throws bell E in The armatures The lamp is lighted by holding battery in stay over against the magnet as each suc- hand and pressing with thumb on strip B. cessive bell is put in circuit, thus keep- A reflector (a nickel-plated thimble will do) ing the circuit thru lower contacts complete. may be fixt to the bulb if desired. When bell F is rung, the battery circuit Contributed by ERW'IX PETERSON. is broken, and all the armatures fly hack. Thus the operation is repeated. The gongs to start the arc—that is, to bring the car- should have different tones to give a pleas- this Circuit-Breaker the Armature In bons together and draw them apart. ing chime effect, and as many bells can be Normally Holds the Spring "A" Down; an A the to Attract simple is to place the crucible on a used as desired. Overload Causes Magnet way "E", Thus Opening the Circuit. Contributed by A. G. CORKRAN. long board, to be used as a lever, fastened to the base by a hinge of leather. "HARD RUBBER" BASES FROM WALNUT STAIN. An interesting experiment can be performed "VICTROLA RECORDS." by filling the crucible with ground glass The following stain is excellently adapted Wishing to make a detector and not hav- up to the lower carbon rod. An arc may to the finishing of wireless and electrical ing a suitable base I procured a piece of oak be started between the two gas carbons, cabinets and instruments, and for various (any wood will do) and an old phonograph and this will heat the glass to redness. other wooden articles which is desired to record. I cut the wood and record to the An arc will then be formed with the car- have a uniform coloring or finish. desired size. I then put a thin layer of bon rod and the hot glass as electrodes. Prepare a solution of 6 ounces of a shellac on the wood and prest the piece of solution of potassium permanganate, and 6 record on it, and left it for a few hours. ounces of sulfate of magnesia in 2 quarts When it was dry I sandpapered the edges of hot water. The solution is applied with and polished the composition rubber. a brush and the application should be repeated. In contact with wood the potas- Ptionogroph record ^^k Wr) sium permanganate decomposes, and a last- ,^^k covering ing walnut color results. If small pieces Wy/ Plumbago of wood are to be thus stained, a very di- Crucible lute bath is prepared according to_ the above description, then the wooden pieces are immersed and left in the solution for Wood ^^k wr / from 1 to 5 minutes, according to whethet a lighter or darker color is desired. Ho - 7 e Contributed by / r-\ (2) VLBERT W. WILSDON.

Do You Want a Hard-Rubber Instrument Base? Just Cut a Piece of a "Victrola" ELECTRIC FURNACE MADE FROM Record and Glue It to a Wooden Sub-Base. PLUMBAGO CRUCIBLE. . .-.- If the above directions are followed very An interesting and' practical ell If furnace can be made of a plumbagi neal bases can be made by the amateur. A Simple "Arc" Furnace Made From Two and gas carbons, the hole in the record dues nol allow a la (used by jewelers) two Carbon Rods and a Plumbago Crucible. in base to be made, cut a circulai of the carbons can be a . 1' the bottom The eyes should always be shielded from the composition rubber and plug ii up hole drilled about " From intense light of the arc by dark gl records that have one side blank of the crucible, and the other held in a the Contributed by HYMAN R, W \Ll.lX. clam;.. But some method must be devi TOM RI1 — EL AMATEURS! ATTENTION!!

Now that we are for the time being, deprived of using our Radio outfits, it behooves us to become proficient in learning the Wireless Codes. Operators who know the Code are, and will be, in ever rising demand. The army and navy need thou- No. FX5I7 sands of operators right now. Can you qualify? Can you send and receive at the required speed, when your country Selenium Cells calls you? Everybody has read about The Radiotone Codegraph is positively the only instrument made that will send such tin- experiments of telepho- an unbelievably close imitation of a high pitch Radio Station, that it has baffled experts. tography (sending photographs over a wire hundreds learner's outfit, consisting of key and sounder. The The outfit replaces the old-fashioned of miles) made by Professor Radiotone Codegraph comprises our famous Radiotone High Frequency Silent Buzzer, a Korn and others. It is also known that if the problem of special loud talking receiver with horn, and a key all mounted on a base. Operated on tele-vision is ever solved, the cells, phone will emit the characteristic high pitch sound, which while one or two dry the selenium cell will play an im- not harsh, is heard all over the room. With little trouble you can learn the code correctly portant role. At present we in 30 days are the only concern in the United States selling these cells. They are the most sen- AND THAT IS NOT ALL: sitive ones made. Better send for a cell to- outfits together for intercommunication work and you and your Connect two of these day and try making an elec- friend five or fifteen blocks distant can converse over a NO. 36 WIRE, so fine that no one tric dog that will follow a birnp, or an electric burglar will see it. Or you can use instead of the wire, a metallic fence and the ground. Or you alarm. It's very instructive lighting line, using no extra wire, only the ground. Full can communicate over your 110 and great fun. (See Novem- directions how to do this are furnished with the instrument. DEALERS: This is the 20th ber. 191fi, issue "Electrical Century instrument that will sell like WILDFIRE. 600 sold in New York in 10 days. Get Experimenter.") our proposition today! No. FX5I7 Selenium Cell. Codegraph complete as described, each, tfj 1 Radiotone 7C Shipping' Wglit.'. 4 oz* $6-00 IMMEDIATE SHIPMENTS IMMEDIATE SHIPMENTS BOYS! Here Are the Stars and Stripes in All Their Glory

Be t h e first one in your town to wear this patriotic emblem. Think of it: An electrically illuminated bouton- niere worn in the lapel hole of your coat. It illuminates o u r Na- tional Flag in the original colors with a brilliant electric light. Just insert Flag in button-hole of your coat, put flashlight case in vest or coat pocket and every time you press the button, the flag in your button-hole flashes up with "ELECTRO" TESLA COILS a beautiful color effect. This photograph shows a seven (7) inch spark.

Tesla Coil, made by us in our shops for a well-known institution. schools, universities. f,ir Illuminated flag, cord and plug (to We build hundreds of special Tests Coils for (postage 10 cents). inches be connected to any 2 cell flashlight), $.60 Stage purposes, etc. Spark lengths from two inches to fifteen Illuminated flag, flashlight case and battery, cord and plug, com- and over. correct designing. The plete as per illustration, $1.10 (postage 15c). We are known for careful workmanship and gap, Tesla Coil, shown above (7" spark), without condensers or spark DEALERS : Write for our proposition today. quotations for special coils. IMMEDIATE SHIPMENTS sells for $40.00 f Send for our THE ELECTRO IMPORTING CO. UK" The "Electro" Rheostat- Regulator 'Electro" Pony Receiver

(Porcelain Base) Our Tony receiver is This illustration represents nur little current without doubt the regulator which rerywhere to regulate for the money battery current. It will prei .rning out of your battery lamps, or will njjulate the speed Points Of superiority ; motors, I other uses. Of your small Hard rubber composl- It makes an excellent automobile lamp dimmer, iiH I beautifully can he used to eul down the glare of the where II polished. Powerful per- headlights. This Llttl I La impossible ttl steel magnet, i to gel out i oi let It iructed ENTIRELY OF PORCELAIN, metal and hard rubber. soft iron core, fibre coll The resistant of nur Rheostat is 10 ohms, the heads, very thin dia- capacity 3 amperes continual!] 1 inches in phragm, brass posts in- r; thickness ot porcelain base is 13/16 ins. side. Hanger can be UH- No. FK5000 Rheostat Regulator, $.60 Bcrewed a n d receiver Shipping weight, 2 will then fit our No. IMMEDIATE SHIPMENTS AX8077 headbands. SOME USES. — For rcmi/fl all telephone o k . w r No. EK 1024 Also for making the small testing outfits for repair men in circuit with only one dry cell No. HK 1800 or flashlight battery. When connected In parallel with your house telephone receiver, you have a double The "Electro" Radiotone ©" o receiver, an Invaluable acquisition to those who in places BUZZER phone noisy or to people hard HIGH FREQUENCY SILENT TEST of hearing. It can also be used for wireless though its low resistance won't per: test buzzer, The RADIOTONE is NOT a mere such good results as a higher resistance It is infinitely more. Mr. H. Gernsback who de- phone. incessantly to signed this instrument labored This receiver is single pole: 2Uxl% Inchi which would imitate the oz. resistance, produce an Instrument ferr 4 ; 75 ohms. IF TWO OF THESE Bound of > high power Wireless station as heard RECEIVERS ARE USED, IT Is POSSIBLE fu in set of phones. This actually has been SPEAK AT A DISTANCE OF 150 FEET WITII- a IM T USING BATTERIES. ONE WIRE achieved in the RADIOTONE. This instrument BEING NOTE SUFFICIENT IF GROUND is USED *n RA lives a wonderful high pitched MUSICAL No. EKI024 Pony Receiver. 75 ohms «pV.OU in the receiver*, impossible to obtain with the No. 5000 IMMEDIATE ordinary test buzzer. The RADIOTONE is built FK SHIPMENTS along entirely new lines; it is NOT an ordinary buzzer, reconstructed in some manner. The RADIOTON'K lias a single fine steel reed vibrating at a remarkably high speed, adjusted to its most efficient frequency at the factory. Hard BINDING POSTS silver contacts are used to make the instrument last practically forever.

Yes, the RADIOTONE is SILENT. In fact, it is so silent that you must place your car on top of it to hear its beautiful musical note.

You will be astounded at the wonderfully clear. 500 cycle note, sounding sharply in your receivers, when operated >ne dry cell. To learn the codes, there is absolutely nothing like it. With the radiotone, a key and one dry cell and ANY telephone, a flue learner's set is bad. Two or more such sets in series will afford no end of pleasure fur Intercommunication work. Particu- larly now that uc ca t use our Wireless sets. the Radiotone is already in wonderful demand. No. B-81 No. B-*7 No. B-25 No. B-8 things as described witli our All the interesting Each $0.12 Each $0.07 Each $0.12 Each $0.08 Codegraph. elsewhere on this page, Radiotone Shipping Shipping Shipping Shipping B-7 nt le performed with the Radiotone, a key, a No. B-8 Weight Weight Weight Weight No. dry cell and a phone. Each $0.15 1 lb. per 12. 1 lb. per 12. 1 lb. per 12. 1 lb. per 12. Each $0.10 Shipping Shipping Radiotone as described each Jj).9(j Weight IMMEDIATE SHIPMENTS Weight 2 lbs. ler 12 IMMEDIATE SHIPMENTS 2 lbs. pec doz. These binding posts are furnished either nickel plated or gold lacquered, They are made

of first quality brass ; holes are accurately bored, well fitting set screws, and highly polished. Each post is furnished with a % in. machine screw and washer (not shown in illustrations). Engravings are full size. HERCULES DYNAMO « » The Electro The Livest Catalog in America Hercules is a dynamo gener- cyclopedia Xo. 18 waiting ating 12 Volts, 9 Our big, new electrical is for complete Wireless and elec- Amperes (100 you. Positively the most print today. 200 Big Pages, Watts) and a trical catalog in 600 illustrations. 500 instruments and apparatus, etc. marvel of elec- "Treatise on Wireless Telegraphy." 20 FREE trical or me- Btg coupons for your 160-page FREE Wireless Course chanical effi- 2H lessons. FREE Cyclopedia No. 18 measures ciency and sim- in Weight x lb. Beautiful stiff covers. plicity. 7x5%". k. "THE LIVEST CATALOG IN AMERICA" It is cspe- before you turn this page write your i illy designed for lighting and charging storage Now name and address on margin below, cut or batteries ; will run IS twelve volt lamps simul- f> stamps to cover aneously. Can also be used as a powerful mo- tear out, enclose cts. charges, and the Cyclopedia is tor developing nearly % H.I'. .Machine is shunt mail return mail. wound; size 7 in. high, by 11% in. long and yours by ('. "j in. wide. It is the cheapest Dyuamo for its THE ELECTRO IMPORTING CO. output on the market. 231 Fulton Street, New York City, No. AGEK 1209. Electric Hercules Dy fljiy Cf\ • •**" nanio ; shipping weight. 40 lbs. Trice. . . .M**

We carry these machines always in stock and can make immediate shipment.

11 FULTON ST., NEW YORK, N.Y. —

122 THE ELECTRICAL EXPERIMENTER June, 1917

A NOISELESS "ALARM" CLOCK. rived, the alarm mechanism operates, turn- Experiment—Take the bulb and hold By K. M. Coggeshall. ing the drum, thus winding in the cord, it near a rapidly moving belt, connected Have you ever stopt to wonder what which in turn closes the switch and lights with machinery which is not grounded. your friend in the next room thinks when the lamp. All this will be accomplished Hold the brass end of the bulb close to the your discordant alarm clock rings each noiselessly. Xo one can sleep with a bright morning? Have you ever wisht you had beam of light suddenly directed onto the face. Furthermore, it is impossible to snatch a few cat- naps before getting up with this light in the eyes. It is therefore imperative that the awakened person arise and open the controlling switch and once out of bed there is little danger of dropping off to sleep again. ELECTRIC LIGHT FOR GUN SIGHTS AT NIGHT. As every hunter knows, it is extremely difficult to aim correctly at night, even tho the Did You Ever Hear of a "Silent" Alarm C lock?—well, game can be seen, for the sim- Here's One. It Awakens You by Flashing a Beam of pie reason that the gun sights Hold an Incandescent Lamp Bulb Near a Light on Your Face. Try It. Rapidly Moving Belt Usually Sufficient barrel cannot be ac- — on the Static Electricity Will Pass to Charge the some method of waking yourself without curately viewed. Lamp as a Condenser. It Will Give Power- disturbing your neighbors? Perhaps you The accompanying illustration shows how ful Shocks. may arise at five-thirty in the morning while a small, frosted, flashlight bulb may be belt and sparks will usually jump from the the rest of the household do not find placed just behind the forward sight, with belt to the brass cap. the necessity of opening their eyes un- a metallic shield over it, so as not to throw Charge in this manner for about five min- til six-thirty. Perhaps some one may be a glare in the gunner's eyes. It is a simple utes, then take it away. Offer it to some- ill and you wish to awake during the night matter to bore a hole in the wooden stock one, holding the bulb by the glass end al- to give him medicine, and yet do not like to of the gun with an ordinary carpenter's ways. When the person goes to touch the disturb anyone else who may be asleep. brace and bit. in which to mount a cell or brass end a nice hot spark will jump to Again you may be looking forward to a two from a flashlight battery, the size of him, giving a considerable shock. before-dawn start on a fishing expedition these individual cellsbeing about \}i"x.7/16" Contributed bv R. G. DEVAXEY. but out of respect to others you dislike to in diameter. Also the cells may be placed in resort to the alarm clock to awaken you. a brass or fibre tube secured under the KNICK-KNACKS FOR To overcome these objections to the or- "RADIO-BUGS." dinary alarm clock, the following apparatus Sr/flcfi grounded By placing one of the E. I. Co.'s load- was designed to awaken one sleeper with- ^^ ing coils against the end of a small loose out disturbing the rest of the household. coupler, I have been able to catch stations, A box-like, wooden sub-base was built using up to 6,000 meters, this being done as shown in the sketch. In its face a round without additional inductance in the sec- hole was cut and into this was fitted an or- ondary, built for only 800 meters. ''fea/amp dinary bicycle spot light. A single pole, Most loose couplers have the primary single throw knife switch was screwed to tube placed in grooves cut in the heads and sub-base. the upper inside surface of the by turning it, a new surface is obtained The lamp was then connected, thru the for the slider. Clean the path of the switch, to a battery of sufficient capacity to A Tiny Electric Light Fixt Just Back of the slider occasionally with a rubber pencil or to utilize its full candle-power. If the sub- Forward Sight Proves a Boon the Hunter at Night. ink eraser. base is made large enough the battery may Use Solderall on the next loose coupler be enclosed and the entire outfit made com- fore-arm section of the gun frame. A you build and you will use no other. pact and portable. switch, of unobtrusive proportions, will Contributed by ASA S. KELLER. The bell, as well as the striker, was reserve to light the lamp bulb when wanted. from an alarm clock. thread SWITCH moved A H. G. AUTOMATIC LIGHT FOR spool was attached to the alarm winding CLOSETS. key to serve as a drum on which the cord GOOD INK FORMULAE. Herewith is a drawing of a little device to operate the switch was to wind. This I made from scrap materials and which These two formulae obtained thru orig- switching device was very simple. A strong has proved very efficient. inal experiments, have been found to pro- cord was attached to the handle of the It is intended to automatically close an duce excellent inks. The ingredients are knife switch, brought up thru a hole in the electrical circuit on opening the door of easily obtained and at little expense. Rain base and attached to the spool on the wind- a dark closet or unlighted room, and by ing key. water may be used in place of distilled thus removing the need of having The mechanical operation of this device water any chemical apparatus. The resulting inks can well be imagined. The apparatus is set are each of a beautiful color, make a per- on the mantel or dresser in the bedroom. manent record, flow easily, and do not corrode the pens. The blue ink can be used successfully and safely in the most wtfi spoo/ delicate of fountain pens. t/rv/na/tocted Blue Ink: Dissolve one ounce of soluble Prussian blue in one quart of cold distilled (rain) water. Add to this solution, 5 grams of oxalic acid. Then filter the solution thru filter or blotting paper. Black Ink: Dissolve one ounce of ex- tract of logwood in one quart of boiling water. When cold, add one- fourth ounce of potassium bichromate and one gram of sodium carbonate. The addition of one- Sma// spotl/gfif suc/i as '.'spar fourth ounce of Prussian blue improves the used on oicye/e A Reliable Automatic Switch for Closet solution. This ink will cost about 5 cents. Light. When Door Opens the Switch Rod Is Is Rigged Be- How an Ordinary Alarm Clock Up Contributed bv Moved Forward by the Spiral Spring as So as to Close the Lamp Circuit of the "Si- comes Evident, and Vice-versa. lent Alarm." CLAREXCE S. LEVIXE. means of a small battery and lamp illum- The spot light is then so adjusted that the EXPERIMENTS WITH inate the interior. full power of the light ray will concentrate STATIC BULB. As the illustration shows, the materials on the face of the sleeper. The alarm LAMP and construction are exceedintrlv simple. should be wound and adjusted as usual. Materials needed— 1 or more burned-out Contributed by H. WALTER. When the predetermined hour has ar- electric light bulbs. W —— —

June, 1917 THE ELECTRICAL EXPERIMENTER 123 Experimental Chemistry By ALBERT W. WILSDON Thirteenth Lesson

ACIDS, BASES AND SALTS. used, the second takes place. An acid of Sodium Hydroxid solution in an evaporat- this. kind can. further, form one sail with ing dish, and immerse in it (£ onlinu, d I a piece of blue two bases, in which one metal is hiii" sub- 1 stated in the pn ious installment, allowing il to remain in the stituted for one of the hydrogen al iur small quantities . the basicity of acids are di termined of 11 AS the acid and a second metal for the Othi r. chloric by the number of hydrogen atoms acid from the beakei \s aforementioned, in the molecuh allowing it to drop " [replaceable by a metal] in its into the evaporat- Hydrochloric acid |11C1| as in Nitric acid ing dish, molecule. Thus: Mono-basic acids in the manner shown by Fig. 66, [HNO I, then 1- but one atom of hydro stirring the mixture. contain one hydrogen atom, :i< Hydro- gen. If, therefore, the act of neutraliza- It will be noticed that the litmus paper tion takes place in each molecule it is com- will probably turn red, owing to the fact plete, and the salt is known as a neutra that the solution has too much acid 1 salt. In normal Sulfuric acid [HaSO«] tained in it. If such is the case, add a there are two atoms of hydrogen in each little more Sodium Hydroxid, by allow- molecule, il and either one or both of ing to drop from a stirring rod in the be atoms may replaced. If only one is re- same manner as described for the acid. If placed salt a having the general formula, too much of the Hydroxid is added the MHSOi, is obtained. This is still an acid, litmus paper might again turn to a blue while it is also partly a salt. This is known color, and if this happens, add a little more Sail. as an Acid oJ the acid, drop by drop, till the liquid It difficult may be for some readers to becomes neutral to the litmus paper. It associate the names Monobasic, Dibasic. may be necessary to keep adding either the Tribasic, Tetrabasic, etc., with the basicity Acid or the Hydroxid. Introduce another of the acids, but as these names represent piece of red litmus when you think the solution is neutral, and if it" is unaffected, immerse another piece of blue litmus paper It Is Always Best to Stir Solutions with a in it, and then if the solution does not Glass Rod. Have Clean Vessel for Each a affect either the red or blue paper it is Acid If You Would Achieve Satisfactory neutral. If Results. the solution is not clear after it has been neutralized, filter it, and throw chloric acid [HC1], from which only one away all but about 15 cc. of it. replacement is possible. Di-basic acids Place the 15 cc. of the solution obtained contain two hydrogen atoms, as, Sulfuric into an evaporating dish, and place on acid [H:SOi], from which two replace- either a piece of fine meshed iron gauze ments are possible. Tri-basic acids contain or a piece of asbestos pad, as shown in three hydrogen atoms, as Phosphoric acid Fig. 67. Apply a light to the Bunsen |ll POi], from which three replacements burner under the evaporating dish, and al- are possible. Tetra-basic acids contain four low the liquid to evaporate [boil] till a as, white solid is formed, hydrogen atoms, Normal Silicic acid Method of Pouring Small Quantities of Acid or in other vt [H«SiO<]. [Note: Normal Silicic acid onto a Glass Rod so That They Drop into a till all the water has been driven from readily parts with half of its water, leaving Beaker or Other Dish Easily. the original solution. ll.SiOs, also called Silicic Acid], from The equation of the reaction which took the number of hydrogen atoms in the mole- which four replacements are possible. place between the Sodium Hydroxid and cule, it may be well to memorize the fol- Penta-basic acids contain five hydrogen the Hydrochloric acid when lowing: neutralized atoms, as Periodic acid [H.JOo], from was : which live replacements are possible. NaOH 4- HC1 = NaCI 4- H.O Sodium The higher the basicity of the acid the Hydrochloric Sodium Water Hydroxid Acid Chlorid greater the variety of salts it can yield. We perceive from If we take the base Potassium Hydroxid this equation, that the hydrochloric acid no to illustrate the replacement of the hydro- longer is contained in the solution, and gen of the acids, we tind that Nitric acid that the Sodium [Na] of the base exchanged, or Hydrochloric acid can form but one or replaced the hydrogen of the acid, salt with Potassium Hydroxid, the reac- forming a salt and water. tions being :

KOH + HNOj = KN03 4 H 2 EXPERIMENT NO. 55— Potassium Potassium Water In the same manner as described in Hydroxid Nitric Acid Nitrat the and KOH 4. HC1 = KCI + H,0 Potassium Hydrochloric Potassium Water Hydroxid Acid Chlorid Other acids ha\ e the power to form two or more salts with the same base. If only half the quantity of base that is required to neutralize the acid is added, Correct Manner in Which to Place "Evap- half the acid remains unchanged, and on orating Dish," Wire Gauze and Bunsen evaporating the solution, the excess acid Burner. will pass off. If only half the quantity of The pre \ means one acid that is required to neutralize the base Mono two is added, hall" the base will remain un- Di— changed. Sulfuric acid [H2SO.] has been Tri— three it Tetra— four found to have the power to form two salts five with Potassium Hydroxid [KOH], in one Penta— of which there is twice the amount of the Thus, when speaking on monobasic acids, metal as in the other. The reactions being: by remembering that mono— means one, KOH 4 USD, — KHSO, 4. H.O and when associated with the basicity of Potassium Sulfuric Potassi Watei .111 acid, mono— meaning one. and the If Two or More Liquids Which Have Differ- Hydroxid Acid [acid] Sulfate basicity being the number of hydrogen ent Densities and Will Not Mix Are Poured : into a Jar, They Will Rest in and again atoms, we can thus see that monobasic Come to the " Order of Their Densities, with the Surfaces 2KOH 1 11 4 H.SO, = K,Sp4 means one hydrogen atom. of Each Separating Them Horizontally. 1 sium Sulfuric Potassium Water Mercury. Water. Oil and Alcohol, When Hydroxid Acid Sulfate EXPERIMENT NO. 54— Poured in a Test Tube. Will Come to Rest Tf to a certain quantity of Sulfuric acid Have two small-lipt beakers, or two test in the Order Named. only half the quantity of Potassium Hy- tubes, one of which will contain 10 a solution droxid that is required to neutralize it is of a solution of Sodium Hydroxid |Na(>H| preceding experiment, prepare a added, the first reaction takes place; but and the other an equal quantity of Hydro- ol both Potassium Hydroxid and Hydro- if twice as much I'otassium Hydroxid is chloric acid [HClj. Pour S cc. of the ontinued on /•• : : : : :

124 THE ELECTRICAL EXPERIMENTER Jl 1917

RECIPES FOR KILLING FLIES. to flies. Put in a saucer, darken the room The United States Government makes except one window and in that set the Wif inkles; the following suggestion for the destruc- saucer. To clear the house of flies, burn pyre- tion of house flies : Formaldehyde and sodium salicylate are the two best fly poi- thrum powder. This stupefies the flies, but sons. Both are superior to arsenic. They they must be SWEPT UP and BURXEI) tRe^iptes have their advantages for household use. Receipes for Stables. Barns and Out-of- doors: —Borax is especially valuable around They are not a poison to children ; they are farms and out-of-doors. One pound of convenient to handle ; their dilutions are 1 'i»j simple, and they attract the flies. borax to twelve bushels of manure will Preparation of Solutions: —A formalde- be found desirable as a poison without in- rhulas hyde solution of approximately the cor- juring its manurial qualities on farm stock. rect strength may be made by adding 3 Scatter the borax over the manure and teaspoon fuls of the concentrated formalde- sprinkle with water. hyde solution, commercially known as for- Lye. chlorid of lime, or copperas (sul- malin, to a pint of water. Similarly, the fate of iron) dissolved in water, crude car- EDITED BYS.GERNSBACK proper concentration of sodium salicylate bolic acid, or any kind of disinfectant may Under this heading we will publish every may be obtained by dissolving 3 teaspoon- be used in vaults. month useful information in Mechanics, Elec- fuls of the pure chemical (a powder) to tricity and Chemistry. We shall be pleased, of course, to have our readers send us any recipes, a pint of water. HEKTOGRAPHS. formulas, wrinkles, new ideas, etc., useful to the A container such as shown below has experimenter, which will be duly paid for, upon What are they, do you ask: The Cen- been found convenient for automatically publication, if acceptable. tury Dictionary defines it as follows : "A keeping the solution always available for copying process in which the writing or flies to drink. An ordinary, thin-walled FREEZING MIXTURES. drawing to be copied is made on smooth drinking glass is filled or partially filled paper in aniline ink. and is then prest When ice or snow are not to be had and with the solution. A saucer, or small plate. upon a slab coated with gelatin, to which a for those of us who do not have an up-to- in which is placed a piece of white blot- part of the ink is thus transferred, and date laboratory that is provided with ting paper cut the size of the dish, is put from which a number of duplicate impres- agencies of cooling power, I am sure the bottom up over the glass. The whole is sions can be made; also, the special ap- following mixtures will prove most con- then quickly inverted, a match placed under pliances, collectively, by means of which venient. the edge of the glass, and the container is this is done." The chance, however, is 1. Xitrat of ammonia, carbonat of soda that you do not want any definition, but and water, equal parts by weight ; the ther- might like some directions for simplifying mometer sinks : the process, which some teachers and stu- 2. Phosfate of soda. 9 parts ; nitrat of dents who want a number of copies of text ammonia, 6 parts: dilute nitric acid (acid oi drawing, are using successfully. Agree- 1 part, water 2 parts), 4 parts. Reduces able to this contingency, we have the temperature from 50° to 21°. Receipt Xo. 1.—Soak an ounce of fish 3. Sal-ammoniac, 5 parts : nitrat of pot- glue in cold water. Drain off the water ash, 5 parts : sulfate of soda, 8 parts put the softened glue into a double boiler water, 16 parts. Reduces the temperature and melt it. but do not bring it to a boil. 46° or from 70° to 24°. This latter is very Obtain six ounces of glycerin, warm it and cheap and easily procured. add it to the melted glue. Add a few If you have ice and wish to reduce the drops of carbolic acid. Mix thoroly and temperature still further, use the follow- pour into your pan. A caramel pan is best. ing: Receipt Xo. 2. —Add 3 ounces of water 1. pounded ice, 2 parts : salt, 1 Finely ! to 1 > ounces of white glue. Heat in a part. This is a very common recipe. double boiler until glue is melted. Then 2. Finely pounded ice, 2 parts : crystal- add six ounces glycerin and pour into pan. lized chlorid of calcium, 3 parts. If too hard, add glycerin. If too soft, 3. Finely pounded ice, 7 parts : dilute With Us. the Now That the "Fly Season" Is add glue. nitric acid. 4 parts. This reduces the tem- Non-Poisonous (to Humans) Wet Blotter Fly Annihilator Shown. Which Is Recommended Receipt Xo. 3. —Dissolve 4 ounces of perature from 32° to 30°. The tempera- by the U. S. Government, Should Prove gelatin in one pint of cold water; then add given are Fahrenheit. The materials Particularly Valuable. tures one pint of glycerin. Pour into a double should be kept as cool as possible. boiler, and when it comes to a boil pour ready for use. As the solution dries out Contributed by MIXARD ROTE. into your pan. of the saucer the liquid seal at the edge of If bubbles appear on the surface, gently the glass is broken and more liquid flows SOLUTION FOR MAKING WORK draw an edge of a sheet of writing paper ACID into the lower receptacle. Thus the paper TABLE IMPERVIOUS TO over the surface before it cools. This will is always kept moist. AND ALKALI SOLUTIONS. remove them. Other Simple Preventives:—Any odor Doubtless, many experimenters, especially General directions for use.—Use noth- pleasing is offensive to the fly and those working with the various cbemical to man ing but unglazed paper, which can be pur- vice versa, and will drive them away. reagents, desire some coating for the work chased at any store where typewriter paper Take five cents' worth of oil of lavender, table that is impervious to both acid and is sold. In ordering, be sure to state that mix it with the same quantity- of water, alkali solutions. The writer has used the you wish to use it for hektography. it in common glass atomizer and following method in his laboratory with put a Use hektograph ink and a coarse stub it the rooms where flies are. decided success, and heartily recommends spray around pen. See that every stroke of the pen In the dinins-room spray it lavishly even it to those who desire a similar formula. leaves a metallic luster when dry, else the on the table linen. The odor is very dis- Two solutions are to be made work will not take. agreeable to flies but refreshing to most Solution 1. Iron sulfate, 4 parts : copper When the ink is dry, lay the face of the people. written sulfate. 4 parts : potassium permanganate, sheet which you have or drawn, Geranium, mignonette, heliotrope and hektograph : press gently over 8 parts : water, 100 parts. down on the white clover are offensive to flies. They or soft Solution 2. Aniline, 12 parts : hydro- the whole surface with the hand especially dislike the odor of honeysuckle five (ac- chloric acid. 18 parts ; water. 100 parts, or cloth. After from two to minutes and hop blossoms. copies are desired) aniline hydrochlorat, 15 parts : water, 100 cording to how many parts. According to a French scientist, flies have gently peel the paper off. intense hatred for the color blue. Rooms Apply two coats of solution Xo. 1, while From the impression thus made, repro- blue help to keep out the hot, applying the second coat as soon as the decorated in will duce all the copies desired, laying one sheet first has dried. After solution Xo. 1 has flies. on the hektograph at a time. dried, the excess of solution which has Mix together one tablespoonful of cream, Hektograph ink all prepared may be black and one of dried upon the surface of the wood is one of ground pepper bought, or your druggist will put it up thoroly rubbed off before the application brown sugar. This mixture is poisonous for you. The following is the receipt of solution Xo. 2. Ink— Dissolve one dram of purple aniline Next, two coats of solution Xo. 2 are The tables are cleaned very easily by in one ounce of water. applied, and the wood permitted to dry washing with water or suds after any work The hektograph solves the supplemen- thoroly. The black color does not appear is finished, and the application of another tary reading question. Each teacher, or any at once, but requires a few hours before coat of oil puts them in excellent order one who desires a number of copies of any turning to a rich ebony-black color. Later for another experiment. text or drawing, can thus prepare as many a coat of raw linseed "il is to be applied Contributed by as needed, at a verv small cost. with a cloth. ALBERT W. WILSDOX. Contributed by F. H. SWEET. June, 1917 THE ELECTRICAL EXPERIMENTER 125

' -ill Our A I iboratory pi ipen to readers, ivhethei subscribers 01 not, The photos are judg,.-,! for best arrangement ami efficiency of iIh- apparatus. I" i :asi the interest of this department we make it a rule not t" publish photos of apparatus un 1 by that of th<- owner- Dark

I photos preferred to light I :s. We paj each month $3.00 prize for the best photi your description brief and us< side of thi

. '"with the Amateurs" Di pi

AMATEUR RADIO STATION H. L. SCOTT TO RENEW HIS when I operated my station, in fact CONTEST RADIO ACTIVITIES. it has thrilled me so much that ' am go- to Monthly Prize, $3.00. Just recently I bought a copy of Tin. ing renew my operations with the old

This month's prize-winner. I ii. raucAL Experimenter, the January (Not until iiftcr the War- lid.)

number, and on reading it thru it has It was when I lived at 15S Hamilton CEDRIC E. HART'S EXCELLENT OUTFIT. brought back pleasant memories of the Street, East Providence, R.I., in 1909 and RADIO 1910, that 1 had my best outfit. About that The switch panel anil cabinet, etc., shown in the accompanying photo have all been THE MONTANA WIRELESS STATION OF HOWARD PASCOE. 1 offer herewith a photograph of "The Montana Wireless Station" which consists 7 ... of 1 K.W. Packard transformer, run on (110 volts A.C.) and a stationary spark gap. '1 he receiving set consists of a loose coupler designed to receive up to 20,000 U meters and a loading coil for 4,01 I meters. One (type D) receiving set of Marconi Wireless Telegraph Co. make which has a range of 2,000 to 4,000 meters or more. One pair of E. I. Co. Republic receivers, Standard wave meter, silicon and Audion detectors (Type R J 9). With this receiving set I am able to hear all the coast stations as such XPE, XPC, Herbert L. Scott and His Radio Outfit, Which and the amateurs 7ZC, 7JN and many Has Done Good Work. others. time I believe I bought a detector from the I have a little sub-station up in the moun- Electro Importing Co. tains, 6,355 feet above sea-level. All my I am sending you a photo of my appa- wiring is run in conduit. On account of ratus I used in 1910, which I still "have in the small space, the station had to be pho- storage. I hope you will find space in the tographed twice. columns of your magazine to reproduce I Electrical Experimenter. read The ..'his photo. For sending 1 used a three It is a fine magazine for the "Wireless inch i. spark coil, run by six V. 60 A.H. E. Hart's Radio Station Salt Cedric at Lake P>ugs." I will be glad to correspond or storage batteries. The coil may be seen be- City, Utah, with Which He Obtained Highly exchange photos of my station with other hind the Efficient Results. loose coupler on the table : over amateurs. the coil on the board is a plate glass con- this HOWARD PASCOE. denser designed and built by myself, and with ; above that is the spark gap and I in receiving ail Butte, Montana (1129 East Galena) then the cabinet have no difficulty helix ; to the right is an anchor gap. of the coast stations and the The sending key may be seen on amateurs within a fair distance the extreme right of the table: of here. 1 also hear Guam, the contact points are two dimes. Honolulu, Alaska, Panama, etc., For receiving I had a loose quite regularly. I have a license coupler of my own make, a and my call is 6SL. My receiv- Murdock tuning coil and a de- ing set comprises the following: tector stand in which I used sili- Navy 'phones, Blitzen tuner, con, together with a pair of 3.000 Blitzen variable, Clapp-Eastham ohm rei eivers, potentiometer, tubular fixt condenser, Turney fixt condenser and Massie sealed- variable condenser, and an point electrolytic detector with Audion cabinet. double pole switch to throw in My transmitting outfit com- either system. I have heard Key prises a 1K.W. Thordarson Vest with this station. transformer. K.B. preventer, HERBERT 1.. SCOTT. commercial key, home-made con- l.i ickstone, Mass. denser, Halcun rotary spark gap, (All radio men should rend home made Telefunken type OS the notice in "Radio Dept." and dilation transformer and a opposite /'a, i.- Erf.) Uncle Sam May Find the Amateur Radio Station of Howard Pascoe, Blitzen hot-wire meter. The at Butte, Montana, of Valuable Assistance. switches on the panel control the "NO MORE 'E.E.*" transformer, power, meter, condenser and savs the newsdealer. "All sold out!" Did inductance. ATTENTION!!! he' tell YOU so last time? MORAL: This set, so far, has proven very efficient \sk him to order a copy for you every Has your station photo appeared in and, being as the panel has not been com- month. Costs you nothing to do so. The "The Electrical Experimenter"? 1 pleted two weeks yet, think that Evans tremendous i tper does not allow Why not purchase the electrotype ton, Wyo., is a pretty good distance to i'\us, printing, s,, we furnish dealers only and have some "real" stationery transmit for the short time I have had it. with a sufficient amount of copies to supply printed with your station picture Here's wishing the EXPERIMENTER prosperi- tlteir regular customers. If you are one, on it? All of the "regular radio- ty in its chosen path. be sure t" tel our newsdealer so. and give bugs" are doing it. CEDRIC E. HART. him your nam iddress, so he'll notify Salt City, you by postal i. you forget to call. Lake i, Utah. .1 nun iniiiiiiiiii I

126 THE ELECTRICAL EXPERIMENTER June, 1917

A PROGRESSIVE CHICAGO RADIO side of Autlion make a complete switch- DE FOREST GIVES $5,000 TO AMER- EXPERIMENTER. over from crystal to Audion apparatus. ICAN DEFENSE SOCIETY. Llit- Also to amplify weak signals there is a My sending set included a ; 4 K.W. Dr. Lee de Forest, the wireless inventor, zen transmitter with rotary spark gap, op- Multi-Audi-Fone and 2.IJ00 'phones. Sta- has offered the American Defense Society tion call 9XV. $5,000 as the nucleus of a preparedness Chicago, 111. ARTHUR R. GATES. fund. AMATEUR HEARS SPY RADIO CODE. A RADIO ECHO FROM Federal authorities hope to locate the LARCHMONT MANOR, N.Y. sender of aerial instructions to German Herewith is a photo of my radio station. spies thru the disobedience recently of The sending set is composed of a 1 inch Malcolm Ronberg, who has (or had) an Bull-Dog spark coil, a sending condenser, amateur radio plant at his home, 0220 Uni- spark gap, key and transformer. In my versity Avenue, Chicago, 111. receiving set there are three loading coils, Ronberg failed to obey the government two fixt condensers, a double slide loose- mandate to dismantle radio stations. He decided to "listen in'' before complying. There was no sound for several minutes, then a peculiar unfamiliar call, repeated over and over again. Then there followed an even stranger grouping of letters, a code One of the Honor Sets Among Chicago Radio message. Amateurs Was that of Mr. A. R. Gates. Mr. Ronberg hurried to the federal building, of "Old Guard Hav- Gates Is One the Boys," turned ing Been a Reader of "Modern Electrics." confest he had been listening and over the message. It was sent to federal erated on 110 volts A.C. with a lamp bank operators at Great Lakes station. They, in series with gap motor. Receiving set is too, failed to decipher it. But the fact that result of reading Modern Electrics and Ronberg received it in his small amateur The Electrical Experimenter for over station has helped the searchers to trace it. 2 /il years and is home-made Ronberg was thanked, instructed to dis- The receiving transformer is designed mantle his plant by midnight or go to jail, Clarence de Witt Rogers. Jr., Rising Radio detectives hurried out a for 3,000 meters with two variable con- and a squad of was Student, of Larchmont Manor, N. Y. densers: one across secondary and one tinder orders of John C. Dillon, chief radio shunted across 'phones. I have two crys- inspector of Chicago. coupler, a silicon detector and a de Forest tal detectors, Ferron and galena, operated Audion. I have two 1,500 ohm 'phones B ith a three point switch. Also a three Young chickens treated with electricity and one 500 ohm 'phone. element vacuum detector for long range by a London experimenter grow more rap- CLAREXCE de WITT ROGERS, JR. work. The two D.P.D.T. switches on eacii idly than those raised without treatment. Larchmont Manor, X.Y. Amateur News Fort Wayne Radio Association of The club is progressing rapidly and is certain were connected with Thursday night were Rock to obtain more members in the near future. A? Island, Peoria. Springfield, Cambridge, Genesee Indiana. yet we have no set but expect to obtain one and Monmouth. Association of Indiana The Fort Wayne Radio soon. Regular meetings are held every Thursday Roy S. Landon had charge of this work, and Year with the installation of the began the New night at 7 :30. All communications should be under his supervision the boys are showing an Carter, President: R. following new officers: G. sent to Harlow Eppert. 841 State Avenue, Kansas unusual amount of interest. Recently the boys May. Secretary and Parvin, Vice-president; D. W. City, Kansas. received and sent messages to the University of F. Hall, Treasurer. Iowa station. We have had some very successful meetings Y. C. A. Wireless of Salesburg, 111., during the winter months. Our best and most- M. Worcester Tech. Wireless Club is Busy. lookt for speeches are given by Mr. Carter, who. Sends Basketball Scores. The Wireless Club of Worcester Tech., elected besides giving good talks, has formulas worked The wireless club of the Y. M. C. A. recently Warren R. Burgess, '16. of Hyde Park, chief out, which enables us to see if we are getting sent out the scores of the basketball tournament. operator in charge of the maintenance of the the most out of our transmitters. These scores were sent out three times a day. at Tech. station. Twelve new members were vote. In an effort to lessen interference, we have a the close of each session. 12:00 o'clock noon. 6:00 in and plans were discust for a series of talks "ORM Committee" to report at our meetings every o'clock after the afternoon session and at 10:00 to be given by Instructor Carleton D. Haigis of two weeks. o'clock after the night session. The towns which the physics department on the theory of electric Several of our members have some fine long- _ waves and other subjects interesting to wir distance work to their credit. They are 9 'P C, students. The president was empowered to ap- 9 W F. 9 V V. 9 T A. 9 K G and 9 U H. AMATEURS point a committee to draw up plans of a new an- We will be glad to correspond with other clubs ALL RADIO tenna to be erected this year. so as to exchange ideas. Address communica- ATTENTION! tions to D. W. May 19 U H). 3021 Hoagland As all of you know the United Avenue. Fort Wayne. Ind. Hoboken, N. J., Wireless Amateurs States is now in a state of war with Secure Clubrooms. Alpena, Mich., Has a Radio Club. Germany, and as true-blood Amer- The Hudson City Radio Association has secured where The Alpena Radio Club of Alpena. Mich., has ican citizens, we are, each and rooms, at 541 Central Avenue. Jersey City, they have erected a large aerial and a sensitive been formed for the advancement of wireless one of us, duty bound to obey every practise is given every telegraphy. Meetings are held every Thursday- receiving outfit. Code the mandates of the U. S. Govern- desire it. evening at the home of the President, 516 State night to those who Election of permanent officers was held with t. The officers are: President. W. A. Pot- ment officials. The Navy Depart- following results: President. Joseph F. Grece; ter; Vice-president, Hugo Sorenson: Secretary and ment has been delegated by our the Consulting Engineer. Vice-president, William Biedenkapp: Financial Treasurer. P. B. Alger; and all or President to close amateur retarv, Frank Y. Bremer: Recording Secretary. Mr- I Mulavey. All communications should be experimental radio stations, no treasurer. William S. Davidson. addrest to the Secretary, P. B. Alger. 119 State Clarence Mavis; are invited to Street, Alpena, Michigan. matter whether equipt for transmit- All amateurs in Hudson County association. Address Clarence M ting or receiving, licensed or un- join the 91 Street. Jersey City. N.J Pa., Radio Men Reorganize. Secretary. Fi rry Allentown, licensed, and therefore we shall all blank. Allentown. an application The Inter-City K ition of have to abide by this decree, October I'M 5. recently re- Pa., organized 28, Club of organized under a new name to be known hence- whether we like it or not. Waterbury Radio as The Y. M. C. A Radio Association of Therefore, beginning with the Waterbury, Conn. Allentown. next issue of "THE ELECTRI- The Waterbury Radio Club was formally organ- in- of field signaling and code receiving recently by 1 5 local young men who are The art EXPERIMENTER." we will ized are now being taught to the members by the Chief CAL terested in Wireless telegraphy. King Sam. the Operator, Harvey Zinger. The following are the endeavor to feature the Electrical Chinese young man who is probably the only Chi- new officers Association: 1>. H. Goodling, Laboratories in preference to any nese wire! in Xew England, took the operators together president; Blair radio stations in the awarding of initiative in handing the local Cunningham, Secretary: Arthur Breisch, Treas- and the nutting was held in the wireless room prize of $3.00 in this urer; Harvey Zinzer. Chief Operator. Correspond- the monthly at the Boys' Club. E. C. Glavin. an inventor and ence with similar organizations will be appreciated. department. Now is the time to a pioneer in wireless telegraphy study, attended Address all communi. D. H. Goodling. get busy and freshen up your elec- the meeting and was named as honorary chair- street. Allentown. Pa. man. The other nffic. bert W. Ctilhert, trical apparatus, and incidentally the Tr.. Chairman: Clinton A Fitch (operator of Radio Activities in Kansas City, Kansas. improve your understanding of Boys' Club wireless set), Secretary and Treasurer. is just now and The Kaw Valley Ra

1917 THE ELECTRICAL EXPERIMENTER 127

EXPERIMENTAL CHEMISTRY. explaim d in the up' unit; of this article. "MAN-HUNTING" WITH THE (Continued from page 123) [f desired Sodium Sulfate [Xa ; S(> ELECTRIC CALLING he prepared in the same manner as above. SYSTEM. chloric acid, and proceed I utralize tlicm in the same manner \n<, they are neu- EXPERIMENT XO. 57— two, three— pause—one, two =: 32 tralized, and after applying thi litmus tests, on the electric call m here illus- X e n traliz e A m m oniu m Hydroxid [il;i, • in ,i i lean evaporating

Acid I I I \l.d.. N< | with Nitric I equation for thi-. reaction is practicallj the the red and blue litmus papers. Evapi same except that Potassium is substituted as before. The product ol this neutraliza- TABLE OF VALENCE. tion cannol be evaporated i mpleti dryness, owing in ilu fact that the nitral TABLE NO. I. hreaks up. n Positive X' \ MlTAI. AND N BCA' MI, i HI . ll\u \H,XO, 4- H.o R IDICALS. ' :!'' M.S: Ammonium Nitric aci,l Ammonium W •^ _; -j _: Hydroxid Nitrat c (4 The above salts which were prepared by >> >. 3 neutralization ol acids and basi an S a H H f. c 5- (~ the .soluble salts. ii M S As Pt V () N C Na la SI, Sn CI s P Si Salts can also he produced by the action K Sr Bi Br so, B Sill, of acids on metals ; below are given methods SI l, l> V Ha An I PI Hg Pb Fe NO- 1 11, I'll, of preparing chlorids, sulfats and nitrats.

N'l l ,1 ', Nil, Cu Cr 1 ., Asl \ i i, 111, ( d Al

Co i H i Put into a clean test tube about 5 grams Mi ClOj of zinc and pour over it about 10 cc. oi II, BrOj dilute hydrochloric acid. It will be re- Si Ii i, Fe CHsO, membered that this experiment was pel formed in a previous installment. [Hydro- As we have been ennstantly referring to metals, non-metals, positive radicals and negative radicals, gen, Experimental; January, 1917. issue the above table is given now, before the study of Electrical Experimenter]. Apply a lighted valence is taken up, so that readers may refer splint to the mouth of the tube and notice to it when metallic and non-metallic elements are mentioned, any familiar action. After the action stops

pour the liquid upon a filter : then evap- for the Sodium, as : orate the /illrat | the solution obtained K<>h + HC1 = KC1 { ii Potassium Hydrochloric r<>tassium Water after filtering] in an evaporating dish, and Hydroxid Acid t hlorid. note what is left. Keyboard of Electric "Man-Hunting" EXPERIMENT XO. 56— The reaction for this experiment is Machine. It Instantly Summons the ZnCl H, Desired Party to the Nearest Tele- Dilute 1 part of Sulfuric acid with three Zn 4- 2HC1 = 2 4- phone. Hydrochloric Zinc^ Hydrogen or four parts of water, and place in a Zinc Acid Chlorid small-lipt lieaker or test tube as in the gas which escapes from the tube is preceding experiments, ami neutralize. The trated. It is the prince of man-hunters, lighted splint hydrogen, and by applying a as it due-, When neutral, filter, and place in an evap- serving to quickly summon any the mouth a slight explosion should be orating dish and evaporate to dryness. to particular individual to the nearest tele- caused to occur. The product obtained in Either one of the following equations will phone, no matter in what part of the plant this experiment is Zinc Chlorid [ZnCl,]. -hup the take place : or he may he at moment. H-..SO, KHSil, lljii The Electric Calling System is primarily KOII + = -J- EXPERIMENT XO. 59— Potassium Sulfuric Potassium Watei the operating instrument, which is con- Hydroxid Acid [Acid] Sulfate Pour about 10 cc. of dilute Sulfuric acid nected by wiring to a line of signals I or [HuSOi] made by pouring 3 or 4 cc. of sisting of either bells, horns, buzzei strong Sulfuric acid to the or whatever other electrical device- it i> water, about 10 cc, stirring the desired to use. These signals are dis- liquid constantly, and adding tributed thruout the establishment in such c the acid in small quantities. S a manner that every foot of floor-space is [Never add the water to the SS within the sound radius of at least one Aluminum Al • acid], on about 5 grams of XB» •••X signal. Ammonium Hit,' scrap iron. It may be nei e The Calling System has no direct con- Antimony St « • •XBXX^»XXXBX^X» ••X^» sary to heat the mixture over for/urn Bo- nection with the telephone, bul is usually •r• phone central station, within easy reach Calcium • • the action has proceeded for fir" •m»mmrmmm»rmwr • *wm of the operator's hand The operating in- Chromium Cr"' • • some time remove from the 8* <»BXBB» r*HBB* • strument may, hoi any- (Moll • • • • Co ••• •DDr«BB» •• flame, and add about 5 or In cc . Copper • • • : • where on the circuit. Co ••r. r.^«. ••• [after the liquid has been fil- Hydrogen n This System operates on a tered]. After the water has Iron fe ••••x«aar«BB* • * • > either lb") or 220, V < or D. C It is lii-en added to the solution, Iron A • • ••BXBBrXBDr*BBr**»B* service and there are no bat- dish always in Lead a b» • »r»Br» •r«r««B«»»»n» place in an evaporating teries to ' ause .*/<,V>'.f. ' K,- • and proceed to c\ aporate. The •ri>HHMH..BHr>> • to • troubb or Manganese lln • *B*BBr*D* ••••••• reaction for this experiment is: be recharged. Uercury He r«* •••••• *bx*b* • »xr» Fe -r-HjSOj IVSi ), 4- H,. Mercury H, ' • •xr»BBrBXXBX»^» • • ^. Iron Sulfuric Ferrous Hydrogen The consump- Hi •• Acid Sulfate t/ic/tel ••••• • nar» • •• tion of cur- fvfossium K < EXPERIMENT NO. 60— rent i- mosl • Silver M r< in«»c r. Mix 5 cc. of water with economical. Sodium Hi ' about 5 cc. of Nitric acid The instru- Strontium Sr • B*r*B*BBra-.B*»BB*»**ni I I X( 1 'lace about | )»]. 5 ment is made Tin Sn • ••• ^* ••••• •• copper scraps in a test tube in univer- Tin Sn 1'•XXiXXiXXX»i»^i»«XI» of one line In • b*x*b*bbb*« *r*BB«* ••• and add the 10 CC of Nitric sal model, acid, prepared as above. If ac- which has a X- Slant tion does not take place, heat calling capac- B • Soluble in tvoter gently over a Bunsen burner ity of 45 dif- - Insoluble in ireiSr and oc/ds D 1 \ deep green solution will 1 1 code • 'Insoluble in ivoter but so/ubie /nripdvcnfor/cMtne.JoXi orJevoAeyio form, and after the action has n n m h c r s . W- Sligntji so/ubte in water stopt, add about S or 10 cc. of There is no ^» Soluble in ivoter ivdh very rr/tte acid. r£\ water and slowly evaporate, as limit to the

inline. If is ii Table of Solubilities. the evaporation n in her of carried to dryness the nitrat signaling devices which the instrument will

It, will hi eak up into the insi ilubli is IKOH ! sn, = K,S(i, 4- H»0 control, provided sufficient current let .ii. nun Sulfuric Pol issium \\ i oxid, which will manifest a black coloi into the line to operate thi Hydroxid Acid Sulfate To avoid this action the liquid w The sitmals are controlled by eight small The reasons that two equations of re- be completely evaporated, but it may

; ' action which may take place is mure fully i ' ontinuc ! '• page 1 t levi 'nn the number eomhinai June, 1917 128 THE ELECTRICAL EXPERIMENTER en t nfc^TE.5 t ... VWt I

novel invention comprising an to operate a pawl and loop circuit will have less resistance A An Electric Photometer magnets land- the indi- than the antenna circuit, as it is electrically driven or propelled 1,218,946; issued to Clayton ratchet connecting with (No. closed and practically all of the torpedo possessing several unique Laing.) cating needle in the manner shown, oscillations produced features. As shown in the illustra- a clever and the dial may he marked off in high frequency This device embodies the tion, the design comprises two sec- photometer for any suitable style and colors. The will flow in this circuit. When electrically operated tions; the forward compartment con- accurately device can be attached to any pool key is opened, the arc oscillations use bj photographers in taining the charge of explosives and table without altering or damaging will charge the aerial instead. calculating the proper exposure for detonating means, while the pivoted it, and each table pocket is con- rear unit contains the electric driv- nected up to the electrical score- Oscillating-Current Generator ing motor and necessary gears. The board. (No. 1,221,034; issued to Lee de Forest.) land-torpedo is dispatched from a constant con- Electrolytic Gas-Generator trench, and is under

, .. , ..„, of a soldier in the trench. It (No. 1,219,966; issued to Isaac H. trol Levin.) should prove useful in destroying wire, and other impediments, Electrolytic apparatus designed to barbed desired produce hydrogen and oxygen gases as when it has reached the operator simply pushes an by subjecting water containing a spot, the electric button which detonates the small quantity of a suitable electro- explosive charge in the war-head of uch, for example, as potassium the torpedo, thus destroying the hydroxid, sulfuric acid, etc., to the obstruction. The torpedo hauls its action of an electric current, which electric feed wires after it, as it ambles away from the trench. An improved method of developing powerful high frequency oscilla- Electric Gas Buoys for Submarine tions with a vacuum tube generator Warfare suitably associated with one or more (No. 1,222,498; issued to Joseph A. oscillatory circuits. The inventor Steinmetz.) provides an evacuated bulb contain- any strength of light and any size ing mercury electrodes, which pro- lens opening. The instrument com- duce a mercury vapor arc within prises a suitable light filter and co- bulb. Two cold electrodes 9, operating shutters, so that ordinary the are utilized, 9 being water davlight may be properly compared and 10, cooled, and 10 being a bent hollow with a standard of light incorporated grid. An oscillating circuit is as- in the photometer. The light stand- sociated with the two cold electrodes ard is composed of a small electric 9 and 10. A second oscillatory bulb, and a dry battery with suitable circuit is provided thru inductance switch. When equal amounts of 20, and capacity 21. With this ar- light penetrate two special trans- rangement, the oscillations produced lucent blocks, they appear as one in the first oscillatory circuit are block; the two halves of the block increased in intensity when the perfectly balancing, so that natural period of the second oscillatory cir and artificial rays are of equal in- cuit is made equal to that of the tensity. first. The output or "load" circuit comprises ground 24, inductance 22 Antenna for Aeroplanes and aerial 23. (No. 1,219,550; issued to Walter Hahnemann.) Combination Radio Receiver and quite new in the realm improvement in design of Something An Detector machinery and comprising wireless antennae for aeroplanes of war 1,219,888 ; issued to Frank series of highly charged poisonous comprising a bamboo or other mast (No. a Wallberg.) "gas buoys," which may be attached to the exterior of the submarine, in clamps, elec- is caused to flow there-thru from and which are held controlled from the one electrode to another, both electro-magnetically The lat- trodes being submerged in water. interior of the submarine. in proximity to a The solution is decomposed in the ter may submerge release one or well-known electrolytic manner, oxy- hostile war-ship and These float gen being liberated at the positive more of the gas buoys. even tho struck electrode and hydrogen at the nega- to the surface and will proceed to tive electrode. This invention re- by shell-fire, they deadly gas fumes, lates particularly to an electrolytic liberate a cloud of to eventually gas generator in which the liquid which are supposed crew of the war-ship. acted upon is contained in a suitable overcome the be released and receptacle, having two sets of in- The gas buoys may or they may sulated electrodes entirely indepen- immediately cut free, supporting one or more insulated position by a cable dent of the receptacle proper. be maintained in fiat-top aerials. The "ground" ele- as shown, so that they will not ment is compensated for by utiliz- Radio Arc Transmitter drift away before their task is fin- ing the metallic aeroplane structure; ished. ; issued to Louis cared (No. 1,220,072 the "aerial" element being Cohen.) for by the special antenna here Hood for Concealing Telephone shown. The inventor has paid par- An extremely compact "pocket (No. 1,221,919; issued to Lillian A. de- ticular attention to the correct wireless set, comprising a tuning Strasburger.) sign of aeroplane antennae, with inductance, crystal detector and tele- respect to the proper maintenance phone receiver, all in the space re- of the stability and operating char- quired for an ordinary watchcase acteristics of the aeroplane itself telephone receiver. The telephone and claims that the addition of his receiver and detector are connected will antenna to an aeroplane not in parallel, and this unit in series in flight cause it to be unbalanced with the aerial, ground and tuning or in maneuvering. coil. The latter is adjustable by means of a switch; the tuning cod Pool Table Register is wound about the shell of the (No 1,220,420; issued to William receiver, and the detector is ex- H. Heffley.) tremely small, being placed within An interesting and practical elec- the receiver-magnet chamber as shown. The device is held to the ear when in use, and the switch Instead of utilizing the "com turned until the signals come in the pensation wave'* method of radiating loudest. telegraphic signals by means of a arc transmitter, radio type the in- Electric Land-Torpedo ventor has developed a novel scheme (No 1,219,028; issued to Abraham Invention provides a specially which operates as follows: With This Must.) devised concealing hood for cover- the Poulsen system, energy is con- ing telephone instruments in tinuously transmitted, but with this the "My Lady's Boudoir," etc. As arrangement energy is radiated only in the illustration, the device the dots and dashes are sent out. shown as comprises a wire framework pro- During the "space" periods no cur- Q^^Ah^^m^™**^^ vided with a spring clip and a doll's rent is radiated from the aena', th< head. The attachment is suitably high frequency oscillations being drapt and at the rear it is pro- shunted thru a variable resistance vided with a sliding curtain. To key 8, condenser 5-a and inductance use the telephone, it is but neces- This does not affect the opera- 2-a. sarj grasp the skirt of the figure the arc and no appreciable to tro-mechanical device for register- tion of and turn the whole outfit around occurs. When the vari- ing the results of a game o sparking ISO degrees, when the rear curtain the pool hall as it able resistance key 8, is closed, the etc., whereby can be slid sideways and the re- falls m'- a pocki PATENTS SUPPLIED AT 10c. EACH ceiver moved from the hook. trical contact. This causes a set of COPIES OF ANY OF THE ABOVE 1917 THE ELECTRICAL EXPERIMENTER 129 Phoney Patents Under this heading are publisht electrical or mechanical ideas which you haven't a smell of the Patent yet. After they have allowed the Pat- our clever inventors, (or reasons best known to themselves, have as yet ent, you must pay another $20.00 as a final fee. That's $40.00 ! ! WE not patented. We furthermore call attention to our celebrated Phoney PAY YOU $3.00 and grant you a Phoney Patent in the bargain, so you Patent Offizz for the relief of all suffering daffy inventors in this country save $43.00 ! ! When sending in your Phoney Patent application, as well as for the entire universe. be sure that it is as daffy as a lovesick bat. The darner, the better. We are revolutionizing the Patent business and OFFER YOU THREE Simple sketches and a short description will help our staff of Phoney DOLLARS! $3.00 FOR THE BEST PATENT. If you take your Phoney Patent examiners to issue a Phoney Patent on your invention in a Patent to Washington, they charge you $20.00 for the initial fee and then jiffy. Phoney Patent Offizz 2UV.A.C. S. T. Raphangr of Rushour, D. T. No. 60° S>. Patent Rattled ( G. SELF PROPELLED TROLLEY

" To Whomsever It Might Concert: all the power and lots to spare besides, turn drives the motors under the car. the the Be it knowed to all unknown and all being furnished by swaying straphang- The motors being geared to axles drive other straphangers at large, as well as all ers themselves. The excess power can be the wheels of the car. The car wheels those confined ih solitary confinement used to light the car and charge a stor- being off center, as observed, will give the lattery, trolley pitching like a ship thruout tin- world, that 1 Salomon Tad- age which in turn may drive the car a motion deus Raphangr of the City of Rushour car when traffic is light. But this i in a swell. This greatly aids in more effec- the iu the State of Deliriumtremens, have de- no means all. By providing all seats with tively swaying and bumping passengers. seated ri>ing vised, designed, designated and developed a spring attachment, the seated passengers The passengers when up an invention of the most Ear reaching con- will hump up and down nicely, and 1 found and down on their spring -eats operate

Straphangers All Over the Universe As Well As Trolley Car Magnates Will Rejoice At This New Invention. Not Only Do the Sw ing Passengers Now Propel the Car, But They Experience All the Variegated Experiences of a Sea Trip and All for a Nickel.

sequences to a long suffering traveling pub- this to be far more pleasing than being gears 4 and the resulting power is also belts this furnishing lic. bumped up and down on hard seat-;. It conveyed to the 3, additional power. It is a well known, altho deplorable fact, is also very healthy, for -the digestion is that the modern trolley car for economic greatly improved, especially after heavy II 'hat I claim is: 1° reasons of all traction companies are equipt meals. It will "settle" the heartiest meal A wireless trolley, operated solely by with rather oval as well as "flat" wheels. wonderfully. If the public comes to rea- straphangers. 2° self propelled fat trolley The tracks too, are of the scenic railway lize this it will patronize my new self- A reducing stimulating digestion and preventing in- type, fashioned after the camel's back, i. c, propelling trolley in a manner undreamt hill and valley with 15 hills and 29 val- of by the most voracious traction com- digestion. trolley car giving passengers all leys to the running yard. These modern pany shareholder. No power house nor 3 A refinements are necessary to shake up and trolley wires being required, the company the experiences of a sea trip for a nickel. In consternation I there- bump the cars vigorously, this action be- will make enormous profits, and it will whereof, have

caused to he app< I ing required to pack the passengers tightly be able to issue a package of chewing gum fore resolved and into the car and to jingle the passengers' and 10 trading stamps free with every and imprest hereunto and hereunder the family shoe tree with my left nickles, so the latter can be extracted easier nickel ride. crest of my

, this 16th after for the conductor's rake-off. Referring to the patent drawing we find uppermost hind foot day "vent of any deceased maiden aunt's Having in mind these points and know- that 1 is the strap on which the strap- the "ad presence ing that passengers always sway to and hanger navigates. Every time be sways he German measles, in the of three fro in all our trolleys in a truly alarming exerts a pull of about 150 lbs. on the strap, witne S. T. R.VPHAXGR. manner, I conceived the brilliant idea of and by means of a pawl and ratchet ar- his Attorney, utilizing this prodigious energy^ now going rangement mounted on a common shaft Wittynesses: By of the trolley, the A. If Gowan, Thomas If. Benson, to waste. In my researches 1 quickly found, passing thru the length I. .If Indutch, Phila., Pa. that if you start the car on an incline, shaft begins to rotate. The power is then C. Titout no further power is required to propel it, conducted by belts 3 to dynamo which in U. :

EXPERIMENTER June, 1917 130 THE ELECTRICAL gUESTION*/&& BOX

experimenters. Questions w.ll be answered here for the benefit of all, but onlj department is for the sole benefit of all electrical This Rules undei which quest.onsw.il be answered. matto of sufficient toterestwiU be publish! three questions can be submitted to be answered 1. Only j written in ink; no penciled matter considered. ntten on ™at 1 to ' 2. Only one side of sheet be* mail free of charge. sheets.f^y u^*tiSn"addrest to this department cannot be answered by Sketches, diagrams, etc.. must.be on separate f^ entail considerable re- 3. «"ffg°™5 tOs^M^eSw each question. If the question i^win^cnar^ed Torrespo^ts^vill be informed as to the fee before such questions are search %&&%8£S?&£fi%&& S£tf ~ answered. _ .

"The Principles of Electric Wave VOLTMETER. obtained from an ideal impulsive excita- Fleming, RECORDING Telegraphy," $10.00; by 1. Zenneck, "Wire- Hassel, Baltimore, Md., asks: tion transmitter. (785.) I. less Telegraphy." $4.00; Eccles' "Wireless is a recording voltmeter? Q. 1. What Telegraphy and Telephony," $3.50. We will voltmeter is an in- RADIO BOOKS. A. 1. A recording send any of these books on receipt of permanently records the (787.) Andrew Colly, Oyster Bay, L. I. strument which price. asks : that exists between points in an potential Q. 2. Are all the Radio Amateurs of during any definite period. electric circuit this country to remove their aerials and more than an ordi- It consists of nothing apparatus in this present crisis? TO OUR FRIENDS. A. 2. Orders have already been given Do you realize that not one day to instruct all Amateurs thruout the coun- 1 passes when we do not receive from try to remove their aerials. The instru- to I 150 to 250 or more letters addrest ments \yere not asked to be removed or m the "Question Box"? If we mere to confiscated by the authorities up to the 1 publish all the questions and answers present time. we would requife a monthly magazine j WIRING DIAGRAM.

sice The ' 1 Hie or six times the of | (789.) Peter Hancock, Toledo, O., 1 Electrical Experimenter with no j wants other matter hut questions and an- I j Q. 1. A wiring diagram of a short wave Calibrating a Recording letters Connections for swers! Of late the influx of m receiving outfit. the Aid of a Standard Volt- g regenerative Audion Voltmeter With has become so heavy that several of • meter and Two Rheostats. 1 jg A. 1. The appended diagram gives the I our associates have been forced to j proper connections. the armature or moving important editorial work, nary voltmeter, I discontinue Q. 2. How can I eliminate the noises carries a small writing the mail. This we element of which I in order to answer produced in the receiver when the Audion traces curve on a moving strip are certain you do not wish. You do pen, that a gj is in operation? This effect is even ob- variation of the e.m.f. in magazine to lower its of paper. The I not 'cant your jj tained when the receiving instruments are the variation of want the the circuit is indicated by lj present high standard. You | disconnected from both the aerial and paper which you kuaze the traced curve. The strip of I best, the very best, and we j ground. the record is moved by a special never have failed you yet. receives j A. 2. The noise which you are experi- clock mechanism. encing is due to a constant electrical charge in- Moreover the multitude of letters g Q. 2. For what purpose are these Audion. which causes unnecessary. Most the P on the grid of the struments most adapted? I are wholly of _ the grid condenser to charge and discharge questions we arc asked every day 2. They are generally employed m I 3 A. unperiodically ; consequently affecting the required to know 1 have been answered before in the m power-houses', where it is receivers. This trouble mjght be eliminated conditions of the line 1 tiiesjion Box. Therefore ere you the exact voltage | to a certain degree by shunting a high re- the day. sit down to write to us. look over during certain periods of I sistance "leak" path across the grid con- instruments sufficiently your] back numbers and nine times 1 Q. 3. Are these denser. It must be a non-inductive leak in laboratory j out of ten you will find the answer, accurate to warrant their use j and can be made very readily by marking work? How are they calibrated? II strive hard to publish only upon a sheet of paper a pencil mark and require a large 'e j A. 3. No. Most of them ends of this line across the I such matter as Inn not appeared he- -g connecting the correction factor. Their accuracy depends 1 fore in our columns, and for that condenser. A little patience in making the degree of voltage variations as j upon the = reason only a small fraction of que- W^ proper, thickness of line will be required friction between the pen and paper is the 1 ties of those received by us are ac- before proper results can be obtained. somewhat great when the moving element j I tually publisht. is caused to move frequently. diagram herewith gives con- The wiring Kindly note, therefore, that in the || voltmeter for cal- nections of a recording 1 future zee cannot, in your own with a standard volt- ibrating the same 1 f crest, answer questions by mail, free m meter. We of charge. IMPULSE EXCITATION. innnedi- I or questions requiring j Paul Magdale, Hackensack, N. J., (786.) ate answer our fee is 25c. for the 5 to know : desires ordinary question and J.;* for impulse excita- Q. 1. What is meant by ; I each additional question. We will J I gladly advise fee for special qucs- | A. 1. Impulse excitation is a method ot ', entailing considerable calcu- g of an oscil- iting the antenna by means or research. Stamped' and damped and y lotions | ouit which is highly 1 addrest envelope should be end or antenna circuit Hook-up for a Short Wave Regenerative the coupled secondary with the queries and. moreover, any or shock from the pri- j Audion Radio Receiver. iving an impact sketches accompanying them should secondary | mary circuit, and permitting this made on separate sheets. And ^ WAVE LENGTH OF ANTENNA. circuit to oscillate with as little damping I please be brief. (790-A) Thomas Lowman, East Pitts- as possible. The primary oscillatory cir- THE EDITORS. M burgh, Pa., inquires : cuit is so adjusted or tuned that a single Q. 1. Can you give me the wave length impulse \< produi ed. mil quenched spark gap system of an antenna which consists of four wires Q. 1. Where can I buy wioeless 1 ks (ill feet high, 100 feet long, and the wires ated on the impulse excitation prin- describing in detail the complete theory of separated 2 feet? ciple? radio engineering, and also a text-book A. 1. The wave length of this antenna A. 2. Yes; but it is not an ideal im- giving complete data as to the design and is 300 meters. pulse excitation, since the primary of the operation of radio apparatus? _'. Suppose I desire to use this an- circuit is not permitted to be highly damped. Q follow- tenna with a transmitting station, which Furthermore, the oscillations of the pri- A. 1. We would recommend the will comprise a 500 watt 60 cycle trans- mary are periodically cyclonic and not im- ing books, which we believe will give you on page 137) oscillations, as that all the desired information: By .1. A. (Continued pulsive i riod June, 1917 THE ELECTRICAL EXPERIMENTER 131 Who Gets $200,000,000 Tire Profits? An amazing condition revealed in the tire business. Terrible waste shown by methods of selling automobile tires. How one tire man plans to cut the cost of tires to the consumer revealed Tire Chain Stores Offer Solution of Problem

By M. E. PHILLIPS, "Staff Correspondent" (Home Magazine)

NOTE.—The following article, written by our staff representa- mendous growth of the automobile industry—consequently of tive, outlines plans for a giant chain of tire service stations and the tire business—makes this one of the most attractive and in- stores which it is predicted will greatly lower automobile upkeep teresting enterprises. We have made every effort to verify the costs. A unique co-operative plan which has been tested out statements made here and to the best of our knowledge the and found successful. Output of splendid factory already secured, statements are accurate and the estimates conservative.— (Pub- more to follow. The success of other chain stores and the tre- lisher Home Magazine.)

Who gets the $200,000,000.00 A YEAR TIRE PROFITS? Do you know that the cost of producing a tire is possibly ONE-THIRD of the price you have to pay? That a small tire you pay $15.00 for costs about $5.00 to manufacture? That the tire costinc about $20.00 to build lias to retail for about $60.00? Do you know that the tire manufacturer is satisfied to sell his tires for very little over the cost, and at only a fraction of the retail price? Where does the balance go? Who then gets this enormous "cut in" on the tires you buy? DO YOU? Of course not. Who, then? Well, the JOBBER gets a BIG slice. The WHOLESALER gets another BIG slice. The RETAILER gets HIS SHARE. The rest goes into advertising, dealer's helps, adjustments, etc. Meanwhile YOU, Mr. Tire Buyer, pay the 100 per cent price and worry about the high price of upkeep of your motor car. WILL TUT TIRE COSTS A clever tire man. a man with intimate knowledge of the tire industry, a man with breadth of vision and economic principles, has The Famous Philadel phia Experimental Tire Service Store that Proved to President Feist seen this enormous WASTAGE in the tire of the National Rubb er Company the Practical Possibilities of Tire Chain Stores, Located at the Corner of North and Broad Streets. business and has evolved a PLAN that will revolutionize the tire selling business.

He argues that TIR1 S< 1 1ST Tl I E CONSUMER TOO MO 'I r Pa., manufacturers of the famous National Speedway Tires and He says there is no reason on earth why the tire buyer should National Red Tu have to pay this enormous burden of profits and selling costs. NATIONAL SPEEDWAY RKDWALT. TIRES are so If tires can be made for ONE-THIRD of the actual retail prices GOOD that they are sold under the strongest GUARANTEE

they can be sold I 1 'R LESS than prices now charged for them and to be had. stili pay legitimate profits. LARGE PROFITS, because of the The company agrees to replace FREE any tire that does not volume of business a company offering such savings is bound to outlast and outwear any tire of any make or price of the same achieve. size tested under thi onditions. This far-sighted man is a PRACTICAL TIRE M \N. As a This company now has a production of 1.000 tires and tubes a manufacturer he has MADE GOOD. He is a PRACTICAL and is being enlarged to a much greater capacity. When BUSINESS MAN, with all a practical man's dislike for waste. the distribution exceeds the capacity plant, new plants will He has proved his genius for organization and big things. rted "i- bought in different sections of the country, or their

This man is Mr. .1. G. Feist, President of the National Rubber outputs contracted for in order to bring up the production to the Company of New York. necessarv number of tire-.. PLANS CHAIN OF STORES Mr. Feist proposes to sell tires at a MUCH LOWER PRICE than is now being charged for ^ooe\ tires elsewhere. Mr. Feist's plan is to establish a chain of tire service and store sta- He plans to give SUPERIOR SERA ICE to tire buyers. tions from Maine to California, and Canada to the Gulf of N He will give them a BETTER TIRE. He anticipates that in The National Rubber Company of New York has been organized doing this his company will prove the greatest profit maker in with strong men behind it and it has already secured the output the country. of one entire factory as the nucleus of this chain store plan. EXPERIMENTAL PLANT A SUCCESS More factories will lie added as the chain extends and the need of mure tires becomes evident. The first factory whose product Mr. Feist is not building his company's future on imagination has been acquired is the National Rubber Company of Pottstown, or theory. Before maturing his plans he opened in Philadelphia 132 THE ELECTRICAL EXPERIMENTER June, 1917

man for cash, eliminates all selling expense, salesmen, advertising, collections, etc., and can sell for a quick turnover, and will yet make more profit in the end. That's how the chain store buyer can buy at such a low figure that he can sell goods that retail generally for 25 cents for 5 and 10 cents. Then, the chain store man nearly always buys FOR CASH. That means he takes advantage of every cash discount and by paying cash he enables his manufacturer to buy for cash and get a similar benefit. So it becomes an endless chain of savings which benefits the ultimate consumer of the product. ECONOMY OF CASH BUYING The chain store man uses his cash to buy everything. He buys everything the same way. He buys his fixtures, his delivery wagons—if he uses them—his every necessity at the lowest bulk price, and bulk with the chain store man means tremendous bulk. If these chain stores, selling articles that retail for such a small price, can earn such fabulous dividends, what will a chain of tire

service stores earn with the big sales it will make ; sales averaging $20 apiece? It doesn't take a prophet to look into the future and see the magnificent accumulations of dividends that should accrue from such an enterprise. It isn't hard to foresee what the earnings of such a chain of stores can pay in say ten years from today. By that time the chain should extend to every city of any importance in the coun- Boston Service Store of National Rubber Company, Located at 557 Columbus Avenue. try. This may mean thousands of such stores, because there are in the United States 1,442 towns of 5,000 or more inhabitants and over 100 cities having a population of 55.000 or over. The a station such as he proposes to establish elsewhere. small towns, say the towns under 10.000, would require only store does: This is what his Philadelphia service station and one such service station, while the larger towns would require ot equal It sells tires below the average price of high-class tires a number of them. size and qualitv. THOUSANDS OF CHAIN STORES It delivers tires PUT ON YOUR CAR. address. You phone in that you need a 34x4 tire and give your To give you an idea of how many stores some of the big chains it in the carrier of a A mechanic picks up the required tire, puts have, it is enough to mention the Great Atlantic and Pacific Tea he takes motorcycle and speeds off to your address. On arrival Company, with over 1,500 retail stores; the United Cigar Stores, on the new" one. No trouble, no mess. off your old tire and puts with over 1,000 retail stores ; the Woolworth Company, with over w'ith him and If you want your old tire repaired he takes it back 1,000 stores, etc. it is delivered as soon as repairs are made. The tremendous growth of the automobile industry—a growth and money. You have saved time, labor, worry that is gathering size and importance every day—makes this pro- The success of this first service station PROVES what REA- jected chain of tire service stores all the more important. SONABLE PRICES. HIGH QUALITY GOODS, EFFICIENT At the beginning of 1917 there were approximately THREE of volume. SERVICE will accomplish. Profits are large because MILLION autos in use in the United States. According to last The Philadelphia service station already has 11,000 CUSTOM- United States census, there were in 1910 (date of last census) ERS. (Not tire sales, but CUSTOMERS.) 91,972,266 inhabitants in the U. S. It is calculated that there are departure With this established PROOF of the value of this new now at least 120,000.000 people in the U. S. At this rate, there has oreanized a company to establish National T service, Mr. Feist is one auto in the L . S. for every 40 people. In many of the all over Rubber Company SERVICE STATION'S and stores states, the ratio is higher than one for everv 16 people. This the country. His plan provides for opening 500 stores the first means that THERE IS A TREMENDOUS POSSIBILITY FOR the company year, if possible, and more stores year by year as MORE MACHINES. grows. According to the best informed automobile authorities, it is OFFERS GREAT OPPORTUNITIES calculated that there will be added at least 1,000.000 auto users during the vear 1917, brincing up the total close on to FOUR The OPPORTUNITIES offered by this chain of tire service MILLION AUTOS in actual use in the U. S. With such an stores are self-evident. enormous distribution of cars, and all the automobile factories CHAIN STORES of all kinds have been enormously success- of any account way behind in deliveries, an enormous supply ful. They have built up some of the greatest fortunes in the of tires will be required to keep these autos running. country- They have made original investors enormously rich. 24,000.000 TIRES NEEDED And this in spite of the fact that most chain stores have dealt only in articles selling for a very small sum. HOW MUCH Very moderate estimates place the number of tires required GREATER should be the profits of a chain of stores selling 3. on each car at EIGHT PER YEAR. Each auto MUST HAVE product whose every SINGLE SALE equals the sale of HUN- FIVE TIRES, four on the wheels and one spare tire. It is an DREDS of the articles sold in most chain stores? ultra conservative estimate, therefore, that places the required The UNITED CIGAR STORES, sellinc cigars, cigarettes and number of tires to meet the needs of 1917 at SIN PER CAR. tobacco, average LESS THAN 20 CENTS PER SALE. The At this rate 4,000,000 automobiles will require 24,000.000 tires. National Rubber Company averages MORE THAN $20 PER This is truly AN AMAZING FIGURE for an industry that is SALE, with proportionate profits. only a little over a dozen years old. THE WOOLWORTH STORES sell 5 and 10 cent articles. The distribution of these cars is centered at present in certain Yet they have made many millions and the highest office building sections. When the other sections have awakened to the advan- in the world was built out of these nickels and dimes. tages and uses of the automobile and its economy for travel and The REGAL SHOE COMPANY with its chain of hundreds of commercial purposes, it is more than likely that the distribution shoe stores, has made its owners rich. So have the Walk-Over will be much more even. Shoe Stores, the W. L. Douglas Shoe Stores. All chain stores. It has been estimated by statisticians that there are OUF.R The TRULY WARNER Hat Store chain has accumulated TEX MILLIO.X men in the U. S. who should he. and probably wealth for its owners. The Great Atlantic and Pacific Tea Stores, the Jewel Tea Stores, the Acme Tea Stores, all chain stores, have made millions. The several chains of drug stores, of grocery stores, of cheap restaurants, have all made fortunes. The reasons for this uniform success are numerous. In the first place, operating a ''chain of store*" of any kind reduces the cost operation—what is known as OVERHEAD EN- PENSE—to the minimum. Secondly, the purchasing power of the buyer who buys for hundreds of stores is so enormous that he can pretty nearly make his own price. He gets ROCK BOTTOM costs on everything. Woolworth can sell for 5 or 10 cents articles that often retail at from 25 to 50 cents because he buys outright entire factory productions. The manufacturer who sells his whole output to one Chicago Store of National Rubber Company, the Third in the Chain. —

June, 1917 THE ELECTRICAL EXPERIMENTER 133

pays soon will be, auto owners. These arc men who, because of their at prices that make the prices the individual store owner for insur- business, their financial condition and their position, shouli is; it pays the minimum for taxes, i- in hulk come automobile owners. i ating carried each There are upwards of seven million farmers in the U. S., and 1,\ tl,,- parent company, ind this is divided pro rata so that ownei ol auto- individual ston only a -mall -urn as its share of the ad\er- ,,f tin i percentage will probablj become mobiles fust now only about 7 per cent of thi pr tising ,,un am, biles. The fanner is today the RICH MAN ol the bought at actual contract price from the manufacturer

i ing the biggest prices ever paid for and o i the store, much cheaper than the average I . S. He has b< yield ol his can buj them. he has 1 >\ scientific farming increased the man

' and 1m en fortunate in getting b ci >p when the prio We then have EXPENSES PARED DOWN TO THE BONE, was highest. vVHAI THEY WOULD BE UNDER ORDI- I'l the most attractive kind For tl ons, THE FARMER IS USUALIA NARY CONDITIONS. And we have PEROUS and lie is putting some of his riches into the comforts of a proposition to offer to the tire buyer—THE BEST TIRE and conveniences of an automobile. OX Till-. MARKET AT MUCH LESS than he would havi With such prospects, with such a tremendous field to conquer, pay elsewhere; A SERVICE NO OTHER TIRE CONCERN with the SUO ESS that has attended the FIRST UNIT of the GIVES oi RANTEED SATISFACTION hacked National Rubber Company chain of service stores, it is not hard up by a company operating a nation-wide chain of stores. to visualize the ENORMOUS POSSIBLE PROFITS from this W it li so much to offer and with such splendid profit-making enterprise. advantages it is not hard to look into the future and see every store paying a big profit and the company earning dazzling dividends. What maj one store earn, you may ask? Let us do a little figuring Firstly, the ENTIRE FACTORY SKI. I. IX'. EXPENSE IS ELIMINATED—the entire output of the factory being sold to one customer—the chain store. The saving of the traveling expense and salesman's salaries and commissions. The saving of advertising and promotion expense. The ad office accounting and credit expense All these are SAVED by the chain stores. In these items alone is found a selling cost of at least 20 per cent. On top of that the JOBBERS' DISCOUNT OF 40 PER CENT IS WIPED OUT. Xo thinking man or woman has to be told that the NET SUM the manufacturer receives Al.OXE COXTROLS THE QUALITY AXD QUAN- TITY of materials used in making tires, because ONLY AXD SOLELY from this NET SUM is the PROFIT derived. Because of the TREMEXDOUS OVERHEAD selling and distributing expense, the enormous discounts demanded by the jobber, the wholesaler and the retailer, if the manufacturing cost were TOO HIGH or even over his competitors, then added charges, as described here, increase out of proportion and the consumers' prices would be prohibitive. Hence, in National Speedway Tires most of the factory selling cost is put in the tire in ADDED QUALITY AXD QUANTITY, and the usual trade discounts are divided with the consumer. PROFITS OF CHAIN* STORES We now come to the question of the profits of the unit of the chain in the Officers and Officials of the National Rubber Company of New York. These Men chain stores of each and Have Made the Making and Selling of Tires Their Life Work. Both as Manufacturers aggregate. and Branch Managers. They are Pioneers in the Tire Business: They Have Watched After a careful scrutiny of costs of manufac- the Tire Business Grow from the Experimental Stage. Today They are Large Fac- operating the chain store each unit tors in the Manufacturing of the Best Tire that Money Can Make. Mr. Walsh. Who turing, of — Is Superintendent of the Plant. Has Been for 23 Years in Active Charge of the and figuring a retail price on the tires at a sensible Making of the Best Known Tire in America. Mr. Sperry Was With the Deere Plow reduction over average price of tires of equal size Co. as Agency Organizer. Mr. Dougherty Has Been a Tire Representative for Years, is still possible an Formerly With the Lee Tire Co. H. A. Lamoree Has Also Been a Branch Tire Store and quality we find that there Manager and General Tire Salesman With Several of the Big Companies. average margin of $5 per tire. This is "AVER- AGED" because some of the tires will pay more HOW PROFITS PILE UP profit while some will pay less, but the average has been shown to be about $5 her tire sold. figures Even a casual consideration of the subject makes the This is evidently a CONSERVATIVE ESTIMATE. run into such amazing columns of profits that the very thought If each chain store sells ONLY 10 TIRES PER DAY. we is staggering. have each store earning a profit of $50 a day or $50,000 a day The great earnings of chain stores of all kinds has been in profit for 1,000 stores. the aggregate. $50,000 profit per day for 365 days in the year— tire service When you take 1,000 stores and pile their profits in one great stations are busier Sundays and holidays than other days which heap, you have a formidable aggregate an aggregate URLS OUT THE ENORMOUS TOTAL OF $18,250,000 \ doesn't have to he very large in the individual case to make up YEAR PROFITS. this magnificent total. You will realize that an estimate of only ten tires per day Let us take into consideration one unit and then see how it is very small. When you consider the tremendous advantages works out. of dealing with the National Rubber Companj Firstly, we must remember that these service stores are oper- the high class product, the low price, the good service given in ated at a minimum of expense. Being administered from the the way of instant special deliveries, placing the tire on the car central office, whose- costs of operation are spread over the whole and taking away the injured tire for repairs, it is not hard to chain, the local stores require only inexpensive help. The man understand why these stores should do an enormous business. who operates a store of his own expects to make \ GOOD Ten tires per day is a very low estimate of the possibilities. LIVING out of it for himself AND A CoOD PROFIT besjdes; i,, conservative, let us cm down this estimate lie has to pay for everything on the high price of individual Pin i„- even more half ii- that the stores only AVERAGE FIVE purchases. II,- has to have efficient help, has to advertise and, by Oi suppose let ti- this figures out. of course, he has fixed charges for rent, light, taxes, insur- S\[ ES PER DAY see how ance, etc. FIYE TIRES \ DAY, showing an average profit of $25 per day per store, one thousand stores will, therefore, pay an esti- CHAIN STORE SAVINGS mated dail\ profil of $25,000. For 3U?~ days in the year. THI-'. and it would The chain store hires only the necessary help, it eliminates ENORMOUS TOTA1 WOULD BE $9,126,000, five tires per day. the owner's living and profits. It buys in enormous quantities mighty small Store that couldn't sell 134 THE ELECTRICAL EXPERIMENTER June, 1917

These figures are staggering when you analyze the accumu- WHAT THIS MEANS TO AUTOISTS lated profits of hundreds of stores all over the country, each contributing its quota of profits from many sources. Let us study it over. $50 invested in ten shares of this underwriting stock will save the automobile owner 25 per cent on A GOLD MINE OF PROFITS his tires. If his bill for tires runs to $200 a year, he will be You will note that no estimate has been made of profits from saved, therefore, $50. That means that the stock will have paid sale of tubes and from the repair department, which should also him 100 per cent on his imestment or 50 per cent on the par be profitable. value of the stock, which, computed on a stock's ability to earn cent, It will, of course, take time to build up such a larue chain 5 per will make his TEN SHARES REPRESENT AN of service stations, but in a few years, with the growth of the INVESTMENT OF $1,000 FROM AN ORIGINAL INVEST- chain and the enormous increase in the automobile industry MENT OF $50. Then if the company begins paying dividends, and number of cars in use, THIS CHAIN OF TIRE SERVICE the stock should go to par and over if the dividends amount STATIONS SHOULD BECOME A VERITABLE GOLD to more than 5 per cent. MIXE OF PROFITS FOR EVERY STOCKHOLDER WHO When the company gets on a 10 per cent dividend basis, the BECOMES INTERESTED IN THIS COMPANY NOW, when stock he bought for $50 should represent an investment of $200. its shares can be acquired at a low initial price. When it pays 50 per cent, it should have an INVESTMENT The National Rubber Company, of New York, is incorporated VALUE OF $1,000.

Section of Tire-making Department. Here a Small Army of Workmen Are Constantly Employed Putting the Finishing Touches to National Redwall Speedway Tires. These Workmen Are the High-skilled Labor and Their Rapidity and Efficiency Are Wonderful. under the laws of the State of Delaware, with a capitalization So when the company is in a position to pay 50 per cent of 500,000 shares of the par value of $10 PER SHARE, ALL dividends, this stock should represent an investment to the auto- COMMON STOCK, SHARING EQUALLY IN PROFITS mobile owner of $2,000, figured on the basis of the dividends and AND CARRYING FULL VOTING POWER. savings it will give him on his tire purchases. And all from THE STOCK IS FULL PAID AND NON-ASSESSABLE. an original investment of $50. For the purpose of establishing the business on a right basis, When the company reaches its full development and its 1,000 the directors have set aside 100.000 SHARES OF THIS STOCK or more stores begin piling up big profits, such as we have already TO BE SOLD TO THE PUBLIC. figured on, profits that mean exceptional dividends, THIS ORIG- Their idea is that by obtaining a wide distribution for this INAL INVESTMENT WILL HAVE ACCUMULATED A stock, they will enlist local interest in the local distributing and PHENOMENAL VALUE. service stations of the National Rubber Company. NO AUTOMOBILE OWNER CAN AFFORD TO OVER- LOOK SUCH AN OPPORTUNITY. • UNDERWRITING STOCK OFFER A blind man could see the possibilities presented in this under- This UNDERW RITING SYNDICATE STOCK is offered in writing offer, an offer so liberal that the directors had to confine it five different allotments. to a small amount of stock. The first allotment will be sold in lots of not less than TEN SHARES and not more than 100 shares at $5 per share, or AN EXCEPTIONAL OFFER half the par value of the stock. The offer of the stock at $5 per share (par $10) is in itself This first allotment of 20.000 shares is the only stock of the a tremendous inducement, but when it is coupled with the offer UNDERWRITING allotment that will be sold at this low price. of the company to extend a discount of 25 per cent on all tire The next allotment will probably be sold at from 40 to 50 per cent and tube purchases made through the company, it becomes so advance in price as soon as the first allotment of 20,000 shares extremelv attractive a proposition that NONE CAN AFFORD is disposed of. Further allotments at further increases as war- TO IGNORE IT. ranted. The savings in tire costs alone should pay for the stock of It is desired—as nearly as possible—to place every share of those who accept this offer.

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The Splendid Modern Character of This Ideal Plant Is Shown Clearly in These Pictures, With Its Strong, Clear Light, Fine Equipment and Good Flooring. Ideal Conditions for Turning Out High-class Work. this UNDERWRITING stock in the hands of owners, or pros- This, in itself, makes the proposition attractive. But when the pective owners, of automobiles, who will become immediate pa- future of this company is analyzed and the possibilities it offers trons of the chain stores and who ARE ALSO OFFERED AN are considered, the offer becomes immensely more attractive. INDUCEMENT TO BECOME BOOSTERS FOR THE TIRE YOU NEED NOT NECESSARILY BE AN AUTOMOBILE SERVICE STATIONS. THIS INDUCEMENT CONSISTS OWNER today to accept this offer. Your stock in the National OF A CASH DISCOUNT OF 25 PER CENT UNDER THE Rubber Company will entitle vou to this 25 per cent discount STANDARD LIST PRICES FOR ALL TIRES SOLD BY on tires and tubes JUST AS LONG AS YOU REMAN A THE NATIONAL RUBBER COMPANY TO ITS SHARE- STOCKHOLDER. Later, when you buy an auto, you'll be able HOLDERS. to buy tires at this great saving. An automobile owner, therefore, has a double interest in buy- You often hear it said' that if you had a chance to invest ing this stock. with Ford, or Willys, of Overland fame, with Goodrich or Fisk The saving alone tire bills in for a year should pay for this or Firestone ; with Westinghouse or Bell, or some of the others, ten shares if he buys at this price and he will have, besides whose companies have earned fabulous dividends, and made the savings in tire costs, and dividends which the company de- stockholders rich, vou would today be ON EASY STREET. clares. This is verv true but the pitiful truth is YOU DID NOT HAVE IS THIS INVESTMENT WORTH WHILE, you may ask? THIS CHANCE. VERY FEW PEOPLE DID. These com- June, 1917 THE ELECTRICAL EXPERIMENTER 135

were all close corporations with the stock held in the

: small group of men. These stocks were not o to the public.

Tire Fabric Cutting Machine. This Machine Can Cut the Fabric for the 1,000 Tires a Day, Doing the Work of 10 Men. Vulcanizing Department of the Pottstown Plant. Here National Speedway Tires Are Hardened to Stand Wear and Tear. This De- partment is Now Vulcanizing 1,000 Tires a Day. A CHANCE IN A MILLION BUT HERE IS A CHANCE. Hue is a company offering would be holding the stock and boosting for the company. UNDERWRITING STOCK, stock that can now be bought at Ten thousand holders of stock scattered throughout the coun- the ROCK BOTTOM PRICE, thru should in time become try would mean a veritable army of boosters, helping build up enormously remunerative. Stock in a company that promises the business IN WHICH EACH ONE HAS A SOLID, SUB- to have tremendous growth. STANTIAL INTEREST. Woolworth and Whalen and the others, who have made tens Ten thousand boosters, working to popularize and make known of millions out of chain stores, never gave the public a chance the high quality of National SPEEDWAY RED-WALL TIRES to come in on the organization. They have sold stock since, and Xational Red Tubes—boosting this way because it is TO lots of it to the general public, but it has been stock in the THEIR IXTEREST to boost this way—would save the com- developed proposition, stock that has been sold on the market AT pany tens of thousands of dollars per annum in advertising ex- THE VALUE IT PRESENTS NOW, a value figured on the pense. company's earning' power. That's the principal REASON WHY THIS STOCK IS OF- LATER YOU MAY GET A CHANCE on the National Rub- FERED TO YOU AND TO EVERYONE WHO BUYS TIRES ber Company stock on the open market but YOU'LL PAY THE OR EXPECTS TO BUY TIRES. PRICE OF" DEVELOPED STOCK. If the company is earn- It is WORTH IT to the company to make you EVERY IN- DUCEMENT to buy this stock. AND IT IS CERTAINLY WORTH WHILE TO YOU TO BUY IT. Remember you

Tlre-Maklng Machines. A Busy Corner in This Department. These Four Machines Shown in the Picture Do the Work of 40 Men. This is the Most Modern Tire-making Machine Built.

ing 100 per cent on its capitalization, you'll pay for it at that rate, which, in that case, would be $2,000 for even' $100 par value, or $200 a share for $10 shares. THIS IS THE PENALTY THAT SHORT-SIGHTED PEOPLE PAY for not accepting opportunities that are offered them. The poorhouse is FULL OF SUCH PEOPLE, "THE MIGHT- HAVE-BEEN S." They lacked the initiative and courage to back their belief with their money. THOSE WHO HAD COURAGE The others, those who are without fear, those who have the courage to back their judgment with their money, they are those you watch spinning past you on the boulevard in luxurious limousines, whose homes line the fashionable streets. MONEY MAKES MONEY, but it takes an exceptional opportunity to bring you big returns from small investments. You read, for instance, that $500 invested in such-and-such stock has earned $250,000; that $500 invested in such other stock has paid $200,000; that $1,000 in Ford stock of the original company is now worth millions. THAT IS ALL TRUE, gospel truth, BUT did YOU ever get a chance to invest in the original $28,000 that started Ford on the- highroad to his present millions? Did you get a chance to invest in the $33,000 that John N. Willys has built 'up into the tens of millions of the "Overland Company? Did YOU get a chance to get in on West- Rubber Vault. In This Vault Are Stored Thousands and Thousands inghouse, or Bell Telephone, or Western Union, or Welsbach of Pounds of Uncured Rubber for Tire and Tube Making. It is Stored Mantles stock? Of course not. And very few people did BE- Here Just as It Comes from the Ships. CAUSE THESE STOCKS WERE NOT OFFERED TO THE PUBLIC when they were at a low price. profit immediately because as soon as you are a stockholder 25 per cent on all the tires you buy. THERE'S A REASON you can save WAITING FOR A MIRACLE 77n\f slock is offered for a reason. wonderful miracle It is offered to the UNDERWRITERS of this company to Every man hopes, some day, that by some will lifted of the life of drudging toil he leads into start it with a nucleus of interested tire buyers and boosters in he be out It is nature even' locality. one of affluence, comfort and independence. our miracles is The directors set A MINIMUM OF TEX SHARES AND to live in this HOPE. But the day of past. Good A MAXIMUM OF 100 SHARES on this offer. It would doubt- fairies do not run around with bags of gold and drop them into less be more profitable to the company if every subscription for the laps of the worthy. this stock was for $50 (10 shares), par value $100, because YOU'VE GOT TO HELP YOURSELF TO FORTUNE. that would mean that the greatest number of people possible You've got to save to get a nucleus of money to invest where 136 THE ELECTRICAL EXPERIMENTER June, 1917

first allotment of 20.000 shares at $5 a share (par value $10 a share) will be snapped up so quickly that WE CONFIDENTLY EXPECT EVERY SHARE TO BE TAKEN UP WITHIN TEN DAYS from the publication of this announcement. After that, there will be no more $5 shares. The price will jump perhaps 40 or 50 per cent. SO ACT NOW. Fill out the convenient coupon attached. Mail it with your first payment, which will RESERVE the stock you want at this LOW PRICE. Then you can take fifteen days to investigate, to make sure that all the facts are just exactly as represented to you. If you, for any reason whatever, are not satisfied, you can Tube-making Department. Here Are Made the Famous National Red release your reservation and your money will be returned to you, Tubes. The Factory is Producing 1,000 Tires a Day. but if you find out that you have invested wisely—as we are confident you will find out —then you can either pay the balance in full the opportunities for profit are large. BUT YOU'VE GOT TO or you can take advantage of the easy method of paying for it, a INVEST if you want them to pay big re- YOUR SAVINGS, little each month. Either plan is equally satisfactory to the turns. directors of the National Rubber Companv of New York One of the world's greatest bankers has said that NO MAN IF YOU WANT ANY OF THIS WILL OF UNDERWRITERS' EVER GET RICH FROM THE SAVINGS OUT STOCK, YOU'VE GOT TO WRITE NOW, at once, OR YOU A SALARY OR WAGES. He must accumulate wealth bv WILL LOSE YOUR CHANCE. PUTTING THESE SAVINGS TO WORK, INVESTING THEM TO ADVANTAGE. Of course, it takes COURAGE to invest money that you have worked hard for, that has been slowly and laboriously accumulated bv privations and sacrifices. But IT IS THE COURAGEOUS WHO WIN THE EARTH. DON'T INVEST ALL YOUR SAVINGS. That wouldn't be the wise course. Keep a reserve of your savings for eventualities, for sickness or loss of position or unexpected calls, BUT IN-

; ^Sa» i' jv^.-.^.:. ;,T.;,r.-^ --^gg

The Magnificent Pottstown, Pa., Plant of the National Rubber Company, Where National Speedway Redwall Tires and National Red Tubes Are Made. Two Floors of This Big Building Are Completed and Occupied. This Is a Strictly Modern Steel, Concrete and Glass Construc- tion Factory Building of the Highest Type. The Big Tire Coming Out of the Building is the National Speedway Redwall Tire, Best on the Market. VEST PART OF YOUR SAVINGS WHERE THEY CAN EARN YOU SOMETHING WORTH WHILE. INVEST FUTURE SAVINGS How You Can Buy This Stock Or better still. HERE IS A PLAN BY WHICH YOU CAN ACQUIRE THIS STOCK WITHOUT TOUCHING YOUR SAVINGS. 10 shares (par value $100) BUY WHAT YOU CAN AFFORD TO PAY FOR OUT OF $10 down, $10 a month for 4 months .$50 NEXT 15 shares (par value $150) YOUR SAVINGS $15 down, $15 a month for 4 months $75 The directors have made it EASY FOR YOU TO GET THIS 20 shares (par value $200) IT STOCK AND PAY FOR OUT OF YOUR FUTURE SAV- $20 down, $20 a month for 4 months $100 INGS. 30 shares (par value $300) You can pav down $10 ON EVERY TEN SHARES OF STOCK YOU 'WANT AND PAY THE BALANCE IN FOUR $30 down, $30 a month for 4 months $150 40 shares (par value $400) EQUAL PAYMENTS OF $10 A MONTH for each 10 shares, making the total of $50 for the ten shares, par value $100. $40 down, $40 a month for 4 months $200 This liberal plan makes it possible for you to buv this stock 50 shares (par value $500) and pay for it WITHOUT TOUCHING THAT PRECIOUS $50 down, $50 a month for 4 months $250 CASH RESERVE you have been accumulating in the bank so $100 shares (par value $1,000) carefully. down, $100 a month for 4 months $500 BUT U'HATEVER YOU DO. DON'T OVERLOOK THIS $100 OPPORTUNITY. You'll never get another such chance. This

APPLICATION FOR UNDERWRITERS' SHARES E. E. NATIONAL RUBBER COMPANY OF N. Y., Pottstown, Pa. Main Office: National Rubber Bldg., Broad and North Sts. PHILADELPHIA, PENNA. Date 191. The undersigned hereby subscribes for shares of the Common Stock of the National Rubber Company of New York, frill paid and non-assessable, and tenders herewith ' (Bank Check or Money Order)x; of to the order of National Rubber Company of New York for % at the rate $5.00 full per share J payment, [part I STOCKHOLDER'S DISCOUNT— It is understood that in consideration of this subscription as long as I remain of less than twenty- a shareholder of record on the books of the Company. I am to receive a Net Cash Discount not five Per Cent (25 per cent) from the Company's regular Printed Price List, on any goods listed therein which all made by I may buy for my own use. I am to have 15 days from date in which to investigate statements the Company.

Issue shares in the name of and forward to addres below: (Print Name Plainly) (Subscriber's Signature) (Street Address) (Town and State) : : : : — h

June, 1917 THE ELECTRICAL EXPERIMENTER 37

QUESTION BOX. MEDICINE HAILS ELECTRICITY. Wo nderf ul (Continued from page 130) "The day of the howling dervish in elec- Mr. Edison's Phonograph former, having a secondary potential of tro-therapeutics is past," declared Dr. S. 1(1,1100 volts. This to charge a group of < ohm in the meel four Murdock block condensers that will Philadelphia County Medical Society, "and be connected in parallel. The discharge to the science now has a definite, dignified take place in a quenched spark gap linked place in tin' estimation of the medical pro- to a primary of an inductive oscillation ion and of the public." transformer. The secondary to be connect- "We must confess with shame," said Dr. ed in the usual way to the antenna and S. Lewis Ziegler, "that the greatest ad- Free Trial application to und terminals. What I desire to know vances in the of electricity Yes. you may keep is come this new Edlton — of. capacity of condenser medicine have thru laymen and not Thomas A. Edison's length of my doctors." Sreatphi ri..«T»r.r, with __ required to reduce the wave i*mr.r .1 rtyliin-apayooi ebon to the Dr. A. B. llirsh traced the history of of record", too, for only f 1. Pay the oscillating system so as to conform balance at rate of only a f rw cenU a day. Try thi» New Ediv*» declared that in your own borne brfore son decile to buy. Band do money Governments 200 meter wave length regu- electro-therapeutics, and an down. Bate-uun your friends with your favorite record*. lation? What formula do you employ in astonishingly large number of diseases re- °"' ?'" Write Today r°', ™"\*Z?iJv2. k'25 this sponded to electric treatment. pJctur<-B of the N'W E*li*oo phonoffrapba. No obliraUooa. determininj capacity? -, ». K. BABSON, I-Mvo* l*honoQTaph Dftributura *7*4 Zanon B'orh. IIHftol. A. 2. The required formula is Ch.cito, ; X C Q. 1. What does a "tone" circuit con- - sist of is it a radio Ci = — — ; and how connected to 3552 L C — K transmitter? Never Mind How STRONG Where A. 1. A tone circuit consists of nothing You are — G is the capacity of the series ground more than an oscillatory circuit shunted condenser for reducing the wave across the gap. This circuit is shown here What d'ye Know? length and it is only used in an impulse exciting X, = wave length desired (here it is 200 transmitter usually. The tone circuit i^ meters) represented by the oscillatory circuit L G. C = Capacity of the antenna A large capacity and a small inductance is L = Inductance of antenna used. Having calculated the values of the capa- Q. 2. Is this circuit tunable? If so, city of the antenna .0004 mfd.; inductance how? 62,090 cm., we then determine the desired A. 2. The tone circuit is tuned to some capacity by substituting in the above for- multiple or sub-multiple of the impulse mula and we get frequency. This is usually accomplished (200) : X .0004 by varying the tone circuit condenser capa- d = ; city. It should be kept in mind, that a 3552 X 62090 X .0004— (200) 2 tone circuit does not improve the tone Solving, we get .003 micro-farad, the emitted by the transmitter in every type capacity of the condenser necessary to re- of gap, as it was found by actual experi- duce the wave length of the antenna to 200 ment that at times it is even detrimental meters. to the tone. They are usually employed Today it's a battle of wits—and braim on low tension arc or spark transmitters ivin. Muscle and brawn don't count so ELECTRON DISCHARGE. such as the Yon Lepel or Chaffee Arc. (790.) Louis Bradenburg, Little Rock, much as they used to. Ark., wants to know The great question now is "What do you know ?" It draws the line between Q. 1. Does the effect of light upon failure and selenium crystal produce a purely electronic El success. discharge? What do you know? Have you special ability in any one line? Could you A. 1. This question is still in the hands "make good" in a big job right now? of some prominent physicists, and they have > For 25 years the International Corre- not come to any conclusions on this mys- < spondence Schools have been helping men terious problem, and for this reason we are i iWiT llf? to get ready for better work and bigger unable to give you an exact answer. We \\C OJ. salaries. They can do the same for YOU. should recommend, however, that you read Transformer L 6~ No matter where you live, what hours an article on selenium in this issue, written @ O -73/ you work, or how little your education by two of the most prominent" and able —the I. C. S. can train you for a more scientists on this subject. Arrangement of Tone Circuit in the Von important and better-paying position. 2. I have had an idea for a number Lepel Chaffee Radio Transmitter. Q. and Arc Mark and mail the attached coupon of years to make an electronic detector for it won't obligate you in the least — converting high frequency currents to it won't cost you anything to find out pulsating currents, or in other MAGNETIC TELEPHONE. direct or this salary-raising (792.) William Olsen, L. I., how you can get words an instrument similar to the Fleming Jamaica, ability right in your own home, during Forest Audion. what desires to know : Valve and de Now your spare time. Q. 1. What is the principle upon which I desire to know is, what chemical will pro- two ordinary telephone receivers when MARK THE COUPON NOW duce an electronic field sufficiently strong TEAR OUT HERE* connected together can transmit the human for producing the same effect as that of the H.INTERNATIONAL CORRESPONDENCE SCHOOLS voice from one place to another by talk- lighted filament? Also, was there any such BOX 5347, SCRANTON. PA. ing to the diafram of either of the device ever made? two Explain. without obligating me, how 1 can qualify for receivers? the position, or in the ub ect, hefort which I mark X. A. 2. Dr. J. A, Fleming, the inventor of p r I.M 1Kb II r NGfJKKB SALESMANSHIP A. 1. principle the Fleming Valve, has built electronic The of operation of Electric Lighting B ADVERTISING Electric Railways ' Window Trimmer such a telephone is identical to the pro- Q tubes employing an exhausted vessel in Electric Wiring _ Show Card Writer duction of electric current by a dynamo- Telegraph Engineer i. Sign Painter which an amalgam of Sodium and Potas- Telephone Work _ KjilrojJ Trainman electric machine, in that magnetic II when a II 1 sium was placed in such a manner that it H Hi Ml.41 r M. INFER I sTRATLNG field is permitted to be interrupted by a Mechanical Draftsman Cartooning produced an electronic field when a beam Machine Shop Practice BOOKKEEPER wire near its field, a current of electricity Gas Engine Operating EStmograpber sod TVplst of light was focussed upon its surface and CIVIL I.M.1M I K Cert. Pub. Accountant is produced in that wire and the intensity in addition a secondary plate was placed Surveying and Mapping i TRAFFIC MANAGER. " MDB FORI M\ hk (HICK 12 Railway Accountant within the focus of the electronic stream. the generated current is dependent upon J Metallurgist or ProqurtOT H Commercial Law the rapidity with which the magnetic field STATloViUY BH61NEBR GOOD ENGLISH The secondary and sodium-potassium plates Marine Engineer Teacher is interrupted and the intensity of the field. C were used for the rectifier circuit of the "ARCHITECT Common SVhool Subjects

It is identical i Contractor and Builder Mathematics electronic tube. with the magnetic telephone Architectural I (raftsman CIVIL SERVICE where the permanent of the re- C magnet ! The two most generally used of all the Concrete Builder rZ Railway Mail Clerk Structural Engineer At TOMOHII.t. OFOU1IN ceiver furnishes the magnetic field, the coil - metals and alloys for the production of an PLUMBIRfl AMi Hr A TING Aato Repairing IL_>!»»oUtaI '_'v of wire or electro-magnet represents the Sheet Metal Worker M Navigation I i.-fB«n electronic field are chemically pure ^™ . CUII II Tl-D and Teitllfl Overwer or Sopt. AC.KIU I.TIRE W^ Frrnc wire, while the interruption the _J highly polished rubidium metal and an alloy of mag- Hit MIST jPoaltrjR&Ulac |„ Italia* composed equally of sodium and potassium netic field is obtained in this case by the vibration of the magnetic diafram. When Name. metals. . Present the diafram of the receiver is caused to Occupation TONE CIRCUIT. vibrate by "talking," the magnetic flux is Street (791.) Roy Jansen, Houston, Tex., varied an. I No ; generating a current in the coil a^ks which operated the distant receiver. City_

Yon benefit by mentioning "The Electrical Experimenter" when writing to advertisers. 138 THE ELECTRICAL EXPERIMENTER h 1917 HIGH FREQUENCY PHENOMENA. (793.) S. Kohn, Brooklyn, N. Y., asks: Q. 1. Can you explain the following phenomena which I recently observed dur- ELECTRICflLEXPERIMENTERS DEMAND ing certain experiments which I have carried on with a Tesla high frequency coil? A large primary of a loose coupler was

located near the Tesla coil ; this was about r , 3 feet away from the same, and it was G0LDSEAL not to anything. the Tesla connected As transformer was set in operation, I have FOR STRENGTH / / noticed streaks of sparks escaping the winding of the isolated coil. If it is possible, I should like you to enlighten me Jf-SfT on this phenomena. A. 1. The phenomena which you have observed is due to the striking resonance effect existing between the Tesla coil and FOR the primary coil ; since the resonance was pronounced, due to the effect noticed, the- :•

f : • wants to know POWER Q. 1. In the design of a radio transformer, what are the most important pre- MANUFACTURED BV cautions that must be taken in order to THIS BATTERY MAS WONDERFUL THE GOLD SEAL BATTERY CO. build an efficient transformer? RECUPERATING A. 1. There are a few important steps NEW YORK CITY that the designer must observe when de- . POWER t signing a transformer, namely: the voltage transformation between the primary and secondary, the latter should be made to correspond with the proper sending condenser capacity, and this must be obtained

beforehand ; the proper arrangement of secondary pies, separated with proper in- Save Dictating Time sulation, and finally, the magnetic circuit DICTAFORM in which great care must be exercised in USE THE designing the same, as 75 per cent of the more stenog- 1 f you are at present keeping one or efficiency will be in this magnetic circuit. raphers busy—you need the Dictaform. It will The proper number of cubic inches of core mean the saving of valuable time in the handling is at first found : this is then split up into letters of your correspondence. Surprisingly few suitable form, the legs of which should Dictaform enables require special dictation. The correspond to the primary and of the sec- you to build a letter-writting system to fit your ondary windings. own business, and gives you stronger, more force- Q. 2. What is the relation existing ful letters. SOME USERS between the primary winding and voltage Carson Pirie & Scott Bryant & Stratton of a transformer? Addressograph Co. Henry Bosch Co. relation the factors Wm. J. Wrigley, Jr. Link Belt Co. A. 2. The of two is Kunstadter Bros. Royal Tailors exprest by the following formula: Commonwealth Edison Co. 10s X £p Banish Dictating Bother A/p = The Dictaform places at instant reference paragraphs, phrases and arguments sparkling with \2tt the fBAc your own individuality. You think out your strongest answers to a question, classifying Where argument under its proper heading, and put it into the Dictaform. Through continuous use of these prearranged paragraphs and letters you will be able to get out, at a fraction of the former Np = Number of turns on primary wind- cost, ten times the volume of correspondence possible if each letter was dictated separately. ing A Score of Other Features Ep = Voltage across primary It makes an ideal tickler—on the back of the first thirty-one cards is our patent clip for the f = Frequency. weights, holding of memos., etc. The DICTAFORM also places before you your prices; sizes, B = Magnetic flux of core (per sq. cm. descriptions, ideas, campaign schedules, proofs of cuts, cost estimates, time tables, lists, of cross-section of the iron core) addresses, phone numbers— in fact everything to which you have occasion to refer. ,4c = Area (express in square centime- Business Buy the Size that Fits Your ters of the cross-section of the With sizes at $6.00 and $9.00 for small companies—at $12 for the average DICTAFORM iron core) concern—and larger sizes at higher prices for bigger offices—every business is enabled to select the size best adapted to its needs. Q. 3. What do you consider the best CALCULATOR COMPANY insulation material for covering the core MEILICKE when the winding is to be made? 420 Thompson Building CHICAGO. ILL. A. 3. Empire cloth is very excellent for this work and it is universally employed for this purpose. A GENUINE "RED DEVIL" GLASS CUTTER FOR 10c THE "BROWN" TELEPHONE FOR THE ELECTRICAL EXPERIMENTER'S TOOL KIT RELAY. The il tool for making and repairing glass }ed B*TJlL&24^ ' plates for wireless condensers. Also a handy household (79S.) Frank Vontair, Philadelphia,

tool for repairing picture frames, window-panes, etc. Pa., de-sires to know : uun Write for free Glass Cutler Booklet. Q. 1. Is the "Brown" relay, which is England, a microphone device? Smith & Hemenway Co., Inc., 107 Chambers St., New York City used in A. 1. This type of instrument is a

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June, 1917 THE ELECTRICAL EXPERIMENTER 139

purely microphonic device and the microphone is controlled by a super-sensitive book review Be a Doctor of telephone relay. A more complete detail Oj of this device was published in the Au- Chiropractic gust, 1915, issue of this journal. Lessons FREE

The Submarine Torpedo Boat. By Allen ;The»el,.,.,k..t. II ; (^ Hoar. Cloth covers; size 8x5$^ inches; is wit celt'-) ffiM.nd.bi iruE cured nl lone ^Of) ^-, rBig Opportunity for Ambitious ' plates. Price, $2.00. Publisht by L>. Van - Men and Women. Resident and Home Study .: .: Courtti. |j.r K i Xostrand Co., /' I6.C New York City, 1916. Easy payment.. tit !• I We you requirement*. V K FREE ! Elbert Hubbard'.' Boe*. "The New Seier.ee."' Mail petal, or ith- valuSDle fet One most ana popular treatments •J! nve book. I I of this all important subject whii h is at the pres- National School of Chiropractic Dept fc-1 ! 421 S. Ashland Blvd., CHICAGO ent time "i interest '" readers of all cla ^ «T Unlike a great mi.ui> b tis nature >U-aling with -such a specific and technical subject a Brownmreloy submarine torpedo boat, Mr. Hoar has given us a well-written and lucid description TransfAoord of this mar a 7ss velous twentieth century war machine. The en-

gineer and layman will both prol g tbi Connection of the "Brown" Amplifying Relay interesting chapters of this authoritative writer, In the Circuit of a Radio Receptor. who is a junior member or the American Society of Civil Engineers. The various chapters take up the early history and development of the submarine Q. 2. What is the binding post connec- torpedo boat, and contain some very interesting illustrations and photographs tions of this relay? How is it connected of practically every distinct type of submarine ever built. The suc- to a wireless receiving set? ceeding chapters deal with the development of the A. 2. The accompanying diagram gives present day submarine; its characteristics and re- the connections. quirements; types of sul. marines; the design of the submarine torpedo boat; the power plant; Q. 3. Are these instruments used ex- means of defense against submarine attack; tacti tensively in this country? cal evolutions of the submarine ; the torpedo; A. 3. No, they are mostly used abroad, tenders and salvage ships; submarine mines, etc. Some of the most interesting sections especially in England. of I be book deal with the approved manner of maneuvering a submarine in order to torpedo an enemy vessel, and also discuss authoritatively the various MERCURY RECTIFIER. technical aspects developing in the general opera- (796.) Thomas Pierson, Richmond, Va., tion and handling of the submarine torpedo boat. wants to know Q. 1. What is the efficiency of a mercury arc rectifier? American Boy's Book of Electricity. By A. 1. The efficiency of this device varies Charles H. Seaver. Cloth covers ; size with circumstances and depends largely Big Money in Electricity upon the load voltage. There is a cer- 8x6 inches; 366 pages, 313 illustrations. tain drop or lost voltage in the tube, Price, $1.50 net. Publisht by David Mc- The electrical industries offer wonderful usually IS to 25 volts, which is practi- Kay, Philadelphia, Pa. opportunities to boys with a liking for Elec- cally independent of the load and the en- tricity. The salaries paid to trained men are ergy thus represented appears as light and The American boy is always interested in a large, promotion comes rapidly and, best of good book treating on electrical experiments of a heat. So if a set was delivering current all, the work is fascinating. practical and interesting nature. There have been at a potential of 15 to 25 volts, its effi- a great many books written in the past few The discovery and development of new years, intended for ciency under these conditions would be, the electrically inclined youths lines (such as wireless telegraphy and tele- of the land, but we do not remember seeing a roughly speaking, about 50 per cent. But phony), from time to time, promise attractive more worthy volume in a long time than here this is rarely the case, and in most com- pit sent ed by Mr. Seaver. The volume is pro- and paying fields to those who wish to mercial installations of constant potential fusely illustrated with clear-cut drawings, which specialize. The txAll to Jo and Special Train- can readily by sets, the full-load efficiency is over 80 per be understood young boys of from ing will bring success to you. ten to fourteen years, and all of the important cent and the efficiency of most constant fundamental magnetic and electrical laws with The International Correspondence Schools current sets will be over 90 per cent at their accompanying actions and reactions have can help you to become an expert in electrical been cleverly and interestingly full load. woven thru the work, no matter what branch you like best. experiments outlined. Q. 2. What is the life of a mercury Thousands of young men have already won A number of excellent half-tone illustrations are rectifier tube? success through I. C. S. help. You can do inserted, showing modern electrical appliances, so A 2. The average life is about 700 you try. Everything is that as the boy studies the different experiments as well as anybody, if hours, but many cases are known where and simply explained laws, he will also be given made so clear that you can learn in your the tubes have run much longer. a clear understanding of the relation between spare time, regardless of where you live or such experimental apparatus and the commercial Q. 3. What is the power-factor of such what your work. No books to buy. instruments and appliances. Mr. Seaver is to be a rectifying system? congratulated upon the adapt ness with which he There's big money in Electricity. Get A. 3. a 50 light set the power-fac- has combined these two important fields of elec- On after it by marking and mailing the Coupon trical endeavor, so that the young reader will tor on the primary of the constant current today. Finding out coits you nothing. not become confused or discouraged by his in- is 65 per cent. transformer about On con- ability to understand the underlying theory of the 1 TEAR OUT HERE stant potential systems it may reach as apparatus described. high as 90 per cent. nINTERNATIONAL CORRESPONDENCE SCHOOLS The book describes how to build substantial ex- Box 5 3 4 PA. perimental apparatus such as small dynamos and 8, SCRANTON, motors; induction or spark coils; telephone and Explain, without obligating me, how I can qualify for the position, or in tne subject, before which I mark X. MEASUREMENT OF IRREGULAR telegraph apparatus; a complete wireless station AREA. of improved design; how to do simple house wir- ELECTRICAL ENGINEER • III Ml* IL 1 M.lM I R F Electrician SALESM \NSHIP ing in accordance with the standard rules; how (797.) Paul Andel, New Orleans, La., P Electric Wiring ADVER nSING MAN to* wire ignition circuits on gasoline engines of L Electric Lighting ' Window "1 rimmer asks the single and multiple cylinder type; how to L Electric Car Running Show Card Writer Electric Traction Outdoor Sign Painter 1. What are the principal methods build small transformers and the principles upon f_ Heavy Q. Electrical Draftsman ' RAILROAD! R which they operate; how to build primary and !>.->. for determining the area of an irregular Ehctrlc Blnrhlni- k-...-r ; ILLUSTRATOR storage batteries; the action of lightning discharges Telegraph I Dl SICN1 K plane surface such as those obtained from how Xpert and to protect buildings from them, and also !_ Practical Telephony ) BOOKKH 1TR indicator cards, etc.? a considerable number of electrical experiments L_ MM IUM< tl l-M.IM- I IE Ktenoerapher and Trplit Mechanical Draftsman Cert. Pub. Accountant in static electricity. strongly recommend this D A. 1. There are three general methods We Machine Shop Practice Ruilv, i\ Accountant book to the American boy. Law for obtaining the area value irregtdar SGas Engineer I Commercial of I Nil OTt IL ENGINEER | GOOD Ml plane surfaces and the simplest of the three Surveying and Mapping I ..mm tin Sttim.l BnbJ-wta MNI TORI *** "» KN«*R CIVIL Sr RVICE is by employing a "planimeter" instrument, ; Matl ] Mi'tnllnrcUt ur Prow BtOf Railway Clerk EXAMPLl S IN \i rERNATING 1*1. -CURRENTS. I I, >>• " ft a device which automatically figures out STATION! R1 1 M.lM B (tilt mci ARCHITECT n.lth II rURSC Bpaabfe of the plane in question. Stub Vol. 1, Second Edition. By Prof. F. E. ti-flilirt-ti.ri.1 Itraftiman \ i\ Igatot the area j ' PLUHBI1U. *M» HI iTINfl Ponltrj Hiil.lnf an instrument consists of a wheel of defi- Austin. U.S., [ E.E. Flexible green leather .1 UlUnUrlrllf-l Worker i | Sheet Metal nite circumference, which revolves when covers, pocket style; size "' _.\5 inches; the lever attached to this wheel is caused 224 pages, 75 illustrations with numerous to trace the perimeter of the irregular Present surface. tables. Price, $2.40. Publisht bv the Occupation- Street second method is by forming a large Author at i fanover, \. I [, A ami No small within the number of squares The second edition of this valuable tr (Continued on page l-ioi of alternating-currents contains a number of ad- Clty_

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EXPERIMENTER June, 1917 140 THE ELECTRICAL

to give illuminating details that the ditions and revisions, and will be found extremely ceeds many average physics student will find both new and valuable to ail students of this subject. Some ot the more practical examples given in alternating- interesting. tuning fork and siren current calculations involve frequency, power fac- Every conceivable form of sounds of any pitch or frequency tor, harmonics, induced A.C. pressures, and tne for producing and described. Among various specific values of A.C. potential, such as is profusely illustrated the subjects discust in a popular scientific manner, the instantaneous and effective values, etc., etc. it by the lay reader as Many practical problems are explained by means so that may be enjoyed pure physics, are the action of examples, and in accordance with the best well as the student of modern methods, covering such topics as the ad- of organ pipes uncluding illustration of an organ length and giving sixteen dition of sine pressures; the product of sine pipe over 32 feet in curves having the same frequency but different vibrations per second,), and such further prac- phase displacements; the calculation and measure- tical considerations as standard tuning forks; the and ment of inductance coils, including the simple law of tone quality; the manometric capsule measurements of this important factor by means revolving mirror, and also the use of the phono- invention, the volt meter, ammeter and frequency meter, graph and Professor Miller's own of a become and including the new inductance formula due to "Phonodeik," by which apparatus it has Brooks and Turner. Further sections of the work possible to intercept a sound wave such as_ a these, magnified treat on the inductance of transmission lines and person's voice, and to project screen so that the various, current and voltage relations, etc.. when many hundred times, upon a body two or more impedances are connected in series voice fluctuations can be studied by a large phonodeik is so remarkably sen- or in parallel. Also the method of computing of students. The it will respond to a capacity of condensers, and the current taken by sitive to sound waves, that them when connected to A.C. circuits. The work frequency of ten thousand complete vibrations per concludes with a number of valuable tables con- second. taining the products of 2 x pi x frequency, and The subject of harmonics has received special modifications of this expression, which are used so attention, and considerable discussion is given on frequently in alternating-current computations. the different types of harmonic analyzers, including the remarkable machine as used by the U.S. government for predicting the rise and fall of tides. Among other interesting subjects covered How To Make Low Pressure Transform- in this book, we find oscillogram curves of the ers. Third Edition, by Prof. F. E. Aus- voices of such famous singers as Signor Caruso and Amato. Also such an interesting subject as tin, B.S., E.E. Board covers; size the influence of horns on sound, and the import- It the Time Wasted ? illustrations. Saves 7 ,x4 ^ inches; 22 pages. 16 ance of diaframs in certain instruments. The By Your Employees In Price 40 cents. Publisht by the author principle of musical instruments, such as the flute and violin are discust, and the music at Hanover, X.H. piano, Answering Unnecessary shown grafically by means of produced by them _ Telephone Calls Another addition of Prof. Austin's treatise on oscillogram curves. One of the most interesting the design and construction of small, low-pressure chapters is that treating on synthetic vowels and favor. is not possible to measure the en- transformers which has found considerable words, and the relation of the art and science of operations ITtire cost of interior telephones by The work takes up numerous practical music which is illustrated by many remarkable the cost of the service alone. Rather, to be followed in constructing step-down trans- cuts of apparatus which have been developt for your telephone expense must also be formers for ringing bells, and for other opera- emitting vowel sounds. giving measured in terms of the per minute tions, and also a design for a transformer A remarkable illustration is that showing the system. time cost of employees using the as high as 174 volts when run on a 110 volt A.C. large group of organ pipes necessary, which -.vhen interior tele- In other words, your circuit. Data is given for these transformers for sounded simultaneously reproduce the vowel a, as economy only phone system is a business use also on 220 volts. 60 cycle A.C. circuit. The in "mat," and stilt another illustration shows the bridges the gap be- which when it directly text matter is written in a clear manner vast number of organ pipes required to reproduce parties tween the two vitally interested can be followed by any amateur and the illustra- the principal vowels synthetically. becomes exactly the to the call, and it tions are made in perspective so as to show ex- it is engaged in man- reverse when plicitly just how the various iron core strips are bv the dragnet process com- hunting — assembled and clamped together, and also how the pelling employees in perhaps every QUESTION BOX coil windings may be wound in sections to sim- department to use up the precious plify the construction. (Continued from page 139) minutes you are paying for, all for the purpose of responding to a useless tele- boundary of the plane surface, and deter- phone call. mining the area of one of these squares, The money saving answer to this Practical Men. the area of each by the problem is "Don't use the telephone at Applied Electricity For then multiplying Allow it to be used Cloth surface. all to hunt men." By Prof. Arthur J. Rowland. total number of them within the the man has been found by only after covers; size 5x7!^ inches, 375 pages. 323 This will give an approximate area, since the aid of the National Calling System, which summons him instantly, no matter illustrations. Price, $2.00. Publisht by it is impossible to erect squares close where he may be about your establish- the McGraw-Hill Book Co., New \ ork enough to the irregular curves of the ment or grounds. The man called then City. plane surface. goes to the nearest telephone and talks the man who sought him. The third and most accurate method is directly with This book has been prepared by an author of time is wasted, no one's work No one's wide experience in teaching practically and theo- by the use of higher mathematics : where is disturbed. he has in- retically the subject to students, and a limiting value of the maximum and min- The National Calling System is effi- matter pre- corporated manv valuable ideas in the sur- cient, moderate in price and a positive prove ex- imum peaks of the perimeter of the sented. We believe this work should money saver in small as well as large tremely valuable to electricians of all classes, as face is obtained by actual measurement, establishments. electrical principles it contains all the fundamental and substituting this value in an integral approved yet so.newhat Scud for Compute Information which are discust in an equation as used in the Calculus. Some and Descriptive Booklet .Yo. 33C. new manner, and gradually the student is intro- operating engineers weigh a sq. cm., or inch of the duced to the principles and practical SCALE COMPANY of dynamos; motors; electric heating ap- chart paper and then, by a simple calcula- NATIONAL features power (ELECTRICAL DIVISION) paratus; the wiring of switchboards and the area of the irregular system: tion, compute plants; principles of the electric trolley Falls, Mass. surface. 6 Rapids Street, Chicopee alternating-current systems, including the various transformers, and just how of National tvpes of commercial Also Manufacturers current prin- Machines and National- they operate and why; poly-phase Counting storage bat- BRIDGE CIRCUIT. Chapman Elevating Trucks ciples; alternating-current motors; WHEATSTONE and wires and wiring. teries: electric circuits (798.) John Brown, San Diego, Cal., Unlike manv volumes of this nature, the author subject in wishes to know fit not onlv explain each For Factories, has seen to simple language at the start, but also to give the Commercial theory and Establishments, elementary formulas governing the electrical apparatus and Hospitals, Schools, operation 'of these various student will find Public Buildings, circuits The general electrical enhance thfi Construction Jobs, this work of distinct value, and to there are a Docks, Ships, etc. value of each lesson he has studied, number of questions and problems given at the end of each chapter which the student can work out. IMR.SMITH By CODE NUMBER 32 The Science or Musical Sounds. Prof. Davton Clarence Miller. D.Sc. I Cloth covers: size S-ux6 inches, pages 187 illustrations. Price. SZ.sO. ^ONE PuMisht by the MacMillan Co., New tanily finds York City. 1916. p-THREE Mr Smith in a remote part on the science ofthe establish- This work bv Prof. Miller treating pretentious i^PAUSE ment. He re- of musical sounds is one of the most I s im- reviewed. A p rta Kfe •u-ience works that we have ever mediately over analyzing appa- [JONE vast array of sound producing and the nearest structure telephone. ratus of hoth simnle and complicated frwo matter is are described and illustrated. The text readily understood exceedingly clear, and can be in a author How a Reversing Key Is Connected bv any student of music or physics. The Bridge. and pro- Wheatstone starts off with the definition of sound, advertisers. Experimenter" when uriting to You benefit by mentioning "The Electrical : ! — —. —

June, 1917 THE ELECTRICAL EXPERIMENTER 141

Q. 1. How arc the connections made of a Post Offii e ti i"' of V\ h< atstone bridi i so that the resistance arms are reversed in the circuit? I understand tins arrangement is used in eliminating errors in measurements which may be due to polarity interferences acted upon the galvanomi A. 1. The diagram herewith gives the proper connections of the instrument you mention. The reason for reversing the connections of resistance arms is to eliminate the errors produced by cross-cur- QODPEDIA CYCLOPEDIA O'CLOPEDM aCLOPHMA CYCLOPEDIA CYCLOPEDIA CYCLOPEDU

rents in the circuit. By obtaining two sets (/ • if if^^^^if vf if of for both reversed positions of of readings APPLIED! APPLIED / pijjjj^|n^ APPLIED APPLIED the arms, such errors are limited to a f| minimum. ELECTRlCmf ELECTRICITY P ALUMINUM QUERIES. (799.) Joseph Hassel, Boston, Mass., asks Q. 1. What are the ores used in the production of commercial aluminum? A. 1. Aluminum oxro is the main source out of which aluminum is extracted. Baux- ite, a hydrated oxid of aluminum, is ex- tensively Used Q. 2. How is the metallic aluminum obtained? A. 2. The only process used at present for the extraction of aluminum is an electrolytic one. The electrolyte consists of a solution of aluminum oxid in melted cryolite. The cryolite is not decomposed, but selves as B solvent only. The mineral Bauxite is used to furnish the oxid. The cryolite is fused and kept liquid by the heat generated during the passage of the SEND NO MONEY current; the dissolved aluminum oxid is USE THESE ELECTRICAL BOOKS SEVEN DAYS separated into aluminum and oxygen by the current. The aluminum collects as a AT OUR EXPENSE melting molten mass in the bottom of the By merely filling in and mailing the coupon below you can get this complete set of the is liberated at the anodes, pot ; the oxygen Cyclopedia of Applied Electricity on trial. Use these books for seven full days before which are oxydized by it. The weight of you make up your mind whether or not you want them. If you keep them, you may equals the the anodes consumed about pay the special advertising price in easy installments of i?2.<)(> a mouth. If you don't weight of the aluminum liberated. 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. TELEVISION. A MASSIVE ELECTRICAL LIBRARY— NOT HANDBOOKS Jelinder, Hartford, C800.) Thomas These seven splendid volumes contain all the knowledge you need in order to earn big Conn., asks: money in the electrical field. They are not thin handbooks, but thick, encyclopedia- brought a Q. 1. Was television ever to size volumes, handsomely bound in half red morocco leather, gold stamped. Each practical stage? one measures 7 by 10 inches, and is 2 inches thick. A. 1. No. This big size permits the use of large and comprehensive illustrations, plates, dia- Q. 2. What method did Mr. Ernest grams, etc. Over 3,000 cuts are contained in the Cyclopedia's 3,500 pages, Ruhmer of Berlin use for his television Cyclopedia will he a revelation to apparatus? The completeness of the Read These Subjects you. Everything electrical is explained in plain, simple A. 2. He employed a large number of Elements of Eleclricttv English—every technical point is made clear. Each volume Electrical Measurements selenium cells placed before a similar num- — UnderuTiii rs' Require is carefully cross-indexed for instant reference. ments ber of lenses. Each of these cells corre- —Theory. Calcula- tion. Design and Con - sponded to a "single eye," similar to the For this sum—an insignificant slructinn of Generator* and Motors — Pynamo- human eye, and the reflection of light from 50c a Week one — this wealth of electrical Electric Machinery— Lighting Machinery the object, the image of which was to be information is yours. But you don't have to send us a penny 1* n w e j Transmission transmitted, was caused to fall upon the until you have used the books for seven days. Then, if you Electric Railway.*— Power Stations - cells. The?e cells were only $2.00 a month — Switchboards various selenium decide to keep them, send 50c a week tin! s» itching — Storage connected to a corresponding number of until the special advertising price of $19.80 has been paid. Batteries Applied Elec- tro-chemistry — Electric electro-magnets which controlled a num- The regular price of these pay-raising books is $35.00. Elevators Elect io u e I ber of diaframs. These diaframs were set int; and Heating Wire and Wireless Telegraphy. in operation in unison with their proper Consulting Service Free selenium cells at the transmitting station. A year's Consulting Membership in the American Technical rectangular image was possible with this A Society —regular price $12.00— will lie included with all or- It was used transmit let- American Technical arrangement. fo for a limited time. The advice of an entire corps of Society ders * Dept. E-744-A Chicago. ters, as it was imperfect enough to be used U.S.A. elect ried experts is yours to help you in your progress to differentiate the actual colors of a pho- for a whole year FREE Please send me the Cyelonedia tograph or image of a human countenance. *t of Applied Electricity for seven » A number of suggestions have been Money—Just the Coupon / days' free examination. If I de Send No • ctde to buy, I will send you $2.00 made to develop a television scheme, but See these hooks for yourself before you buy. Remem- * in seven days, and the balance at the inventors only went as far as making * the rate of $2.00 a month, until ber, you don't risk a penny or assume a single ob- 9 suggestions, but never went into the $19.80 has been paid. Then you will ligation. The books will be sent by prepaid express * send me a receipt showing that the trouble of bringing out their ideas experi- * and Die to any one within the boundaries of the United set of books $12.00 consulting mentally. membership are mine and fully paid <"' Canada, and they may be returned' at , States foi It 1 think that I can get along our expense if they fail to please. Butyommust / without the hooks. I will return them after if your expense. TRANS-PACTFIC RADIO COMMU- act now! This generous offer cannot be con- ' NICATION SUSPENDED. tinned indefinitely. Send the coupon now. J tfatne - Wireless communication to Hawaiian AMERICAN TECHNICAL SOCIETY beyond Honolulu has been sus- territory Dept. E-744-A CHICAGO, U.S. A. Address. pended. Messages to other islands will be mailed from Honolulu. J Reference

to adtertiscrs. Veti benefit by mentioning "The I rperimenter" when writing .

142 THE ELECTRICAL EXPERIMENTER June, 1917 CHANCES FOR ELECTRICIANS IN THE NAVY. MIGNON UNDAMPED WAVE (Continued from page 86) reciprocating steam engines, steam turbines, internal-combustion engines, magnetism and : WIRELESS electricity, dynamos, motors, motor-gener- A a, 1 ators, alternating currents, interior commu- ' * nication, lighting, batteries, etc. Members of X ' ^^ 1 APPARATUS the radio class are trained in all the duties 9 of a radio operator and are given constant Amateur and Commercial Use practice in the use of all the apparatus employed in radio and especially in receiving and sending by the systems employed in This latest Mignon invention is entering a new- the Navy. field in Radio Engineering, eliminating the so Enlistments in the Navy are for a period and LOAD- of four years. A man will not be ad- familiar LOOSE COUPLERS vanced to chief electrician (with rank of ING COILS, and introduces adjustable DISC 'chief petty officer) during his first enlistment, but he may be recommended for that impossible. CORES, heretofore considered position towards the completion of his first DISTANCE RANGE UNLIMITED. enlistment, with a view to advancement upon re-enlistment if any vacancy exists. Mignon Wireless Corporation NEW METHOD OF MEASURING PRESSURE OF LIGHT. ELMIRA, N. Y., U. S. A (Continued from page 102) Write Catalogue and mention Electrical Experimenter for The 32 c.p. lamp was enclosed in a metal box whose front face had been replaced by a glass screen covered with a few thin

wires. Inasmuch as it is required that the radiation should be normally incident, the MULTI-AUDI-FONE lamp was not brought too close to the tube, a calculation of the limiting approach having been previously made. The current SPECIAL NOTICE passing thru the lamp was maintained at the same value thruout all the experiments. We have just placed on the Multi-Audi-Fone .... $18.00 The reflecting and transmitting powers of market a new loose coupler the foils used were then tested. Gold and Two Step M. A. F. . . . 75.00 built of mahogany with all aluminum reflected 90 per cent of incident Short Wave Regenera - metal parts highly polished radiation.

tive Attachment . . . 22.50 nickel plate. Calculation of the Deflection of the Strip.

Multi-Form Receiver . 100.00 —Since the foil reflects 90 per cent of the New in design and wonder- 35.00 incident radiation, and since 7 per cent is ful in efficiency. reflected from the glass of the tube, the Fixed Condenser .... 1.00 Made in two sizes. total pressure of the radiation is given by

M. A. F. Detector. .. . 3.00 Type "AD" 150 to 3000 Meters $6.50 £(1+0-07x0-9) (1+0-9) or2-04£, Type "AU" 4000 to 15000 Meters $12.00 M. A. F. Loading Coil. 2.00 where £ is the energy density of the incident beam. A certain amount of radiation, however, MULTI-AUDI-FONE strikes the back of the glass tube, and some of this is reflected to the back of the strip. 275 Morris Ave. Elizabeth, N. J. For a strip three-quarters the width of the tube it is estimated that the normal compo- Send 2c for Circular nent of this radiation is about 1 per cent of

all that is incident on the strip. It is, therefore, necessary to substitute 2.02£ for 2.04£. It can be shown that a uniform flexibig i^, New Undamped Wave Coupler No. 749 strip when deflected by a small uniform pressure still remains straight. To a close Special Introductory Price, $18.00 degree of approximation, therefore, we may Our new coupler No. 749 Is 32* long, 9* wide, and calculate the deflection of a strip such as 10* high, overall, and on an average-sized Antenna tunes to 15,000 meters. This coupler, used with the that represented in Fig. 1 by taking mo- new CHAMBERS" SYSTEM or CIR- ments about the axis of rotation. The de- CUIT, will bring In signals from domestic and foreign Arc Stations surprisingly tails of apparatus used are given in the and difference In loud clear. Note the original paper, as well as the thermo-kinev- size of our No. 748 and No. 749. We claim to be the original Inventors of ic reaction and a table of results observed aSYSTEM or CIRCUIT for the reception of the undamped waves without the in succession. use of Loading Coils or Oscillating Colls, as they are sometimes called: as with our SYSTEM or CIRCUIT only two Inductively ELECTROLYSIS SURVEY PRO- . Coils are necessary. Circuit supplied with each coopler. POSED IN MONTGOM- This CHAMFERS' CIRCUIT saves you money. of coupler only $18 0*1 Place order Think of itl No extra coils to pay for. and price ERY, ALA. now so as to be in on too introductory price. Orders filled in rotation. Send for descriptive matter. The Bureau of Standards has been asked to make an electrolysis survey in Mont- F. B. CHAMBERS & CO., 2046 Arch St., Phila., Pa. gomery, Ala

benefit by mentioning "The Electrical Experimenter" when writing to advertisers. ' '

June, 1917 THE ELECTRICAL EXPERIMENTER 143 DENVER WIRELESS STATION TEXAS

CUP. ' WINS PRIZE LOVING , l)allas RS I i I ontinued from page 1U7; R orlett, 5 ZC, Dallas

I TO I. L. Antrv, 3 ED, lou the K'"><1 times thej used to have whili 1 GREAT i . \\ G in, I'M. Austin working on the- several re-lays which we OPPORTUNITY! have run for their benefit. VIRGINIA Next month we will start by giving orai i St. and offer them DOW BELOW COST. It ' Ml gossip about the famous Washington's k. R happi II, 3 Richmond

( i , . Robinsi m, 3 St, Richmi md Birthday Relay, and also give the first in- From tuudllns, ire all for rol r. F. Wohford, .5 WF, Roam HO stallment of a complete set of instructions particulars may be liaii by applying W. T. Gravely, 3 l'< i Danville about how t" make a Ilall Wireless Rela . 3—UH.P. D. C, 110 voltf. each $19.00: list price. E. 3 TY, N'ewport New- $24.00. 3— B H.P.. D. C., HO volts, each $9.00: list as this instrument was shown in this ma J. Krone, price, $15.00. I— 2 H.P.. D. C. 110 volts, each $37.00: A. X. Johnson, 3 TY, Newport News list zine some time ago, under the list of pat price. $46.50. I— i I6H.P., 0. C. 110 volts, each $7.00: list price. $9.00. the issued ; ami as has received ents writer \VI ST VIRGINIA a great number of inquiries concerning it, Electro Importing Co- 1 . Law. Xo call, Clarksburg ur will all he interested J. believe that you V Z31 FultjnSt., Ntw YorLCily.N. Y. II. E. Burns, 8 U.I I, Martinsburg in reading about tins instrument, which is L00 very simple in construction, and which all WISCONSIN of you may make, with just such tools and II. I Crawford. 9 W'T. W'ausau material as is always at hand in a radio 4I4PAGES Ouinn, 9 ARD. Neenah laboratory. C. 1-4 ILLUSTRATIONS M. P. Hanson. 9 XM, Madison 5 The war will not last forever, Ama- E. II. Hartnell, 9 BV, Salem teurs. Now is the time to make efficient A. Rufsvold, 9 Marinette ADI, ELECTRICAL ENGINEERS instruments to be used after the war and O. R. Terry, 9 HQ, Stoughton HANDBOOK 50' to "brush up" on all Radio Matters. DO YOU TO RECHARGE THIS CELL—FILL ELECTRICITY! own a wireless station, either for WITH WATER. just the book on Bending or receiving? If you do, HERE'S don*t fail to join the greatest Wire- The "HsO" Cell, as it is termed by its Electricity that you need less Association in the country: OF English sponsors, was introduced to meet to answer your many ques- THE RADIO LEAGUE knotty AMERICA. If you believe in the tions—to solve your preparedness of your country, if you problems, to teach you new kinks, to tables, rules, help Uncle Sam, if you wish to have your station be your memory for wish to and officially recognized, join the LEAGUE, a national, formulas and other Electrical non-monev-making organization Beautiful engraved Mechanical facts that some people try and sealed certificate, FREE to all members. NO to carry in their heads—and fail. DUES OR FEES WHATSOEVER. With this "Little Giant" I. C. S. Elec- Honorary Members: W. H. G. BUL- trical Engineer's Handbook in your your work LARD, U. S. N.; PROF. REGINALD A. pocket, tool chest, on FOREST; bench, drawing table or desk, an hour FESSENDEN: DR. LEE DE or a day need not be lost "digging DR. NICOLA TESLA. up" some forgotten rule, some unfamiliar fact; Send stamp for large 8-page information booklet. you'll just turn to the very complete index and DO IT NOW. 233FULTON STREET, NEW YORK get it "in a jiffy." Just a few of the subjects treated are: Symbols: of List of "Perfect Score" Electricity and Magnetism; Electrical Continuation Batteries; Circuits; Magnets; Direct and Al- Stations in Trans-continental Amateur ternating Currents; Dynamos and Motors; Relay as publisht in the May number. Belts; Shafting; Electroplating; Electrical Measurements; Meters; Arc and Incandes- OHIO cent Lamps; Mercury Arc Rectifiers; Trans- formers; Insulation; Electric Cars; Single and D. Schellcnbach, 8 IF, Wyoming Multiple-Unit Control; Transmission; Rail R. A. Duerk, 8 AHI. Defiance Welding; Tablesof Wires— Sizes, Capacities, etc.,— Mathematical Rules, Formulas, Sym- i . Linxweiler, 8 LJ, Davton bols; Tables of Constants, Equivalents, Roots, (No Name), 8 ATG, Tiffin Powers, Reciprocals, Areas, Weights and C. Candler, 8 XH, St. Mary's Measures; Chemistry; Properties of Metals; Mechanics; First Aid, etc. L. Berman, 8 ML, Cincinnati Principles of Scott High School. 8 ZL. Toledo The Electrical Engineer's Handbook is one of 22 I. S. Handbooks covering 22 Technical. Scien- Merle Sager, 8 /.SW, Tiffin C. tific and Commercial subjects, all crowded with N. Thomas, 8 FX, Marietta value. They have the contents of a full-size book M. B. West, 8 AEZ, Lima condensed into pocket-size ready to go with you at your instant command. PL, Cincinnati anywhere and be I. F Eckel, 8 They are substantially bound in cloth, red edges, J. ( ). Hibbett, 1113, Ottawa goldleaf stamping, printed from new, clear, read- L. M. Clausing, 8 YL, Lima able type on good quality book paper. There is New English Type of Primary Cell an illustration at every point where a picture have OKLAHOMA Which Is Recharged by Simply Filling will help. Hundreds of thousands been guarantee of satisfaction. It With Water. It Is Known As the sold on a money-back A. & M. Steddon, 5 AB, Oklahoma City "H,.0" Cell. PENNSYLVANIA The regular price is$1.25,but foraLIMlTED TIME you can buy the ones you want, post- II. Carlisle only cents. T. Mapes, 3 AUC, the demand for a wet cell smaller and more paid, delivery guaranteed, for 50 Chris. M. Bowman, 3 PC, Lancaster compact than the "Leclanche," and in this I Mull Station. 8 IS, Bellefonte Run No Risk ! Money Back if Desired! School respect it appears to have gained its ad- You I.. II, City & Alexander, 8 ALE, Grove vantage. This cell may he stored for any International Correspondence Schools 1\. R. Goodwin, No call, Roulette length of time and in any climate without Box 5 3 4 9, Scran ton , Pa. \l. II, Mandelkern. 3 MR, Philadelphia any deterioration. It is not liable to creep- ______M .TEAR OUT Mtm . m _ __ . School. Pittsburgh Peabody High 8 YZ, ing or evaporation while in use. Its inter- \\ & S, S! RS, Vandergrift INTERNATIONAL CORRESPONDENCE SCHOOLS p, nal resistance is low, and it does not polar- 3 Reading Box 5349, SCRANTON, PA. F. J. Anderson, QD, ize in use so quickly as wet batteries of the F. II. Brian, Smithport for which send me postpaid the "Leclanche" type, it is claimed. I enclose $ Handbooks marked X, at 50c. each. I may return any or all C. II. Stewart, 3 ZS, St. David's The addition of water only is needed Eor and get my money back within ten days irom receipt:

hi I bo<.. 3 CT, Philadelphia charging, and its active life is equal to any Electrical Engin aA.K eraser*! '_ Bit-in. *> \1 iii's Karl E. llassel, Oper., 8 YI, Pittsburgh relapb.and I -J.tr- Luclu high-grade cell of similar size. If the cell is Met tunic's Bookki R, C. Clement, 8 VJT, Washington st, .mi 1 ngincer in. I t urr.-i|>ouilrtil'a required for instant use, it is recommended Wi-ttiiiKhou&e -' Salesman*! St. Joseph's College, 3 Xj, Philadelphia thai the cell be filled with warm water; dis- il Ei ec s u ladow Trimmer** .i Worker's i D Miners ^_ Cotton Textile being ;h RHODE ISLAND tilled water used, if possible, this i_ Concrete Engineer*! Farmer*

I (i.l. - niin'j T tends tn prolong the life of the cell bj Ituiiding tPoultn i > .mil 1 hi, i -. C. E. Davis, X o call. Edgew 1 El'linnli. Msrlner*! Automobile son of the absence of iron or lime impur- Chemist's i_ M. V. Pollys, lr., 1 EMG, Bristol ities, which are Frequently found in hydrant 11. W. Thornley, 1 AI. Pawtucket Name water. TENNESSEE In order that the condition of the zinc and No. S. II. Sheib, S CY, Nashville electrode and the interior parts of the cell Clty_ ' container R I lelahunt, 5 /.I), Memphis may be examined, the consists of

You benefit by me\ 'The Electrical Experitm i i writing to advertisers. ; ; : ; '

144 THE ELECTRICAL EXPERIMENTER June, 1917

a clear glass jar. A. ( See diagram.) Into the bottom of this jar some bitumen is poured while in a hot condition. This serves to fix the porcelain base, B, in position. This base forms the support for the sack, C, keeping it in a central position. and AMATEURS! also a support and spacer for the zinc cylinder, D, keeping it always the correct distance from the sack. It is this narrow space between the zinc and the sack which, MOW is the time to overhaul your set and to a large extent, the makes internal resist- to buy your apparatus at a low cost. ance of these cells so much less than Le- chanche batteries. The top of the sack has a rubber ring, E, round it in the last forever, order to Remember, War won't and further safeguard against the zinc cylinder when the ether is free once more for all, YOU touching the sack. Above the sack a specially shaped porcelain ring, F, is slipt over want to be the first one to listen in with a the carbon rod. G, and this serves as a support for a waxt cardboard disk, H, which REAL set. supports the sealing compound. Two holes are arranged in the sealing compound and

Besides, there is the possibility that the Govern- the cardboard washer ; in one of these is a fiber tube. This tube forms the funnel will allow to operate receiv- ment soon again us thru which the water is poured when the ing sets during the War. cell is required for use, and is normally sealed with a cork. The other hole con- ready ? tains a small glass tube to allow the gases Are you generated when the cell is in action to escape. A lead connection strip, is sol- Write for our printed matter. J, dered to the zinc cylinder, and this is brought up at the side of the cardboard AudioTron Sales Co., 315 Lick Bldg., San Francisco, Cal. washer and thru the sealing compound. This lead strip is provided with a punched hole to allow of connection to an adjacent

T * battery. A brass cap. K, is forced on to •: ; ; '•; ; ; ; ; ": •' n '-7 -• i. '.' •: j ; : v ; v ; •; vj. 7 : : J : : : 'K 7 ------2 - - - Tcr?T£^ c iii ji.^ 2M2 SS 2J the carbon rod, and the nut for wire connections screws on to a pin riveted and soldered, to the cap. The ammonium chlorid crystals, L, are placed in the cell at the time of manufacture: so that all that i- A Motor and a Re tor for $5.25 necessary to make the cell ready for use is to remove the cork, fill the cell with We have built 5000 of these outfitc, consisting of a motor water, and replace the cork. that will operate on a. c. or d. c, ^000 to 6000 r. p. m., 100 POWERFUL HYDRO-ELECTRIC to 1'0 volts. SALVAGE APPARATUS TO An aluminum rotor, per- RAISE SUNKEN SHIPS. fectly balanced, machined (Continued from page 95) and insulated. may have gone ashore in shoal waters. Supposing that a vessel has become em- bedded in the sand. Upon arriving at the price Regular of scene with one of the Linquist hydrostatic these outfits, $8.50 $4.00 lifting units of the type already described. this is set up out in the deep water at a con- Introductory offer Motor only siderable distance, say one thousand to as above, while 1,500 feet from the vessel in distress, and they last. Act $1.50 a heavy cable is attached to the oceanward quick. Rotor only side of the vessel. In certain cases, and when necessary a line may be shot over the When ordering rotors give size of shaft vessel to carry out this part of the operation. The cable which is secured to the stranded vessel is carried from the Lin- The Fosco Corporation quist apparatus, and passes thru two large pulleys secured to a stationary truss on the 1355 N. Western Ave., Chicago, III. base of the "fort," and in proximity to the vertical member of the lifting apparatus. Send postage for catalogue motors and supplies of The free end of the cable is secured to One-hall" actual size the top of the telescopic movable cylinder of the Linquist device, and this is made to ° rise by becoming more buoyant thru the THERE'S MONEY IN IT agency of the electric pumps (supplied "At: with electric power from the lines on shore), LEARN TELEGRAPHYf^i water being pumped out of the movable telescopic cylinder causing it to rise, and -"L-MORSE ANDWIRELESS-"- when this occurs a force of thousands of tons is brought into play, giving sufficient upward pull on the cable passing thru the TEACH YOURSELF stationary pulleys to haul the vessel off the shoal. in half the usual time, at trifling cost, with the wonderful Automatic Transmitter, THE 0MNIGRAPH. The inventor of this truly remarkable Sends unlimited Morse or Continental messages, at scheme for raising sunken boats, etc.. say> any speed, just as an expert operator would. that if his device had been available at the in the Adopted by U. S. Gov't. 4 styles. Catalogue free. time the U. S. Submarine F-4 sunk Honolulu harbor some time ago, that he OMNICRAPH MFG. CO. could have raised the submarine in four four months, which 39L Cortlandt St. New York days instead of taking was the time required by the only method available, when this deplorable accident

You benefit by mentioning "The Electrical Experimenter" -alien writing to advertisers. June, 1917 THE ELECTRICAL EXPERIMENTER 145 occurred. One of the divers who worked A COMPACT FARM LIGHTING ..ii the Sul. marine F-4 and who had nego PLANT. tiati.il depths of 306 Eeel (corresponding to Mesco Wireless Practice Set a pressure of 135 pounds to the square inch) The farm lighting plant illustrated is device and believes that Mr. rated at 1,000 watts and operates at 30 volts has seen the For Learning the Wireless Code cited are In cases or a 4-h.p. I inquist's calculations as just not most a 2, 2yi at most only practical hut feasible. engine is required to run this system. The generator has a heavy flywheel pulley with tapered shaft. ELECTRICITY AND WATER TO A feature of this equipment is that regardless of variation in the number of RUN OUR AUTOS. lights being used, the generator will auto- (Continued from page 88) matically furnish the current necessary for these lights, in addition to that which it has and air will eliminate all carbon deposits, already been furnishing for charging the and in so doine will add to the life and lattery, thus allowing the battery to receive power of any motor, and that is not all, for normal charging rate automatically, re- we obtain our gas from water, which nature its gardless of the number of lights being has provided abundantly, and so easy to se- The Practice Set comprises a regular tele- turned on and off. An automatic electric graph key, without circuit breaker, a special cure that the post is practically nothing. winding is incorporated in the nigh pitch buzzer, one cell Red Seal Dry in this electrolytic cell governing Those interested Battery, and four feet of green silk com 1 which prevents the variation in the gas generator intended for a substitute for design flexible cord. lighting load from affecting the amount of .i ..line in driving automobiles will un- The key and buzzer are mounted on a current going into the battery. Lights may highly finished wood base, and three nickel doubtedly find interesting a U. S. patent on be used at any time either direct from the plated binding posts are so connected that a similar cell, hearing the number 1,219,906 the set may be used for live different pur- generator, if the engine is running, or di- which is discust in the "Latest Patents" puses, as illustrated on page 24. the battery, if the engine is not department on page 128 of this issue. rect from For the beginner, the set is of exceptional running. value, for it may be used for individual code practice or for operation of a two party line, The manufacturer also claims that by which is an excellent method of quickly using this self-regulating winding for start- learning the code. After the beginner has DECISION IN THE "HETERO- mastered the code, the set may be used in his wireless outfit for setting the detector DYNE" RADIO RECEIVER in adjustment, and also the key may be used CASE. to control the spark coil. Recommended for schools, as it gives ex- On April 2 Judge Mayer, of the United cellent service for class instruction in code work. Full directions with States District Court for the Southern each set. The main object of the set is to enable the District of York, handed down an New beginner to master the wireless code, and opinion in the suit of Samuel M. Kintner the buzzer reproduces the sound of the sig- and Halsey M. Barrett, receivers of the nals of the most modern wireless stations perfectly. .National Electric Signaling Company, Every beginner needs one of these sets, plaintiffs, vs. the Atlantic Communication and as it is the equivalent of live different Company, August Merckens, P. C. Schnitz- sets, the price is very low. ler and K. G. Frank, defendants, in which List No. Price. he found for the plaintiffs. This suit was 342. Wireless Practice Set, with Battery and Cord $2.25 a charge of infringement of based upon 344. Wireless Practice Set only, no bat- United States letters patent 1,050,728 and tery or Cord 2.00 1,050,441, being respectively for the method and apparatus employed in a receiving sta- Send for Our New Edition of our tion of a radio telegraph system. These patents, issued January 14, 1913, cover the Catalog W28 Ready June 15 invention known to the art generally as It Is pocket size, contains 248 pages, with over 1.000 the "heterodyne" or heats method of re- Illustrations and describes In plain, clear language ceiving radio telegraph signals. all about Bells, Push Buttons. Batteries. Telephone and Telegraph Material. Electric Toys, Burglar and The court found that Reginald A. Fes- Fire Alarm Contrivances, Electric Call Bells, Electric the inventor of this system, had Alarm Clocks. Medical Batteries. Motor Boat Horns. senden, Electrically Heated Apparatus. Battery Connectors. produced an invention of great merit and Switches. Battery Gauges. Wireless Telegraph In- struments, Ignition Supplies, entitled to a hroad interpretation. He etc. found that the prior art cited by the de- IT MEANS MONEY SAVED TO YOU fendant as anticipating the Fessenden in- to have our Catalog when you want to buy. vention had failed to teach the art anything in respect to the use of beats and, at most, A New Compact Electric Generating Manhattan Electrical Plant Mount- merely disclosed a local source for oper- Having the Switch-board ed Rigidly on the Dynamo Frame. Supply Co., Inc. ating some particular form of receiver. He decided against the defendants' conten- New York: Chicago: ST. LOUIS: 17 Park Place 5th Ave. tion that the invention should he given a 114 S. 1106 Pine St. San Francisco Office: 604 Mission St narrow construction, in view of an earlier ing duty, engines, regardless of their type, patent of Fessenden. can be started without abnormal strain on The defendants' sole effort was directed the battery plates. This condition applies towards securing a construction of narrow specifically to engines of 8 h.p. or less. Learn Watchwork, Jewelrywork and the patents. They contended that the Fes- Twice the starting torque with one-half the ^ ** ne tra(*e commanding a Rood sal- 1-illglFnPTAvinoavillg. patents entitled arv _ anrj senden were not to a hroad current is said to be produced by means of vour sen-ices are always in demand. Address HOROLOGICAL Department. interpretation but should be restricted to test this this winding. In a recently made, Bradley Institute. Peoria, III., for our latest catalog the use of the particular form of appli- unit, with an 80-ampere current, easily ance shown in the issued patents. The started a 4-h.p. special electric engine. A court decided against this, holding the in- shunt wound generator failed to start the vention to be of such merit as to entitle same engine with the ammeter reading 140 it to a broad interpretation of equivalents. a'-nperes. This plant permits the lights to The court also stated that Fessenden or burn at practically the same brilliancy at his company, the National Electric Signal- all times. If the lights are being used direct ing Company, were the only ones to teach from the generator and should the engine WANTED— Railway Mail Clerks the art anything of value of this method stop, the electrical connections will he COMMENCE 575 MONTH INCREASE TO $150 MONTH of operation between the date of appli- changed automatically, so that the lights will Common cJiKatiun cation of his original patent in 1902 and then receive their energy from the storage sufficient. the date of applications for the patents Franklin Institute battery. The switchboard is equipt with Sure pay. in suit, 1905. large scale instruments, an automatic re- Life job. Dept.C104 Rochester, N. Y. verse current circuit breaker and only one Pull unncc- Sirs; Send me without charge, essary. ample Railway Mall Clerk Ex- lighting switch. All internal connections amination questions; lilt of other paid government Jobs now easily To overcome the difficulties the factory. batteries used big of navigation are made at The obtainable and free book describing them. in the Kara Sea the Russian Government with this plant are made in both the Faure has established three wireless stations that and Plante types, assembled in either rubber Name.

inform vessels of ice conditions. or glass jars. Addresa. . —

146 THE ELECTRICAL EXPERIMENTER June, 1917 SHIPS WHICH THE RADIO SAVED. DO YOU? By Albert W. Wilsdon. CONSTANT AMPLITUDE The U.S. Government cites the follow- marine in fig- ing disasters which wireless RECENTLY I bought a copy of the TEST BUZZER ured during the period July 1 to Decem- ELECTRICAL EXPERIMENTER ber 31, 1916: AND I read it through July 11.— Steamship Ramos foundered in DURING the time a gale while en route from Philadelphia to Cartagena, Colombia. SOS calls were an- THAT I swered by the Miami land station and the HAD to spare EVERY day that I could. steamships / an Hogendorp and Illinois, all but five persons on board being saved. July 22. — Steamship Matatua, stranded EVERY time in rocks seven miles south of St. Mary's LOOKING thro " on 1 1 Price, $1.20 Dimensions 2 /4"x2 /2 Light, Cape Race. Vessel shot line to ELECTRICAL magazines which I thought Postage 10 cents shore and passengers and crew were re- CONTAINED news moved. The distress call was answered by THAT would help the OVER 1200 SOLD the steamship Stephana, Red Cross Line, READER in his work, I always found Our special Constant Amplitude Test which stood by until passengers were safe- Buzzer contains some entirely new features ly removed. CERTAIN articles that were and closely resembles the tone of a 500- ALWAYS vague and which cycle Telefunken set. This is due to the September 15. — Steamship Congress, LEFT me in the dark. arrangement of the contact which is pro- with 445 persons on board, caught fire off back-check which pre- vided with a lenient Coos Bay, Marshfield, Oreg. The vessel vents the armature from overreaching and EVER thinking that the amplitude becomes constant. This you was headed toward shore. SOS calls be- XPERIMENTERS like myself will find in no other Buzzer. The contact ing sent out continuously, which were re- points are of pure silver which prevents magazines ceived by the land stations at Marshfield, PURCHASE burning and the entire mechanism is en- EACH month for the purpose of closed in a non- resonant dielectric case. Oreg., Cape Blanco, Oreg., and Eureka, articles You will never know you have a Buzzer in Cal., and the steamship F. A. Kilburn. Res- READING your circuit as far as attention is con- IN which binding cue vessels were dispatched by the Marsh- cerned. It is provided with three MANY new wrinkles, posts and is highly finished. field station, and all persons on board were saved. EACH new, and NOVEL, are to be found. EUGENE T. TURNEY CO., Inc. September 23. Steamship Bay State ran — TYVAS for this reason that ashore off Cape Elizabeth, Me.; total loss. 2595 Third Avenue, New York City EVERY month I now Distress calls were answered by the Coast READ the ELECTRICAL EXPERI- Guard cutter Ossipee and the naval station MENTER. at Cape Elizabeth, which dispatched the tugs Portland and Cumberland. All per- THEREFORE BE IT ENACTED by sons on board, approximately 200 in num- ENCLOSED all experimenters and the general public, ber, were saved. that everv Experimenter who has not read ROTARY GAP October 7.— Steamship Antilla, with fifty- the ELECTRICAL EXPERIMEXTER do This gap has been designed six persons aboard, caught fire off the Vir- so at once, without delay. to sell at a low price and to ginia Capes while en route from Guanta- meet the demands of ama- namo, Cuba, to New York. Approximately THE PENALTY for failure to do so is enclosed teurs for a good, a fine of 15 or 20 cents, which is paid for and silent gap. Finished in twenty-five vessels responded to the dis- other as well as the loss of dull black, it will add to the tress calls, and all persons were saved. magazines, appearance of your set. articles which cannot be found or obtained October 19.— Steamship Araphoe lost It is made in one style only, elsewhere. for all powers up to I-KW, Iter rudder twenty-five miles north of Cape Apologies to "Casey Bee." and can be mounted in al- Lookout. SOS calls were answered by the most any position. steamship Henry R. Mallory and the Coast The gap is enclosed in a circular iron housing 8 inches Guard cutters Seminole and Tampa, which town answered SOS calls. Crew trans- in diameter and 2j^ inches towed the vessel to Xorfolk. ferred to Coast Guard vessels and passen- thick, with removable cover gers were taken to New York on the steam- (for inspection). The adjust- October 28. —Steamship Chicago, with ment can be as close as desired 265 passengers and crew, caught fire at sea ship Jamestown. between sparking points. and arrived safely at the Azores Islands. December 25. — Steamship Maryland Rotating disc is of brass with 12 projecting sank at sea, position as given in SOS call round brass arms (total diameter 6 inches), Communication was established with ves- mounted on shaft running in bronze bearing sels, but assistance was not needed. 380 miles east of Sandy Hook, with crew and is belt driven by small motor giving a of thirty-four. Distress calls answered by October 29. —Tug Vigilant disabled 150 variety of tones depending upon the speed. several Coast Guard cutters, but they were miles off Irish coast. SOS call answered When in operation this gap is very quiet unable to locate the disabled vessel. by the steamship Ryndam, which towed the Price complete, without motor, $S 50 tug to Queenstown. J. Herbert Ferris, Zll Catalpa Drive, Royal Oak, Mich. November 25. — Steamship Powhatan, en 750,000 HORSEPOWER WASTED IN route from Boston to Baltimore, caught fire NEW YORK. off Block Island. Fire was controlled be- Electric power sufficient to turn every fore arrival of Coast Guard cutters, which wheel and illuminate every dwelling and answered the distress call. factory in New York State could be de- November 27. — Steamship Niels Xiclson veloped from the water power which is lost propeller in heavy gale. Distress calls running to waste every day in the rivers, were answered by several vessels, which streams and canals of the State, Attorney assisted the disabled vessel to make port. General Woodbury declared in his annual November 28. — Steamship Coronado lost report submitted to the State Legislature. propeller off Tillamook Head. Distress He estimates a daily waste of 750,000 elec- For Wire ' ess Rapids SPARK COILS calls answered by Astoria, Oreg., station, tric horsepower on the Long Sault and along the line of the barge canal. He STYLE C SPECIAL which dispatched tug to assistance of dis- COIL abled vessel. urges the Legislature to establish a policy Postage extra 1 $3.50 the State will reap some benefit December 3.—Steamship Carolina, Good- by which resource, the value FINE RESULTS WITH THIS COIL rich Transit Co., struck rocks off entrance from this stupendous which has been estimated by conserva- SCHUG ELECTRIC MFG. CO. to Sturgeon Bay Canal. Distress calls were of at $250,000,000. Attorney Gen- 2S4 EAST LARNED, DETROIT, MICH. received by the Manitowoc, Wis., station, tion experts the Long which dispatched a tug to the assistance of eral Woodbury points out that River, the disabled vessel. Sault Rapids in the St. Lawrence recently regained by December 12. Steamship Sumner control of which was POCKET BOOK °/ ELECTRICITY fight which was carried grounded in fog off Barnegat, N.J. Six ves- his office after a States Supreme Court, could FREE sels responded to SOS calls, and all per- to the United be harnessed to yield over 700,000 electric Distributed asV supplement to onr bitf Handy Book sons on board were saved. during temporary n>TsrnnWDt 1Usponsion of wire- horsepower, while the dams and other loss. Lists now thine* tn cxwrJmcnt with. Aho December 14. — Steamship Powhatan, en motors, flashlights, telefmiph apparatus, puzzles. structures along the course of the barge magic outfits, bock*. athletic eond*. chemical sets, route from Norfolk to Boston, sank in col- i fishing tackle rinvo I ties. Handy, interesting. For canal impound an excess of water over ery boy in America. Free on Re

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SPRAGUE DEFENDS ELECTRIC DRIVE FOR CRUISERS. After consultation with Secretary of the VIOLET- RAYS! Navy Daniels, Frank J. Spraym-, Chairman of the Xaval Consulting Boanl Committee NEW LIFE, POWER, HEALTH and BEAUTY in on Electricity and Ship Construction, has the marvelous delightful VIOLET-RAYS. Newest come out strongly against the critics of and most powerful form of electricity, causing neither electrical drive for the new battle cruisers. muscular contraction nor pain of any kind. In a letter to Senator Swanson, Chair- man of the Senate Committee on Naval THE VIOLETTA

been re- vl Affairs, Mr. Sprague says he has • **. High frequency instrument is endorsed by thousands of Physi- luctant hitherto to join in public discus- cians who use it dailv. Produces SOOTHING, I.W sion of the decision of the Navy Depart- TGORATLNG, CURA- TIVE VIOLET-RAYS. Wonderfully quick results ment to adopt electric drive. obtained in treating SCALP, FACE and BODY. "I feel that perhaps I am now justified Health bringing OZONE forced into the blood, producing an abundance of VITALITY. in so doing," he adds, "in view of the Sent on Free Trial fact that such discussion, which I assumed Simple in construction and operation. The VIOLETTA was begun from patriotic motives, seems is especially adapted for personal use in the home. to be taking on the nature of an active Will operate on alternating or direct current or battery. commercial propaganda, incidentally sup- ABSOLUTELY SAFE and GUARANTEED. ported by a number of gentlemen, most of whom, however representative and en- Write for New Free Book Send for our new beautifully illustrated book on dowed with experience along the lines of VIOLETTA. Tells all about the marvels of Violet-Rays. Read what scien- their individual professions, are utterly un- tists and doctors have to say. Post card brings book and all trained in naval affairs, and hence are not particulars of special low price and free trial offer. possest of sufficient knowledge of this D Dept. particular subject to indulge in the ava- £!t7 BLEADON-DUNN CO. 1A 208 NORTH FIFTH AVENUE, CHICAGO lanche of criticisms which have been lev- eled at the department." Referring to what he describes as "the successful installation of the electric drive on a comparatively small scale on the col- lier Jupiter and the adoption of similar UNIVERSAL ELECTRIC MOTORS power for three battleships," Mr. Sprague OPERATING ON A. C. OR D. C. -110 TO 130 VOLTS reminds Chairman Swanson that "the 1/40 TO 1/8 H. P. CATALOGUE FREE Navy Department, reinforced in their opinion by what had been done in electrical de- THIS MOTOR .00 velopment in c,reat power plants, decided j$|3 1/20 H. P. 6000 R. P. M. \Jf Complete with upon electric drive also for the battle Pulley Being Used Successfully for Grinding, Driv- cruisers, each of which is to be equipt with Polishing, Emery Wheel ing Small Machinery. Sewing Machines. Fans, Wireless Spark Buffing Wheel engines of the large total of 180,000 horse- Gaps, Electric Fountains. Check Endorsers, Humidors, Valve Chucks power. Grinders, Electric Hair Clippers and numerous other appliances. Cord and Plug "The wisdom of this decision," Mr. A MOTOR OF UNIVERSAL APPLICATION Sprague continues, "was challenged by Base Pulley and Chucks Easily Detached Charles Curtis of the International Curtis If Your Dealer Cannot RACINE ELECTRIC SALES CO. Marine Turbine Company, which company Supply You, Order From Us Direct 304 South Dearborn Street CHICAGO. ILL. would, if geared turbines were adopted instead of the electric drive, be a beneficiary by a large amount of royalties. It is, of course, difficult for one engaged in a com- MAGNETIC mercial enterprise which may be seriously RECTIFIER affected to be, if F-F BATTERY BOOSTER even unconsciously so un- Patented affected in his judgment by personal inter- April 1916 Keep your storage battery fully charged if you'd get the most out of it in service and ests, but I prefer to believe that Mr. Curtis length of life. was actuated by a desire that our cruisers Plug into any convenient 110 volt 60 cycle should be the best afloat, even if I disagree alternating current lamp socket and connect the somewhat with his methods and conclusions. charging leads to the battery terminals. The rectifier utilizes the Full Wave of cur- "Failing to get a reconsideration of the rent, has Carbon Electrodes and makes Re- charging a Profitable Business where batteries Department's decision, number of Navy a ^HP ^ are taken in to charge. prominent engineers have been requested to 3W $ 1 5 Complete F, O. B. Cleveland write, and several have written, letters based rjT) Get Bulletin Xo. 12. on certain adverse information supplied them, some condemning without reserve the W > THE FRANCE MANUFACTURING CO., Cleveland, Ohio decision of the department and others urg- ^^ — ^^3 States ami Canada ing that the matter be referred to the Naval Consulting Board or some other board of civilian engineers. "Among those other than Mr. Curtis, Super-Sensitive Microphone Only $6 who have been quoted as authorities are This instrument is offered at an extremely low price. It is ex- Dr. S. S. Wheeler, President of the (.'rock- cellent for building your own radio amplifier. Can also be used in many experiments where a sensitive microphone is required. er-Wheeler Company, manufacturers of electrical machinery, who has been vol- DETECTAGRAPH, $12 uminous in his cTiticisms: Dr. Francis This detecting instrument of marvelous sen- sitivity can be used for detecting secret Crocker, an associate of Dr. Wheeler; conversations. Outfit consists of Sensitive George Gibbs, Consulting Engineer "f the Transmitter. 25-ft. Black Cord. Receiver. Pennsylvania Railroad: Dr. Michael Pup- Headband, Case and Battery. in, a distinguished scientist and inventor of Send for One Today and Convince Yourself a system for increasing the efficiency of MICROPHO- DETECTOR the long-distance telephone; [sham Ran- dolph, a well-known civil and railroad en- COMPANY gineer; Prof. William H. Burr, a widely- GASTON BOISSONNAULT President known consulting engineer; President 26 CORTLANDT ST., NEW YORK Makers of Super-Sensitive Microphone Apparatus Falk of the Allis-Chalmers Company,

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148 THE ELECTRICAL EXPERIMENTER June, 1917

FREE manufacturers of electrical machinery; "It is inconceivable," says Mr. Sprague, Luther Lovekin, Chief Engineer of the "that with all the known facts in hand the while they last New York Shipbuilding Company, and Cal- Navy department would or could surrender vin Tomkins, former Dock Commissioner to outside advisers, directly or even infer- of New York." entially, the selection between two known Observing that this list "contains many and accepted methods of drive, with their names not only of men of prominence but varying influence upon the distribution of of men standing high in their professions," weights, 'ocation of turrets and armor, size -Mr. Sprague says: "But the question may and disposition of compartments and the properly be asked to what extent are these results of flooding, the distribution of fuel, gentlemen qualified to criticise, what is the the distances of machinery from the skin training and experience which would war- of the ship, provision against torpedo rant them to sit as judges in so vital a damage, the necessities of handling ships in matter, and what is it they really seek to emergencies and the results of failure of accomplish. any parts." "The discussion." Mr. Sprague contin- Mr. Sprague declares that generators and ues, "seems first to seek to condemn the motors of the size indicated can be built, adoption of electricity on the score of in- and that if necessary they can even be con- creased weight and cost, or impossibility trolled by a push button from the bridge. of construction, or safety in operation, and "1 am." he says, "generally credited with second, a reference of the whole matter to being the pioneer of the modern electric the Naval Consulting or some other board. railway and am certainly the creator of that system of train control, now used the world over, which makes it possible to aggregate A PRESENT-DAY ELECTRIC any amount of power required under a GIANT. single control." One reason why Mr. Sprague was select- While we may not have the human giants ed for the Naval Consulting Board was that of old with us, their places are admirably he had served as President of four technical societies—the American Institute of Electrical Engineers, the American Institute of Consulting Engineers, the New York Electrical Societv and the Inventors' Guild. JOHN CARTY, TELEPHONE ENGINEER,J. NOW MAJOR

I ll.:li.l,l'l,l[ I lllHl'IIL'L'll'U CARTY. Mr. J. J. Carty, chief engineer of the American Telephone and Telegraph Com- 5 big features pany, New York City, and recognized as I —Self-lock *^ ing. adjustable dies one of the foremost authorities in the Self-centering guides; 3—Xo reset- world on wire communication, has been ting of dies to size; 4—Xo loose commissioned senior major of the Signal bushings: 5—Xo small parts. Every Officers' Reserve Corps, the reserve auxil- BULL iary of the Signal Corps, U. S. A. The DOG addition of Mr. Carty to that organization will be a decided accession and one which will be widely applauded. It is believed other appointments will follow from the ranks of leading American engineers. The importance of the telephone system in any plan of national defense has been accepted by officials of the War Department. The adaptability of the American telephone lines was thoroly proven last summer when the entire A. T. & T. Com- GENERATORS! ALTERNATORS! pany's service was turned over to the Gov- We have a complete line of sturdv, efficient gen- ernment for a test under hypothetical war erators and alternators from 100 to 1000 watts. conditions. In 45 seconds Secretary Dan- \V e furnish complete parts for these finished ready to assemble with instructions to wind. iels was in communication with the Pen- Transformers made to order. Send for catalogue. sacola, Fla., Navy Yard, and in 28 sec- ALL AT FACTORY PRICES The Largest Self-control Induction. Feeder onds more was talking with the navy yard Bergmann Molor Works, 442-446 Niagara Si., Buffalo.N.V. Voltage Regulator Ever Built. at San Diego. The Secretary of the Navy later exprest his pleasure over the "wonderful success" of the experiment. When filled by the gigantic mechanical and elec- S THE MIDGET SLIDE RULE the country's National Guard was mo- will add. subtract. molHply. divide, trical apparatus that modern genius has solve problems invomnireven and un- bilized last summer a complete telephone even roots and powers. It will also evolved, as for instance, the device shown give the Logarithms of numbers and exchange was established at Camp Whit- th- Sines. Cosines, Tangents and Co- in the accompanying illustration. This pic- tangents of all angles. man, in New York State, in less than 24 Its operation is very simple and with ture shows the largest self-control induc- this instrument one can quickly solve hours after the troops were called out, any mathematical problem. This slide tion, feeder voltage regulator that has ever rule is made of wood and metal and It connecting Washington with Albany, N. Y., is adapted for shop work as well as been built. The regulator is of the oil- office use. and all the vital points necessary to the Size 3 1-4x3 1-4 in. Price, with insulated, self-cooling type, and was built by Instructions, 7&c. Your money back movement. The commissioning of Mr. if ;nu are not satisfied. GILSON a Pittsburgh concern. It is rated at 600 SLIDE RULE CO.. Niles. Mich. Carty as an officer in the Reserve Corps kva. (kilowatts I 3-phase, 60 cycles, 13.200 may be taken as a further step to have volts, with 10 and 20 per cent regulation this important branch of the country's de- For shop, factors-, at 262 and 131 amperes. It is designed for ready, not only in ma- garage and home operation outdoors with full-automatic con- fensive system TOOLS terial, but in personnel. —many high class trol self-contained. tools attractively priced in our Odds and This regulator was built for the South- Ends pamphlet which is mailed free on re- ern Power Company and is to be connected "E. E." WAR NEWS ! ! quest by to the low voltage side of a 6000 kva. (kilo- DON'T THINK, NOW THAT WE watt) bank of 44,000 to 13.000 volt trans- Montgomery & Co., Inc., 105 Fulton St., N. Y. Cry formers on the power company's line at ARE AT WAR, THAT YOU CAN Spray, N. C. By the use of this regulator DO WITHOUT THE MONTHLY the power from the line will be delivered VISIT OF TheElectricalExperimenter. Send for catalog of our tools m i nim for to the Thread Mill Company mills owned wood and metal. Also Mechanic's KEEP UP-TO-DATE IN ELEC- Handbook. <* by the Marshall-Field's interests, with the IT MILLERS FALLS CO.. Milieu Falls. Mass. voltage maintained continuously at normal TRICITY BY READING value. "EVERY" MONTH.

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June, 1917 THE ELECTRICAL EXPERIMENTER 149

Edited by H. GERNSBACK.

In this Department we publish such matter as is of interest to inventors and i FREE 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 BOOK- BULLETINS & ADVICE are publisht here for the benefit of all readers. If the idea is thought to be of im- REGISTERED, ATTORNEYS 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. LANCASTER^lALlWl 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 2SS OURAY BLD'G, WASHINGTON, D. sheet should be written on. C. Don't Lose Your Rights We publish form' called BELL SOFTENER. the device are very ingenious indeed and "Evidence of Con- ception'* by which you can establish your rights hold out a possibility of a good invention. before sending the (152) E. T. Jones. New Orleans, La., invention to anyone. It is your however, would our best protection. We issue up-to-date writes as follows We, advise corre- bulletins of improvements wanted; aid inventors to spondent to simplify the idea, as at pn promote "I, a subscriber t" your wonderful maga- their rights; render reliable opinions free of charge it seems too complicated, having too and secure zine, would greatly appreciate your opin- mam- valuable patents and trade-marks on parts. We would also advise our corre- reasonable terms. Personal service assured by our ion iin the following 'phone-attachment, Service Guarantee Contract. References: spondent to submit the idea to a patent at- printing same in your Patent Advice de- 2nd National Bank, Washington, The John P torney with a view to obtaining copies of Roth Packing Co., Cincinnati. partment in one of the following issues prior patents on this particular class this year, as soon as possible of SIMPLY MAIL COUPON work. LANCASTER ft ALLWINE, 255 Our»y Bld|f..H.iblnpto», "Alter reading over your article on pat- D.C. Send me free book "Inventions— Patenting and ents wanted. I devised a scheme by which Promoting." Bulletins of Improvements Wanted any tone desired can be had instead of INTERRUPTER. and blank form "Evidence of Conception."

using bells. 1 have drilled and tapt the (155) Geo. Shaw, Talmage, Neb., has Name . armature knob of the ringer and screwed conceived an idea for the improvement of Address . thereon a certain device; on a protruding interrupters for small wireless sets and stand, I have a mandolin string, which is other outfits requiring the use of a small adjustable (any note can be had): when transformer or spark coil. The idea is to the 'phone (rinu;s) the device passes over use a certain form of interrupter in an the string and I have attained a dull, air-tight chamber, under sufficient air pres- soft-pitcht tone which is audible three sure to prevent the burning of the con- rooms away. tacts. He thinks that a small hand air "I would appreciate your opinion on the pump could be secured to the chamber to above arrangement, and 1 highly recom- pump sufficient up pressure. Is the idea a Morgan Elliott & CO. mend more suggestions on your part in a good one and is it patentable, and would PAT magazine which 1 and a million or so there be a demand for it? ENT attorneys others cannot do without, as it is the only MECHANICAL. ELECTRICAL & CHEMICAL EXPEN Ans. A scheme of this sort is decidedlv live one out to-day. I read it from cover not satisfactory because it has been shown 716-724 WOODWARD BUILDING to the last page and find old copies inter- that comprest air will retard an ordinary WASHINGTON, D. C. esting even after they have been fully vibrator spring or, for that matter, any read." moving part which is supposed to operate Ans. The idea, while a very good one, under high speed. If instead of using does not seem very practical for the rea- comprest air you use a vacuum, enorm- son that the device would take up toe ously better results are obtained, as, for room. If an arrangement were ob- much instance, in the Moore J'acuum Interrupt- tained whereby the long string could be er. Personally, we have no faith in com- done away with, we think a more practical prest air interrupters, as we have never arrangement would he had. but we believe seen one work satisfactorily. PATENTS a patent can be obtained on the idea. Send Sketch or Model of Your Invention for ELECTRIC Free Opinion as to Patentability INVISIBLE PERISCOPE. CIGAR MOISTENER. Our Certificate of Patentabil- Moreira, Lowell, Mass., (156) Charles Bicker, Salina, Kans., ity is Evidence of Conception (153) Jose M. your invention and may says that he has idea of submits a design of a glass periscope, his an in the construc- prove valuable to you. Our tion of a device idea being to make it invisible. to moisten cigars and Credit System enables you to tobacco in show file your application for Patent Ans. While this is a good idea on cases. The idea is to make steam by heat developed and proceed without delay. Every paper it does not work out in practise for from stor- case receives personal attention of age batteries, and two reasons, one of which is that glass is to evaporize the steam one or both members of the firm. too dangerous a substance to be used for in a certain manner. Patents wo secure advertised at «ur ex- Ans. pense in Popular Mechanic* Magasin* a periscope which has to stand enormous While a patent might be obtained on a scheme of this kind, we do not know Write today for Free copy of 101-page book strains due to rushing thru the water as it •'How lo Obtain a Palenl and What to Invent" valuable it on. Furthermore periscope stick- how will be without knowing speeds a Talbert& Parker, Patent Lawyers, full details. There are some very good ing out of the water can never be invis- 4287 Talbert Bldg., Washington, D.C. and cheap electric tobacco moisteners ible, that is, while the periscope itself may on not be seen at a distance, it forms a white zvakc as it runs in the water, which is Write for List of Patent Buyers who very noticeable. It is not the periscope PATENTS WANTED desire to purchase patents and What itself that the enemy will see, but the To Invent with valuable list of Inventions Wanted. $1,000,000 in prices offered for water trail which the periscope leaves be- inventions. Send model or sketch for Free Opinion as to patentability. We have a hind. As Iriuo- js nothing is found to do Special Department devoted to Electrical Inventions and are in a position to assist away with this wake, it is usele c s to make and advise inventors in this field in the development of their invent inns. the periscope itself invisible. MODERATE FEES—WE ASSIST INVENTORS TO SELL THEIR PATENTS AUTOMATIC TUBE CLOSER. Write To-Day for our Five Books sent free to any address. (See attached coupon:) (1541 James D. Miller, Montreal, Que- bec. Canada, submits to us several draw- VICTOR J. EVANS & CO., Patent Attorneys ings of collapsible tubes such as are used NEW YORK OFFICES: 1001-1007 Woolworth Bldg. PHILADELPHIA OFFICES: 1429 Chestnut St. with tooth-paste and shaving creams, the idea being to do away with the annoyance Main Offices: 779 9th Street, N. W., WASHINGTON, D. C. of unscrewing and screwing on the cap Gentlemen: Please send me FREE OF CHARGE your FIVE Books as per offer. which so often exasperates us. Name Address Ans. The drawings submitted to us of

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150 THE ELECTRICAL EXPERIMENTER June, 1917

the market to-day and we have one in JOE'S EXPERIMENT. mind which seems to have the greatest (Continued from page 101) sale, whereby an electric incandescent forming the circle which surrounded lamp is plunged in a basin filled with the erect and alert chief, his water, which owing to the heat of the pale face drawn and anxious as he eyed the watch lamp, is made to evaporate. he held in one hand. "Do you think they'll stand it?" he —the ONLY kind Wanted and AMPLIFICATION TRANSFORMER. asked in husky, worried tones. Manufacturers. "Sure, BOUGHT by ( 157) A. J. Camile, New York, N.Y., there isn't much load on," Pete Send 8c. postage for book of new sends in a sketch and description of a Foley assured him. Extraordinary Interest to Inventors. transformer which is supposed to amplify It was just a minute before twelve. The R. S. & A. B. LACEY alternating current ten times or more generators below were purring smoothly, 63 Barrister Building, Washington; D. C without any other means. He proposes in filling the whole building with a vibrant, a sketch and description, that it will trans- steady hum. form 110 volts 2 amperes into a current Fixe seconds past — ten — twenty — Inventions the Wanted! of 110 \olts 31 am feres! group grew silent, watching the chief, Mr. mufacturers constantly writing us Ans. No matter what a scheme of this Robertson, as he squared himself in front for patents. List of inventions actually requested and book "How to Obtain a Pat- kind may consist of, it is absolutely im- of the main control panel. Twenty-five ent" Bent free. Send rough sketch for free report refrarding patentability. Special assist- possible. You cannot obtain energy for seconds past—thirty—forty. ance given our clients in selling patents. nothing and you might just as well try to At ten seconds before twelve Mr. Rob- Write for details of interest to every inventor. lift yourself by your own boot straps. It ertson reached for the push-button in the Chandlee & Chandlee, Patent Attorneys the Est. 21 Years 950 F St, Washington, D. C. simply cannot be done. center of panel marked, "Main Switch." His hand rested on the metal disc for a PATENT ATTORNEYS. moment and then as the watch field in his left hand marked five seconds (158) Edmund von Szuppiny, Pater- before twelve, he prest the button. PATE NTS son, N.J., writes as follows There was a purr of mechanism behind the THAT PROTECT AND PAY "Wishing to find out thru whose services marble panel as the big main switch fell Edison, Maxim, or Lewis obtained their into Books and Advice Free place. The generators dipt a note or two in patents, I sent for the literature of a If you want to sell your patent, take it out through my their hum, and then rallied as more water orflce. HIGHEST REFERENCES. BEST RESULTS. good many patent attorneys. came thru on their turbines. The group WATSON E. COLEMAN, Patent Lawyer "Many of them list a considerable num- watched the on 624 F. Street, N. W. Washington. D. C. ber of names and addresses of their clients voltmeter the panel anxiously, and as the seconds past and who, however, are almost all unknown to it did not waver, Air. Robertson heaved a the world at large, and no matter how I great sigh of relief and satisfaction. MONEY IN PATENTS tried, I failed to find the names of Tes- ^~~ ^ secure your patent or return our fee. "It works! It works!" he shouted, in We la, Hammond, etc., in any one of their Send sketch or model for free search of Patent sudden released exuberance. "They've got lists. Office Records and report on patentability. their power and we've got our franchise." Manufacturers are writing for patents secured through u "This makes the impression upon me that J A white-linened, diamond-pinned director (Write for free book, "How to Secure Your Patent," and I i inventors of this magnitude do not care of patents wanted. We assist in selling your patent reached for the chief's hand. k to intrust their inventions to the adver- P. R PATT1SON & CO, U. S. Patent Attorney. tising "Don't congratulate me," Mr. Robertson 42? Barrister BIdg, Washington. D_C patent attorneys. "Will you kindly inform me what means hastened to forestall him. "We're saved because some one thought of very or what agencies this—say Edison or Tes- a simple expedient. Here, I'll show you." la—uses when wishing to patent one of their inventions." He stept to a panel at his right, followed the interested group. paused Ans. The answer is a simple one in- by He before a rheostat, glittering in bright metal. From Manufacturers deed. We have good reasons to believe ' are Writing for patents pro- that several of the greatest inventors of its connections two wires led down to a cured through me. FREE: 72- coil of wire on the floor. pagt* guide book, "Successful Patents"; "Stepping Stones" this country patronize the advertising pat-

; coil," said, it, (containing hundreds of inventions wanted) and "Patent ent attorneys, but they usually restrict at- "This he indicating "is a Promotion" (tells how to sell your rights; chief causes of resistance coil. It is connected in series failure, etc.). "Patent Buyers" publishes over 400 letters torneys from using their name for obvi- from those who desire to buy Often Patents. Send for with the field windings of the exciter. In ous reasons, as it is naturally to their in- them. Free manufacturing facilities. Advice free. this the voltage of the exciter has been RICHARD B. OWEN, 164 Owen Bldg., Washington, D. C terest not to disclose who does their work way the for them. Personally, we think you will lowered, thereby reducing strength of get cheaper and better service from ad- the alternator's field, which in turn lowers Upon electrical ap- the voltage of the machine itself. As a pliances are in de- vertising patent attorneys than from those result we have the voltage of the high mand ; manufacturers who do not advertise, for the simple rea- PATENTS!are writing for patents tension line lowered to such a point that secured through me. son, that the former do a larger business Send sketch or model for advice; I assist you market and consequently can work cheaper. The we are sending current directly into the your invention. Prompt personal service. Booklet and service lines inter- advice free. quality of a patent obtained certainly does Merwin without any vening step-down transformer. very not make a lot of difference whether it is A VV1 I 740D- Woodward Bldg. JD Y turned out by an advertising attorney or clever and simple expedient, which will .Pt.IYEiLLl WASHINGTON, D. C by one that does not advertise. work until the transformers arrive. And so I congratulate the man who suggested The editor, who is the owner of some " it to me, Mr. Peter Fo Get up-to-date in House Wir- eighteen patents, might state that nearly ing 1 Save Time, Money. "No, you don't. Not me," Pete inter- Labor and Material. by usinor all of these were obtained from advertis- Electricians our 98 Genuine Blue Print rupted, as Mr. Robertson turned to him. Drawings, containing all the ing patent attorneys. latest diagri andc __ house wiring---every diagram "Here's the boy you want to thank. He and connection UD-to-the- d by first class electricians for wirinK Bells. Burglar Alarms. Lights, Annunciators. Fire larms saved your plant and not me," and he ami Electric (.as LIGHTING. These drawing are bound in the form of a flexible book <9xl2i for convenience in using on the job. Send for TOY ELECTRIC HAMMER. pushed forward Benson from the shel- them, and if they don't make you more efficient as a wireman and save Joe vi m many times their coat as a contractor, return them and money (159) R. DeWitt Dufneld,_ Van Wert, ter of the post where he had been standing. will be refunded—you can't afford to be without them. One Dollar ' d PATENT SPECIALTY COMPANY Ohio, has submitted to us a simple design "He told me about this trick and asked 462 Sanchez Street San Francisco, Cal. of a toy electric hammer and wants to me to tell you. So just give him the thanks know if such an article is on the market and the reward," Pete went on, eyeing in already and if it is worth while patenting. triumph the astonished faces of the group SMALL ENGINES Ans. This indeed is a very excellent about him. idea and one of the best schemes for a "It wasn't much. Any electrical man Perfected Gasoline Engines H. 1 and — cheap electric toy that we have seen late- 1,'i h.p-—for Farm and Shop use. Price could have thought of it," Joe said mod- $19.50 and up. Also ly. While there is 11.. tiling particularly new estly, blushing happily in sudden confusion. WASHING MACHINES in the principle, we are certain that a "And anyhow I couldn't have done it, if We ship on trial. Send for Booklet and Special Offer patent may be obtained on the construc- Pete hadn't showed me things so well the Sieverkropp Engine Co., 1401 19th Street tion of same. .Wis. day I was here looking around." Starter for Ford Cars ( htr correspondent also submits to us a "Yes, that was the day he was in the sketch of an electrolytic interrupter on way," Pete said, with a significant glance which desires advice. scientific stunts galore he our toward Mr. Robertson. are fully Illustrated in Edelman's 256-page book Ans. Nothing new is shown in this de- \ the chief recovered from his "EXPERIMENTS." $1.50 and 2 lbs. postage. sign, and similar interrupters are in use But had I Qts : Research, Invention, Private Labora- surprise and had stept forward to the blind all over the world a patent can cer- tory, etc < 'frcular Free. and P. E. EDELMAN, Pub.. 1802 Hague Ave., St. Paul, Minn. tainly not be obtained on this device. (Continued on page 152)

You benefit by mentioning "The Electrical Experimenter" -when writing to advertisers. June, 1917 THE ELECTRICAL EXPERIMENTER 151

8c in - Stamps 300 PAGE ELECTRICAL Brings You DUCKS and WIRELESS CATALOG You then have everything in wireless and electrical supplies worth while at

prices that mean a substantial saving to you. Our catalog is recognized by all experienced and advanced amateurs as the Beacon Light on what to buy. Ask your wireless friends. Great cost of catalog and low prices prohibit

distribution unless upon receipt of 8 cents, which you may deduct on first dollar purchase.

TUNER FOR I.ON(; WAV I- IINCTMN ductance of the winding la varied bj ;v is 8 This tuner la designed especially foi ail In Bllders being eliminated., 1 i ctlve tuning. Tin*

i'. net ins from the lonj wave length un- rai led In steps of two turn- each and U i -

i This tuner Is of thi .ill that this is the ideal construction, mourn- :

iimi I l * finish throughout It The Instrument occupies i Inches squar This instrument is in a class by length! rrom 2, I to 16,000 meters on the ('limiting table, while the old style Were The windings are of Silk Covered Wire, ma- n Quires three feet. tive merits and advantages of all winmti mi stihsiiiiitial unshrinkable is chine The secondary counterbalancecd and the . (50.00 would not s tubes. The primary tune is in \ touch of s finger moves it to anj position. blbltlve pri< e to -J; for tliis Instru Is its The secondary tubo 7 in. I 12 In. The in- When raised tu extreme height the coup- No. A 1 776 Tuner $27.50 Shippitig Wvight 30 lbs.

THE WILLIAM B. DUCK CO., 230-232 superior St., Toledo, OHIO WIRELESS RECRUITS NEEDED

The work of directing the Armies and Navies in this great World War is being done by Wireless. The Wireless Operator is absolutely indispensable in achieving results as has been proven in the Battles along the Somme. The Wireless Sections are now one of the largest and most important factors in the Royal Engineers. Our Army demands an efficient corp of Radio Opera- tors. Each one of the thousand new Merchant Marine Ships will require 3 Wireless skilled Operators. Our Big Shore Stations and New War Vessels need Operators. To meet this demand the Xational Radio School will open a Special 8 weeks' Course in the Theory and Practise of Wireless Telegraphy. Classes begin in June. Price $60 in advance or $66 on the installment plan. Men and women are in demand for this Service. The School is located in the Heart of the Xational Capital where one may feel in close touch with the needs of Our Country at this Crisis. Several of our students have just passed the Tests for the Navy and are now in service at the large Arlington Wireless Station. Our Correspondence Courses have helped many, who could not attend our school, to get a Com- mercial License. Enroll now in one of our Courses so you may be prepared to serve when the call comes. Send stamp for catalog which gives full information. NATIONAL RADIO SCHOOL 14th and U Streets, N. W. WASHINGTON, D. C.

YOU NEED AN 0MNIGRAPH-N0W

We have been telling you for years of the merits of THE OMNIGRAPH AUTOMATIC TRANSMITTER. We have been telling you that the Omni- graph, connected with a wireless Buzzer, will send you unlimited Continental messages at any speed and at any time. Now that your wireless outfit is temporarily abandoned, you MUST keep up your code practice, and you surely need an OMNIGRAPH.

If you are already an operator, it will increase your speed and make you a better one. If you are only a beginner, it will make you an operator in the shortest, easiest and least expensive way.

In addition there is nothing to compare with THE OMNIGRAPH for quickly learning the Morse Code or for practice with the Morse Light. THE OMNIGRAPH has been adopted by the U. S. Government and leading Universities, Colleges and Telegraph Schools. Send for free Catalog showing four models ranging in price from $2.50 to $18.00, or order direct from your favorite Electrical House. THE OMNIGRAPH is sold under the guarantee if not as represented, your money back for the asking. This cut shows an Omnigraph aluminum disc with message milled around the edge. It is only one of hundreds of different styles of THE OMNIGRAPH MFG. CO. 41 Cortland St., N. Y. discs we make.

mentioning "The Electrical Experimenter" when writing to advert EXPERIMENTER June, 1917 152 THE ELECTRICAL

JOE'S EXPERIMENT. tremely pronounced. The machine has the added advantage that there is no trouble- {Continued from page 150) some spark gap to adjust, the strength of circle of directors could boy, before the the current being regulated by a many- him. close in on stept rheostat in the primary transformer "Shake," he cried, gripping his hand. circuit. boy who can think of a thing like "Any Much has been done in adapting high- deserves a chance to learn more, that frequency currents to the treatment of whether he can see or not. So if the com- disease, but much remains 3'et to be done pany doesn't out of gratitude, I'll see to before we shall be able to avail ourselves myself that you go to the best technical it of the wonderful healing and vitalizing school in the country.'' powers which these currents undoubtedly possess. The writer hopes to be able to ELECTRICITY AND LIFE. continue his studies along this line, be- (Continued from page 105) lieving that when we can scientifically apply to our patients pure undamped waves of and other pulmonary troubles often culosis definite form, frequency, amperage and yield to the "effleuve" treatment. voltage, we will obtain results far surpassing anything that we have dreamed of up to 3. Perhaps the most remarkable therau- the present time, and that in the future peutic effect of heavy high-frequency cur- the scientific use of high-frequency currents is their power to liberate heat in the rents will the greatest method ever tissues of the body. For this purpose the become for the healing of disease, the so-called "D'Arsonval current" is used. discovered promotion of health and the maintenance This is a secondary current of .high amperage derived from the heavy coil of of a "More Abundant Life!" copper strip shown in Fig. 6. The lower BEFORE they .started to coast terminal of this coil is connected with the past which the patient is this hill they knew from condenser pad on EXPERIMENTAL PHYSICS. electrode is held they were taking seated ; the tubular metal experience that (Continued from page 106) no chances—they knew that they in both hands and connected thru a Milli- could rely absolutely upon, the pow- amperemeter with the upper turns of the . goes out solidly, so that now our siphon erful grip of the famous coil. The clip is moved to different turns has its "arms" filled and acts the same as as in wireless tuning, until the meter shows the ordinary siphon. the highest reading for a given amount of is an exciting current. The patient's circuit is EXPERIMENT 28—The following interesting and amusing experiment. It can in thi:T way tuned in perfect resonance with the primary oscillations. After a few be made to appear mysterious, and is im- moments the patient's wrists become hot, portant because in it lies the principle of the submarine. In Fig. 24-A, 3 is a jar or DUPLEX COASTER BRAKE the heat rapidly extending up the arms and other cylindrical glass vessel about two- into the body until profuse perspiration carry thirds full of water. 2, is a small, light There can be no improvement on is produced. Ordinarily we do not as this: the safe glass bottle, or better, a small glass vial. this brake. It is powerful, it is dura- the treatment as far average patient being not 1, is a piece of sheet rubber stretched over ble, it is simple, it is reliable. dose for an milliamperes for twenty minutes. the top of the jar. Before placing 1 in on your hub you over 700 With a Corbin Duplex position, vial 2 is partly filled with water is "D'Arsonval Autocondensation", are in a position to handle quickly and con- This and inverted so that it just floats upright. yinumlv any situation that might arise on and is applied with great benefit to patients dizzy hills on the sheet rubber the road or street. Elbow turns, suffering with Arteriosclerosis ("harden- On pushing down laden thoroughfares present not and traffic arteries"), and in a variety of vial (Cartesian diver) sinks and on releas- the slichtest difficulty. It gives you coming of the ing it rises again. When we push down plete mastery over your bicycle, a freedom other diseased conditions involving mal- the pleasures and air ami control that doubles nutrition. on the sheet rubber, we compress the of riding. It has no equal. possibilities in the jar and hence it forces more water Assured" 4. In diseases in which we wish to in- "Corbin Control Means Safety into the vial. Since it was originally ad- duce a regenerative inflammation, promote Sold and equipped by all justed so that it just floated, the addition of Specify it. cell request. circulation and absorption, and increase dealers. Catalog on more water into the vial makes it heavier activity, the method known as '•Diathermie" and hence it sinks. On releasing the sheet is emploved. Instead of the hand electrode THE CORBIN SCREW CORPORATION rubber the pressure in the jar becomes nor- and condenser-pad the D'Arsonval current The American Hardware Corp* Successor and hence the pressure in the applied thru two small sheets of block- mal again, 216 High Street, New Britain, Conn. is about inches. These are applied vial causes the excess water to come out Branches: New York Chicago Philadelphia tin 2x4 to the skin on either side of the affected and the vial returns to its original position. Makers of CoTOin-Broirn Speedometers part and a current employed which gives Fig. 24-B, shows a more mystifying form the patient a decided sensation of penetrat- of the same experiment. 3, is a Florence ing heat. Average treatments use from flask, while 2, is the same vial adjusted treating con- 1000 to 1600 milliamperes. In exactly as in Fig. 24-A. 1, is an ordinary one sumption (pulmonary tuberculosis) cork stopper. After the vial is adjusted, placed on the back and the electrode is the stopper is put in carefully. (It may be the chest over the affected lung. other on necessary to adjust the vial so that it floats Tuberculosis Hospital in which this One almost upright so that on pushing in the treatment was given daily to a number stopper, a little more water enters the vial of patients reported 85 per cent of cures' and it just floats upright.) On holding the The author is working on an apparatus the hand it is found that one can. which will make possible the use of Dia- flask in air and make thermic treatment in the homes of patients by squeezing it, compress the the suffering from this disease. the diver perform. Thus one can make Convert Your Bicycle Into diver obey one's command to rise or sink, For office use and for the Electro-medi- the audience perceiving the cause. a Motorcycle cal specialist ("Electrotherapeutist") the without flask which will yield to writer has recently designed an apparatus Obviously a thin Motor fits any wheel. Best, experiment most reliable. Best hill climber. More from which remarkable results are being squeezing is necessary for this STEFFEYS tn use than all others. A fine flask answers motor for running small Dynamos, Lathes and obtained (see Fig. 6). The Tesla and and the ordinary Florence .-.lii'iis only low email Motors as as S16.95. D'Arsonval coils are excited by a wireless the purpose very well. The real submarine Mlg. Co., 5025 W. Brown St., Phila, Pa. "Hy- water can Sleffey transmitting set of the well-known boat is so constructed that no rotary quenched gap with ex- tone" tvpe. The enter it, even if it is wholly submerged, high-spark frequency pro- its exceedingly cept at the will of the occupants. It is almost sustained wave in the our MOTORCYCLES duces an able to float like any other ship just as and BICYCLES at cut prices. High-frequency coils. Both for the Tesla the SlDg.es and twins $2o To $100. vial can float. If the occupants wish Tires $3. treatment the writer be- New Motorcycle and D'Arsonval is allowed to enter Automobile Tires S3. Best boat to submerge, water this apparatus superior to any that Belts $5. Carbur- weight Motorcycle into special compartments until the etors $6. Spark coils J6. S*corj«i- he has used up to the present time. The bandBicyclea *&. Tandems $15. New Bicycles at Factory Prices. the weight of effects are ex- of the boat slightlv exceeds Denlnger, The Price Cutter, Rochester, Mew York vitalizing and exhilarating writing to advertisers. You benefit by mentioning 'The Electrical Experimenter" when :

June, 1917 THE ELECTRICAL EXPERIMENTER 153

the water it displaces. When they wish Machine Shop (bench work). to rise again, some of this water is forced Magnetism and E lei tricity. out. Alternating Currents. EXPERIMENT 29—We are all familiar A. C. and D. C. Instruments. with the fact that objects weigh less in liatteries. water than in air and that some things Motors and Motor Control. float in water. No one who has ever taken kadi' i I 'i .« er ' Circuits.

,i bath has failed to notice this, and as a Primary Circuits matter <>f fact the great Archimedes, who Sei ondary Circuits. first formulated the- law oj bu first Condensers and Oscillating Currents. noticed the buoyant effect of water while Radiating Currents. taking Ins daily or yearly bath (I do not Transmitting Sets. ( Chiropractic know which). If a block of wood, a piece Recen ing 'it cuits. of stone or marble, or a brick and a piece Receiving Sets. ^ Advanced Science of Spinal Adjustment of cork of the same size and shape are Service Radio Sets and Rom This is the day of druglesa healing! The fallacy of "doping and dosing" has been ex- weighed in air, they are found to have Wave Meters and Measuremi i 11 Science has triumphed again! Treat- different weights. If then each is weighed Radio Regulations and Fleet Work. ment by spinal adjustment is the thing of the hour! You can Doc-tor of Chiroprac- are now become a in water (see Fig. 25-A) they again Radio License Booth. tic through home study during spare time! found to weigh differently but they all Review and Examination. You can know wealth, honor, prestige and position! Makes no difference where you live weigh less, and as a matter of fact it is To the above course is added several or what you do— you can qualify easily, rapid- noticed that the LOSS IN WEIGHT is in weeks of practical work and special details. ly for this great profession. each case the same, except in the case ol Students enter the Electrical School at any Earn $3,000 to $5,000 a Year the cork which floats and does not weigh time and commence the course on the Many of our graduates earn much more—some op- anything. If next we fill a can until it Monday following their date of entrance. wards of $10,000 a year. Dr. M. D. Moore, oi Ken- nearly and immerse one of our Each corresponds to a class or grade tucky, reports an income of $9,000 a year. Dr. L. H. overflows week Roche, New Jersey, $5,500. Dr. Hanna. Florida, over objects (except the cork) in it, and catch and shows the subject which the student $5,000 yearly. We could name hundreds of more who are making big incomes. See the facts in our Free tin- overflow water in another can and is studying, and the lapse of time since Book. It'B only a question of preparation on your part, to enter a profession that is paying others weigh it ( subtracting the weight of the entrance to the school. $3,000 to $5,000 or more a year. Think whatitwould can), we find that 111,' weight of the water The first eight weeks of the radio course mean to you to have this money rolling in and to be your own boss with your own office and your Inst own displaced is equal t<> the weight when are devoted to subjects pertaining chiefly hours. Truly this is a glorious chance for youl tin- bodies were immersed in the first part to general electricity and serve as the of the experiment. In Fig. 25-1'.. abed, ground work for the study of radio. Text represents the cross-section of the body books used in the first eight weeks are 20 LESSONS FREE pressure at ad, is equal to the Lessons in Practical Electricity" used. The "Swoope's Also $15 Set o! 8 Anatomical Charts and eoad. The pressure and "Enllard's Naval Electricians' weight of the column, Text $16.50 Set of Nerve and Pain Area Charts of ai cb, is equal to the weight the column, Book." Yes, free to you without a cent, now or later. As ceob. Tin' difference between the two is Both the Continental and Morse codes an extra inducement to secure quick action, we will give absolutely free, our big, 6i-page book; a $15 set the resulting buoyant force at cb, and is are taught. Two operating tables, each of 8 Anatomical Charts, beautifully lithographed in lifelike colors, and alsoa complete Bet of Nerve of water of are fitted and equal to the weight of a column with a capacity twenty men, Pain Area Charts, regular value $16.50. which of course is the amount of with head 'phones, sounders, and trans- adeb, Our Lessons Teach You How to Make water displaced. The cork being lighter mitting keys. The instructors are Chief Spinal Adjustments For Speedy Relief of than water, if it were immersed the buoy- Radio Electricians. Each instructor is as- Headache Neuralgia Constipation Pleurisy ant force would he greater than its weight signed an operating desk having control Indigestion Neuritis Dyspepsia Jaundice Lumbago Catarrh Rheumatism Asthma, and therefore it is forced to the surface. over a certain number of tables. The stu- Epilepsy Fevers Paralysis Etc. Hence the cork will sink only until enough dents are assigned to tables according to Learn at Home In Spare Time water is displaced so that the buoyant force skill in receiving and are advanced to Wetrainyoubymail. We make everythingso clear, so equals its weight, i.e.. only fart of it will faster tables whenever necessary. Final simple, so easy to understand that you can't help but learn. Give us a portion of your spare time, and we ship floats it is sink. The ordinary because examinations are held after the comple- will soon have you a Doctor of Chiropractic, ready to constructed so that if it were immersed, tion of the twenty-second week. The av- step out and take a position of prestige in the world. a f*rj* %T^^TITI Why slave your life away the buoyant force would be greater than its erage operating ability of the students work *»^*AI * 11IN I J WWW.' in- that you don't like weight. completing the course is 25 words per V Work thatdoesn't fit with your ambition? Here's the chance you've been look- (To be continued) minute. A great many of the students, ing for. Here'B the opportunity your ambition bas approach a speed of been yearning for! Write today and Bee the suc- however, 30 words cess that is awaiting you as a Doctor of Chiroprac- NAVAL RADIO OPERATOR. per minute. tic Act now. Don't delay. THE AMERICAN "TJNTVERSrrr, is believed that completing the (Continued from page 109) It men Manterre Building Dept. g©^ Chicago, HI. radio course at the Electrical Class suc- Members of the Electrical Class are cessfully have obtained an excellent gen- quartered on the receiving ship at either eral knowledge of radio and have fitted Island, or York. The school Mare New themselves for rapid and sure promotion DON'T BE THIN! buildings are situated in the Navy Yard. Physical Perfection at- in this branch of the Naval service. tracts men and women, for Outside of the regular school hours a we all admire a well-de- course of instruction is contemplated veloped person. Have you noticed that it is the whereby they will be instructed in the regu- ( THE HOW AND WHY OF RADIO chesty fellow whogetsthc lar duties of man-o'-war's-man; this is a a best job? Infact he seems APPARATUS. necessary, as every man aboard ship, irre- togctahcad in every way. I mil give you a straight spective of rating, is a member of a mili- (Continued from fage 113) back, a full chest and an tary organization. Shore leave is granted chanical pressure can be exerted axially clastic stride, three of the in accordance with the regular Navy cus- upon them, in order to make the gaps thoro- best signs of vigor; besides, I guarantee to in- tom, usually from 4:30 p. m. to 7:30 a. m. ly air tight. For outputs above one-half . iut weight 10 to every other day. Leave of absence is K.W., the gap often becomes unduly heated, 30 lbs., by buik up scientiBcally, ratur- granted after completion of course. and it is common practise to place a small ally, without apparatusor course at the Electrical School The com- motor-driven blower or fan beside the gap, drugs, in the privacy ol prises twenty-two weeks of advance work in order to cool it by carrying off heat from your own room. Write today for information. and three weeks of examination. The the cooling flanges. EDWARD J. RYAN, Martin Bldg., Uticn, N.Y. schedule of marking is based on 4 as per- At Fig. 4, we have what is known as a fect and a final average of 2.8 is neces- rotary-quenched spark gap. This particular sary order to obtain rating elec- in the of design of gap has met with considerable trician upon graduation. Each man is favor, especially for small radio transmit- assigned a mark upon daily oral recitations ters, of from one-quarter to several kilo- and weekly written examinations. The watts output. This gap possesses the dis- big pay In short hour-. final examination is in writing. In the tinct and remarkable quality of producing TRAFFIC INSPECTOR I" radio course the greatest is placed emphasis 1 a high-tone in the telephones at the receiv- We train you in '• to J months f™* upon the ability to send and receive the to till tins rtesirahli.' position *-rw^B^l*Jgg ing station, even tho it is used on a low '-' Morse and Continental codes, also radio Learn railroading fi — frequency or 60 cycle transformer at the experienco of travel ^^jr^ V^f.^^ regulations. InfluenUaJ men gel In -^^- transmitting station. r sure promotion. Every r 8. railroad and capable traffic men OUTLINE OF THE RADIO COURSE. In the first place, this gap operates with bio positions. a remarkably small clearance between its i j ,,M the how Today writ.- f.r I | f U information. U»ra employment bureau hclpa Kr».1u*tf« to trood position*. The outline of the radio course is as two semi-circular fixl spark electrodes and our FRONTIER PREP. SCHOOL, Buffalo. N. Y. follows its rotary electrode, or having « gap about

entioning "The Electrical Experimenter" when writing to advertisers. — :

154 THE ELECTRICAL EXPERIMENTER J une, 1917

three-thousandths of an inch in length. to have the sparking distances constant and The gap operates in an air-tight chamber similar. A typical gap of this class has the PORCELAIN formed by a heavy metallic casting, which sparking surfaces and the copper on both carries suitable cooling vanes, and besides stationary and rotary elements milled with "THAT'S OUR BUSINESS" which there are provided a number of aux- thirty-six radial slots, so that when rotated iliary cooling vanes as shown in Fig. 4, at by a small motor at 1,800 R.P.M., the re- Standard and Special Shapes, Regardless the rear of the gap. Being air-tight at the sultant tone corresponds to that of a 540- 1 of How Difficult It start, this gap operates in the same manner cycle alternator. is necessary that the We Illustrate one hard shape we make. as the design shown in Fig. 3, known as width of the spark segments are so propor- A pair of rolls 7H" long and 1^" in the Telefunken gap. To obtain a high tioned that sparks will occur during not diameter with 8t»oles on ends and middle. They must be perfectly straight and we spark note with the rotary quenched gap of more than one-half of the total time, as make them so. It's hard but not for us. Fig. 4, the two fixt and also the rotary elec- otherwise the telephone diafram at the re- We can make your difficult! designs also. trodes have their faces accurately machined ceiving station is retarded in its excursion Send US blue print for quotations. or milled-out at equal distances, resulting away from the magnet, thereby resulting- in a number of teeth, between which the in a decrease in the sound intensity. Union Electrical Porcelain Works spark occurs. These gaps have to be built ]Tlw3f interested in this spark gap "ci'i TRENTON, N. J. very accurately of course, as the gap itself do li'fl/ to look up the matter in the excel- 3 lent measures about .003 inch, and it is desirable paper by Mr. Melville Eastham, entitled "The High Tone Radio Telegraph Trans- mitter" in the December, 1914. issue of the proceedings of the Institute of Radio En- gineers.—Editorial Note.] Chemists Are More in Demand Be Prepared. Than Ever Before. No One Can HIGH-FREQUENCY APPARATUS Afford Not To Know About The AND EXPERIMENTS. Wonderful Science of Chemistry, {Continued from page 117)

Send for Chemcraft. it is just what you need to start so rapid that it will not produce an audible laboratory. You will learn thousands of ymir chemical sound in the receivers, so that the discharge valuable and interesting things, besides having all kinds of fun. of an Oudin coil cannot be used for the CHEMCRAFT NO. I. PRICE $1.50, POSTAGE PAID ANYWHERE IN UNITED STATES OR CANADA. Con transmission of wireless messages, altho tains fourteen chemicals. Test Tubes, Glass tube. Measure, who can say, if it is properly conducted to etc., and a valuable instruction book telling how to work 36 wonderful experiments in Chemistry and Chemical Magic. the aerial, that it does not travel as far or CHEMCRAFT NO. 3. PRICE S5.50. DELIVERED EAST farther, than an undamped wave. OF MISSISSIPPI. MISSISSIPPI THE WEST OF THE It is very probable that high frequency OR TO CANADA. $6.00. Contains 4S chemicals and lots of extra apparatus, such as a Blow-pipe, Test Tube Holder, current of a periodicity which is not de- Test Tube Brush, Alcohol Lamp, etc.. in addition to the tected by the senses, will play apparatus contained in the other outfits. With Chemcraft an important No. 3 you can work more than 200 fascinating experiments. part in radio thought transmission. CHEMICALS AND APPARATUS FOR THE EXPERI- This picture shows Chemcraft No. 2. which con- If experimenters will build apparatus, MENTER. have just completed a price list of chemi- with complete apparatus and We tains 32 chemicals nid apparatus for experimenters. Send 10c in coin similar to that described, they will never re- Instructions for working 85 experiments In Chem- or stamps for a copy of this list- It will be valuable to you. istry and Chemical Magic. Price, postage paid. gret the little amount of time required for West of the Mississippi and to Canada. $3.00. $2.50. THE PORTER CHEMICAL CO. its construction. Dealers: Write for Discounts on the Chemcraft Line. Dept. B- Hagerstown, Md. EXPERIMENTAL CHEMISTRY. {Continued from page 127)

be left in a closet, or some place else for STORAGE BATTERIES FOR ALL PURPOSES a week, or until the water has disappeared. The reaction for this experiment is Better Batteries for Less Money 3Cu + 8HNO3 = 3Cu[NOs ] 2 4- 4H.O + 2NO \&t Copper Nitric Copper Water Nitrogen Acid Nit rat Monoxid Backed by An Exceptional z&& Guarantee MADE FROM ACIDS AND SALTS. *>: EXPERIMENT XO. 61— Capacity The Mark-o'Quality G« Put 5 or 10 grams of marble chips into ;*> Quality Price a wide test tube and add about 10 cc. of 8*° dilute Xitric acid. [HXOa] [half acid and half water]. Apply the splint test by ap- *® WE MANUFACTURE BATTERIES plying a lighted splint to the mouth of the V* FOR EACH MAKE OF AUTOMOBILE test tube, after the action has progrest for «l a short time. After the action has stopt, if clear, filter, and evaporate most PAULM.MARKO & CO., Inc., 1191 Bedford Aft., Brooklyn. N.Y. N. Y. Depot—974 8th A*e., N. Y. City and not of it.

Factory Rebuilt, Like New, at $65.00 The word "rebuilt" has been abused and misused until it has become a meaningl trade term. When we rebuild a Fox Typewriter we take it alt to pieces, re-nickel the nickel parts, re-enamel the frame and replace all worn parts with new ones. The same men who originally built the typewriter do this rebuilding and do the work s just as good. 50% New Parts and Three Years* Guarantee We offer a rebuilt Fox Typewriter. Model No. 24—Just like new—for $85.00. These have standard carriages, taking paper 10 *A inches wide, any kind of keyboard, any kind of type, rubber, covers, tabulators, back spacers, two-color ribbons, complete with Instruction books and cleaning outfits, and are guaranteed for 3 years, the same as new ones, and have not less than 40% of new parts.

Send any amount you ran spare, from $5 up, as a first payment, arid par the balance JS-OO monthly. 5*& discount for all cash, Purchaser must pay transportation. If In Pay Ot in. ire is sen I with order we will include FREE a verv fine Metal Case. Mition to the rubber cover, together with a hieh-cla<^ bran padlock for locking case when tvpe- ! not in use Please order direct from this offer and inclose any amount you can spare $5.00

ire and mention The Electrical ¥.\ : r June FOX TYPEWRITER CO., 8702-8752 FRONT AVE., GRAND RAPIDS, MICHIGAN Monthly

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June, 1917 THE ELECTRICAL EXPERIMENTER 155

KXPI I MM I. XT NO. 62— chloric acid will act. The carbonat 1 limestone, I is I 'mi 2 or 3 grams of Ferrcus sulfid aCOs, or marhlcj, plentiful, [FeS] in a test tube and cover it with and hydrochloric acid attacks it with water, i'l.uc this near an open window, great vigor. The reaction would he:

or in a place where a draft of air can be I aCO, + 21li l CaCl n < >

I alcium Hydroi I created to carry away the escaping fumes. hloric alcium Watei n.,1 Acid CI 5 cc. of Hydrochloric acid |ili'll nil. Add II. I Or Marble] [keeping in a draft of air | . Winn the action stops, filter and evaporate. Equa- Insoluble substances, salts and bases, are prepared in, the tion : laboratory almost wholly by one process, FeS + 2HC1 FeClj + IIS Precipitation. An insoluble I .us Hydrochloric Ferrous Hydrogen salt or base may he made by mixing two Acid Chlorid Sulfid Sulfid solutions, one of which contains a com- EXPERIMENT XO. 63— pound of the metal, the other a compound Put ID grams of line salt [Sodium oi the non-metallic part of tin- insoluble Chlorid] [NaCl] in a large test tube, and salt, which will appear in the mixture as BE A METER ENGINEER add Hi cc. of concentrated Sulfuric acid a precipitat. Lead sulfat [PbSCh] is made by solution Don'l villi a small, underpaid job all [HaSOi]. tarry on this experiment near pouring a of lead nitrat <>W to Get the Big Job

i -i l'b| XO.|...| solution Meter Englni 1 1 The profession a window or where a draft of air can [ upon a of Sodium I trie Light a

sulfat . be created. Heal the solution oxer a I'.nu- |Xa,SO,l Plants need men — thousands ol them .it hbch salaries. We have trained bin sen burner very cautiously, and moderately. PbfNOj], 4- NajSOj PbSO< 2NaNOa 1" Lead Nitrat Alter the action has progrest for 5 or 10 Sodium Sulfate Lead Sulfate Sodium ifltable employment all the fear rutin d. Lprecipitatsj Nitrat You Can Qualify. Write today minutes let the tube cool, then pour in 15 Acids arc usually made by acting with EARN $1200 to Special 2ll cc. of dilute or dissolve the or water, to $3000 A YEAR 1 time a less volatile acid, as Sulfuric acid .1. solution. If the liquid is not clear, filter

1 1 [H«SO«], on a salt of the acid required. 1 it, and evaporate the liltrat [the liquid and ex- : ' ien have seen that salts can he made 1 .v. is to start passes thru the filter paper]. If We by the supply many fold. which . the union of an acid and a base, and we ult, big sa.l.11 concentrated sulfuric acid is present, it will being offered for cod rig, right away. 11.. Writ- for full now learn that an acid can be obtained 11. Dm par- destroy the filter paper. ticular)! state in the union are _ NOW from its representative salt. Sulfuric acid hold- Ing responsible positions and earning $1200 Equatioii : to $3000 a is generally used, for making acid, he- i ai i ou can do the same. Bend your nan 4- II-..SO, Na~SO, 2110 addresf for tuli particulars FREE 2NaCl = + cause it is one of the less volatile acids, — inn Sulfuric Sodium Hydrochloric WRITE TODAY FOR FREE LITERATURE thus it readily its t'hluri.l Acid Sulfate Acid and parts with hydro- Just your name and address on i posl card Is enough. will We Bend you absolutel) I gen and takes a metal in its place. Soluble and Insoluble Substances. A naul, complete Information on Electrical Met gineering and full details of the salt of the acid desired must be put with special scbi I offer we an- now making. Write now ti All the ci .union acids arc Some soluble. the sulfuric acid ; for example, if Hydro- Tins offer Is Limited. of the bases are soluble, some insoluble. chloric acid [HO] is wanted, Sodium FORT WAYNE CORRESPONDENCESCHOOL An insoluble substance is one which does chlorid [NaCl] or some chlorid is used. Dept. A -244 Fort Wayne, Jndi< not dissolve, or which dissolves very slightly If Xitric acid [HXOi] some nitrat, as Po- in water. Besides water there are many tassium Nitrat [KNO.iJ, should be used. other solvents, as, alcohol, chloroform, Soluble bases, especially the alkalis, may ether, carbon disulfid, and the various be made by acting with calcium hydroxid alkalis, and acids, and unless a certain sol- on certain salts of the base required. vent is mentioned, water is the one re- Other bases, for example Sodium or Potas- ferred to. To he able to distil fuish clearly sium Hydroxid, may be used in place of between soluble and insoluble substances, Calcium hydroxid. Ammonium hydroxid CHEMISTS! is the basis of chemical analysis. [NH.OH] is prepared from a salt of Soluble salts, are usually prepared by Ammonium, as, Ammonium Chlorid neutralization, as in experiments 54, 55 [1] [NH..C1], Ammonium Nitrat [XH,N0 3 ], and 56; [2] by the action of an acid on Ammonium Sulfat [NH.J-SO., etc., by a metal, as in experiments 58, 59 and heating it with a mixture of calcium hy- 60; [3] by the action of an acid on a salt, droxid [Ca[OH] 2 ] [slaked lime]. as in experiments 61, 62, 63. 2NH 4 C1 4- Ca[OH],. = CaCL. 4- 2NH.OH In experiments 54, 55 and 56, we pre- Ammonium Calcium Calcium Ammonium pared a soluble .salt by Neutralization. Chlorid Hydroxid Chlorid Hydroxid [Slaked lime] Upon making a mixture of the acid and Sodium hydroxid is made from Sodium base [in solution) a reaction took place DON'T BE HAMPERED Carbonat [Na-COa] and a salt was formed. As a salt usually and Calcium Hydroxid. Insoluble bases are made by mixing two gives a neutral reaction, a point is reached, by LACK of APPARATUS solutions, one of which contains a base in the mixing, if it is done very care- the other a of fully, at which the whole mixture was and compound the metal YOU CANNOT SUCCESSFULLY neutral to litmus. If the solvent water of the base required. Ferric Hydroxid STUDY CHEMISTRY WITHOUT IT. [Fe[OH] 2 ] can be prepared by adding So- was evaporated at this point, the salt COMPLETE SET. SHOWN ABOVE. FOR dium hydroxid solution to a solution of should he obtained as a solid, which in WRITE FOR some cases may break up owing to ex- Ferric chlorid [FeClj]. Any other soluble PARTICULARS THE $4.00 ferric cessive heat. [but not ferrous] salt would do as well, and any other soluble hydroxid. PENSEE LABORATORIES In experiments 58, 59 and 60, we pre- ASSOCIATED Ferrous hydroxid [Fe[OH*] requires pared a soluble salt by dissolving a metal s ] a 1221 FIRST ST EVANSVILLE, INDIANA by an acid. The result which we obtained soluble ferrous [not ferric] salt. is called a chemical solution and consists SOLUTION:— of two stages; [1| the metal combined Cents a Day In S [August, 1916, issue with the negative part of the acid, and Experiment of Par* for Thi » Cornet An astounding; offerl Elicctrical we illus- <$n|y formed a salt; [2] the salt dissolved in The Experimenter] Jay boy* U-ia iapari) Tni-lo Silver trated Solution by experiment. found Oom.t. Fr*o Trial before you the liquid, the larger part of which is We » j decide to buy. Wv> rite for burbur. oiler. that dissolving the sugar in water, we water. Thus it is clear why a salt which by WURUTzEP. Free Band Catalog J™; big 2&0-p«,g«j Band formed a Solution. Sugar is said to he Catalog. Bock-bottom is insoluble in water is not usually made airect-lrom-nxAinit&sturnr'a prieia on all kinds of Soluble in water, and the water is termed itiBtnimt/ntd. t>ay at rate of a few in this manner. Carrying Caie Free cente a dny. Gcnerove allowance for eld with this Buperb Initrumanta. r rro trio). the Solvent. The sugar is the Solute. We au D ply the In experiments 61, 62 and 63, we made A triple silver plated I wTnment. Write todav The Rudoloh Wurlltxvr Co.. D.pt £ is said solution in Lyric Comet, -744 a soluble salt by the action of an acid substance to he in a 4th SI .Clnclnnatt.O. S.Waoaati Av-Chleaao on other salts or compounds. Metallic given liquid, when it is evenly distributed oxids, carbonats, and sulfids are the most tlvruout the liquid in such tine division common of these. Suppose we wish to that its particles cannot he seen, and which do not settle or precipitate upon stand- in, ike some calcium chlorid [CaCls]. We WOULD YOU BE UP-TO-DATE? know that it is soluble, and suppose that ing. The most important property of water This is the 1 1\ .h ochloric acid |H('I| will probably dis- Age of Electricity is its ability to dissolve a large number solve the calcium. But we also learn that Electrical which do not sepa- Read "The Experimenter" calcium is not a common metal in the of substances. Liquids laboratory, so we look for an inexpen- rate but form a uniform mixture when everv month sive compound upon which the Hydro- (Continued on page 156)

you benefit by mentioning "The Electricai Experimenter*1 when writing to advertisers. 1917 156 THE ELECTRICAL EXPERIMENTER June,

brought together, such as alcohol and water, gas from a liquid in which it is either Learn Wireless Under or glycerine and water, are said to be generated or has been held by pressure. Miscible. If a crystal of washing soda is exposed Marconi's Chief Instructor An insoluble solid, like starch-powder to the air in a dry place, it will lose its or clay, can be dispersed thru water by water of crystallization and become covered Serve Your Country shaking, but the mixture will be Turbid with a fine powder. This is called Efflo- turbid mixture of rescence. Copper Sulfat [Bluestone trained capacity. Several thousand like muddy water. A in an important in ordinary operators will be needed for our new njerchant marine a solid and liquid is called a Suspension. CuS0.5H;0], retains its water preferred, men who hold com- and supply snips. If suspended matter will settle, air but in very dry air it turns white and mercial licenses, by entering the Naval Reserve, can In time the enter the Electrical school of the Navy Department leaving the liquid clear. Dissolved matter Effloresces rapidly. without enlisting for four years. Men and Women will never settle. CRYSTALLIZATION :— :— When a saturated liquid is cooled and will now be accepted in limited afternoon class. SOLUBILITY FACTORS A. solid precipitates, the latter is quite Tultio] h to members of any T. M. C is de- the Employment Department The solubility of most substances or T. U". C A. The licensed likely to form crystal's, especially if the finds temporarv dav employment for those who must cidedly affected by the temperature. Solids earn while learning. Beginners can be prepared for cooling is slow. Evaporating the liquid in two are usually, but not always more soluble emergency certificates (telegraphic skill only) from a saturated solution precipitates the months; first grade commercial licenses six months' in liquids at high than at low temperature. evening stu-ly. Ask for folder "B." solid, often in crystalline form. These In Experiment 5, we found that sugar EASTERN DISTRICT Y. M. C. A. solution. They may also than in cold. are crystals from Ave., near Broadway Brooklyn, N. Y- was more soluble in hot water Marcy be obtained from Fusion, i.e.. melting a Calcium Hydroxid, used in the preparation crystalline substance and allowing it to of limewater, is more soluble in cold water cool slowly. Another method of obtain- than in warm water. ing crystals is to make an insoluble com- WIRELESS The solubility of gases decreases as the pound in the usual way, by mixing two College or Prep. School man. temperature rises. Ammonia and Carbon for the solutions. Generally precipitates obtained graduate, etc. The U. S. dioxid are less soluble in hot water than High School are or indistinctly water. Different sub- in this way Amorphous i .. iv't needs you in its Xaval Reserve. they are in cold crystalline, as time is not given for the Militia and Signal Corps. stances vary very much in their solubility Naval forces of crystallization to arrange the Attractive openings. Special three in a given solvent, and different solvents molecules in crystalline form. Crystals months' Summer course starting June differ in their power to dissolve the same may also be obtained by the sublimation 25th prepares you for either Gov't or substances. from a vapor. Some substances do not Commercial Service. Endorsed by SATURATION :— crystallize at all and are termed Amor- U. S. Gov't and Marconi Co. Day and If a small portion of salt is dissolved phous, meaning without crystalline form. Evening classes. in a large quantity of water, such a solu- 63— Send for special literature. EXPERIMENT NO. said to Dilute. The- sub- tion is then be Fill an evaporating dish half full of stance is uniformly distributed in all parts EASTERN RADIO INSTITUTE water, heat it [using asbestos pad on tripod the liquid in a dilute solution, as it is 899 B Boylston St. Boston of or ring stand support], and add to it alum, larger propor- in one containing a much either powdered or in small pieces, until substance. tion of the dissolved the liquid shows a tendency to become slowly adding' salt to a measured By thick. Stir it, and remove the flame, and that there Prepare volume bf water, it can be shown stretch across the dish a narrow piece quantity which the water To Serve Your Country as a is a limit to the of calico or cotton cloth so that the middle liter of water at 20° C. will dissolve. One portion will hang in the solution. Set Wireless Operator quantity of salt up to 360 will' take up any aside to cool. It may be well to allow and at the same time learn a grams, and no more. to stand a week before examining. This solution is said to be VALUABLE PROFESSION At this point the experiment illustrates crystallization from demand for competent words, the water In this crisis the Saturated: or in other a supersaturated solution. is enotmous and very urgent. all salt it can under operators has dissolved the EXPERIMEXT XO. 66— and Evening courses in Radio Elec- given conditions. If any more salt is Day Cautiously boil about 5 grams of copper tricity, Radio Engineering, Radio Laboratory thrown into such a solution it will simply Codes, Traffic and Laws preparatory sulfat [CuSOt], pulverized, in 10 cc. of Work, fall to the bottom and form a layer which, for License. water in a test tube until it is dissolved. Completely equipped Laboratory—expert no matter how thick, does not increase the Then place the test tube in an oblique Instruction — Dormitories — Employment. amount dissolved. position let the liquid cool. It should Write for catalogue and EXPERIMENT XO. 64— be allowed to stand for some time. The Y. M. C. A. Radio School Take 100 cc. of water and saturate it crystals obtained can be dried between New York City 145 East 86th Street with sugar at 20°. It will take up 200 filter or blotting paper and preserved. grams. Xow heat the liquid to 100° and This experiment illustrates crystallization dissolve more sugar in it. It would prob- from solution. WIRELESS OPERATORS ably take up 300 grams additional, but only EXPERIMEXT XO. 67— the liquid to SEE THE WORLD add about 20 grams. Allow Melt IS or 20 grams of brimstone (Roll 20°. solution must be Positions always open. Good again cool to This Sulfur) in a short, wide test tube. Cover salaries.Dayand event rig sessions- allowed to cool without any disturbance cardboard Correspondence cou rses. Wireless its mouth now and then with quiet in a clean bottle: apparatus for home Use. Send and kept perfectly if the sulfur should take fire. After com- catalog. the extra 20 grams of 6c in stamps for the separation of plete fusion let it stand still till it starts PMIa . School of Wireless Tele?. sugar may not occur for a long time. to solidify on the surface ; then pour off 10 Parkway Bids., Philadelphia, Pa. contains more sugar than the This liquid half of it into a dish of water and set saturated solution contains, at the same the rest aside to cool. Examine the part and when in such a condition Employed] temperature, in the water, pulling it to note its elas- Healthy Men said to be a Super-saturated Solution. They must be dependableiable—Must be on the job every hour! is ticity, etc. When the part left in the tube of the day And everyt A*vday WoWe haveharp nonn timetimp for physicalTjhYSical crystal of sugar into the above — Drop a is solid, break the tube and look for crys- weaklings or nervous wrecks- At the best they are uncer- solution, and if the ex- tain quantities—So say the captains of Industry everywhere super-saturated tals. to-day. Can you meet these rifild requirements of our mod- periment has been performed correctly, this ern strenuous life? If not you are already EXPERIMEXT XO. 68— foredoomed to failure in the race. The cr\ stal will precipitate, or throw down, the Put 3 or 4 crystals of Iodine into a doors of opportunity are closed to you extra 20 grams of sugar in crystals, and The relentless hand of unsentimental busi wide, perfectly dry test tube. Have a - everywhere turned against the saturated solution will be formed. stirring rod in the right hand, and S roll are the undesirable citizen. dry How About You Young Man? DELIQUESCENCE :— with the left hand, hold the tube contain- > haTe wrecked your future by di If Potassium Carbonat is exposed to the ing the Iodine in the flame of the Bunsen I habits, not realizing the conse- you know that the STRONG air, it absorbs the moisture from it. be- burner. As soon as dense purple fumes FORT METHODS can lift you out of th solution. depths and bring you back to the hloon o tines damp, and finally forms a begin to rise in the tube, remove the tube and Suc- and vitality of Real Manhood This, if substances absorb sufficient mois- from the flame, and thrust the stirring rod cess. Tour 1. shows plain it your face and the world loves healthy peo ture to dissolve them, or become wet, the into the tube, nearly to the bottom, be- pie. So be Healthy—Strong—Vital. That's deliquescence is applied to this being careful not to touch the sides of the living. Don't think tco long; send 4 cents name in stamp9 to covpr mailing of mv book. havior, and the substances are said to be tube with the rod. Keep it there until and Cul- "Intelligence In Physical Health Substances which so absorb settled, and examine ture." written by the strongest physical In Deliquescent. the Iodine vapor has

I In the world, and leam how to fit moisture from the air are also said to be both the rod and tube by means of a lens. : to command the D6SI positions. Write a short history of your condition Hygroscopic. This experiment is the same as Experi- vliH'h I will treat In the strictest confi- ment 12 [Electrical Experimenter, Sep- dence, and advise you without charge. EFFLORESCENCE:— LIONEL STRONGFORT This term should not be confused with tember, 1916, issue], and illustrates the for- Physical Culture Expert mation of crystals by sublimation. 130 Park Building WFWARK. W- J | Effervescence, which is the escape of a

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Jv 1917 THE ELECTRICAL EXPERIMENTER 157

EXPERIMENT NO. 69— Statement of the Ownership, Management, Circulation, etc., required by the Act of Con- Place a piece of Ferrous Sulfat gress of August 24, 1912, of The Electrical Experimenter, published monthly at New York, [FeSO«5H»0], in some place where it may N. Y., for April 1, 1917. be exposed on a piece oi paper for a week ''.'. EleWicLTaht "i N ew York, County ol \ or so, after which time examine for white State Before me, a .Notary Public in and for the State powder. This experiment illustrates Efflo- and count) nail;, appeared Hugo rescence. Gernsback, who having been| duly sworn according foi-Your 1 « 1 i Home to law. 1 id thai I that EXPERIMENT NO. 70— Tin Electrical Experimenter and the following / The Uni-Lcctric is a complete electric is to the ot his belief, a true best knowledge and f service station in home size. Genemt'-s piece of Calcium Chlorid ' Expose a statement oi thi p, management, etc., of standard UO-VOlt direct current. Bi^ ca- |CaCl=] on a paper for a week or more. the aforesaid publication lor the date shown in -operates one to 50 lights, electric ' motors up to I h. electric irons, electric ahn\, required the Act of August p., Note any phenomena. This illustrates the caption, by vacuum cleaners, force pumps, 24, 1912, embodied in section 4*U, Postal Laws churns, separators, wanning machine*, etc.— Deliquescence. and Regulations, to wit: 2A hours a day, everyday in tho year if you precipitation state: wish. Uses standard lamps and fixtures, \| The laws of 1. That the names and addresses of the pub-

[1] That when two substances are mixed lisher, editor, managing editor, and business i ager are: Publisher, The Publishing in solution, a new compound can be formed Experimenter No Belts-No Batteries Co., Inc., 233 Fulton St., New York City; Editor, Our pat'-ntird, h(irh-9n«AHugo Gernsback, 233 Fulton St., New York operate* tho modern, htirh'ftponl frenr-ratar with «uch such compound will he formed and will Managing Editor, Hugo Gernsback, 2ii Fulton St., smoothness that all ntceaaUv for storage battatfea Is appear as precipitate. Ntu York City; Business Manager, Hugo Gerns- eliminated. Thus the renewal of batteries and batterr a Up-ltMp emit In entirely done away with. eomea back, 233 Fulton St., New York City. Outfit la \1\ When, on mixing different sub- one amall compact unit. PSSd* for quick Installation. 2. That the owners arc: The Experimenter Simple, dependable and economical. The entire outfit a new substance that is volative (ruaxantaed for five stances, Publishing Co., Inc., 233 Fulton St., New Yurk years. Write today for free copy of oar new catalog- on farm Utchtins plants. can he produced hy the rearrangement of City; Hugo Gernsback, 233 Fulton St., New York York the atoms of the partaking substances, City; S. Gernsback, 233 Fulton St., New City; Mrs. K. Hymes, 233 Fulton St., New York Waterman Motor Company new substance will be produced and J such City; H. W. Secor, 233 Fulton St., New York City. 112 Mt Elliott Ave. Detroit, Mich. / will appear as a gas. 3. That the known bondholders, mortgagees, V Tht nrM) home sii« lighlina plant th>it holding 1 \ and other security holders owning or operate* without EXPERIMENT NO. 71— per cent or more of total amount of bonds, mort- elornQ» batter- securities are: None. Suppose we wish to prepare Silver gages, or other two paragraphs next above, giving Chlorid [AgCl], We know that this com- 4. That the the names of the owners, stockholders, and security pound is insoluble. Therefore we must bidders, if any, contain not only the list of stock- upon select a soluble salt of silver, and also In, Idei 5 .ind security holders as they appear company but also, in cases where a soluble chlorid. Silver Xitrat (AgNOa] the books of the the stockholder or security bidder appears upon being the only soluble silver salt in com- the books of the company as trustee or in any other the person or cor- mon use, we make a solution of it. We fiduciary relation, the name of whom such trustee is acting, is given: may also take most any chlorid, because poration for also that the said two paragraphs contain state- they are mostly all soluble. Sodium ments embracing affiant's full knowledge and be- Chlorid [common table salt] being one lief as to the circumstances and conditions under which stockholders and security holders who do not of the cheapest, we shall use it. Take a NJ'.'l-H:H«V.eV appear upon the books of the company as trustees, little Sodium Chlorid and dissolve it in hold slock and securities in a capacity other than water. Pour one of the solutions into that of a bona tide owner; and this affiant has no in any other person, association, KNAPP the tube containing the other, and the reasun believe that m4.IWJIJIU.llM LEADER or corporation has any interest direct or indirect c precipitat of silver chlorid which we wanted in the said stock, bonds, or other securities than is thus obtained. Save the precipitat for as so stated by him. The Big Power Motor for Boys $ That the average number of copies of each the next experiment. This experiment also 5. issue of this publication sold or distributed, through A compact, highly illustrates a substance which is insoluble in the mails or otherwise, to paid subscribers during efficient reversible water. the six months preceding the date shown above is mot or, perfect in every EXPERIMENT NO. 11— detail. 1 he reducing (This information is required from daily publica- Prepare some Silver Chlorid [AgGl as gear, easily adjusted, tions only.) transforms the high in Experiment 71. taking not over 5 cc. of H. CERNSPACK, Editor. speed to more power each solution and using for one the silver Sworn to and subscribed before me this 16th at slower speed. This salt prepared. Let the Silver Chlorid sub- day of April, 1917. E. D. JUNIOR. motor is guaranteed by us to be exactly side and pour off the upper supernatant (Seal.) 1919.) as represented. portion of the liquid, leaving the solid (My commission expires March 30, with some liquid. Add a little Ammonium men with training are always in Hydroxid [NHiOH], cover the mouth of demand. Having trained over At All Live Dealers ELECTRICAL— — 20U0 young men in the naat 23 ,on your dealer showing you the KNA.°P the tube with the thumb, and shake well. eara in tho fundamentals of Applied Elcetncity . Thk Bliss Electbi- Insist goods arc best. Ifynurdealcrcannot If the solid does not all disappear, add line —KNAPP supply you, order direct. Send for FREE illustrated more Ammonium Hydroxid. Upon the catalogue showing a complete line of Electrical addition of Ammonium Hydroxid, the pre- ENGINEERING Motors and Novelties ranging in price from 10c up. cipitat should be dissolved and a clear including1 Mathematics, Strum and Gas En. (tinea. Mechanical Drawinjr. Shop Work and KNAPP ELECTRIC & NOVELTY CO. translucent solution formed. Thus we Theoretical and Practical Electricity, in all branches. Students actually Construct dyna- Street, N. City have prepared a solid from two clear mos, install wiring and test efficiency of 523 West 51st Y. electrical machinery. Coarse, with diploma, liquids, and then dissolved the solid with complete another liquid. This experiment shows that IN ONE YEAR substances which are insoluble in water, Electric Row Boat Motor are made soluble in various other liquids. Makeyour Row Boat 260 Takoma Avenue, Washington. D. C. :i Electric Launch. (7*0 be continued. ) n Buya Jewel l>etuehable Eton Boat Motorrunt

i tv. No odor c dan?" roua easoiine. Simple, nola i< Handy Binder a n a powerful. Attaches to any Row Boat and for the Electrical Experimenter runs on two six ilt Batteries. TUls U our 5th successful year. Holds and preserves 12 issues, each of which can be OPEN BATTERY will, tools. Will keep WINDOW inserted or removed at without Look Inside your storago battery through tho your magazines perfectly for all time or just preserve patented open window. Sco condition of THE plates and height of electrolyte. If you need a them like new till you bind them permanently. Made of new automobile starting Battery buy a. jewel heavy material, extra strongly reinforced »* and save money. tl-tlO Special S8. 50. ELECTRIC^; f\r* Motorcycle Electric Lighting System at the back and covered with handsome "^ I l*" The Jewel Generator Motorcycle Storage Battery nd Is in great demand. green cloth, suitably lettered in gold complete lighting system EIylTER %J \J wanted. Write tor ririrrs and catalog K. EXPERIM Shipping weight _' lbs. Add sufficient postage, other- JEWEL ELECTRIC COMPANY, 112 N. Fifth Av., CHICAGO wise we will have to send binder by express, Order a BinderTo-day and Preserve Your Magazines. STROMBERC - CARLSON

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158 THE ELECTRICAL EXPERIMENTER June, 1917

Eead ikis Remarkable Oflei 1

fXPERlMENTALv| > TRlXITr COURSE;^

S.GERNSBACK ^.LESCARBOURA 7M.W.5ECOR

ra^?l

THIRD lO.OOO

This masterpiece contains 160 pages. 400 illustrations. Size The most comprehensive Wireless Course ever printed. Con- Size 9." of book 5" x 9". Printed on extra thin paper, so book can tains 160 pages, 350 illustrations. of book 63^" X be slipped in pocket. Handsome stiff cloth cover. Very fine flexible linen cover. Price $1.00 if bought alone. FREE with a year's subscription. Price $1 .00 if bought alone. FREE with a year's subscription

This is a very limited offer. It may be withdrawn at any time, due to the tremendous cost of paper, which IS JUST DOUBLE WHAT IT WAS ONE litt YEAR AGO. We only have about 2000 each of these fine books on hand ; after they are gone we cannot reprint the books until conditions become normal again. THIS MAY BE TWO YEARS OR MORE. Now is your chance. The publishers of this journal have earned an enviable reputation of giving Profit ^Electrical more than 1 00 cents' worth for each dollar spent with them. by this liberal Experimenter — opportunity NOW; it may never be made again. 5 HERE'S THE OFFER S/J Subscribe to THE ELECTRICAL EXPERIMENTER for one year, at 1 PS the regular subscription price of $1 .50 per year (Canada and for- of 6-17 eign $2.00 I and we will send you FREE POSTPAID, either one ^T' the above books. If you subscribe for two years, BOTH BOOKS ^^rQr^v, ' Gentlemen: WILL BE GIVEN FREE, POSTPAID. o^ ' Please enter w my eubecrlptlon If are a subscriber at present, take advantage of this vou / to THE ELEC- wonderful opportunity anyway. If you do, we will extend 'X ,' TRICALEXPERI- your present subscription for one year. '\Y M ENTER for the L1GHTNII r_0,' terra of year O,' 'or which I enclose here- This Offer Limited. Act Now TO,' with $ Yon will also send me at once

FREE prepaid your book.. .

12 copies of THE ELECTRICAL EXPERI- EXPERIMENTER PUB. CO., 9" 2" 4" MENTER make a book x 1 and thick. r This book will weigh 7 lbs. It is the greatest 233 FULTON STREET, tV Electrical and Wireless reference tf*1 CA Name. work in the world. And all for «P*.iW NEW YORK CITY IS Address. . .

You benefit by mentioning "The Electrical Experimenter" when writing to advertisers. — ! !

June, 1917 THE ELECTRICAL EXPERIMENTER 159

«^~ Scientific Exchange Columns UNDOUBTEDLY you have at the present time some things for which you have no further use. Do you Vish ur exchange them for something, for which you have immediate use? There is no surer and quicker way to do this than, by advertising your articles in these columns. The very people, the Only people, who could possibly have a use for your things read this journal. More t will sec your ad. It is furthermore thx cheapest advertising medium for you in the country. Dealers* advertising accepted in Opportunity Ex< hange Columns only. The rates are: Three cents per word (name and address to be Counted) i minimum space 3 lines. Count about 7 words to the line. Remittance must accompany ati orders. No advertisement for less than 50c. accepted. We reserve to ourselves the right to refuse any advertisement which we consider misleading or objectionable. Advertisements for the July issue should reach us not later than May 25. The Classified Columns of "The Electrical Experimenter*' Briny Positive Results. Subscribers experiencing trouble in dealing with any advertiser should notify the publisher very promptly. OVER 75,000 PEOPLE READ THIS JOURNAL Jjnv 4

stop! look: FOR SALE— Silicon Detector without cat EXCHANGE—Complete set of parts for a Ford " 75c; engine, with exception of crank shaft flywheel yA Spark Coil, $1.50; large accurate Voltam- whisker wire, 50c; 1.000 ohm Receiver, and meter, $3; large Static Machine, 17" plates, oper- Galvanometer. 25c ; Telegraph Set, 50c ; Leather- for a panel type receiving set, typewriter or wire- ates large X-Kay tubes, worth $40, for $15; Load- covered headband, 50c. Remittance must accom- less supplies. J. Yates Van Antwerp, 35 South ing Coil, $1.25. All rest E. I. goods. $1.25 Fixed pany order. Write Harry Layman, Davidsville, Perry St., Johnstown, N. Y. Variable Condenser, 75c; $2. Rotary Potentio- meter, £1.10; 2,000 ohm headset, $3. Call or SALE OR EXCHANGE— B-Flat cornet, $12; write, all answered. Satisfaction guaranteed. C. shotgun, $3; incubator, $3. John Enos, "A'ellneet, Koa wood, $10, or trade for Krummenackcr, 1034 73rd St., Brooklyn, N. Y. UKULELE— Mass. camera. Give size, lens, style, make, etc., or guitar. Clyde B. Marx, Kaskela, Oregon. WANTED—Tents, Scouting and Gym supplies. FOR SALE— iy2 H.P. Gas Engine, 500 watt 110 Have Wireless Instruments to swap. Dean Wil- volt *D.C. Generator, small lathe, % H.P. 110 volt D.C. motor, Jeweler's Foot Wheel. Write son, Alpha, III. FOR SALE Otis Clapp Static Machine in first- — for description. Clemmer, W. class condition. Two 19 plates on hand operated J. H. Blue Creek, FOR SALE—Receiving Set, consists Arlington end. Ten 29" plates on power operated end. Ya. Coupler, H-C 3000 ohm Phones, Murdock Con- Several Leyden jars and various discharging de- Motor, Headset, 1-inch denser, Perikon Detector, Switches and large vices to go with machine. Cabinet measures FOR SALE— $10; $4; Coil, $3; a Potentiometer, Detector, quantity Crystals. All new. Only $14. J. Smith, 66"x66"x30* wide. All enclosed in glass, $75, $3; $2; Spark Gap, $1; Sending Condenser, $2. Paulding, Can- T rout Run, Pa. f.o.b. Mattapan, Mass. Cost $450. Fritz Henrici, Mattapan, Mass. terbury School, New Milford, Conn. One Junior Cyclecar at $6S. A FOR SALE— FOR SALE—Alternating Current Electric bargain. Jacob Uau, Bathgate, N. D. Sewing Machine Motor, $15; new condition ; cost $30. H. N. Richmond, 1628 Washington Ave., MOTORCYCLE—Thor, clutch, chain drive, mil Colorado Springs, Colo. good tires, fine running order, $45. Also parts for cyclecar, twin engine with magneto, wheels, WANTED—Second-hand generator suitable for etc., cheap. L. H. Murdock, 3315 Stettinius, charging storage batteries. Must be in first-class Park, Cincinnati, Ohio. TALK ABOUT RESULTS Hyde condition. Archie E. Banks, Delmar, Ya. WANT TO TRADE- Bicycle and wireless FOR SALE— 5,000 mile Audion Receiving Set, goods, for motorcycle in running order. All let- complete, $40. George Leonard, 1 1 Hamlet St., ters answered. Roy Phillips, Hartford, Michigan. 17 PRYER LANE, Uphams Corner, Mass. Larchmont Manor, N. Y. WANTED—Trade foot-power lathe. Post drill. EXCHANGE— 6 volt, % horse-power motor; 25-20 Mailin pump rifle for wireless goods. Write 110 volt, 1/16 horse-power motor, 110 volt for particulars and state what you have to selJ ammeter. Want audion, 1 K.W. <|uenched gap, or or trade. Lee Jones, 706 Lillmore, Amaillo, Texas. The Experimenter Pub. Co. other apparatus. Ira Wright, Closson St., Me- thuen, Mass. FOR SALE—Amateur receiving set, good con- York City New 28 ft. Curtiss dition. Write Dock Stuart, Troy, N. C. FOR SALE OR EXCHANGE— aeroplane, without motor; crated; will sell ch ap; want rash. Make offer. G. Gustafson, WANTED— Battery Rotary 2-inch Spark Coil, Dear Sir: $100 V. Joliet, 111. for instruments I have. Write for list. August

< >tta, Moweaqua, 111. Talk about results! You've HAVE—Oliver Typewriter, Model 3. Want cash or receiving apparatus. Make offer. All let- WANTED—Omnigraph and dials. Also got to give it to the "E. E."" ters answered. Herbert Richter, Collegeville, "Smith" Flyer or motor wheel. Must be cheap. Minn. Cash only. E. Wilson, Gwynedd Valley, Pa. to reach the right people. On BARGAIN—Complete new Blitzen Receiving 3 l film cameras. set with extra equipment. Holtzer-Cabot Phones. FOR SALE—Two AxSy? the day after "E. E." came Ansco, $10; Eastman, $6. Smith Premier Type- In perfect condition. Write for particulars. Chas, writer, $15. Automobile magneto, $5. Dvnamo- out I received a reply and Bayliss, 68 Peterboro St., Detroit, Mich. motor, $1.50. Lawrence Johnston, Fairfield, 111. they have been coming in at FOR SALE—Complete Audio-Tron on panel with all controls and 4-40 storage battery. Panel QUICK—FOR SALE— Oscillation transformer, has 2 D.P.D.T. mineral change-over switches regenerative set, navy type coupler, audion panel, one a day. If I the rate of wired on. Used 10 hours. $10. Also "Arlington" age battery. Extremely low prices. Lester 4,000 M. Coupler, cost $9, for $6.60 and $4. Fawcett, Independence, Iowa. anything else that ever have Murdock Oscillation for $3. George R. Ham- mond, OeKvein, Iowa. AUDION and Amplifier cabinet set, including I want to sell I will send my tuning equipment, $50. Audion detector broken WILL EXCHANGE my Twin-Cylinder, 6 H.P. bull), $8. Want Blitzen coupler; pair undamped ''ad" to you every time. Merkle motorcycle, in perfect condition, for good coupler coils, $2.50. McMurdo Silver, 264 West wireless apparatus. Francis Joannini, 3326 17th 57th St., New York City. Yours truly, St.. Washington, P. C. Cyclopedia Applied Elec- FOR SALE— ^ HP. 2 Cycle Engine, $12. FOR SALE— Set of tricity. for description. All letters an- 12 volt 8 ampere generator, $8; physicians micro- Send swered. N. Boyington, South Galena Ave., scope, Bansh and Lomb make, $20; cost $65. Clarence de Witt Rogers, Jr. J. B. Roehling, 3705 N. Hermitage Ave., Chicago, Freeport, III. 111. FOR SALE—Three undamped wave loading coils less sliders, $5. Brand new Chambers Xo. loose coupler, bargain. Write Guenzel, FOR SALE—A first-class violin and bow (less lllllllllllllll Illlllllllllllllllllllllllllllllllllllllllll 749 H. A. bridge and strings) A-l condition. Cost $20, 410 Buttonwood St., Philadelphia, Pa. sell for $15. Marcus Harbs, Wilton, Conn. WANTED— Brandcs or Murdock J 1 "u TTZ\ BARGAINS— Leaving home, must sell. New headset for $3. A. Taylor, 105 East 1 02nd St, OMNIGRAPH Will pay cash for WANTED— Electron Relay, $3; slightlv used, $2. Loose Coup- X e w York. niunigraph in first-class condition. B. Cochran, 500 volt D. C. 1/3 horsepower Holtzer Georgia. ler. $1. WILL EXCHANGE first-class wireless set for Box 55, Palmetto, motor and rheostat equal to new, $15. Cabot 'Sniith'* motor wheel, or Motorcycle. Bernard P. 1,000 ohm phone, headband, cord, $1.23. D 1 ivn, T roy, N. C. FOR SALE—200 watt transformer. Steps 110 Electrolytic detector, 75c. Telephone magnetos, to 10, 20, 30 or 40 volts, $10; 40 watt dynamo or solid armature, 50c, laminated, $1.. .$10 Remv 6 SLIGHTLY used printer's type for sale cheap. 1/12 H.P. motor, $7; Inch Spark coil; fine fat volt automobile mautu-to, good condition, $3. Six- Geo. Wasserberger, Neillsville, Wis. Spark, $4; Testing magneto, $2.50; 20 ohm sensi- inch parabolic reflector, 50c; new bulbs, 20c. advertising course. 6 tive pony relay, $1.50; 20 ohm giant sounder and High resistance ringer coils, 15c each; telephone $75 Chicago University for sale for $8 Write steel kev, $2.50; Portable Voltmeter, 1-20 range, transmitters, 50c; receivers, 50c; induction coils, volumes with questions $1.50; Filings coherer, $1; 75 ohm wireless re- Silver wire, 35c; 2 lb. it interested Geo Wasserbexger, Neillsville, Wis 20c; y2 lb. 22 German ceiver with headband, $1.25: 1/12 H.P. water antenium wire, 40c; quantity 2 strand steel guy Keystone Bli lit-voltmeter, motor, $1.50. C. M. Adams, Milford, Ohio. wire cheap. Premo Junior No. 2 Camera, new, FOR EXCHANGE— llcnt for research work and isure- $1. Mechanical, electrical magazines cheap, Pri or i ther small 1M V. 60 cycle lesson Taxidermy Course, $0. Trade paid except magnetos, motor, wire. Stamps SELL—40 or «diat have ? information. \ I motor, opera glasses, you 3 yrs. Youth's Companions for Al, 2 slide tuner. money order, or write foi further Samuel Cohen, 1936 Pitkin Ave.. Brooklyn, N. Y. William Litwitler, Hopedale, 111. Kenneth Bard, Manawa, w ia writing to advertisers. You benefit by mentioning "The Electrical Experimenter" when — :

160 THE ELECTRICAL EXPERIMENTER June, 1917

3BBT Opportunity Exchange \70TJ will probably find more opportunities and real bargains in these columns than anywhere else in the country. Most good things in * life are hard 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 th.s section 4c. a word for each insertion. Count 7 words per line. Name and address must be included at the a!.ove rate. C;.sh should accompany all classified advertisements unless placed bv 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 accepted. Advertisements for the July issue should reach us not later than May 25. OVER 75,000 PEOPLE READ THIS JOURNAL EXPERIMENTER PUBLISHING CO., INC., 233 Fulton Street, New York, N V. 2|1UBI»» 4

BOOKS BOYS!—Funny blotters, 10c per bunch. Other IDEAS WANTED— Manufacturers are writing samples included with order, with wholesale for patents procured through me. Four books Read the TO GET BETTER PICTURES— prices. The Noveltv Distributing Agency, Box with list hundreds of inventions wanted, sent Weekly; illustrated Amateur Photographer's 382, Marshalltown, fowa. free. I help you market vour invention. Advice criticisms; many weekly prize competitions; print Free. R. B. Owen, 130 Owen Bldg., Washington, unique features, $1.50 per year; three months' CASH YOUR SPARE TIME INTO MONEY. trial subscription, 25c; Abel Publishing Company, One young man made $1,800.00 in two months. 401 Caxton Bldg-, Cleveland, Ohio. Sells to every automobile and motorcycle owner. PATENTS ON EASY PAYMENTS—Send interesting "BOOK OF KNOWLEDGE"—An Representatives wanted everywhere. Be first in model or sketch for Free Search new and and Certified book revealing valuable trade secrets, your territory—write quick for free sample and Registration of your Invention for your Pro- Send 25c scientific discoveries and old mysteries. particulars. Everhold Fabric Patch Co., Chanute, tection. Free book tells what to invent and bow Tripp Ave., in coin to H. J. Kunow, 2246 N. Kansas. to obtain a patent on easy payments. C. C. Hine- Chicago, 111. & Co., 593 Loan & Trust Bldg.. Washington, DO YOU WANT back numbers of THE ELEC- FOR SALE—Tents, one 40x80 ft., round top, TRICAL EXPERIMENTER? Send for bound four 20 ft. center poles, 9 ft. wall; bargain; $°-0. issues from May, 1915, One 16x24 ft. hip roof, square end, 7 ft. khaki volume No. 3, containing PATENTS—Without advance attorney's fee-; drill wall, $20. One 12x19 ft. square end, 6 ft. t to April, 1916. Price, $1.25. Postage on 7 lbs. Not due until patent allowed. Send sketch for 8 in. wall, $14. All tents complete ready set is extra. Experimenter Pub. Co., 233 Fulton St., to free report. Books free. Frank Fuller, Washing- New York City. ______up. V. G. Gustafson, Joliet, 111. ton, D. C. Scientific and wireless supplied. Let BOOKS— BARGAINS— Selling out music. Over $3 we will quote you. us l_iow what you want and value for $1. Sample 10c. B. Scholz, Majestic St., York PHONOGRAPHS Experimenter Pub. Co., 233 Fulton New Theatre Co., Sheboygan, Wise. ( ity. BUILD VOUR EVERYBODY WANTS IT— Folding Pocket OWN PHONOGRAPH or A BINDER for THE ELECTRICAL EXPERI- manufacture them for profit. Drawings, Coat and Hat Holder. Can attach anywhere and instruc- MENTER will preserve your copies for all time. tions, etc., twenty-five cents. Satisfaction guar- remove instantly, nickel plated. Sample 10c. Big Price, 50c. Postage on 3 lbs. is extra. Send for anteed. Circular free. Associated Phonograph seller for agents. Wedge Mfg. Co., "Km" Bing- one todav. Experimenter Pub. Co., 233 Fulton Co., Dept. E., Cincinnati. hamton, N. Y. St., New" York City. CHEMICALS 25c Diminishing card trick, apparatus included STAMPS COIN'S—CURIOS for 5c, just to introduce big free catalog. Aladdin, CHEMICALS FREE for growing chemical Neillsville, Wis. plants. To introduce our chemicals and appara- 50,000 coins, medals, notes, Indian relics: 35,- tus to Experimenters, we will send free, the neces- 000 antique firearms, daggers. Catalogue, 4c. Second-hand drafting instruments. sary chemicals to grow trees, grass, etc. Send WANTED— Antique Shop, 33 South 18th St., Philadelphia. Highest prices paid. Send complete description 10c coin (refund on first order) for postage and catalogue. Zenith Chemical Laboratories, 307 and we will make offer. Deutsch, 2358 Pitkin Ave., Brooklyn, N. Y. STAMPS— 75, all different, free. Postage 2c. West Second St., Duluth, Minn. Mention paper. Quaker Stamp Co., Toledo, Ohio. CHEMICAL EXPERIMENTERS!! MARCONI—We have a limited number of I can supply you with any chemical known, pictures of Guglielmo Marconi, Nikola Tesla and tn any quantity, dirt cheap. Also formulas. Write Charles P. Steinmetz that are done in sepia on WIRELESS for price list. The Swimmer Chemical Co., 1904 fine India paper. Fine for decorating your wire- postpaid. Experimenter Park Place, Brooklyn, N. Y. less room. 10c each ELECTRON RELAYS, Moorhead tubes, Len- Publishing York Cit; Co., 233 Fulton St., New zite detectors, Racine motors. Authorized repre- EXPERIMENTERS— Are you interested in PATENT ATTORNEYS sentative. S. & T. Sales Co., 69 Freeman Ave., novel chemical experiments? Send 10c for large East Orange, New Jersey. collection. Merel Sager, 44 Apple St., Tiffin, Ohio. PATENTS— R. Morgan Elliott & Co.. Patent HELP WANTED Attornevs, Mechanical, Electrical and Chemical FDR SALE—$35 R.A.-6, $28. Special $42.50 Experts, 716-724 Woodward Bldg., Washington, R.A.-6, genuine polished mahogany Formica panel, THOUSANDS MEN, WOMEN— 18 or over, D. C. $33. $15, 3,000 meter coupler, $0.75. Regener- WANTED for U. S. Government jobs. $75.00 ative panel with vacuum bulb, variometer, con- to $150 month. War means many vacancies. densers, rheostat, etc., $14. 1,000 meter coupler, Steady work; short hours; rapid advancement. special for above panel, $5. 5,000 meter loading Common education sufficient. Write immediately coil, switch and 12 points on hard rubber panel for list of positions now obtainable. Franklin to be used with above coupler, $5. All above Institute, Dept. C 27, Rochester, N. Y. high grade, brand new instruments. Also one —- used electron relay cabinet, damped andi undamped MISCELLANEOUS 151 LAKE AYE.. hookup with bulb, $8. Y. G. Gustafson, Joliet, III. Lancaster, N. Y. ELECTRICIANS—Send 5< for 1U Blue Prints of Motor and Generator Connections. 28 for Feb. 22, 1917. FOR SALE—To dispose of the following instruments, I $1, 10 A. C, 4 D. C. Motor Winding Diagrams am offering same far below the orig- for $1 or 20 A. C, 4 D. C, and 4 Rotary Con- inal cost. Three sections, Murdock Moulded Con- densers, verter Drawings, $1.60. * Winding made easy. Gentlemen $4. One K. W. Oscillation Transformer, $4. Sayville Rotarv Spark Gap, $o. E. I. Co., Martin Electric Co., 329 Irvington PI., Denver, I wish to tell you that my ad. in Colo. Transatlantic Phones (2,000 ohms) $4. The the E. E. was a great success, and above-mentioned instruments are in first-class condition. If interested, write for particulars. Wi >KN < iUT DRY BATTERIES CAN BE re- RECHARGED for less than one cent. Send exceeded all expectations I had Charles W. Havlena, 934 18th Ave., E., Cedar twenty cents Rapids, Iowa. for formula to E. Bohner, 1009 plies before I had received a copy of South Wabash, Chicago. the issue myself. This goes to show AMATEUR BENCH LATHE—Austin make, WE WANT HUSTLERS to handle fast sell- with 8" between centers, 3 spedd pulley, very strong, ing household necessities. Big profits, beautiful that every issue is looked for neat and efficient. Price only $3, worth double. premiums, free particulars. Variety Supply, :i great interest, and the wide field your Limited supply on hand. Louis E. Schwab, 3708 East St., Providence. R I Brooklyn Ave., Cleveland, Ohio. paper covers. I certainly will recom- FOR SALE—Cameras, 400 Exposure Kodak with stereopticon enlarger; for cost $56; sell $30. mend it to the amateurs that have WANTED—One K. W.— Have Willard Storage One 5x7 Seneca folding camera, 3 plate holders, Batteries to exchange. Large Tesla and Oudin tripod, carrying case, etc., cost $2, $2.50, sell for something to trade or sell. coils, $3.24 and $2.75. Panel loose coupler, $4.25, $12. One 4x5 magazine camera, aluminum plate Yours respectfully, etc. Telephone ringers, 60c; coils, 3 for 25c. holders, carrying cas« , eti . cost $15, sell for $6. Stamp for pictures. Garden City Radio Club, G. Joliet, 111. G. W. r.RAHFOPD. V. Gustafson, Garden City, Kansas. ATTENTION! Secret ink; invisible when written, and can Ci IILSI COILS! ("oil S' nnlv be seen by our special process. Price 10c. 1 4" spark coils, excellent condition, $1.50. Sat- The Swimmer Chemical Co., 1904 Park PI., Brook- isfaction guaranteed. Jacob Eisgran, 1520 St. lyn, X. Y. mIIIUMI M.trks Ave., Brooklyn, N, Y.

You benefit by mentioning "The Electrical Experimenter" -juhen writing to advertisers. 1

***!»» /*\i \1 tI DOING

FIVE minutes of actual practice properlj directed is worth more t" a man than years ami years of book study, indeed, Actual Practice is the only training oi value, and graduates "i New York Electrical School have proved themselves to be the only men that are fully qualified to satisf) EVERi d<

mand of the Electi ii -inn.

w; At this "Learn by I ' i n " School :i man acquires the art of Electrical Drafting; il. business method and experience in Elei Contracting, together with the -till t'> install, operate and mainla'n all svstems for producing, tnitting ami ustnq electricity A

t t i )M and Young. Individual instruction. Letters from Successful Men

"I have done well since leaving school and iow Superintendent of tin- light, telephone and Mcani heal company here." "Beginning last April, extensions to the plant called for an additional equipment ol 300 kw., mi I prepared plans anil specifications foi a 600 kw. sub-station—looked after the erection of the building and then installed the equip

ment. The cost of the equipment was • Tins plant has been in operation for 51 months—without a hitch —and for its size is the best sub-station in the camp. "I am now preparing plans for another station of the same size, for the North Thompsun Mines, with whieh this property (Vipond) has lately been consolidated. The equipment of this property inside of a year probably will be 1,000 to 1,200 kw., etc., etc. "I hope this resume of my work has not been too lengthy. During this year I acquired a wife and home. With best wishes to all." "I have a friend that is pointing for a degree in Electrical Engineering, and I have advised him that he is making a mistake when he con- siders anything other than the course given by

1 m \\ V. E. S. Best wishes for the school." "As this card indicates I arrived here in Petrograd, safe and sound. Censorship forbids mentioning the work that I am doing for the Government, but of course you can guess what it is. Regards to the instructors." "Am in Central Station work, and am manager of the local system. I took charge June, l'H.l. I started at $90.00 but at preseni am pulling down $150.00 with another substantial advance in sight." New York the Center

We are located in the heart of New York City and you can see the advantage of that. New York' is the heart of everything electrical — there are big plants nearby, electrical exposi lions, libraries and facilities for good, quick work in an atmosphere of industry. A large number of our students come from other cities, from all over the United States. They realize the advantage of coming to New York to learn electricity. About 4,500 in all have gone out from our school into sua You can do the same. We believe that with us you can learn more thoroughly and more quickly than anywhere else because we give vim prtti tice. We teach you only what you And Now

If you have an ambition to make a name for yourself in the electrical held you will "' wan I to join the New York Electi ical Ii will be .in advantage to you to start at onci Then you should hurry to send for our 64 page book which tells you alt about the school, with pi< tures of our equipment and students

,11 work, and a full description of the 1

!. You need not hesitate to send for this I It is FREE to everyone interested in electi It will not obligate you to send for it. Send the coupon or write us a letter. Hut write us now while vou are thinking about the 5 of electricity.

School open to visitors 9 A . M. to 9 P. M.

New York Electrical School NEW YORK ELECTRICAL SCHOOL I 29 W. 17th St., New York, N.

29 WEST l7i£ST., Please send FREE ami without obligation to me your 64 page book JEW Y0RK,N.Y. NAME J ADDRESS

n entioning ' The Electrit a 1

ticcee Th/s interesting story shows you the way to greater success in the Electrical Field. 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 position.

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 M For the man not getting a in Electrical Engineering, presenting the information in a college training and even in that case. 1 can sincerely S3y I it. Only 81.00 per yolume and owners of way you can use theset do not believe there is a better say there are no better electrical books published at any price. set of books in the market today." Lloyd D. Huffman They fit your Dayton, O. Specially Arranged for pocket and your *' We consider Hawkins Elec- trical Guides the moat compact Reference and complete set of electrical Home Study and {SSUfeSn^* references in the market." flexible black Noggle Electric Works buckram with gold edges. Easy to read and handle. Monterey, Cal. You can i i. volume about with you until you "Hawkins surely knows the have i it contains. Written in the form of questions you -would art of condensing informa- ask and the answers to them—in plain. tion." Elbridge F. Ball practical, everyday 1 complete, concise, authentic and Buckland. Conn. to the point. Over 32 rid more than 4,000 illustration:

10 NUMBERS IN ALL

A Number PAYABLE 00 A Month Shipped to You FREE

YOUR% r A Send no money. Examine the books first. Decide for yourself that they are the most FREE ^^. complete library of Electricity ever published and that you cannot afford to be without them. Every book is complete in itself, but the complete set is the best bargain. The COUPON ^^ ^^^ last volumes are just coming oft the press. ^^ CACV DAVMFNTQ Accept this unusual offer now— to-day. Each Theo. Audel & Co. N^^ CAwl rHf InClllO page—every illustration will convince you of 72 Fifth Avenue, N. Y. the big value we are offering. See the ^^^^ SUBJECTS Please send me for FRi first, then decide. If you de- A FEW OF THE ^^^ books Magnetism—Induction—Experiments— Dynamos ination Hawkins Electn. • ^^^^ 1 * 1 .. .u~™ . .^.. ~~« -«~l-~ —Electric Machinery—Motors—Armatures—Arm- ,p r ..nee cide to keep them you can make jee sinp at -^^ ature Windings— Installing of Dynamos— Electn- prepaid the TEX numbers. 1 ^^^^ settlement at only SI. 00 monthly cl Instrument Testing — Practical Management isfactory I agree to scud you $1.1 of Dynamos and Motors—Distribution Systems- month until paid. ^k> until paid for Wiring—Wiring Diagrams—Sign Flashers—Stor- age Batteries— Principles of Alternating Currents and Alternators— Alternating Current Motors- Signature Transformers—Converters— Rectifiers—Alternat- ^W Theo. Audel & Co. ing Current Systems—Circuit Breakers—Measur- Occupation ing Instruments—Switch Boards— Wiring—Power 72 Fifth Avenue Stations — Installing — Telephone — Telegraph — Business Address Wireless— Rells— Lighting— Railways. Also many NEW YORK Modt-rn Practical Applications of Electricity ana Residence Ready Reference Index of the 10 numbers. Reference E. E.