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www.americanradiohistory.com The Electrical Experimenter Published by Experimenter Publishing Company, Inc. (H. Gernsback, President; S. Gernsback, Treasurer; M. Hynes, Secretary), 233 Fulton St., New York Vol. III Whole No. 32 CONTENTS FOR DECEMBER, 1915 No. 8 FRONT COVER-"A CANAL SCENE ON MARS" THE RADIO TRANSMITTING SET AT ARLINGTON, VA 406 From a painting by Thomas N. Wrenn - I :NITER S'T'ATES ARMY FIELD RADIO SET 407 RADIO LEAGUE OF AMERICA 381.389 L.titOR. \TOl4Y EQUIPMENT FOR ILLUSTRATING THE PRINC1- BARON MUNCHHAUSEN'S NEW SCIENTIFIC ADVENTURES.. 1'I.LS OF ELECTRO-hIAGNETIC, MAGNETIC AND ELEC- By Hugo Gernsback. 386.388 TItO- DYNAMIC I'll ENOMENA. By Harlan A. Eveleth 414.41; HOW THE "WIRELESS WIZ" CELEBRATED XMAS HOW TO t\1:\KE AN ELECTROLYTIC RECTIFIER By Thomas W. Benson. 389.390 ., R. Barmckol 41G BUYING BY MAIL. By Thomas Reed 391 A l'Ei(tIANEN1 M\GNET TYPE VOLTMETER TO FOIL SUBMARINES WITH UNDERSEA SEARCHLIGHTS... 392 By Earle Reisinger. 417 11Y WIRELESS 'PHONE FROM ARLINGTON TO PARIS 393 "HUN-TO- M. \KE-IT" DEPART\MEN1 419 AUDION BULBS AS PRODUCERS OF PURE MUSICAL TONES.. WRINKLES, RECIPES AND FORMULAS ...... 423 By Dr. Lee de Forest. 394 -395 "\\'ITII THE AMATEURS" DEPARTMENT 424 -425 THE UNITED STATES ADVISORY BOARD AND ITS PER- LATEST PATENTS . 426 SONNEL 398.399 Titi IIVCV nATCIVTC 427 THE ELECTRICAL BURGLAR OF THE 20TH CENTURY 400 OFFICIAL LIST OF LICENSED RADIO AMATEURS 428 A REMARKABLE ELECTRIC PIANO PLAYER FOR THE OFFICIAL CODE CHARTS GIVING INTERNATIONAL RADIO "MOVIES." By Frank C. Perkins 400 SIGNALS, CONVENTIONS AND ABBREVIATIONS 429 MARVELOUS ELECTRIC SIGN THAT ACTUALLY SPELLS 401 "QUESTION BOX" 430 HIGH FREQUENCY CURRENTS AND APPARATUS (Concluded). "PATENT ADVICE" 441 By H. Winfield Secor, E E. 405 BOOK REVIEWS 446

11J1111111111111J1 ,JLL+J 1.11.,1-10.1-11,ilAgtaJkilf,c19 1.1-11,1,1 111, t ,J Ok Edison and Tesla F the recent cabled reports be correct, every inventions which Mr. Edison has patented up to this American will note with great satisfaction date. The incandescent lamp would not have been o the awarding of this year's Nobel prize in much of avail to humanity had not Edison perfected G'l'vg `1 physics to Thomas A. Edison and to Nikola at the same time the necessary adjuncts to feed the Tesla. current to the lamp. He had to make dozens of in- When Alfred Nobel, the multi- millionaire inventor ventions to accomplish this ; the lamp itself was the of dynamite and nitroglycerine died in 1896, his will least of his troubles. Exactly so with the phonograph provided for a series of five annual prizes to the most and the cinematograph several hundred inventions deserving persons in physics, chemistry, medicine, lit- were necessary before either .4 as ready to leave the erature and for the best work done in the interest of laboratory. Thus it is a far cry and a weary road universal peace. from his first tin foil phonograph record to his gold These prizes have been regularly awarded since moulded unbreakable Aniberol record. 1901, and the learned Academies of Sweden while ad- Equally as great as the three above inventions are mittedly well informed and fair as to the award of Edison triumphs in the field of telegraphy, which he the prize, have in the past, we believe, overlooked sev- revolutionized. His quadruplex telegraph. his tele- eral scientists who by all means were entitled to the phone transmitter, his alkaline storage battery, his prize long ere this. stock printer, his machine for separating magnetic ores, We are quite convinced, for this reason, that this his Portland cement process, his concrete building year's choice of Edison and Tesla will not only be ac- standardization. are all inventions of the first order. claimed in the United States, but in the world over. While Tesla's inventions have not been so numerous For, if the world is indebted to two physicists, Edison as Edison's the world nevertheless owes Tesla a tre- and Tesla are certainly the biggest single creditors. mendous debt. The modern transmission of power The awarding of the Nobel prize in a single year electrically is due entirely to Tesla. Perhaps his great- to these two world renowned inventors naturally leads est invention is the alternating current induction motor, to the question: Who is the greater man, Edison or whose wonderful flexitility and vast usefulness have Tesla? A natural question such as this which surely made electrical power what it is to -day. His pioneer will arise in the popular mind is manifestly unfair, be- work in high frequency currents showed the true cause the two illustrious sciertists have been working genius of the man. This art is as yet but in its in- in dissimilar fields and their accomplishments are fancy and no one can foretell where it will lead us. vastly different. Besides, Edison as well as Tesla are but it certainly has already opened the way towards hard at work at this minute. and for that reason it is the transmission of power without wires. It is not impossible to foretell what they might not still accom- popularly known, but the fact remains that Tesla in- plish. vented a system of transmitting wireless impulses Without wishing to minimize Edison's tremendous through the ether in 1F93, three years before Marconi amount of work, the fact is well known that he is not began his historical wireless experiments. His won- so much an original inventor as a genius in perfect- derful researches on vacuum tubes under the influence ing existing inventions. of high frequency Tesla currents have practically dem- !kJ In this respect Tesla has perhaps been the reverse onstrated that the day is not far off whe'n the 95 per for he has to his credit a number of brilliant as well cent. of electrical energy now waste... in heat in all as original inventions which, however, have not been incandescent lamps will be turned int- cold light, that sufficiently perfected to permit commercial exploita- is light without heat. In the long list of brilliant in- tion. ventions of Tesla, we particularly wish to mention the If the average man were asked what Mr. Edison's following: His Sun motor for the utilization of solar greatest gifts to the world are, his choice probably energy, his new fluid propulsion turbine, the Tesla would fall on the Incandescent lamp, the Phonograph high -frequency coil, his rotary transformer, etc. Mr. and the Cinematograph. Undoubtedly this is a good Tesla's patents now number above 100. selection, but it is but a small fraction of the 1,400 II. GERNSBACK.

1,11010)4141.41.11.10.11119-1.1-l0,10f - _1.11-19411A11.1.1141) ..,.JJ TILE ELECTRICAL EXPERIMENTER is published on the 15th addressed to: Editor, THE ELECTRICAL EXPERIMENTER, 233 of each mouth at 233 Fulton Street, New York. There are 12 num- Fulton Street, New York. Unaccepted contributions cannot be re- bers per year. The subscription price is $1.00 a year in U. S. turned unless full return postage has been included. ALL accepted and possessions. Canada and foreign countries, $1.50 a year. contributions are paid for on publication. A special rate Te pald U. S. coin as well as U. S. stamps accepted (no foreign coins or for novel experiments; good photographs accompanying them are stamps). Single copies, 10 cents each. A sample copy will be sent highly desirable. gratis on request. Checks and money orders should be drawn to THE ELECTRICAL EXPERIMENTER. Monthly. Entered as order of THE EXPERIMENTER PUBLISHING CO., INC. If you second -class matter at the New York Post Office, March 1, 1915. change your address notify us promptly, in order that copies are under Act of Congress of March 3. 1879. Title registered U. S. not miscarried or lost. A wrapper indicates Patent Office. Copyright, 1915, by E. P. Co., Inc., New York. The g -een expiration. contents of this magazine are copyrighted and must not be repro: All communications and contributions to this journal should be dneed without giving full credit to the publication. 379

www.americanradiohistory.com 380 THE ELECTRICAL EXPERIMENTER December, 1915

MAKE YOUR WAY M E S C 0 L I T E SAFEWILL and BRIGHT

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The MESCOLTTE can also be supplied with a "Special" two cell dry battery which will give approximately GO hours of continuous and 120 hours of intermittent service.

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0414Maa)-on benefit by opentio n, nnwww.americanradiohistory.com "The Electrical Experimenter" when Titi np fo advertisers. II 4,,,THE ELE.CTRICIL EXPERIMENTER

H. GERN 5 B ACK EDITOR H. W. 5ECDR A55OCIATE EDITOR Vol. III. Whole No. 32 DECEMBER, 1915 Number 8

The Radio If deague of America HONORARY MEMBERS Captain W. H. G. Bullard, U. S. N. Prof. Reginald A. Fessenden. Nikola Tesla. Dr. Lee de Forest. Manager, H. Gernsback

A Retrospect. activities of every wireless enthusiast in thermore succeeded in enlisting the press of URING the past year the need of the country. the country in taking up the cry to save the a national body to champion the This, of course, brought the amateurs to amateurs from hostile legislation. All this D cause of the wireless amateurs their senses speedily, but had it not been had the desired effect, and when finally in in the United States has become for the formation of the Wireless Associa- 1913 the Alexander Wireless bill, amended, moro and more was signed by President pressing. There are now over Taft, thereby becoming law, 300,000 radio. amateurs and it contained almost word for about 350 local clubs in exist- word Mr. Gernsback's histor- ence in the United States, but ical recommendation of his there is no national body to editorial in the February, safeguard the interests of moo. sus* 1912, issue of Modern Elec- the amateurs. r-..u,.186E0-p; trics. As is well known, that When H. Gernsback, in NAVY DEPARTMENT, editorial called the attention 1909, organized the Wireless U. S, NAVAL RADIO SERVICE, to the lawmakers that in case Association of America, Dmv O. x, errt.i.T,.o[ . the amateurs were to be re- there did not exist at that RADIO, VA, stricted the latter should be time a wireless club in the allowed to operate their sta- United States. There were tions at a wave length below then, of course, numerous 200 meters, and they should radio amateurs in this coun- furthermore be allowed the try, but the wireless art -as use of power up to one kilo- saved far as the amateur was con- 8 Cernabaok; Salter watt. This suggestion cerned only in its earli- The Reperimenler.Publiehi Co., the day, and the amateur at -was 238 Fulton street, est infancy. Mr. Gernsback, New York, N. T. last had come into his own. who at that time sensed ap- With the passing of the S 1 r: proaching danger to the wire- wireless act in 1913 the use- In a000rdenee with our telephone oenverastion last even- fulness of the Wireless As- less amateurs in the form of ing and confirming it, I have no objeotion to be considered as hos'i'e legislation, succeeded sn Honorary Member of the Radio Leese., end will -be glad to be socia'ion of America had $Ieooiated with others interested in the general aubleot of mobi- come to an end, and thus in banding together the ma- lising the amateur radio operatore of this country with the view jority of wireless enthusiasts, of enlisting their aervioee towards a general uplift of the matters rested. oieaoe in general as well ea cooperation in preventing lateen, and the membership of the ease with the legitimate handling of government and commercial association grew rapidly till buaineea end further with the idea of enlisting their interest In operation whereby their eereloee man be made available under gov- A Formidable Defense at the end of 1912 there had ernment supervision if the time ehenld ever arise when the govern. Weapon. been enrolled no less than ment would feel that their aervioes were desirable, and neoseaary. 22.300 members. HE advent `of the In those early days the great European war wireless amateurs in this in 1914 found the country were a rather reck- United States in less sort of element and be- an unprepared con- came more and more disliked dition as regards its defenses on account of their growing and vigorous steps were mischief. False distress and promptly taken to wake us alarm calls by perverted up from our lethargy. Presi- "humorists" were the usual dent Wilson's recommenda- "smart" acts, and when a tion to the country for a vast coastal station received a increase of our army and C.Q.D. call in those days the navy has been so much dis- Captain Bu Ilard's Letter of Acceptance as Honorary Member In the Radio thought was always upper - League of America. cussed of late that no further flfi most in the operator's mind reference to his valuable ad- that the call was one of the usual amateur lion of America a year earlier, all efforts vice is required here. It suffices to say hoaxes. Despite Mr. Gernsback's vigorous would have been in vain and the amateur that probably a vast majority of citizens warnings through his editorials in Modern would to -day be as dead an issue as he is indorse the President's defensive military Electrics, of which publication he was at present in Europe. Through the Associa- program. editor, the mischief continued, till in 1910 tion Mr. Gernsback caused thousands of But there exists to -day a formidable de- several bills were introduced in Washing- letters to be written to Washington offi- fense weapon, which up to now has not ton which fairly promised to throttle the cials by the wireless amateurs, and he fur- been exploited by Uncle Sam. We refer

www.americanradiohistory.com 382 THE ELECTRICAL EXPERIMENTER December, 1915 to the thousands of amateur The Duty of the Amateur. radio stations scattered broad- F Uncle Sam grants the cast through the en.ire length amateur the free use and breadth of this fair land. kS of the ether it is cer- There is hardly a hamlet to- tainly up to the ama- COMPAGNIE FBANÇAISE.NES CÂBLES TÉLÉGRAPHIQUES ` "'"' day which dos not boast of teur to give something several amateur wireless sta- in return for the privi.ege. It tions, and their number is in- was with this thought upper- creasing by many hundreds es most in his mind that Mr. each day. ... u".r ' 4 Gernsback in July, 1915, first As the European war has L04/7"11117 TuA

Professor Reginald A. Fess- Nikola Tesla's Acceptance enden's Acceptance as as Honorary Member in League of Honorary Member in the the Radio Radio League of Amer. America. Ica.

Abose: Dr. Lee de Forest's Acceptance licensed since 1913. The reason for this enemy and whole sections of country are the as Honorary Member in Radio is found in thereby isolated. Such sections are then League of America. surprisingly small registration helpless and no important messages can the fact that the law does not require re- licensed, small be safely transmitted in either direction. ceiving stations to be nor All this helps the enemy enormously, and bay temporarily. It is conceivable that this sending stations located in the interior of the thus isolated section is then entirely at small body of men might have neither send- large States, where the effect of a weak his mercy. If France or Belgium had pos- ing nor receiving radio apparatus. Some- spark coil would not extend over the State an effective amateur wireless scout where back of the hills the United States borders, Such stations are exceedingly sessed to run service there might possibly be a different regulars are coming to the rescue of the numerous and have been estimated story to tell to -day. In these days of fast sorely pressed militia men. They want the above 300,000. Now, then, there appears no military movements, quick reporting of war latter to hold out for a few short hours and reason for doubt that sooner or later the law requir- intelligence is of incalculable importance, want to tell them of their comir.g. The Government would pass a new this is true of Europe, it is even radio message containing this intelligence ing the registration and licensing of such and if in truer in the United States, the country of is flashed over the hills, but is not received stations order to have such stations case stress. such vast and undefended coast lines. by the exhausted men. However, just as available in of national can such One needs not be a dreamer in order to all hope is given up, a lad of 17 years with No one foretell what surprises a new law bring amateurs, and for appreciate how easily a hostile fleet could streaming hair runs up to the major of the will the approach our long, badly patroled coasts small band and breathlessly conveys the that reason it cannot be denied that it is better and more to give this and try a landing of an armed force. There cheering news to him. He caught the mes- far patriotic necessary information the might not be a telegraph or telephone line sage over his pitiful 30 -foot aerial on top voluntarily to around for miles, or if it did exist, it is of his barn, but it saved the day. He did Government, instead of waiting till a new law is passed which be detri- certain that spies operating on land would not even have a sending station. His out- might perhaps mental the viewpoint the amateur. have found little trouble in putting it out fit comprised only a cheap home -made re- from of of commission beforehand. ceiving "set"! But it did the work, just the But there will be a lone radio amateur same. The League's Charter. on the alert who has seen the approaching Such occasions are almost certain to arise HE Radio League of America was fleet and within 30 seconds Washington will in the future, and it is thus of the utmost T organized at New York under have the priceless intelligence. Vice versa, importance that every patriotic radio the laws of the State of New there might be a handful of poorly equipped amateur should offer his station to his repa York in October, 1915. United States militia holding the enemy at country. Its charter follows:

www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 383

CERTIFICATE OF INCORPORATION will publish the league's news from month or in person, and that I will do everything OF THE to month, thereby keeping up the interest of in my power to bring assistance to the RADIO LEAGUE OF AMERICA, INC. its members. party or parties thus in danger. Rule 6. That I will communicate to the State of New York The League's Rules. League such information concerting the City of New York SS.: VERY wireless amateur of god construction of mv radio sta- standing, Ile has a send- operation and County of New York whether be helpful or instructive to the ing a receiving station, is eli- tion as will E or members of the League. We, The Undersigned, of full age, citi- gible for membership. There other zens of the United States, a majority of are but two conditions: Rule 7. That I will, when requested, fur- whom are citizens of the State of New 1. Ile must be a citizen of the United nish information concerning mv radio sta- York and resident therein, being desirous States. tion and observations, which intormation is of associating ourselves together for our 2. He must own either a sending or re- to be used by the League in its compilation mutual welfare and advancement, as here- ceiving station, or both. of wireless st- tistics. inafter is more particularly described. pur- Each member will be supplied with an Rule 8. That I will carefully read and suant to and i:1 conformity with Chapter official membership certificate furnished adopt any suggestions published by the Forty (40) of the Laws of 1909 and known free by the Radio League of America. Our League for the benefit of its members, and as the Membership Corporations Law, do illustration gives a good idea of this beauti- the transmission of wireless communica- certify and declare as follows: ful certificate, but it must be seen to be tions. hereby to hirst-That the name by which the said fully appreciated. It is lithographed on a Rule 9. That its case of my removal corporation hereby to be formed shall be heavy bond paper in green and gout. and its another address, or in case of the per- known and distinguished is and shall be size is 15x111/4 inches. The text follows: manent discontinuance of my station, I Radio League of America, inc. will immediately communicate such facts Second-That the purposes for which CERTIFICATE OF MEMBERSHIP to. the manager of the Radio League of the corporation is to be formed are as TO THE America. follows: RADIO LEAGUE OF AMERICA. Rule 10. That I will display my mem- To promote the art of amateur wireless organization bership certificate in the League in a con- United A membership organized un- in my radio telegraphy and telephony in the der laws of State of New York. spicuous place station. States among the members of the said In witness whereof I have signed my corporation; to have available for the Gov- I, the undersigned, a radio amateur, do name and address, etc. ernment of the United States or any of its hereby apply for membership in the Radio Each certificate is numbered and a mem- officials a complete list of all the amateur League of America, upon the express con- ber is entitled to one membership certifi- radio stations Its the country pledged to the dition that by so doing I do not assume or cate only. Before the League can furnish service of the Government for use in times incur any liability either for dues, assess- a certificate it is necessary that the pros- of national danger or need ; to establish a ments or any financial obligations whatso- pective member shall fill out an application uniformity in the transmission of wireless ever, and, if accepted, I do agree to follow for membership; a convenient blank being messages by amateurs; to uphold the pro- and abide by the rules and regulations of printed below. (If it is not desirable visions of a law known as the Wireless Act the league as set forth herein, and all other to cut up the magazine, a blank will be of 1912 and all subsequent laws pertaining roles and regulations which may hereafter promptly mailed on receipt of a 2c. stamp to wireless telegraphy; to assist the Gov- be adopted. to cover necessary mail charges.) ernment of the United States or any of Rule 1. To observe all rules and regula- No blank is valid nor can it be accepted its officials in apprehending offenders there- tions of the Wireless Act of 1912 (as set unless it is filled out properly as prescribed. to of ; to prevent the sending of misleading forth on the back of this certificate). Two persons must sign as witnesses wireless messages; to give information to Rule 2. That I will at :.11 times have my the signature and these may be two friends, the members of the said corporation con- station in readiness and at the service of or your father and your mother, or a sister cerning new and useful devices in the oper- the United States Government for use in and a brother, etc. ation of wireless telegraphy and telephony any defensive or offensive purpose in Upon receipt of the application blank the and to provide an organization for the in- periods of war, riot or disaster. official membership certificate will be in coin terchange of ideas concerning wireless Rule 3. That I will at all times allow mailed. Ten cents in stamps or telegraphy and telephony for the benefit of my station and equipment to be used by the should be inclosed to cover mail charges, the members and the public at large. United States Government or any of its handling, as well as the heavy cardboard Third -That the number of directors of officials, and will assist, if possible. in ap- tube to insure safe delivery. the said corporation shall be and are five prehending offenders violating the Wireless Upon receipt of the membership certifi- (5) in number; and that the names and Act. cate by the member it must be signed at residences of such &rectors who shall man- Rule 4. I furthermore solemnly and dis- once in ink in its proper place, and it age its concerns until the first annual meet- tinctly pledge myself not to send out at any should then be suitably framed and hung ing are as follows: (See below.) time whatsoever, a misleading cast, particu- up in the station in a conspicuous place. Fourth -That the territory in which the larly a distress call (S. O. ... - - - It will give your station official recogni- operations of the corporation are to be . .) nor knowingly allow anothe: to use tion, and within the next few months the principally conducted is the entire United my station for sending out such a call. amateur who cannot produce an official States, and that its principal office shall be Rule 5. That I will at all times. in case membership certificate will hardly be looked and is located in the Borough of Manhat- of necessity transmit a distress call to the upon on a par with officially recognized tan. City, County and State of New York. nearest official, either by wireless, by wire, amateurs. He will have but little standing the said corporation shall 1111111111 Fifth -That 'ln!IIIIII!11119'l'l', III "rlllAllll9111111'd' : :IIIIIII1IppIIN' I''9111'.'gall^ IIIIAIIIIIIIIIIIIIIallllllllll !IIIIIII111111' 11111: l: IIIAIIIIIIIIIIIIIIlIl1IIIIIIIIIIIII11111 P,IIIIIIIIpIIII !1pInIIIIIlI1'n111' VIII' lllllllll! IIIIIIp1111pp111p hold its annual meetings on the first Mon- day in October in each and every year be- ginning with the year. 1916 (October 3, Application for Membership in the Radio League of America 1916), and annually thereafter. In Witness Whereof we have made and ' THE UNDERSIGNED, a Radio Amateur, am the owner of a Wireless Sta- signed this certificate in duplicate and have tion described in full on the back of this application. My station has been hereunto set our hands and seals this 25th in use since , and I herewith desire to apply day of October, 1915. for membership in the RADIO LEAGUE OF AMERICA. I llave read all the Hugo Gernsback, Sidney Gernsback, rules of the LEAGUE, and I hereby give my word of honor to. abide by all the Milton Hymes, Harry W. Secor, Frederick rules, and I particularly pledge my station to the United States Government in the H. Pruden. event of war, if such occasion should arise. is a purely As will be seen, the League lm sent to the United States Government P. are no dues, I understand that this blank with my signature will scientific organization. There at Washington, who will make a record of my station. no membership fees to be paid. It has been officials organized under the auspices of the world's Witnesses to signature: Name greatest wireless men, who thoroughly in- City dorse its principles. It is not a money mak- ing organization, nor is it conducted by a tState t commercial wireless company for its bene- E Date 1.91. fit. The Electrical Experimenter has been Describe the apparatus of your station on the back of this application. eelected as the league's official organ, as = In the event of national peril, you will volunteer your services as a radio operator in the this journal, with the largest circulation of interest of th IT. S. Government' reaches any wireless publication at present, it. either directly or indirectly almost every This last question need not be answered unless you so desire

I III .1II,Lin VIII I111111111I11'31:1l II IIII II IIIIII11111111111111111111IIIIII1111 '111111011111:1:11111 C' :a".':11111121111I!!!I l':II I'I I'11I I II III wireless amateur in the country to -day. It d111111111111111111111I1111111111IIIIIIIIIIII II! 1141!11111111111I11111111111I11 VII1111111111111IIIIIIIII1111I11

www.americanradiohistory.com 84. THE ELECTRICAL EXPERIMENTER December, 1915

NAVY DEPARTMENT, ment messages might be received by un- them to their operators, with the result that many S. scrupulous amateurs not friendly to the civilian operators have engaged U. NAVAL RADIO SERVICE. home government renders some form of themselves to enlist in the Navy in time of 'OFFICE OF THE SUPERINTENDENT. protection necessary, and, I might add, will war. Could we not do something similar be advocated this coming Congress. to enlist members VA.. of your League, and RADIO, The Naval Radio Service is particularly would you lend your efforts to co- operate H. Gernsback, Editor, anxious to increase its operating person- along these lines by giving the matter a SIR: nel in time of public peril when many pri- little publicity? From the mon.hly list you I beg leave to acknowledge the receipt vate stations, ship and shore, would prob- propose to furnish we can get the names of your letter of November 8, 19:5, sub- ably be taken over by the general govern- and addresses of many amateurs, among mitting information concerning the Radio ment, and the thought has arisen that whom we might find many who would League of America, together with a copy through co-operation with the Radio wish to enroll themselves. Of course, the of the Certificate of Membership. League many of its members would like forwarding letter accompanying the circu- It seems to me that yeu have undertaken to enroll themselves for active service un- lar would have to be modified, but that to carry throug't a very patriot :z motive der the Navy Department at such times as could easily be done to call the attention of in banding together the great number of their services might be required. amateurs to how they can really serve their amateur wireless operators in the United You can readily understand that any country in time of need. States, which, as you state, now number information collected by the Radio Please accept my thanks for thus being probably over '10,000, of which only about League will be of the greatest value allowed to bnng to your attention certain 3,000 have been licensed; it being pre- to this service and this office will be views in connection with the Radio sumed that the remainder operate receiv- glad to avail itself of your kind offer League, an organization which can be made ing stations only, and under the law are to furnish such free of all cost, this to to be of the utmost help to the govern- not required to have lic ^uses. This latter contain the names, locations, etc., of all ment, and by focusing the attention on ex- proposition I regard as a very serious detri- amateurs in the United States. isting laws bring home to every amateur ment to the proper government control of I should like further to take advantage the desirability of co-operation all along wireless stations, and am of the belief that of this opportunity to ask your co- opera- the line to correct the great question of in- legis'ation should provide that all stations, tion in enrolling members of the Radio terference with proper government, com- whether for transmitting or receiving, League for government (Navy Depart- mercial and other legitimate correspond- should be licensed by the Federal Govern- ment) operation in time of war, and take ence handled by means of the wireless art. ment. Al.hough the teadio Act provides this opportunity to enclose a circular pre- Very truly yours, penalties for divulging any information pared in this office which we have sent out (Signed) W.H.G. Bullard, received by means of wireless receiving cir- to operating wireless companies in the Captain U. S. Navy, cuits, yet the fact that important govern- United States, who in turn have distributed Supt. Radio Service. as a wireless amateur, for he obviously lationship between you and these members In this book, to be issued once a -ear, refused to pledge his station to his Gov- depends entirely tiro., yourself. Thus the will be found all the important League ernment. news. a full listing of all the clubs and as- sociations, as well as a complete list of all Privileges of the League's Mcmbers. the members. NASMUCH as the League has The League particularly indorses and been organized for the benefit encourages the rendering of scientific lec- 00 of the wireless amateur, its tures by their members. The latter should members are entitled to the The League's write scientific papers, particularly those following privileges: Official Button. that have a wireless subject as its theme. introduction to other members. League will be highly instrumental in The president of the club should select the All members are registered on cards at bringing together members and cementing best paper in his oninion, and it should be the headquarters of the League. The names their friendship. sent then to the editors of the Electrical are filed by State and town. Experimenter. 1f it has sufficient merit it geographically Associations and Clubs. will Let us suppose you live in Plattsburg, O., LOCAL wireless association, or be published in due course in the Elec- and that you own a wireless receiving out- trical Experimenter. It will show the title radio club, to be officially of the author fit. You very much desire to know sev- A recognized by the League must as well as a sub -title, giving eral radio amateurs in your vicinity, but the name of the club to which the author have at least six members. belongs. you have no means of making their ac- EQ; There should be a presi- quaintance. As member of the League The Once a year the best-paper from among dent, a treasurer and a secretary. those that were you mail a letter to headquarters asking for address where such a body meets should published in the Electrical the names of any w'reless amateurs located Experimenter will be selected by the editors be stated. Clubs and associations should and this prize 1: your vicinity. Such information will be meet at least once a month. The above re- paper will be published in given free to members, providing a two the official year book. This honor will only quiremcn's are necessary to secure publica- be accorded to one paper. cent stamp is inclosed with the inquiry to tion in t'le Electrical Experimenter, as well cover postage. As a member of good as recognition in the "Radio League of standing in the League the other members Official League Insignia. America's Official Year Book." will receive you gladly, and the future re- V official button securable only by the JIIIIII'IIIIIIIIIIIIIIIIIII!IIIIIIIIII!IIIIIIIIII!IIIIIIIIII IIIIIIII IIIIIIIIUIIIIIIIIIIIIIIIIIIIIIIIII II IIIIIIII IIHIIIIII IIIIIIIIIII IIIIIIIIIIIIII IIIIIIIIIIIIIIIII IIII!IIIIIIIIIIIII II IIIIIIII IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIHIIIIIIIIIIIIIIIIIIIIIIIIIII IIIIIIIIIIIIIIIIIIIII IIIIIIIIIIIC League's members is illus- A tra'ed herewith. This distinc- tive, as well as striking, de- Description of My Station and Apparatus sign measures % inch in diarreter. It is inlaid in real, hard enamel in the three national colors, red, white and Sending blue. The aerial design as well as the mast is in gold on a dark blue background. The button is heavily gold filled and is guar- anteed by the makers not to tarnish for two years. It will positively not turn brassy. You will be proud to wear one of these distinctive buttons. The League furnishes the button at coat; the price, including mailing, being 20e. Both the membership certificate and the Receiving button will be sent for 25c. prepaid. A solid gold button as described above is furnished for $3 prepaid to those not desiring a gold filled one. The snlid gold button and the membership certificate will be furnished for $2.05 prepaid, the actual cost of both. All communications should be addressed to (OVER) THE RADIO LEAGUE OF AMERICA, IIIIIIIIP. 233 Fulton Street, New York City. www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 335

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www.americanradiohistory.com 386 THE ELECTRICAL EXPERIMENTER December, 1915 Baron Münchhausen's New Scientific Adventures By Hugo Gernsback

as always, at ex- is about 60 feet high, with an im- PUNCTUALLY,actly 11 P.M. the next even- Münchhausen is Taught "Martian" mense golden transparent cupola ing, Münchhausens dear old forming the ceiling. The tables, the voice once more sounded in my receivers. huge thing was as flexible as a velvet chairs, all the furniture, as well as all the There was the usual preliminary talk, after portière. When our host was but 10 feet objects for which we had no names, seemed which the Baron went on: away from it, it suddenly blazed forth in transparent. Even the walls seemed trans- "I am very much pleased, my dear Alier, a brilliant golden light which seemed to parent, as well as the soft, rug -like carpets that my Radiotomatic re- on which we walked. But lay station on the Moon the wonder was centered works so well. Up to NE of the greatest puzzles our astronomers and scientists had to not solely in the trans- last night neither Flitter - parency of the strange nix nor myself were sure contend with during the last decade is the problem of how water material, but in the fact if we could bridge the is moved in the Martian "Canals." Nearly all scientists of note that it gave forth a soft, 60 million miles between who have studied them do not question their existence, but they are all white light. Imagine a Mars and the Moon by at odds as to what agency moves such enormous quantities of water. It solid chair of glass, wireless, but by means glowing in a mellow, of our wonderful ultra is singular that most of them suggest a form of pump to move the water white light-not a bril- sensitive radio -active de- in the canals, as our present -day knowledge of science and mechanics liant light-and you have tector we were enabled leaves them no other choice. a good idea what we be- to 'listen in' successfully. held. It struck us at When I had finished talk- But what makes our rivers flow on Earth? What agency condenses once that this wonderful ing last night, it was billions of tons of ocean water and brings these waters down in form of material could be han- about 9 P. M., your ter- rains, which keep our rivers from drying up? The Sun, of course. Why dled at will by the Mar- restrial time. We got can't the Sun move the waters in the Martian Canals also? This instal- tians ; for, the luminous our receiving instru- rugs on which we stood ments ready at once and ment contains a new idea, how the Martians might accomplish it. were soft as velvet. promptly at 11 P. M. I while a desk -like object could hear ,myself talk- nearby seemed hard as ing. The message which I had sent a come from nowhere. Simultaneously the steel. The next thing which attracted most few hours before had been faithfully huge door, for this is what it was. rose of our attention were the luminous walls. recorded on the telegraphone wire of quickly up in the air just like a theater They were all paneled in a curious manner, my Radiotomatic on the Moon, and as curtain. Our host now entered into a and, of course transparent and luminous. soon as the automatic clock released the large circular salon -like room, followed Each panel had a vast amount of small sending machinery, the vibrations carrying reluctantly by us. hexagonal plate -like facets arranged some- my voice were hurled back to us over a I say reluctant advisedly. I have absn- what in honeycomb fashion. These hexag- distance of 60 million miles. From this lutely no adjectives to do the thing justice. onal cells were constantly changing in we knew that you must have heard the Our state of mind upon entering that soft colors, and the most unique. as well message too, for you are but 238 000 miles room was probably the same as if you had as pleasing, geometrical designs in colors distant from the Moon. While my 'canned' brought back to life Julius Caesar of the were thus unendingly produced. It was a voice undoubtedly must have sounded un- year 50 B. C., and had suddenly trans- fascinating sight, and we found it hard to canny to you -excuse the pun -I assure planted him some night on blazing Broad- take our eyes from these. walls. you that it gave me the creeps listening way in New York. His mind would have "At the far end of the room we noticed to my own voice, flung 60 million miles reeled at the -to him -marvelous sights. four Martians whom we recognized at through the ether! It would have taken him days and days once as females on account of their mass "But to come back where I broke off of asking questions and explanations of all of hair and their more delicate features. last night: I told you how several Mar- the impossible things he saw before him. Their heads seemed somewhat smaller tians had approached us and had placed a "Exactly so with us. Only Caesar would than those of the males, but they appeared soft metallic cap on our heads. I also have made a jump of but 1,965 years, to dress exactly like the men, except that told You how we then followed the august where we made one of over 200,000 years. the color of their metallic looking dresses Martian into the church -like structure. We were but uncomprehending children, was of a much lighter shade. But it was "While we walked over the hard metal- and our eyes and senses were absolutely not the 'girls' that drew our attention as lic- appearing walk, which conducted us to inadequate to do justice at once to the much as what they were doing. We could the structure, we became conscious of higher plane of civilization on which we not rid ourselves of the idea that these strange flashes in our brains. We also had been thrown so suddenly. We have females were some sort of secretaries to caught distinct, though faint, bars of a been on Mars eight days now and still we our host, and it was manifest that they soft music, which was followed by weird know practically nothing of this most were 'working' at something. And they pictures flashing through our minds. All miraculous world. Every day brings more appeared to be working earnestly and dili- this took place within our heads, and as tremendous surprises and at night we are gently, too, but there were no pencils, no I closed my eyes for a few seconds to test usually exhausted from all the excitement books, no paper, no typewriters; in fact, myself, the music as well as the picture of the continuous bombardment of new nothing whatsoever that a terrestrial secre- flashes persisted: I knew then that I did and wondrous things on our brains. tary requires to get up her superior's re- not hear the music with my ears, nor see "But to come back to the wondrous ports. the pictures with my eyes. I reasoned salon of our host, who. as we found out Instead each girl sat motionless in correctly that both had their origin with- later. was the reigning Ruler of the Planet front of a small glass -like table which was in my brain. Mars. The house in which we were entirely bare and flat, except for the center, "Before I had time to puzzle it out, we was a sort of executive mansion or from which projected two small glass -like had entered the structure at the heels of palace, and the room in which we were rods each about 4 inches high and as thick our host. We passed through a magnif- standing was what you might call the as a pencil. At the top they bent over and icent archway, constructed entirely of Ruler's office. formed a gooseneck pointing in the direc- some transparent material, decorated in "Here I must stop again to advise you tion of the girls. The rods were both superb taste in green, white and gold. that it is extremely difficult for me to ex- pointed at their ends, and while one ap- One thing struck us immediately; the hall- plain in existing terrestrial terms what peared luminous, the other seemed dark. way appeared as light as day, but we could we see, hear and feel, for everything on "The 'operators' were watching the point not see where the light originated. Later, Mars is so totally d'fferent from what we of the luminous rod intently, and the ex- though, we were to find out about this. are accustomed to al Earth. that my best pression of their faces was as if they "As the end of the hallway was a pon- comparisons with tr-restrial things must were reading something. Every once in a derous massive panel with a door -like of necessity fall far short of actual con- while they seemed to relax and at that appearance. It must have been at least ditions on Mars. Ho .vever, I will do my moment a curious white ray seemed to 125 feet high and 30 feet wide. It looked best to convey a true picture to you. pass from the light point of the rod into very much like cut glass with all its prisms "The thing that struck 's with greatest the point of the dark one. That was all and fancy cuts; we first thought it was force at first was that everything in this we could see. glass, but when we came closer to it we immense room appeared transparent. The "While we were still wondering our host changed our minds, for we saw that the room, which is about 150 feet in diameter, motioned us to sit down on the comfort- Copyright, 1915, by H. Gernsback. Ali rights reserved. www.americanradiohistory.com Decemb.r, 1915 THE ELECTRICAL EXPERIMENTER 387 able looking arm chairs. These chairs, as as if I had tried to think intently of the and stones. then we saw for a long period already mentioned, appeared like trans- terrestrial globe, as it stands silhouetted the slow evolution of Mars down through parent glass, but when we put our hands against a dark sky. Then in quick succes- the ages till a civilization similar to that on them they felt like satin and not at all sion followed our 'Interstellar,' the Planet of present terrestrial conditions was hard or cold. The transparent seats, Mars, a picture of our capture by the reached. There were the wars, the bar- which had a moment before appeared as Martians with their yellow rays and their barism and the thousand other evils exact- glass, were soft and flexible as an air - floating fortresses, then an exact picture ly as those experienced by man on Earth. cushion and extremely comfortable. The of how we appeared at our landing on Evolution, after all, is the same through- only trouble with the chairs was that they Mars. out the Universe, given like conditions. were too big for us. Built for large 8- It then dawned on us that our host was "As the story of the evolution went on foot Martians, our feet hardly reached the 'talking' to us, not in words and not in a we could see how the Martian's small head/ floor, so we sat in the chairs just as chil- strange language, but motion- picture -wise. and his small chest both kept on increas -, dren sit in big armchairs, that is with our I1'e had experienced the first transference ing with each subsequent generation. WO backs resting against the inside back of of thoughts, and had understood every- were shown how big oceans and inland il the chair and our legs and feet projecting thing our host had 'said: because he seas, as well as vast rivers, dried up grad -' straight out on the seat; and only then thought in pictures which were perfectly ually, and how the whole population turned were we quite comfortable. familiar to us, not in words which would into mechanics, electricians and chemists. "This position, ridiculous as it doubtless have had no meaning for us! When there No true happiness and contentment, how- was, evoked a faint smile from our host, was a lull we opened our eyes in astonish- ever, seemed to exist on Mars until thought who sat down in his own chair in front ment and blinked bewildered into the transference was established, till gravity of a large piece of furniture that was a smiling eyes of our august host. He was conquered and money was abolished.Í cross between a rectangular table and a seemed highly amused at our amazement There had been wars and disorders up to flat top desk, garnished in its center with and once more he motioned to us to close that period, but it seems that these three a huge birthday- cake -like affair with 10 our eyes. things, apparently invented and originated transparent and 10 dark glass -like candles, "For the next hour or more we liad our at about the same time, finally emancipated curved in gooseneck form. first lesson in 'Martian.' In easy stages the race completely. As we found out "Our host then turned around to us and our host first flashed simple pictures into later, this period was reached some 14,60Cí looked us over long and earnestly. His our minds, which were then followed by years ago. large, liquid blue eyes were wonderful in scenes with various actions and explana- "Beginning with that period only die, their depth; in them shone a wisdom as, tions just as in a moving picture scene, the Martians really become great. WI: indeed, we had never before beheld. His where the mind must infer what the actors saw how in less than five generation', face had a very benevolent expression, and are saying to each other by the expres- speech had been entirely abolished, it bed the features were clear and sharply de- sion of their faces and their obvious ing possible to 'converse' over considerabb fined. He appeared tremendously in- actions. distances by thought transference. Vv 41; tellectual, yet will power and strength of "There was a short pause, after which were shown the evils of too man; character radiated from his face in an our host launched into the 'Evolution of languages and the race hatreds producer amazing manner. We thought at last that Mars.' We were first shown how the thereby, and how finally one universa he was going to speak to us, instead he planet, millions of years ago, was but a language was adopted by all races ani

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. -r--s- a Lowell Observatory. MARS -1896 -7.

Photo courtesy Prof. Percival Lowell, Lowell Observatory, Flagstaff, Ariz. The above map shows Mars and its canals in Mercator's projection. As not seas, but vast stretches of vegetation. Particular attention is called objects appear upside down in the telescope, it should be remembered when the numerous circular dark spots, only to be found at the intersection of n studying the above ma., that the top is South, the bottom North; East is or more canals. These dark spots, termed Oases, are thought to be circa f. left, West is right. Note how the majority of the canals run North and vegetational tracts, containing vast farms, parks, cities, etc. South (or South and North), toward the poles, which is necessary in order The above map was made by Professor Lowell at the last opposition to convey the water from the melting polar snow caps equatorward. The 1896.7 when Mars was but 40 million miles distant from the Earth. the win canals can be plainly seen running over the dark areas, which are therefore regions at the top and bottom are the snowcaps of the poles. motioned to us to close our eyes, which, nebulae floating in space and how the nations. We saw the abolition of pres of course, we did. The following then nebulae slowly became a solid sphere. The dents and rulers over small and big n took place, and I will describe it as well early life of Mars was then pictured, tions, and the inauguration of a Univers as I can. No sooner had I closed my eyes which must have been exactly like the Council and a Planet Ruler, both elect( than a clear picture of the Earth with its evolution of our own Earth. We saw the by popular votes. continents was flashed in my mind, just prehistorical Martians with their clubs \Ve witnessed how the once dense a J

www.americanradiohistory.com 388 THE ELECTRICAL EXPERIMENTER December, 1915 became thinner and thinner and how fer- as possible and to forget speech entirely. wally by constant slow practising and giv- tile valleys turned into deserts on account He also cautioned us that as all thought ing the brain a chance to recuperate from of lack of water. \Ve saw the transmu- transmission took place through the medi- the strain. tat;on of the metals, as well as the trans- um of electricity, it was necessary that the "As if our august host had divined the mutation of all other matter. Thus we flexible metallic cord hanging from our strain on our minds during the past hour were shown how iron or lead was turned metallic -like caps should touch some con- and one -half since our landing. he imme- into gold or copper, or into 'any other ductor, preferably the ground. As we diately began to divert us, and he did this metal. Or else new marble or stone was could easily guess that this was necessary admirably by letting us see for ourselves turned into steel or gold or other metals. in order to provide a return circuit for with our own eyes, instead of making us the same as clay can already be turned the currents we soon learned how to keep 'see' with our minds. into aluminum on Earth to -day. in contact with a conductor, when we "However, we quickly began to under- "Simultaneously with these discoveries, wanted to transfer our thoughts from one stand and appreciate his wisdom in first we witnessed the unlocking of atomic to the other. giving us his historic lecture, because if. forces, which was the last great Martian he had not done this most of the things discovery in the final mastery of the we saw during the next hour would have Planet. SYNOPSIS been meaningless to us. Thus you will "Where extermination had stared the understand that what I am going to tell in on account of their I. M. Aller, an eccentric young scientist Martians the face of Yankton, Mass., who claims as his own you now, including the explanations, did constantly decreasing water supply, the many new as well as startling inventions, not originate entirely in my own mind. new atomic engines, combined with the far ahead of anything as yet discovered, Most of my explanations are, naturally, conquering of gravity, dispelled all fears owns the largest radiotelephone plant in the country. One evening he hears strange based upon that important lecture. for the future. During the next few gen- noises over his phones and immediately a "We followed our host outdoors, where erations we were made to see the creation rg sepulchral voice 's heard. It is Münchhau we boarded his private flyer. This ma- of the monstrous waterways which not sen, one of the greatest yarn and story k. tellers of all times. Müncbbausen explains chine was. of course, an anti -gravitational alone were to bring water from the two how it came about that he did not die in flyer, propelled by atomic engines. It be- poles. but also were to irrigate existing 1797, as popularly thought, and he further- haved much like our own 'Interstellar' agricultural districts as well as barren more gives unrefutable proof that his home be- is on the moon at present. that is. it had no wings, nor planes, deserts. We saw how the Martians finally Mier wants to know why Münchhausen ° cause it is not dependent upon the air. harnessed the Sun and how the latter was went to the Moon and how. The latter then - The gravitational attraction of Mars is now moving the waters in the vast water - explains how Prussia persecuted him and a how he went over to the Allies and suc- neutralized by the atomic engine to cer- ways, which you know as 'canals.' ceeded in capturing Berlin in a wonderful tain degree. The more the gravity is neu- "In quick succession we were then - - manner. However, it was not a complete tralized the higher the machine rises. shown the past progress and evolution on success, so the Baron left Europe for ff Emana- America. He immediately constructs a Now, in order to steer the flyer an Mars during the last thousand years. f machine which is to take him into space to tion Ray is used. This ray is the joint do not attempt to go into details here, as the moon. Mùnchhausen has discovered product of several elements not known on you would surely not grasp the meaning. bow to neutralize Gravity by means of a an- Electricity, and he applies this invention to Earth; the nearest, although poor Neither do I attempt at this time to ex- his space flyer, the "Interstellar." The alogy, is found in your Radium emana- plain all the wonders that took place on machine proves a success; it responds and tion, but the latter is several million times 10,000 because is lifted with tremendous speed towards the Mars during the past years, moon. weaker than the Martian Emanation Ray. you would not understand most of it, pre- Queer things are discovered on the way This ray is projected into space by means cisely as we did not grasp everything dur- to the Moon, among others that bodies lose of electricity and another source of en- ing our first 'lecture.' It therefore be- all their weight inside of the "Interstellar." as yet un- Finally a landing is effected on the Moon ergy, which I shall term ION, comes necessary to explain the wonders to in a desert, but great hardship is encoun known on Earth, and to be described by you by way of examples and comparisons tered on account of the Moon's rarified Ray can be atmosphere, me later. The Emanation with existing terrestrial terms. This 1 The party then leaves for the is in a nearest mountain range, where they dis- stored just as electricity stored will do during our stay on this Planet. i= cover a huge suhterranean cave and a lake storage battery. When it strikes an im- "After our host had concluded his first filled with luminous fish. Bread trees are movable object it acts exactly as an oar 'lecture' he watched our titter amazement also discovered. Mùnchhausen next gives a vivid description of the Earth, Sun and does when the latter is used in 'pushing with the benevolent smile a fond mother the firmament as viewed from the Moon; he off' from a dock, i. e., the boat will move will bestow on her four -year -old child also explains how the continents and oceans away from land. Precisely so with the after she has finished telling him a particu- of the Earth appear from the Moon. He then tells of the ponderous meteors which Emanation Ray; it is used in controlling larly interesting fairy story. continually crash down on the Moon. the horizontal motion of the gravity -neu- "After a short time we could understand Finally one falls down near him and the tralized flyer, and by its means the latter him fairly well by motions as well resulting concussion hurls Münchhausen in his as a bottomless crater, which goes straight can be guided into any desired direction.. by more picture talk without our eyes be- through the Moon. He falls clear through "Our flyer was round in shape, resem- ing closed. He then made us understand to the other side, but his momentum brings him bling a disc, and measured about 25 feet that he desired us to transfer thoughts hack to the starting point, where he our is saved by his companion. They then de- in diameter. It was almost 6 feet thick, to him. Accordingly we tried the experi- cide to depart for the Planet Mars, hut and like other things we had seen they leave behind them an automatic Wire- most ment. Flitternix's turn being first. He = less Plant, on Mars it was, of course, transparent. failed utterly, for our host shook his head the "Radiotomatic," which will relay the messages from Mars to the Moon In the center was a dome that looked like smilingly. I then tried my hand, or rather and thence to Alier. A popular lecture the conning tower of a submarine, and a my head at it. But as the metallic -like on Mars is also given by Mùnchhausen. Within 86 days they arrive at Mars, but slender metallic pole extended from it al- cap, which one of the Martians had placed when they attempt to land, three floating most 25 feet into the air. It branched out on my head, made me too warm, I foolish- forts capture the "Interstellar" by means of at the top into three short brackets. at the ly proceeded it a yellow ray which benumbs them, and to take off. Of course our g. guides the 'Interstellar" end of each was a transparent ball about host me it to the Planet smilingly made put back again, Ruler's revolving mansion where a landing 10 inches in diameter. Between these and only then did 1 remember that he had is effected. Flitternix speculates on the balls the Emanation Ray played, and the shown us during our lecture that thought probable appearance of the Martians and gives his reasons on which he hases his as- latter could be thrown at will into any transference was impossible without the sumption. Immediately after landing, the direction Martians desired. medium of the complex 'cap; which I shall place soft metallic caps on the flyer was an open one and not cov- later describe to you. travelers' heads, and they are then con- "Our = ducted to the Ruler's mansion. ered on top, and there were two 'drivers,' "I then proceeded to concentrate my which you probably would call chauffeurs, mind and began thinking real hard of Flit - This story started in the May, 5915, one forward and one aft. There were no how he appeared just then. For - Issue. Back numbers will be supplied ternix and E. at loc. each postpaid. steering wheels and no brakes, nor a horn. some seconds I did not seem to be success- The two drivers sat in transparent chairs, ful, for our host looked blank. Finally. II11111IIIIIIIIIIIIIIIIIIIIIIO" IIIIIIIIIfIIIIIIIIIIIIIIIIIIIIIRIilllllllllllllllllllllllllllllllllllllll not unlike our own, and in front of them with the perspiration running down my was a little round table with small key forehead from the unaccustomed effort. "As our host had to go to the other an Amer- end the room then a few min- levers like 'listening in' keys on the Ruler's face lit up and he pointed of just for ican That was all. much utes, Flitternix and myself tried thought telephone switchboard. similingly at Flitternix! I was elated "As soon as we were seated, our host over this success. my first transmission of transmission at once, and we surprised a how well it worked. Not only sitting between us, our 'drivers' pressed thoughts, or rather one thought! For a ourselves we shot upward with to make could we 'talk' in pictures almost at once, lever or two, and few minutes our host then tried amazing speed. In a few seconds the us understand that it would take some but after a while we could tell each other unusual Emanation Ray went into action, and we days of practise before we could hope to whole sentences. Of course, the into an easterly strain gave us a headache long before our began to fly or rather float even 'talk' by pictures, and perhaps months direction. From the position of the Sun, before we could begin to actually 'talk' host returned, which was only to be ex- 'Noon,' as pected; we had never been used to such I concluded that it was almost in words without using our tongues or was about overhead; this must ears. He then recommended that Flitter - hard mental work, and we understood the Sun nix and r-yself should practise as much quickly that we must learn the art grad- (Continued on page 442.)

www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 389 How The "Wireless Wiz" Celebrated Xmas By Thomas W. Benson yES; I was burning the midnight oil, or and, lo! a "wave meter" was revealed nes- room was darkened, and half of it was rather juice, constructing a high- tling in a bed of cotton batting. I reached taken up with a platform about two feet speed key for the "Wiz." I knew forward to touch it, and - "ouch! " -I nearly high and about six feet wide. On one end that he wanted this more titan anything else dropped the whole thing. I grinned, for I of the platform was a massive Christmas and it had to be "scale key." Time and had detected a soft, buzzing sound issuing tree, slowly revolving, and at the other end money were no consideration, and neither from the box that explained everything. was mounted a miniature lighthouse on the was spared on this work of art. I was Using extreme care, and taking a few more rocks, against which water appeared to be buoyed up to m task by the anticipation shocks for good measure, I succeeded in dashing. The platform was decorated to of the look on the Wizard's face when he getting the wave meter o` of the box. imitate a mountainous country in the win- would open the box and lift out the shin- The "Wiz" had included a small but "hef- tertime, and over the whole scene hung a ing piece of apparatus on which I was ty" medical coil and had arranged two clips half -moon that vied with the ever -changing spending so much time in making. that made contact as soon as the lid was beams of light from the lighthouse for su- The noise I made in the basement was removed. A few wires twisted around the periority. outdone by that in the ether, for my wrist box and one to the condenser had served On the edge of the platform were laid

The "Wiz" liad Quite Outdone Himself. A Miniature Lighthouse Blazed Forth, tV'hiie Toy Electric Trains Passed Each Other True to Life. The Tree Revolved While the Lamps on it Blinked On and Off Repeatedly.

was nearly gone, returning the good wishes to give me a shocking surprise. It was a the gifts for the children. and with a shout of the season via wireless. In disgust I wave meter that anyone would have been -of joy they dashed for them without wait- had shot the closing signal and slid away proud to own, and I knew the "Wiz" had ing to pay any attention to the ever- chang- to the haunts of the rats and cobwebs. The spent some time in his "Lab." constructing ing, ever-flashing, vari- colored beams of clock in the kitchen had struck one, yet I it. light that made a charming scene; one in- ceased not. After I had eaten my breakfast I went deed never to be forgotten. There was an * * * * * * out to call on him and, of course, bumped electric curling -iron for the "Vii s" sister, Time sped on, and that Saturday morning into the usual Christmas morning crowd Olga. She left immediately with an abash- came at last, on which the world does hon- roaming around half -dressed. They ap- ed smile to try it out in the privacy of her or to the birth of its Saviour. At six bells peared to be waiting for the "Wiz" to start own room. There was an electric chafing - I kicked the blankets off and sat in, garbed something, and as I came into the room dish for mother, and an electric shaving only in my bathrobe and slippers, and near- he said, "You're just in time for the cere- mug for dad, lying beside the usual collec- ly had the 'phones burned out by the dis- mony. I'm taking the kids in to meet tion of Teddy Bears and Trumpets that the turbances in the ether which carried the Kris Kringle." kids were fighting over. I turned and saw good wishes that came literally pouring into He stood in front of the door leading to them standing at the door with a smile the set. the parlor and clapped his hands. The door that would not come off, and dad was feel- I was the first one down that, eventful swung slowly open, and to the strains of a ing his jaw, to see if he was ready to test morning and was waiting for the postman Christmas carol, played on the Victrola, we out the new shaving mug. as he came whistling up to the door and walked into the land of wonders. I looked for the "Wiz," as I wanted to fairly snatched the box out of his hand. I Wonder is a pretty poor word to express compliment him on his work of art. but could not count the time in minutes or sec- my sensation when I beheld the work of found him bending over a small switch- onds that I consumed in opening the box; art the "Wiz" had wrought over night. The board, showing Toe how to dispatch the

www.americanradiohistory.com 390 THE ELECTRICAL EXPERIMENTER December, 1915 trains on the railroad system. After watch- The tiny fir trees on the mountain side, the moon shone forth in all its glory, and ing the action for a few minutes. I was the rising and falling of the semaphores. the lighthouse once more sent its beams practically speechless. He had laid out a the whistling of the locomotives, all made out to sea as I bade the "Wiz" farewell, to railway system which consisted of two sta- such an enchanting scene that it was hard go my regular Christmas rounds. tions and a side -track. By closing a switch to realize that I was standing in a warm As I left him I promised I would be back light in /i9ht house J

/2 //

Tree

To arc light ,,o Pott o

To /iyhfs on tree Sketch A"

Complete Layout of Toy Railway Tracking, With Automatic Reversing Switches, Side- tracks, Stations, et cetera. he would start a freight train from one room in the city. and not seated on a moun- for the full details of this wonderful dis- station and simultaneously start an express tain top, surveying a picturesque mountain- play, and asked him what he had received train running in the opposite direction ous seashore. in the line of presents. With a half- depre- around the loop. It looked like a head -on The moon was the final touch to the ciating smile, he replied, "Well, old man, collision, till he pressed a button, and the scene as it shed its pale rays on the land- outside of your high -speed key, I got a freight train would shoot on to a side- scape, and casting faint shadows just like a couple of pairs of slippers and a smoking track and let the express through. After real moon. Mountains were painted on the cap, besides several boxes of those famous the express had reached the home station, back scene, and the moon appeared to be or, rather, infamous Christmas cigars. I the freight train would be backed off the just rising over the peaks. It was the kind siding and run to its station. This action of moon that jewelers and housefurnish- could be changed indefinitely and many in" dealers delight in, being an accessory peculiar and exciting situations came up be`ore the fact of many of their sales. during the action. He would have the ex- The only object that would spoil this press train about to overtake the freight flight of fancy was the Christmas tree train when- click -the "freight" would be slowly turning, while among its branches were flickering numerous tiny lights, and the colored rays from the lighthouse lit up the tinsel and shining fol-de -rols on its branches. I have seen Christmas trees, many of them, but they all lacked something. Some- thing was always missing, a subtle, but per- ceptible something that all things should possess when used in the worship of a celestial Deity. They had the gaudy ap- E°?`//,'.iQ'v'S=FJ JGïG.a.í-'=,,,`%< pearance that oftimes means cheapness and . PIM14EXt+- Brushes', IIW1N NMy Commutotor lack of refinement. únalOINOW This tree, however, was decorated very "for/0/5 agree simply, yet did not look bare. It turned Tree! pi slowly on its axis, as though it were show- Box you, tor /eooyytree Be to AA/ ing but not without a little hesitation, 11aaD:11-M.lallll..e... Detail Sketches "B" and "C." the wonders attached to its branches, proud house of them, but endeavoring to suppress its switched out of the way, with only two pride. inches to spare. My attention was then attracted by the The action was quite natural, for the rocks on which the lighthouse was mounted trains would blow their whistles and and they appeared to be glowing in the emerge from the stations with headlights semi- darkness.. When the lamps in the flashing, glittering on the imitation snow, lighthouse and tree were turned off and Detall Sketch "D," Showing Suspension and and with a little stretch of imagination the the moon had faded away to a faint glim- Base Mounting of Xmas Tree. beholder could readily believe himself on a mer, the rocks shone forth in the darkness mountain peak looking down at a scene in in resplendent glory and the tree, revolving haven't had time to open all the packages one of our many inlets in New England with its phosphorescent trimmings, put the yet, though." during the winter. final touch to the enchanting picture. Again (Continued on page 397.)

www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 391 Buying By Mail By Thomas Reed

IWONDER who the wise man was who pression "Stung!" had not been added to keeps "; 'though I assure you no dealings first discovered that a boy's trade was the language, but the sting was certainly were permitted on margin. Well, this boy - worth having. As I look over the ex- among those present in all advertising col- wealth, accumulating as slowly and painful- perimental supply catalogues of the present umns. ly as any other wealth,- eventually blos- time -with everything that a "bug" could Those were the days of shin- plasters. Do m need into the small copper coin of the up- want pictured out so exactly, offered in the you know what "suspension of specie pay- per realm, finally to ripen into the glorified smallest quantities, and priced so cheaply - ment" means? Say no; and say it with fruit of fractional currency. I have had I am reminded of the humble figure we gratitude. Uncle Sam was paying his heavy the pleasure since of gazing upon a rather "old bugs" used to cut in the "marts of war expenses in paper money, and Unc's large banknote (not mine, to be sure -it trade." gold and silver coinage had fled from the was for $50,000, or such a matter), but it Those marts certainly bore us in no high light of day. That's what economists call a entirely lacked the haughty impressiveness esteem. It was a dreaded ordeal for us to necessary consequence, and you have to of my first 25-cent shin -plaster. meet the lordly hardware clerk and pre- take their word for it; but I saw its inner And even while I gloated over my mag- sume upon his august attention for five workings. Whenever I peeped into the fam- nificent aggregation of capital, frenzied cents' worth of copper wire, or a quarter ily strong -box I saw there a little roll of finance got it. I can see that seductive ad- of a foot of brass rod. Our reception va- silver "quarters," hoarded since the begin- vertisement now, picturing a bewildering ried from an amused indulgence that made ning of the war, when the word went round medley of articles-a printing press, a Japa- us afraid to come again, lest we wear out that they would be "worth a premium." nese parasol, a trick spider, and a dozen so kind a welcome -down other lures of childhood -all for through a snappish compliance exactly my fund of 25 cents. that usually carried a crushing Wonderful coincidence, the overcharge -down, down to the chance of a lifetime. Really icy depths of "we don't deal in worth $1. Sell them for their such small quantities." real value and grow rich. How many times I have timid- The old folks were sceptical- ly inquired the price of some the Pacific Bank, it seems, had coveted material, such as copper spoken in some such strain -but the answer : burrs, to receive I better. Good-night, 25; much a pound." A pound! knew "So a fond farewell! To New York A vast, uncertain quantity that it went, and for days I waited, would make me the envy of my With in one partic- each day a year long. fellow "bugs" that every rumble of a wagon I was ular and bankrupt otherwise! see the express "pound" gives me a at the window to The word package trundled in. It was the shiver to this day. who handed And people never sold fin- postman, however, out a box two inches by four - ished parts. "Oh, no," they said, a "we're too sharp for that. If plenty large enough to contain you could buy that one impossi- world of woe. Every article was ble piece, you would make the there, but in ,miniature form- whole article, and we should toys for a baby to suck the paint lose a sale." Such was the logic off, not goods commanding of merchandising then. So the traffic in boy- commerce. The ad- "boughten" commutator that we vertisement had not mentioned wanted to put the finishing that detail. I was face to face touch on our home -made dyna- with the dreaded "ketch." mo remained unbought. But I considered my young life might what booted it ? -as Shakespeare blighted, of course, but it was wont to inquire. We found have given me some comfort a substitute; and the stingy ven- had I known that the mail order dor, instead of selling a thou- was blighting itself as well. It sand commutators, sold no dy- took a generation of time, strict namos. or few, and disappeared laws, and the teaching of experi- from the haunts of men. ence that honesty is the best You lucky "bugs" of later policy before the mail order, in times, take a day off and use it partnership with the square deal, to realize your blessings. You came into its own. can buy a single milled nut, or You young "bugs" really don't an inch of Wollaston wire, or fully appreciate how good the ten cents' worth of galena crys- world treats you these days. No tals, and have them delivered at more "ketches" in these days of your door, and not grudgingly, watchful post -office inspectors, but with a hearty "thank you; f " * it was a Dreaded Ordeal for Us to Meet the Lord tY Hard- no sir -e -e! When you stick your come again." And parts? "Why, 1 ware Clerk to Purchase Five Cents Worth of Copper Bu rrs. money order with your letter in sure; make all of it you can, the envelope, and send it off to and buy the rest from us." The best in Mother had put them there, and I think that big mail -order house, .you know the house is none too good for the amateur her most reasonable hopes of profit took just how long it will take till the now. the form of a walnut chamber set. Mother postman hands you that pair of long - The mail order! There can be great dis- was speculating. Dear old mother, she nev- coveted "classy" 'phones. And, believe coveries entirely outside of the physical sci- er speculated on anything else, except on me, "bugs," those 'phones will be a whole ences. The modern mail -order system is as the love and loyalty of her children; and lot better than the cut showed, or the de- truly an invention as the gas engine and, sometimes, I fear, she must have placed scription read. And on top of this, if like it, was formed from several contribu- those in the same disappointing category as you're finnicky and don't happen to like tory sources. The development of illustra- the silver quarters! them, why of course you send 'em back. tion through the photographic half -tone and So we used "fractional currency "-little And in due time the mail order returns the machine -line engraving was necessary young paper bills, about three inches by your money, if you want it. for the exact description of goods by cata- two, representing 50 cents, 25 cents, even 10 Take it from an old "bug," you young logue. But another factor, intangible cents; and, believe me, even that humble "buglets" have lots to be thankful for. though it is, was requisite before the sys- form of money was hard to get. Boys had tem could be a success -an insistence al- no "allowances" in those hard times -ex- The largest electric range in the world most fanatical on the square deal. cept the allowance to have nothing; but has been placed in the Montana State Hos- It is greatly to the credit of the mail or- deep down in the boy -world there was a pital at Warren Springs, Mont. The range der that it lived down the errors of its system of trade and finance. We collected is more than 30 feet long. It is equipped youth. 'Way back in the '70s it was in rusty nails, swapped knives. Instead of with eight ovens and will prepare meals for decidedly ill -repute. The picturesque ex- stock transactions, we played marbles "for more than 1,500 persons daily. www.americanradiohistory.com 392 Ti-IE ELECTRICAL EXPERIMENTER December, 1915 To Foil Submarines With Undersea Searchlights THE submarine and mine constitute communicated to the gunner, who then tration shows, so that a protection would be two of the greatest menaces to discharges a special form of projectile re- afforded the gunner and sighter from ordi- warships and other vessels under sembling a torpedo. This projectile, of nary rifle and machine gun fire. modern war -time conditions and to offset course, is so aimed as to strike the mitre For details regarding this latest scientific the utility and efficiency of same has in- or other submerged devise, and it is not invention for the detection of submarines, terested many inventors both in this coun- detonated until it is close to the submerged etc., the following considerations will help try and abroad. Inventors and scientists body proper. It is then exploded by the to make clear the modus operandi of the have advocated from time to time various gunner, who closes an electric switch, apparatus in general: methods whereby they hoped to render causing a current to flow along the at- At the top of the tube, the latter being the submarine at least an obsolete engine tached wires to the projectile, fusing a fine represented by the figure 10 in the diagram, of destruction. wire detonator inside the missile. is a powerful electric searchlight 11, of any What bids fair to be a successful com- On first sight this invention may seem approved kind, which throws its rays batant of these submerged terrors of the to be a mere theorist's dream, but from through lenses 12 and 13, arranged to hold sea is the invention recently brought out tests that have been made in the taking of the rays in parallel relation. These rays by Prof. Herschel C. Parker and Edwin G. pictures under water by means of a power- are directed against a mirror 14, which is Hatch, of New York, mechanical engineer, ful searchlight, it is definitely asserted that arranged at an angle at the lower end of associated with Prof. Parker in his en- submerged objects can be seen in this way the tube, and refracts the rays through the gineering and research projects. for distances of from 1,000 to 2,000 feet. lens at the outlet of the tube. This latter The accompanying illustrat:o.i will give These distances, of course, may be greatly lens can be shaped to throw the rays in

Latest Scheme for Locating and Destroying Submarines, Mines, etc., by M - -tes of o Powerful Under-Water Searchlight and Periscope Device. Developed by Prof. Herschel C. Parker and Edward G. Hatch, M. E., of New York. an adequate idea as to the method of util- increased by using a proportionately parallel relation or to give any amount of izing this arrangement as perfected by greater amount of energy in the search - divergence desired. Messrs. Parker and Hatch. Simply ex- light projector. The larger projecting The tube, with the searchlight. lenses and . plained, it makes use of a powerful search- tube, into which is fitted the search- refracting mirror, is attached to the out- light beam which is projected through a light lenses, mirrors, etc., is termed a side of the vessel. Inasmuch as the search- suitable focusing tube, fitted with reflect- helioscope, and the instrument mounted in light is to be used on deck, a light of the ing lenses and mirrors and an instrument the smaller sighting tube through which highest power can readily be used. The termed a inarisaope (but really the same the submerged body is viewed is called a tube can be adjusted so that it may be as the periscope used on all submarines) niariscope by the inventors. In the illus- raised or lowered to bring the light to any is used to sight through the water along tration herewith given it is, of course, to desired point. Likewise the mirror can be the light beam, aforementioned, and which be taken into consideration that the pro- moved for the same Purpose, but the details is turned about on the axis of the project- portionate distance between the mine and of this adjustment have not as yet been ing tube until it intersects a hidden mine, war vessel proper is quite close, but in considered exhaustively, because they do the hull of a submarine boat. etc. When practise the distance would naturally have not concern the general scope of the inven- the mine, or other engine of destruction, to be greater than that shown, for the rea- tion. If a light is projected on both sides is accurately located by this apparatus, the son that the explosion from such a device of the bow, the field which it is possible to range of same, as well as the angle at would affect the vessel undoubtedly unless light is almost equivalent to the field of which it lies from the hull of the war it was more than 300 feet away. If this human vision. vessel, is measured accurately by scientific device is actually tried out and adopted by When the submerged field is lighted, the instruments, such as used on regular can- the navy it would have to be arranged most next step is to 'observe it properly, and to non. These angle and range figures are probably in some such manner as our illus- (Continued on page 450.) www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 393 By Wireless 'Phone from Arlington to Paris THE spoken word uttered in Arlington, t:te Eiffel Tower in Paris have heard interference from high -power stations in Va., has becii heard in Paris, speech sent out by engineers of the Ameri- tile neighborhood and from static disturb- France, on tare different occasions can Telephone & Telegraph Co. from ap- ances, speech was successfully transmitted recently, and particularly on the evening paratus developed by that company and the on several occasions since. of Oct. 20 last. On that memorable date Western Electric Co. and installed at In a cable message received by Mr. Carty the human voice was projected across the Arlington, Va. The equipment used was concerning the results of the tests, Mr. Atlantic for the first time in history, and that employed a few weeks ago in talking Shreeve reported speech received by him "Hellos" and "Good- byes" spoken in Ar- 4,900 miles by wireless telephony to San and the time of its reception at Paris. The lington were heard and understood in the Francisco and Ionolulu." matter received at Paris was that sent French capital, 3,800 miles from the point That speech has actually been transmitted from Arlington, where R. A. Heising, B. of transmission. from Arlington to observers stationed at B. Webb and other telephone engineers Announcement of the epochal achieve- the Eiffel Tower, Paris, marks the con- were manipulating the apparatus at the ment was made officially by the American clusion of another chapter in the experi- transmitting station. Mr. Webb did the Telephone & Telegraph Co., following ment undertaken by the American Tele- talking throughout the final experiments. cabled confirmation of the success of the phone & Telegraph Co. When Mr. Carty's Simultaneously with the reception at wireless telephone experiments received in engineers commenced work on the long - Paris, speech sent out from Arlington was New York and in Washington from the distance wireless telephone experiments ob- received on the wireless antenna at the company's engineers in Paris. servers with receiving apparatus were sent \ Vestern Electric laboratories in New York H. E. Shreeve and A. M. Curtis, of the not only to Panama, an Diego, Mare and at the temporary station of the Ameri- staff of John J. c an Telephone & Carty, the chief en- I elcgraph Co. at the gineer of the Amer- Pearl Harbor Navy ican Telephone & Y a r d, Honolulu. Telegraph Co., went Mr. Espenschied at to France to repre- Honolulu reported sent the company in that he heard the transatlantic ex- t h e conversation periments. throughout the en- Owing to the fact tire schedule and that France is at that Mr. Webb's war and that wire- voice was e a s i l y less is playing a recognized. most important part After the an- 'in the working out nouncement was is- of the French mili- sued Mr. Carty, who tary communication was in Chicago, was system, it was with called up on the extreme difficulty long distance tele- phone -' that officials were and asked to persuaded to permit tell the story of the the use of the 1,000 - achievement. foot Eiffel Tower "Tell us all about station at Paris for the Paris achieve- the receipt of the ra- ment," said an offi- diophone messages cer of the company from Arlington. in New York. Only a few sec- "Is anybody 'lis- onds at a time, in tening in?'" Mr. periods far apart, Larty asked, quickly were allowed the guessing that news - American engineers, pepermen also were during which they at the New York were permitted to end of the line. listen for the greet- Mr. Carty laughed ing from far away when told he had Arlingtdn. In order guessed rightly, and that there could be after a little pe no doubt of the suasion told the genuineness of t h e story of the test. tests, officers of the It was on the French Government, night of Oct. 12 or more Graphic Illustration of Arlington to Honolulu and Arlington -Paris Radio phone Tests Recently first two of Conducted; the Distances Covered Being 4,900 and Miles when the signal whom represented 3,800 Respectively. from Arlington was the army, were with Messrs. Shreeve and Island and Honolulu, but also two engi- caught by Shreeve, in Paris. Shreeve heard Curtis in Paris, while Colonel Samuel neers, H. E. Shreeve and A. M. Curtis, the 'Hello' of Webb at Arlington several Reber, of the United States Army Radio were sent to Paris. Through the courtesy times. Again, the following night, the words Service Captain W. H. G. Bullard, head of the French Government, limited facilities were heard, and on Oct. 20 the words were of the United States Naval Radio Service, for listening at the Eiffel Tower station again heard, not only in Paris, but in and other American army and navy officers were placed at their disposal. Honolulu, by Lloyd Espenschied, who watched intently the experiments at Arling- Full appreciation of the interest and ex- cabled to -day that he heard the 'Hello, ton. treme courtesy of the French Government Shreeve,' and the 'Good -bye, Shreeve,' ut- Mr. Carty, who not only heads the en- can be understood when the great value of tered by Webb in Arlington so plainly that gineering staff of the telephone company the Eiffel Tower station for military pur- he was able to recognize the voice as that but is president of Cie American Institute poses is remembered. Due to the military of Webb. of Electrical Engineers, directed the ex- necessities, the amount of time available "The announcement of the success of the periments. Following the announcement for the wireless telephone experiments was experiment was deferred through courtesy of the success of the tests, he predicted that so limited as to constitute a serious handi- to the French Government, and it was not wireless telephonic communication between cap to a speedy completion of the work. until Oct. 22 when further cable confirma- New York or any other American city and Added to this was the handicap resulting tion of the success that has attended our all the great cities of the world was but a from the fact that all regular communica- efforts made it possible for us to take the matter of time. tion between Mr. Shreeve and the engineers public into our confidence and tell what has The announcement given out at the of- in America had to be by cable and was sub- taken place. fices of the American Telephone & Tele- ject to long delays. "While Webb was talking to Shreeve he graph Co. follows: Notwithstanding the difficulties of com- repeated the 'Hello' and 'Good -bye' several "Transatlantic wireless telephony is an munication. the limited amount of time times, and they were heard each time in accomplished fact. Observers listening at available for receiving, and despite heavy (Continued on page 448.)

www.americanradiohistory.com 394 THE ELECTRICAL EXPERIMENTER December, 1915 Audion Bulbs as Producers of Pure Musical Tones By Dr. Lee de Forest NOW that the attention of the public phone detector and incidentally as an ampli- of altering the pitch and quality of notes. has been drawn to the astonishing fier to be used on long distance telephone Acting on these discoveries and sugges- use of the incandescent vacuum lines I made the discovery years ago that tions I found it was a comparatively simple lamp, not only as a receiver in trans- when the circuits of the audion were con- matter to arrange a crude scale similar in continental wireless telephony, but as a nected in a certain way a clear, musical function to that of an organ, with switches generator of power necessary to transmit npte was heard in the telephone receiver, in place of the ordinary keys, so that by the voice in the first place, it may be in- which was connected in one of these dr- pressing certain keys I could cut out, or in, teresting to know that this incandescent cuits. The quality of the note was very more or less inductance or capacity or re- lamp, or " audion," has another entirely beautiful, and I found after a little experi- sistance, thus changing the notes emitted different field of utility -that of producing menting that I could change this quality of from the telephone receiver at will. sound or music. Music from light -that, timber into a great variety of sounds, imi- In order to bring the volume of sound in a word -is the latest magic of this lamp. tating, for example, the flute, oboe, cornet, out large and full in the room it was neces- Tradition has it that on the plains of stringed instruments and other sounds sary to connect a number of loud speaking Egypt three thousand years ago the giant which, while pleasing to the ear, were quite horns connected with telephone receivers statue of the Memni emitted weirdly beau- unlike those emitted from any musical In- similar to those which you have sometimes tiful notes when struck by the first rays of strument with which we are familiar. The heard in the central railroad stations as

The Audion Piano May Entertain Us in the Near Future With Music Purer Than That Obtainable With Any Instrument Now Available. Also it IN Imitate Faithfully Any Orchestral Piece. the rising sun. To -day, after three thou- pitch of the notes is very easily regulated train announcers. With these horns dis- sand years, it is interesting to know that by changing the capacity or the inductance tributed in different parts of my laboratory, we have at last reached the point of trans- in the circuits, watch can be very readily or grouped together in one place, the sound mitting light rays directly into sound effected by a sliding contact or simply by can be made to emanate from all quarters waves that which has hitherto been only turning the knob of the condenser. In of the room or from one corner, as I for the pleasure of the eye can now be fact, the pitch of the notes can be changed choose. made a pleasure also to the ear. by merely putting the finger on certain In producing pure musical tones with an In my laboratory there are a number of parts of the circuit or even by holding the ordinary audion detector bulb, or with the small spherical incandescent bulbs, from hand close to parts of the circuit. In this special large size audion oscillator bulbs, which I am able to obtain a succession of way very weird and beautiful effects can the arrangement is shown diagrammatically musical notes, clear and sweet, of surpris- be obtained with ease. herewith. At A there are placed in circuit ing volume, the pitch and timber of which At the earlier stage of these investiga- two inductances, inductance No. 1 being of can be varied almost at will to imitate any tions I found that the pitch of the note adjustable value, while inductance No. 3 musical tone of an orchestra. Here, then, could also be varied by a simple,arrange- has an iron wire core within it and also in the laboratory we have for the first time ment, such as a graphite pencil mark on a has taps taken out at equidistant numbers the music of the lamps. piece of paper or slate, connected across of turns to E connected to a series of While working on my experiments in between certain parts of the circuit, and switches or keys (and it is well to use, say, developing the audion as a wireless tele- that this afforded the most ready means eight keys corresponding to a musical oc-

www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 395 tave, thus giving eight notes). Of course, actly the method which is used at Arlington effect variations in the audionbptb circuits. to produce more tones it is necessary to by the Western Electric Company in gen- Each bulb is capable of prodttéing an octave use more inductance taps, or condenser erating sufficient energy to send the voice or eight notes. The large keyboard similar No. 3 may be of the adjustable type, so as via radio to Honolulu. to those used on organs is well suited to to produce a variation in the musical tones In al: my work with the audion -and I this instrument, with which it will become developed in the circuit. Using an ordinary audion detector bulb, the high voltage battery No. 4 may give 45 to 50 volts, composed of the ordinary 3 -cell flashlight batteries. Where the large size oscillation generator bulb is employed 110 volts D. C. is adaptable to this part of the circuit. A D. P. D. T. throw-over switch may be used, as shown in the dia- gram, to throw the tone -producing audion on to a pair of ordinary radio receivers or on to a loud -talking receiver. The ex- permenter who wishes to try out this ar- rangement should try making different adjustments in the circuit, including the Above. Dr. de Forest': Laboratori filament current applied, until the best re Where the Musical Audion Bulb sults.are obtained. Was Developed. The Large Tubes Several years ago, as the public of New are Cooled by a Fan as Perceived. Note Elaborate Tuning Variable York remembers, a very elaborate under- Condensers In Foreground. taking was started for producing music by gigantic electric dynamos mixing the tones At Right: Close View of de Forest from WC or more machines in accordance Audion Oscillator Bulb, with Tun- N:ith ing Condenser in Case. Some of the wishes of the skilled performer These Tubes Measure Seven Inches who in that way produced musical tones of in Diameter. They Actually Gener- large volume, and which siinilated almost ate High Frequency Oscillations. those of every instrument in an orchestra This instrument was termed the telhar- monium. The idea was to generate this can imagine no device in the whole realm possible to reproduce imitations of any mt.sic at a central station, where highly of practical physics of greater fascination band, orchestral or stringed instrument, etc. trained organists were constantly at the than this little audion principle -I have Extra oscillator bulbs for emergencies for keyboard, and distribute it through tele- never found any phase of its unlimited pos- use in case one should break, a-e seen lying phone wires throughout the city to hotels, sibilities quite so interesting as this of on the stand at the left. It should be restaurants, lobbies, concert halls and producing musical notes. Although not a thoroughly understood that music produced private residences. This was a most meri- musician myself, I have always been ex- by suc.i an instrument as this is much torious idea and deserved great success. ceedingly fond of music. The idca of pro- purer in every way than that produced by However, the extraordinary heavy cost of ducing beautiful musical tones by an en- any other type of musical instrument now the original plant, the maintenance of the tirely new method unknown to all our known to the art and, moreover, the music wire cables, etc., rendered it commercially great composers and perhaps offering to is electrically produced in contradistinction a failure. future composers new fields fo their to that produced by the usual musical pieces genius, has truly captivated me. In the which yield sounds mechanically, so to Now, with the audion or incandescent speak. lamp as a efnerator of musical tones, we next twelve months I hope to be able to be far have on : small scale all of the possibilities produce an instrument which will PENETRATIVE POWER OF COL- of the large telharmonium. enough perfected so that I can turn it over and ORED LIGHTS. Now, this same little bulb which I have to musicians to work out the thousand It may interest those engaged in sign just described, in addition to being a re- one details of musical perfection which lighting and signaling to know that lights ceiver of wireless messages and an ampli- such men alone are capable of introducing. worked of different colors show varying degrees fier for long distance wire telephones (in The illustration here presented as of ability to penetrate the atmosphere. which use it is now employed on the trans- out by the editor of this journal shows the piano" Some calculations, based on experiments. continental lines of the American Tele- probable appearance of an "Audion give the following results for the minimum phone & Telegraph Company), can be made of the not far distant future, utilizing the by which intensity visible in a clear atmosphere at a to actually generate alternating current. It de Forest musical tube principle, range of two miles. (In these calculations receives the energy which is expended in means it is possible to produce the purest light sources of any value ever obtained by any of equal area are assumed.): these currents from the dry battery or tones Red 2.37 candle power dynamo. The audion is, in other words, a existing means. The various controlling are observed the front of the Green 1.96 " transformer of energy. The alternating handles on White 1.71 " current, if of low frequency, can actuate eosovt The range of visibility of any light source the telephone diaphragm and make musical H!!Bolt loudfo/rhe 4 depends, of course, upon the intensity of notes which the ear can hear, and this is the source. However, it must not be sup- the germ idea involved in the musical in- -- posed that by doubling the intensity the strument which I have just described. The T range will be doubled. The relation be- bulbs for musical purposes which I have Z tween the range and intensity varies for thus far used are not larger than three PD different colors. inches in diameter. The great absorption of light in an at- At the present time I am using one bulb lYi09 mosphere laden with water vapor is a well - for an octave on the musical scale, with knewn fact. A few years ago the German the arrangement of keys and switches such 6rid- Government found that arc lights of 1,000,- that from this one bulb I can produce the 000 C. P., which were installed in a light- notes of that octave by pressing the appro- A house, had less pliility to penetrate á fog priate keys. For the next octave another Qudion bulb than a 10,000 candle power oil lamp. This bulb is used, and so on. The output of all indicates that electric incandescent lamps these bulbs is made common to one set of having more red rays would be superior to telephone receivers or loud speakers, so arc lamps for use in light- houses. that the total energy in the form of sound 'Vron wire are lone Dust and smoke unquestionably interfere is that of all the bulbs which are operating /regs 6 d60. -T more with the transmission of blue or at any one time. green light than with red light. Therefore, In the I same way when used as a wireless Rheos/ot--- when viewed through the atmosphere, all transmitter or generator the high fre- lights should appear redder. On weighing quency alternating current from the vari- Diagram of Connections for Creating Pure Mu. the evidence, it seems that reddish illu- ous bulbs is combined on the same trans- sical Tones w,th Any Audwn Bulb. minants should have more penetrative mitting aerial wire or antenna. Thus, if piano, and the music is emitted from the power that bluish lights, and where details one oscillator is "developing" one -half large horns on top of same. - A storage are to be distinguished at a distance the horsepower 300 of these bulbs connected in battery of small size will supply sufficient red light is more readily focused than by parallel and acting on the same antenna current for this wonderful instrument, and any other color. Hence the use of red dan- will develop 150 horsepower. This is ex- the feet might be utilized in assisting to ger signals on ships and railroads.

www.americanradiohistory.com 396 THE ELECTRICAL EXPERIMENTER December, 1915 claimed. The accident was the result of Wireless Telegraphy Aids the Teutonic Allies insufficient temporary guying. It had been The photographs presented herewith il- The larger illustration shows a tele- erected to its full height, but was not en- lustrate some of the up-to -date wireless scopic steel radio mast which can be ele- tirely completed. I: wa; made up of struc- telegraph equipment in use by the Ger- vated to a height of 100 feet very rapidly, tural steel with a cross -section of 3 feet 4 man army and also by the Turks. The and the machinery for performing this inches square, and followed the same di- smaller photograph shows a complete Mar- work is mounted on the truck here de- mensions all the way up; the total height was 305 feet. The plans called for three sets of guy ropes at intervals of 100 feet \l of height. The two lower sets of guys ' were permanently in place, but some 5-16 - inch steel rope was fastened temporarily to the top. As the design called for %- inch crucible steel guys for the top, it is evident that the guys used temporarily had an ultimate strength of only 1 -12th that called for by the plans. The high wind of September 26 last parted the temporary 5 -16 -inch steel rope, allowing the top of the tower to sway out, thus bringing into play enormously high stresses at the next lower set of guys. This undue strain snapped first the middle set of guys and then the lower ones. Some interesting features were nóted in the falling of this tower. There were no signs of buckling, the tower falling as a unit indicating great rigidity. It fell across a street railway line, cutting down the trolley wires and feeder cables act-ass the Above: Turkish Sailors Being tracks of the Boston & Maine Railway, Instructed in the Rudiments derailing a locomotive. When the loco- and Operation of Wireless Te- legraphy. The Apparatus Shown motive fender caught the end of the mast it Here is of'Marconi Type. Wire- dragged the tower 50 feet down the tracks, less Has Revolutionized Mod- twisting the steel somewhat. It was re- ern Warfare. markable, however, the way the steel held together, shearing off the bolts rather than At Lett: Remarkable Collapsi- pulling out the bolt holes. ble Steel Mast for Radio- teleg- The tower was insulated from the raphy as Used in German ground. Some of the base insulators Army. It Can be Elevated to re- a Height of loo Feet Very mained intact, although a few were crushed, Rapidly. due to the side thrust of the falling mast. Photo by Paul Thompson. The rebuilding of the tower was started immediately. After the new insulators were in pace and the cement hardened the coni radio set as used in teaching the pilled. Suitable guy wires are providea steel work was started anew. It is now Turkish sailors the rudiments of the art. for strengthening the mast as it is pro- up 60 feet and should be completed within The outfit as perceived includes a multiple jected upward, and the total work of rais- valve tuner of the latest Marconi style, as ing same to its maximum height, ready for well as a magnetic detector. The trans- the purpose of transmitting and receiving mitter comprises a 10 -inch spark coil, to- messages over a fairly large range, can be gether with storage batteries and other accomplished in a few minutes by the well auxiliary apparatus. Regular wireless mes- trained German radio corps. The wireless sages are being received by the students apparatus is contained in another cart not here shown. The Turks have made good shown in the picture. The whole equip- use of wireless telegraphy in their numer- ment forms a very compact and easily ous brilliant maneuvers on land and sea. portable outfit. VINELAND HIGH SCHOOL RADIO lated wireless station in the world. The ASSOCIATION. station crew is made up of three operators, The Vineland High School Radio Asso- two engineers, a cook, a machinist and ciation, of Vineland, N. J., was recently three laborers. No women are permitted organized. Leslie H. Adams was elected to land on the island. Men who express president; Firman A. DeMaris, vice- presi- a willingness to go to Swan Island are dent; Franklin Lamb, secretary, and Frank obliged to sign a contract whereby they M. Comfort, treasurer and advisory presi- agree to remain at least 18 months or waive dent. their right to free return transportation. The association has secured permanent Those remaining the full period of service rooms, through the kindness of the Board are returned to their homes by way of one of Education, in the physical laboratory of of the Central American ports and are the new Vocational High School. granted six weeks' vacation with full pay. The aerial will have an average height Strangely enough, there is no difficulty of 100 feet and a length of 250 feet. The in obtaining men to man the station. Ap- set will consist of a V2-k.w. transmitting set plicants, indeed, exceed the number of va- and a receiving set of standard make. cancies. Board and lodging, of ,.ourse, are The object of the association is to bring supplied, a boat bearing all provisions the amateurs of Vineland and vicinity in necessary, including fresh meat, and the closer relation and to purchase elaborate mail as well, arriving regularly every two equipment which would be impossible weeks. Some men have remained on the otherwise. island as long as two years and a half and, subsequently, The association would like to get into have been glad to return to Two Views of Fallen 305 =foot Steel Radio Tower communication with other clubs. All cor- the station. at Tuft's College, Mass. respondence should be sent to Franklin Lamb, 623 Elmer street, Vineland, N. J. 305 FOOT RADIO MAST BLOWN a short time. All the anchor blocks were DOWN. perfect, showing no trace of the strain ex- On September 26 last the 305 -foot steel erted when the tower fell. THE MOST LONESOME RADIO wireless tower of the American Radio and STATION. Research Corporation was blown down at Never dust electric globes while un- On Swan Island, in the Caribbean Sea, Tufts College, Mass. Through carelessness lighted. The static electricity generated is situated what is probably the most iso- in erection details the tower fell, it is will break the filaments.

www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 397 POWERFUL SEARCHLIGHTS judged from the picture., this unit forms sume from 5 to 15 kilowatts. Some search- WORK WONDERS IN MOD- a part of the wonderful German signal lights require less, where they are used for ERN WARFARE. corps equipment, which is said on good minor work, and likewise some of them authority, to be second to none in the take more energy than above mentioned. In modern warfare some of the great- world to -day. It must be remembered that The American Army and Navy are equipped est battles are not fought in the daytime, in most instances, not one or two search- with some of the largest projectors but at night, when darkness provides a lights are used on the battlefield, but whole extant, several of which measure 60 inches mighty impenetrable blanket over land and sea. For that reason the enormous armies now engaged in the titanic struggle in Eu- rope invoke the use of powerful electric searchlights which blaze forth over thc +IS battleground at night, so that advances and MF sorties may be made regardless of nature's handicap. Our illustrations show a clever method for handling, to the best advantage, a powerful electric searchlight projector and, moreover, its mounting is cleverly placed on a specially constructed wagon, as perceived. This vehicle carries at the rear two large reels of flexible cable, which serve to supply the arc lamp with current from a petrol engine and dynamo plant similarly mounted on a wagon, but located in most cases at some distance from the projector. wagon lias rcached When thc searchlight r.- the point where it is to be used on the field the telescopic, collapsible framework here shown is elevated in a few seconds to any desired height and the searchlight can Above: German Signal Corps About to Put now be swung to whatever direction de- into Operation One of Their Powerful 36- Inch Electric Searchlight Projectors for Night sired. A flexible electric cable leads down Fighting. Left: Supporting Frame Elevated. from the projector case to make connec- Note Screen of Trees to Help Disguise it tion with the wires leading back to the dy- From Enemy During Day. namo truck, as aforementioned. Photos Copyright by Underwood & Underwood. This outfit is also equipped with a mili- tary type telephone instrument, whose cir- cuit runs back to the rear army guard. batteries of them are brought into play and more in diameter across the reflector. Note how the truck is partially covered simultaneously, so that the ground is bril- The front opening of the lamp cases are with pine boughs in an effort to conceal liantly illuminated for several miles, thus closed with glass, but this is not in one the outfit as much as possible from the re- for all practical purposes they take the piece. It is divided up into several narrow connoitering aeroplanes of the enemy dur- place of the sun Itself. Occasionally one strips to permit greater facility in replace- ing daytime. Some of these schemes are of these powerful searchlight beams spots ment, and also to more efficiently take care carried out in such detail that the appara- an enemy's aeroplane at night, and in sev- of the unequal expansion and contraction tus cannot be observed at all, even when eral instances it has resulted in the flying of the glass, due to the enormous amount the scouting aeroplane flies but a short dis- scout being brought to earth in short order of heat developed by the arc, and which tance above the earth. The particular by the effective use of anti- aircraft guns. is moreover reflected against the glass by searchlight here shown has done effective The majority of these devices operate the parabolic mirror in the rear of the duty in Northern France, and, as may be on 80 to 110 volts, direct current, and con- lamp housing.

HOW THE WIRELESS "WIZ" "Are you ready for the dope now ?" in- train's station, 'B'; then, by closing the CELEBRATED XMAS. quired the "Wiz" that night at 11, as he switch 1, the freight train is started out ' (Continued from page 390.) sank into the chair at his desk and drew on the main track and runs in the direc- forth a few sheets of blank paper, on which tion indicated by the arrow. When it has "Well, see you later in the day," I sang he proceeded to make some sketches. "Well, just passed the express station we may out. * * * I'll now 'wise you up' on the railroad stunt throw the current into that track by closing first. I was certainly stuck for a while on the switch 2, and the express train will the switches for this system, till I got into communication with a New York electrical firm and managed to get hold of a com- bsu plete list of miniature railroad supplies to fill my bill. I used two stations -'A' and la) 'B' (see sketch A) -and one siding made of fined. box standard track. riJ Igrg - fastened "The three switches were electrically oper- to wall ated from the switchboard and were made similar to this sketch B. Two magnets were mounted with a pivoted magnetized arm to -F- play between them. This pivoted arm was fastened to the bar that swung the switch, Re %y and by throwing the current in one direc- Cmtod t0 tion or the other I was able to open or open circa close the switch. "The third rail on the side -track and sta- tions was disconnected from the main sys- B. fitita =r tem, and I had switches 1, 2 and 3 arranged ,,r to control them, while switch 4 controlled Motor the current to the main track. The electric (Microphone -6- switches 5, 6, 7, 8, 9 and 10 controlled the operation of the track switches. I also Figs. F. and G. Details of Electric Arc and rigged up magnetically controlled reversing Microphone Control Relay Used to Open Door. stops at several points, marked X, con- start out in the opposite direction. It will trolled by keys 11, 12, 13, 14, 15 and 16. look just like a head -on collision, but by These reversers also operate the sema- depressing the key 9 the switch is opened phores by means of the sliding rod, 'R,' that allows the freight train to run onto pushing the arm into 'Danger' position. the side-track ; and the button 14. control- "Now the operation of the system can ling the reverse, is pressed at the same Fig. E. /tow Revolving Flasher of Search- be briefly outlined as follows: Making the time and the reverse gear will cause it to light is Constructed. freight train's station, 'A,' and the express (Continued on page 151.)

www.americanradiohistory.com THE ELECTRICAL EXPERIMENTER December, 1915 The United States Advisory Board and Its Personnel

TI lE newly- appointed United States Na- present wonderful success as a captain of sidered an authority on physics. val Advisory Board of scientists, in- industry and invention. 'It would be hard The two members nominated by the ventors and engineers, which is the indeed to find a man with a more general American Society of Civil Engineers were outcome of an excellent idea originated by and widely extended education than Mr. Alfred Craven and Andrew Murray Hunt. the Secretary of our Navy, Josephus Dan- Edison and, as we know, he has been re- The former gentleman has been for many iels, recently held its first meeting and sev- sponsible for many of our greatest mechan- years connected with the various branches eral important matters were taken up at ical and electrical devices of untold benefit of the municipal engineering department of that session. A consulting staff of special- to the human race, such as the electric light, New York City, He is a son of Rear Ad- ists, such as here brought together, should phonograph, motion picture machine and miral Thomas C. Craven and a nephew of have been available for the benefit of our storage batteries, etc. In all, this phenome- Alfred W. Craven, for many years Chief Government many years ago, and it is real- nal man has taken out over 1,200 patents Engineer of the old Croton Aqueduct. He ly remarkable that such an idea was not on various inventions. was born in Bound Brook, N. J., in 1846 formulated and carried through long before Two well -known mathematicians were and graduated from the United States Na- now. nominated to the Board by the American val Academy. In 1910 he became Chief En- The photograph herewith shows the mem- Mathematical Society. These were Profes- gineer of the Rapid Transit Commission of bers of the Advisory Board at their first sor Robert Simpson Woodward, of Wash- New York. His experiences have been va- meeting in Washington, D. C., and below ington, D. C. and Professor Arthur Gordon ried and most thorough, and his opinion on is given a brief outline of the qualifications Webster, of Worcester, Mass. The former engineering and technical matters is taken of the savants and engineers who make up gentleman is a well -known engineer and an as final. Mr. Hunt comes from San Fran- this staff, which is headed by Thomas Alva expert in astronomical matters. He was cisco and occupies a prominent position as Edison as Chairman of the Board. born in Rochester, Mich., in 1849 and grad- an engineer in that city. He also graduated Mr. Edison is probably one of the most uated with the degrees of Civil Engineer from the United States Naval Academy in

Photo Copyright by International Film Servlce- In the above illustration looking from left to right, the following members of the new Naval Advisory Board appear as indicated: t. Josephus Daniels, Secretary of the Navy; 2. Thomas A. Edison, Chairman of the Board; 3. Elmer Ambrose Sperry; 4. Arthur Gordon Webster; 3. Hudson Maxim; 6. Lawrence Saunders; 7. Benjamin G. Lamme; 8. Frank Julian Sprague; 9. Henry Alexander Wise Wood; io. Lawrence Addkks; it. Howard E. Coffin; H. Spencer Miller; 13. Thomas Robins; 14. Wm. L. Emmett; is. L. H. Baekeland; 16. Beni. B. Thayer; 17. W. R. Whitney; 18. Peter Cooper Hewitt; 19. Joseph W. 20. Alfred Craven; 21. Andrew Hunt; zz. Andrew L. Riker; 23. Robert Simp- son Woodward; 2.. Matthew B. Sellers.

widely read and experienced scientific men and Doctor of Philosophy. He has also re- 1879. He is a specialist in steam and gas available in this country to -day, and so we ceived honorary degrees from the Univer- engine plant design, as well as hydro -elec- may indeed congratulate ourselves in hav- sities of Wisconsin, Columbia and Pennsyl- tric developments of large extent. ing such an able electrician and inventor at vania. Part of his experiences covered The Inventors' Guild selected two mem- the head of this illustrious body of well- positions as assistant engineer in the United bers for the Board, namely, Peter Cooper trained specialists which, in its entirety, cov- States Lake Survey, assistant astronomer in Hewitt, of New York, and Thomas Robins. ers practically all branches of applied sci- the United States Transit of Venus Com- Mr. Hewitt is a New Yorker born and bred, ence with which we are familiar to-day- mission, etc. He was at one time Professor and first saw the light of day in 1861. He f rom navigation to wireless. of Mechanics, Physics and Mathematics at graduated from Stevens Institute with the Thomas Alva Edison was born in 1847 in Columbia University and also served in the degrees of mechanical and electrical en- Milan, O. His early education was entire - capacity of president of Carnegie Institu- gineer. He was also honored with a de- ly self- acquired, and he very early took up tion and has besides served in various ca- gree of Doctor of Science from Columbia the vocation of a railroad telegraph oper- pacities in numerous scientific societies. University. He has performed very exten- ator. However, his leaning toward scien- Professor Webster is Professor of Physics sive research work in the direction of mer- tific and technical matters caused him to at Clark University, Worcester. He was cury vapor and mercury arc devices, such invent at an early age an attachment for born at Brookline, Mass., in 1863 and grad- as rectifiers, illuminating devices, etc., and telegraphic apparatus. He finally disposed uated from Harvard University. He has latterly has taken up the work of develop- of one of his inventions at a goodly sum, spent much time abroad at scientific schools ing special generating and amplifying mer- which really started him on the road to his in Berlin, Paris and Stockholm, and is con- cury vapor apparatus for use in radio -teleg-

www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 399

ETHEREAL ELASTICITY. ether of space, and if the earth was pulled of successful wireless telephony from the The Danish physicist Oersted, in 1819, out a million miles farther into space and Atlantic coast to Honolulu suggestions are discovered the magnetic effect of electric released, it would go back into position so forthcoming of possible life -saving uses at currents upon needles. It created a great gently that we would never know it hap- sea for this latest scientific miracle. If the deal of excitement at the time because it pened. Now, if we change Newton's device had been perfected a few years was the first clew which had been found famous law of gravitation and use elec- earlier the Titanic disaster might have been that a relationship existed between elec- trons instead of bodies, here is the result: averted, for President Vail, of the Ameri- tricity and magnetism. The idea that a Any two masses of electrons (meaning any can Telephone & Telegraph Co., predicts third electricity existed was never advanced magnets) in the universe attract each other the employment of the apparatus as a pro- until my "Electrical Theory of the Uni- tection to liners against icebergs. The idea verse" was published, says Prof. G W. Mognelic is to equip a lifeboat with a wireless tele- Cooper, suggesting that an electron of elec- phone, and when a ship gets into a fog tricity was composed of positive, negative PosiJire Nego}ire where ice may be met, to send the boat and magnetic electricity, magnetic occupy- ahead as a scout to give warning of danger. This use would also guard against col- ing the center of an oblong electron. The 71111 ether of space has been referred to by many 11 lisions between vessels in fog, which have R - A - R scientists as the elasticity that holds our cost so many thousands of lives in mari- earth to the sun, or bodies of the universe . A A i time history. in their respective places, but no scientist R. A R Again, when a man has fallen overboard, has ever attempted to explain what that it often happens that rescuers sent out in elasticity is. If we accept the theory of a small boat cannot see him, although he three kinds of electricity and allow each may be plainly visible from the ship's electron in nature to set universally north Diagram Showing Arrangement of Positive. crow's nest. It is pointed out that the and south, unless otherwise deflected, and Negative and Magnetic Electrons. At- lookout could direct the rescue if the life- that like electrically repels and unlike at- traction at A; Repulsion at R. boat wcre fitted with a wireless telephone. tracts (meaning positive and negative elec- Then, too, there would be with a force which is directly proportionate the value of tricity) ; also that magnetic electricity wireless telephony to castaways from ship- positive, negative and magnetic. to the product of the masses and inversely wrecks. Communication attracts proportional to between their The drawing will illustrate this arrange- the square of the distance boats and passing ships would be compara- ment of electrons, showing lines of attrac- between thcm ; also, every electron in the tively easy. The wireless "telephone" has tion and repulsion. If we pull the electrons universe attracts every other electron with an immense advantage over the wireless endwise and let go will instantly a force which varies inversely as the square "telegraph" in it dots not for apart they between the two electrons. that call the fly back to place; if we pull them apart or of the distance presence of a skilled operator, and the push them together sidewise and let go mechanism is much simpler. Thus the they will return to their former position. HUMANE USES OF WIRELESS newest marvel of modern science bids fair If we accept this theory we have the 'PHONE. to rob sea travel of much of its danger only explanation of the elasticity of the Since the recent wonderful achievement and suffering. raphy and telephony. Thomas Robins is a Pa. The latter gentleman-Mr. Sperry-is the New York 'Central Railway. Mr. Lamme resident of Stamford, Conn. He was born well known to -day for his inventions per- was born on a farm near Springfield, O., at West Point, N. Y., in 1868 and graduated taining to the automatic stabilizing of aero- and graduated as a mechanical engineer from Princeton University. He is in busi- planes. He also is an electrical engineer of from the Ohio State University. He has ness in his home city, holding the position ability, besides having had wide experience had a large amount of designing and other of president of the Robins Belt Conveyor in many other lines of engineering and in- experience with the Westinghouse Electric Co. He also serves as secretary of the In- dustry. He was born at Cortland, N. Y., in Manufacturing Co. at Pittsburgh, and at ventors' Guild and is a member of a num- 1860 and received his degree from Cornell present holds the position of chief engineer ber of technical societies. University. He is a member of many scien- with that corporation. He is one of the The American Society of Automobile $n- tific and technical societies and should prove best -known men to -day in the field of large gineers is represented by Andrew L. Riker indeed a very able and valuable member of size alternating current electrical machinery and Howard E. Coffin, both of Detroit. The the Naval Advisory Board. design, and the mighty generators at the former was born in New York City in 1868 From the American Society of Mechani- Niagara Falls power plant are constructed and is a graduate of the Columbia Law cal Engineers there were nominated Will- after his designs. He holds many patents School. He later became greatly interested iam LeRoy Emmett, of Schenectady, and on electrical machinery. One of his particu- in the problem of mechanical propulsion of Spencer Miller, of South Orange, N. J. Mr. lar pleasures is in discovering and assisting vehicles. One of his early inventions was Emmett was born at Pelham, N. Y., in 1859 young men of ability along the lines of that of the first electrically propelled vehicle and graduated from the United States Na- his chosen profession. in this country. His experience with gaso- val Academy and has also received the hon- In the field of aeronautics two well - line engines and vehicles adapted to propul- orary degree of Doctor of Science from known men have been appointed by the sion by this means has been vast and varied. Union College. He has specialized in elec- Aeronautical Society of America in the per- Probably one of the best -known men in the trical engineering. At present he is con- sons of Hudson Maxim, of Brooklyn, N. automobile line is Howard E. Coffin. He nected with the illuminating engineering de- Y., and Howard Bacon Sellers, of Balti- was born at West Milton, O., in 1873 and partment of the General Electric Co. Mr. more, Md. The former is well known studied at the University of Michigan, Miller serves as chief engineer in the cable- throughout the world for his original and where he received the degrees of B.S. and way department of the Lidgerwood Manu- important research work on high explosives M.E. He was for several years in the facturing Co. He was born in Waukegon, and his activities have covered many other United States Civil Service, along the line and graduated from Worcester Polytechnic fields of sociology, philosophy and science. of internal combustion engineering and was with the degree of B.S. He has made a He was born in Orneville, Me., and at an for some time in charge of the Olds Motor number of inventions relating to apparatus early age he engaged in the publishing busi- Works' experimental department, at which for saving life at sea and cableways for ness. Later he took up the work of in- plant he later served as chief engineer. coaling vessels at sea, which devices are ventor and experimenter, developing the Since 1910 he has held the office of vice - used by the Navy Department of the United first smokeless powder ever used by the president and consulting engineer of the States Government. United States Government. This invention Hudson Motor Car Co. In electrical science two brilliant men he later disposed of to the Du Pont de Ne- From the flying world two well -known in- were selected by the American Institute of mours Powder Co., of which he became the ventors were selected through the courtesy Electrical Engineers; namely, Frank Julian consulting engineer and expert in research of the American Society of Aeronautic En- Sprague, of New York City, and Benjamin work. In later years he has evinced great gineers. These representatives are Henry G. Lamme, of Pittsburgh, Pa. As a pioneer interest in aeronautical science and has A. Wise Wood and Elmer A. Sperry. Mr. in the development of electric railways and made many valuable suggestions along this Wood hails from New York. He has per- devices for the control and operation of direction. Mr. Sellers was born in Balti- fected and developed many appliances in same, Mr. Sprague is well known and he more and there he received his early educa- the realm of printing machinery and for has served in many important capacities tion. He studied in the Law School of which he was awarded a gold medal by the with various corporations. He was born in Harvard University, from which he later Franklin Institute. Among his societies is Milford, Conn., in 1857 and graduated from graduated, and then followed up this work the Society of Naval Architects and Marine the United States Naval Academy. He was with courses in the Laurence Scientific Engineers. For some time he has been an at one time assistant to Thomas A. Edison School and the Drexel Institute in Philadel- enthusiastic student of, and a writer on, and has acted as consulting engineer to the phia. He was the first editor of Aeronau- aeronautical subjects. He was born in New Edison General Electric Co., the General tics and is also a member and past chair- York City in 1865 and received his early Electric Co., and as a member of the Ter- man of the technical board of the Aero education in the Media Academy at Media, minal Commission for the Electrification of (Continued on page 450.)

www.americanradiohistory.com 400 THE ELECTRICAL EXPERIMENTER December, I915

and one is here shown illuminating the The Electrical Burglar of the 20th Century combination lock dial of the safe. IT is, indeed, surprising what ingenuitp side of the building or also within same. A cable is perceived dropping down and ability are.shown among the criminal In this case the supersensitive microphone from a convenient electrolier and terminat- classes in quickly adapting the latest transmitter of the detectaphone is placed ing in a large disc fitted with a carbon advances in the electrical and mechanical cvtside the front door of the building or electrode and insulated handle, which lies in front of the burglar who is attempting to open the safe. A pair of smoked gog- gles are necessary in conjunction with the use of this electric arc burning apparatus. Whenever the safe lock refuses to yield to the treatment aforementioned, it is a matter of but a few moments, relatively speaking, to ground one side of the elec- tric circuit to the safe and by means of the shielded electrode just mentioned, an arc is readily established between it and the surface of the safe door. This "arc" is one of the hottest fusing agencies known to modern science. It has a temperature of from 6,000 to 7,000 degrees Fahrenheit, and it is needless to say that the hardest nickel steel, even though Harveyized or chilled, will soon be melted by the intense heat of the incandescent electric arc gaseous stream thus produced. As may be readily imagined, it would take but a short time to literally "bite" the lock mechanism right out of the safe door. When this work has been performed it is a simple matter to throw the bolts and open the door in most cases. However, in this instance as well as in most others, and in accordance with the old proverb, "There never was a smart man but that there was a smarter one," it is safe to say that sooner or later the most clever and cunning tricks of the best yegg- men are ferreted out or compensated for by equally clever counteracting ideas as promulgated and devised by our modern detective and police experts. The selenium cell is probably one of the best devices with which to foil the would -be safe - breaker, for the minute he flashes a light on the spot where the selenium cell is concealed, an electric bell ring in any The Modern Burglar UtlCzes Electricity to Find the Combination of a Safe and for Numerous will Other Purposes. part of the building desired or at police headquarters, notifying the proper parties sciences to their art -if we may so call it- down the length of the hall, as the case instantly as to where the alarm originated. of breaking into safes, vaults and buildings. may necessitate. Thus it is that the march of science is The up -to -date burglar has many marvelous While on the subject it may be of in- constantly toward a higher plane, en- scientific devices at his beck and call, and terest to state that the yeggmen and deavoring to eliminate any weak spots in most of them require but little knowledge second- story "artists" of our day use noth- diversified applications to th,; needs of so- of science or the trades in order to oper- ing but electric flashlights or battery lamps, ciety and the fine arts. ate them very effectively. Our illustration herewith depicts a 20th SEEING A BASEBALL GAME BY photograph which depicts an exact repro- century burglar in the act of blindly check- WIRE. duction of a baseball field, but on a minia- ing up the combination lock on a steel safe One of the most novel and entertaining ture scale. The action of the complete de- by means of a very sensitive telephone out- fit, known as a "Detectaphone." The microphone transmitter of this supersensi- tive telephone set is held, by means of a rubber suction cup. against the front of the safe door in proximity to the combina- tion lock mechanism. When the knob carrying the numbered dial of such a lock 3'v0Re_'.4, gw%SCOOt is rotated, ( the movement of the bolts on 'i,$.12315678,1 the inside of the door can be heard, and liliüiilñil' " IY3f56784 in some cases the interlocking of the vari- NEWARK lll/if/lU R H E -. :RHE ous parts of the lock mechanism proper CfR-GBELL \al K ELLEY can be perceived by this arrangement. It 11 ; / ti L Y ERAS thus becomes an easy matter for a clever _ 4 j, - (/ I >/ safebreaker, with a little patience, to readi- aen -31ifi I~it ly open any ordinary safe or vault door R 11111111101175:01 fitted with this type of lock, without blI, 3lllfi knowing the actual combination numbers i 11/11.1. ¿ Ti0Z1311 . BER IIY by which it was locked in the first place. IE Ä=i1 í [ r LK:rrO., s .. , L[cEf The telephone set is completed by a pair pBB UtlfYltE UMPIRE Be S!' A of sensitive telephone receivers placed over ,` HOWELL (8313 the ears as our illustration indicates, and P11UIt'41W _. 11111I11.lilliiidlli the battery for this set may be carried in -- the pocket as depicted at B. A second detectaphone set is often util- ized by a confederate, for the purpose of indicating the approach of the police, etc., on the outside of the building. The ac- This Electrically Operated Baseball Diamond in Miniature Duplicates Every "Play" Made. comp:ice is stationed at the door in the inventions of the 20th century is that en- vice is very human; that is to say, each illustration thus pictured, in the act of de- abling one to see a baseball game by wire. performance of the player is so naturally tecting the approach of any persons out- This is illustrated in the accompanying (Continued on Page 454.)

www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 401

ELECTRICAL PROSPERITY WEEK. UP -TO -DATE SHOPPING tanners coming inside at all. An increase in By John A. Randolph. BY TELEPHONE. sales has resulted. Newark, N. J., has a new shopping idea. Here's the way the new electrical seller (The Society for Electrical Development.) is worked out: A desk equipped with or- OPTIMISM, enduring, persevering, Usually there are two ways of shopping - der books. Inter -phones and electrical de- finally triumphant, made the bibli- either by telephone or going personally into vices has been placed just inside the show cal legend of "Job" a classic. Job the store. This shopper goes to the window window. One of the office force sits at the looked on the sunny side. kept plugging, of the store, which in this case is the West- desk in plain view of the passing thousands. and achieved prosperity in the end. The 'He is a very busy young man. His desk moral is obvious. ern Electric Co.'s supply depot at 64 Park 'phones are connected up to lines which of several With the same faith in destiny, hope for place, picks tip one the Inter- reach to the outside. A customer comes the future and confidence in truth, the united electrical interests of the country have planned a big sales campaign for the week of Nov. 29 to Dec. 4. They have called it ELECTRICAL PROSPERITY WEEK, a fitting name, fraught with wholesomeness and charac- terized by-the spirit electrical. It is to be an event, a six -day celebra- tion, in which the people throughout the United States from the Canadian frontier to the borders of Mexico, from ocean to ocean, will be shown the wonders of elec- tricity as never before -will be taught how inseparably linked with modern progress this all pervading force has come to be. In short, the purpose is to advocate, dem- onstrate, promulgate, electricity. The Goddess Electra. -The emblem of the celebration is a design beautifully sym- bolical of the broadness in scope, the clean- liness, convenience, economy of electricity.. The central figure is the "Goddess Electra' " in the act of closing an electric switch. A look of confidence and satisfaction il- lumines her countenance, as our illustration -. portrays. Electricity is her servant. The attractive background shows a residence section on one side and a city street on the other, with electric light and power everywhere. The home scene is peaceful. It suggests things as they ought to be- where drudgery has passed, to give way to cleanliness and purity,..the,light of truth The city street is suggestive, at once, of efficiency, system, speed -tasks done auto- Electrical Supply Store Uses Telephone Outside of Show Window to Attract Customers. matically, everything moving at the push of phones extending through to the street side along, sees some electrical appliance that a button. of the window, and talks to the clerk in- he needs, picks up the outside Inter -phone. The design was as carefully chosen as side, as perceived from the photo. speaks quickly to the clerk in the window, the other features of the campaign. It was Experts in selling goods to the public who is there to take down orders, and asks selected only after weeks of careful con- often say that if a dealer can only get the clerk for further details about cost, sideration, during which a large number of people inside his store he will sell goods. etc., of devices in the window. Usually a other designs produced by many of the That's why so many bargain days are con- crowd stands about waiting for a chance to ducted. People come for the bargains, but ask questions. Addresses are obtained and also buy otter goods. Just to try out the the mailing list improved by the arrange- giving public an ex- I ELECTRICAL'PROSPERITY WEEK, psychology of this claim the local manager ment, besides to the NOv. Z9 - DEC.4 of this store decided to find a way to sell cellent idea of how an up -to -date concern goods and take orders without his cus- handles its office work.

^ The winner was Miss Florence Cassasa, of readings, addresses embodying the elec- Brooklyn. trical spirit. The spirit of the celebration will be ¡,/, HEAT education. The public will be shown as ELECTRIC SHOWER FOR A BRIDE HOT never before that electricity is a necessity, TO BE. not a luxury; is economical. not expen- It is the Custom among young people to r sive; is simple, not complex; is broad in give a "shower" to a bride to be and be- scope, not limited; is safe, not dangerous; stow upon her gifts that she is likely to %!_ ^ Piti is, in short, the most willing, reliable, able need in her future home. There are linen I servant mankind has ever known. showers and handkerchief showers, tinware :;'i ` Displays, exhibitions, lectures, parades, and woodenware showers, but the very shows will be held everywhere- present- latest is the "electric" shower! ing, demonstrating, explaining things elec- Miss Irene Brothers, of Nela Park, 4 trical as never before. A blaze of illumi- Cleveland, was the fortunate recipient of ..,wyiL... _ _ I -DO IT ELECTRICALLY s.--- nation from coast to coast will come at such a shower recently when her engage- night as a climax to the activities of the ment was announced. The event took place day. Myriads of electric lamps of all in a beautiful ravine in Nela Park. Elec- types, shapes and sizes will take up the tric Japanese lanterns were strung among light where the sun leaves off. The cool- the trees. An electrically cooked supper Official Design for Electrical Prosperity Week. ness of the year will make people actively was served. Among the electrical devices receptive. Meetings in full sway every- presented to Miss Brothers were an electric foremost artists of the country, were sub- where will offer unbounded facilities for coffee percolator, toaster, grill, electric mitted for approval. lectures. iron, hair drier, tea urn and table lamp, all The story of the choosing of the model The schools will be in session, and will of which can be utilized to best advantage for the "goddess" was published in the provide a means of setting forth the ad- in the modern home. newspapers throughout the country. She vantages of electricity to the coming gen- was chosen by contest, the final selection erations by prize essay contests upon elec- Man to man -can you afford to miss a being made by a jury of well -known artists. trical subjects. "Electurettes," recitations, single issue of this magazine?

www.americanradiohistory.com 402 THE ELECTRICAL EXPERIMENTER December, 1915

SUBWAY IMPROVEMENTS CAUSE electric power and other cables. It is as- their protective system work so that Lon- GREAT CHANGE IN ELECTRIC tonishing to the uninitiated who, for the don could sleep in peace. WIRES. first time, happens to behold one of these The detection system which Dr. de For- Owing to the vast amount of under- exposed sections of a New York thorough- est proposes to work out is as follows: ground excavations now having to be fare, when he observes the tremendous Several delicate microphones are placed on made in New York City in building the amount of underground wires, cables and a geometrical figure, probably each on a new subway lines, which extend for many pipes which seem to intertwine and pass mast. These microphones are equipped with miles, the electrical engineers of the tele- each other like so many huge snakes. The Audions so that any vibration reaching them phone and power companies have had their magnitude of this task becomes more ap- is magnified several hundred times, each of hands full in taking care of the continual parent when it is considered that there are the Audions being of the same recording shifting and rearrangement of the hun- often a dozen different voltages, both high power. The microphone on that point of the geometrical figure nearest the approach- ing airship will record vibrations of a greater strength than the microphone on the most distant point of the figure. The effect of the vibrations upon the inter- mediary microphones will, of course, be of varying force, according to the relative dis- tance of the, microphone' from the source of the vibrations, the approaching airship. From the varying effects of these vibra- tions on individual microphones is calcu- lated the line of direction of the approach . of the vibrations on each microphone. These lines of direction when extended form the outline of an imaginary cone, at the apex of which will be found the ap- proaching airship. When the location of the airship has been determined, Dr. de Forest's task ends, and that of the aeroplanes and airship guns begin. It is planned to send aeroplanes out above the dirigibles after the location has been determined.

GIRL RADIO OPERATORS. No girls have as yet qualified as licensed radio operators in this country, although it is stated unofficially that hundreds of girls are transmitting messages in amateur sta- tions controlled by their licensed brothers. Many French girls have qualified as wire- less operators, and are now in active serv- ice in the war zcne.

Showing Vast Net Work of Electric Gas. Water and Steam Conductors in a New York City Street Exposed During Building of New Subway. NOVEL ELECTRIC VIBRATOR STRAPS ON HAND. dreds of underground cables and wires and low, being carried by these various used for telephone, light and power cables and wires, and, also, the pipe lines A very neat and efficient type of elec- service. which pass and repass these electric lines tric massage vibrator is shown in the The illustration we present herewith contain gas, live steam and water. Besidcs illustration and, as perceived, it can be shows a section of Dey street where it in- this, there are the huge sewer lines. All strapped to the back of the hand. The tersects with Church street, in New York of these various transmission cables and vibrations from the device may thus be City. In the foreground may be seen one conduits have to be invariably rearranged transmitted tirough the hand to the face of the telephone cable manholes, in the and shifted about in the construction of of the patient, etc. It is of great use to process of reconstruction. At the left of the subway, even to different levels, or barbers and facial specialists. It is the picture may be observed a myriad of from one side of the street to the other. supplied for 110 -volt direct -current or alternating-current circuits, and comes DR. DE FOREST TO HELP DE- In this plan an instrument fashioned on the complete with flexble cord and attachment TECT ZEPPELINS. principle of the Audion was used to magni- plug, which may be inserted in the regular A middle -aged American inventor with fy the impluses recorded by the micro- lamp socket. Undoubtedly this is one of an electric bulb arrived in London recently phones at sea, but on a hurry -up call from the British Gov- that form of Audion ernment to show Sir Percy Scott how the was not perfected to British capital may avert danger from the stage of Dr. de Zeppelins. And when the American in- Forest's recent inven- ventor has done his work in London he tions. will cross the Channel to devise a system T h e effectiveness of protection from air attack for the treas- of the coast defense ures and the lives of Paris. The inventor system suggested to is Dr. Lee de Forest, of New York City. the English authori- As our readers are well aware, Dr. de ties a similar plan Forest is the inventor of the Audion am- for defense against plifier, an adaptation of the incandescent invading airships. But electric light, by which feeble electric im- conditions were dif- pulses can be magnified to a point at which ferent from that of they can be registered with considerable dealing with sub- force. marines, because For several months England has used for microphones could coast defense a system of microphone de- not be placed high tection against submarines by means of enough in the air to which the vibration of the propellers of record the vibrations German subi ersibles was picked up by of the propellers of Unique Electric Vibrator Straps to Back of Hand. microphones at sea and transmitted to a approaching Z e p- base, so that the approaching submarine pelins. The success of the de Forest Audion the smallest practical massage vibrators could be located. This defense has been was brought to the attention of the British of the electric type ever devised and one credited by London with being responsible authorities, and they sent for the man who that will appeal to everyone interested in for the destruction of many submarines. had invented it to come over and make any way in this art. www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 403

A REMARKABLE ELECTRIC music for battle scenes and the like, alle- conceived the idea, and through his sugges- PIANO PLAYER FOR THE gretto or fast, lively music of various char- tion Secretary Daniels obtained the co -oper- "MOVIES." acter to correspond with animated scenes ation of the news agency and the telegraph By Frank C. Perkins. such as horse or automobile racing, mod- company. Only officers and sailors who The accompanying illustration shows the erato for social or dramatic scenes, dimin- are thousands of miles from home, in mechanism of a wonderful electric piano uendo, or slow music to coincide with strange waters, by strange shores, can fully player, controlled from the filin booth by pathetic or sentimental pictures, Indian appreciate the value of a service of this a series of buttons. By the use of sets of music to make American Indian action kind. endless perforated rolls the movie operator more realistic, staccato chords for high- Not long ago some 300 jewelers in- is enabled to instantly change the type and waymen or burglar action, the music pro- formed Secretary Daniels that they had duced having auto- equipped themselves with radio apparatus matic expression. just to catch this twice daily time flash It is stated that in from Washington. Time signals are said addition to the above to be of immense benefit to vessels on the musical effects t h e high seas, which now possess for fhe first more expensive ma- time an accurate means of checking their chines are equipped chronometers, which is of the greatest help with elementary ap- in fixing longitude. paratus controlled by As soon as the new wireless section in the picture operator the Philippines is completed it is believed for 'producing battle that an interchange of messages between chaos, shooting, thun- the Philippines and the United States Can d e r, lightning and be made in 30 minutes. wind. Instantaneous changes from one se- WOMAN MAKES TELEPHONIC lection of music to INVENTION. another with change Knowing nothing of the workings of in tempo, at the in- electricity or the telephone, but living daily stant the scenes are with a 'paralyzed husband and mother, who shifted on the screen, in her absence could not lift the receiver is a most important to answer the 'phone, a Memphis, Tenn, factor for the suc- woman has invented and patented an ap- of a pliance to the telephone which enables one cessful display to talk and hear without using the hands film. all. is pointed out at It The appliance is on the order of a phono- that in this the ordi- graph is made by is horn and the connection nary piano player pushing a little button which is mounted deficient and the ef- on the stem of the 'phone. This can be fects desired are done with a pencil held in the teeth if oftentimes spoiled. necessary, and the connection once open, The common auto - the sound may easily be received and sent matie piano is almost 15 feet away from the device by talking in worse than useless a moderate tone of voice. for the picture thea- This combination 'phone will be espe- ter on account of lack cially desirable in hospitals or with invalids of music control, for who have no use of their hands, as they it may play "Onward, may talk and hear with the greatest ease. Christian Soldiers" This appliance also enables one to cut while burglars oper- out the branch 'phone in the house, as the ate, tango music for instrument placed on the landing or stair- New Electric Piano Player, Designed to Replace Orchestras and Capable or a by "Movie" Operator. a battle scene way with string attached to button enables of Accurate Control waltz for a funeral. tempo of music from the rear of the house It is, of course, apparent that the right without any other attention to the piano. music at the right time and in the right Bellows are eliminated by a series of elec- time, is most vital for the success of the trical contact points which actuate ham- motion picture house; for without it the mers that play on the keys. proper effect of the pictures is nullified This electric piano player makes possible which means eventuallythe lossof patronage. the instantaneous change from one piece of It is held that with the new player in- music to another at any moment and is par- stalled to operate the piano, the musical ticularly adapted for playing pianos in program is directly under the control of moving picture theaters, eliminating the the picture operator as it should be and at services of the pianist and the disadvan- his will the music changes instantaneously tages and annoyances incident thereto. on pushing a button, even to the breaking It will be seen that the player is placed off of playing one selection at any note, before the piano, the latter remaining in its and the beginning of another of different usual position before the picture screen, tempo the next second -so flexible is the and is controlled by the moving picture op- electric current in connection with this erator from his booth by means of a sim- mechanism. It is thus possible at all times ple electrical controller. The musical pro- to have melody to correspond and be con- gram embraces crescendo and thunderous sistent with each picture shown. DAILY NEWS RADIO NOW GOES Not only baseball scores, but the latest TO NAVY IN DISTANT WATERS. word about the Kaiser and the war and Even the oldest inhabitant of Port -au- William Jennings Bryan's latest opinion . Prince, Hayti, cannot remember the time penetrate the tropical evenings. The offi- before now when the tropics received the cers and men of Uncle Sam's warships in baseball Telephonic Loud Speaking Device Invented by a scores every evening. West Indian waters are now able to learn Woman. Somehow one doesn't associate the of the things going on at home and abroad. thought of the blue Caribbean and scorch- Every night the day's news is boiled one to answer calls and hear perfectly with- ing semi -equatorial sunshine with the down to 200 words -just as it should be, out going upstairs or down. thought of "New York, 4; Pittsburgh, 6." someone says -and is telegraphed to the The newest patent for the "Hatch Com- But it's an actual fact, just the same. naval wireless station at Key West, Fla. bination 'Phone" is the collapsible horn and Secretary Daniels has been bitterly as- Then the wireless sparks begin to sputter the sound intensifier; by the use of the for- sailed as the man who took the Demon and out over the Gulf, the Caribbean and mer the 'phone has the appearance of an Rum out of the navy. But the officers and the South Atlantic flashes the news "from ordinary instrument, and by putting it over men in Southern waters bless his name as home." the lips and using the intensifier properly the man who gave them baseball scores Capt. W. H. Bullard, Superintendent of one may carry on conversation as privately every night. the Naval Radio Service, is the man who as if he were in a sound -proof booth.

www.americanradiohistory.com THE ELECTRICAL EXPERIMENTER December, i9t5

HEARS JAPAN WIRELESS MES- Marvelous Electric Sign that Actually Spells SAGE AT GREAT LAKES, ILL. ARECENT innovation in the multi- Complete sentences are spelled out in Sitting at the desk in the new wireless tudinous array of electric signs this way, but of course only a section of station at Great Lakes, Ill., at 4.10 o'clock appearing along the "Great White the sentence, as two or three words appear on the morning of Oct. 1 last, G. F. Reiling, Way." otherwise known as Broadway, in the course of a couple of minutes, while one of the wireless operators, heard one New York City, is that advertising "Pebeco" the letters form at the right and move of the new stations in Japan, about 5,000 tooth paste. The illustrations herewith across the sign, so to speak. miles distant, talking to Kokoa Head sta- show four distinct views of this extremely To more clearly illustrate the action of tion in the Hawaiian Islands. He also de- clares he heard a wireless telephonic mes- sage from Mare Island, Cal. That there is no doubt about the effi- ciency of the new wireless station at Great Lakes is seen by the fact that Reiling gives word for word the message which he heard flashing from the Japanese staticin, as fol- lows: "Hello! Hello! How do you hear me? How are you? What do you want? Please copy: 543210. Do you get this? Please copy (repeats figures) that's all; that's all. Good -bye." Reiling worked the same morning at 4 o'clock with the San Diego, Cal., station and the operator there told him that the message sent out from Great Lakes station was heard very distinctly. He in turn, at Great Lakes, could hear the California message very plainly. The Great Lakes station is in daily sclted- tile with San Diego and Arlington, Va., and the clearness of the messages sent so far has caused officials at the station to feel that the local plant is about as efficient as any in operation at any place in the country. STEEL JACKET CATHODE HELPS COOL X -RAY TUBE. One of the principal troubles encount- ered in modern X -ray work and particu- larly where medium or small sized tubes are utilized, lies in the large amount of , ;, hum:' ":, .nwiüÌl'MIti}¿.' heat generated within the tube, and es- `..+«5 pecially at the cathode electrode. In some , cases water cooling is resorted to, in ari effort to help cool the tube, and electric fans are also employed in a similar effort, It has remained for a western X -ray con- Changing Night Effect and Daytime Appearance of New Electric Sign in New York City that cern to bring out a very simple device Spells Out Successively Continuous Sentences. which seems to possess considerable prom- novel advertising attraction which, of this highly ingenious sign we may glance course, is only to be seen at its best at at Fig. 1. Here we see tie words "nearly night time. all," which form part of a Pebeco adver- The sign is, a large affair, measuring tisement sentence. To start with, only the about 100 feet long by 50 feet high, and it "N" is observed, and this is formed at the is supported on a steel framework mounted right and gradually slides over toward the on top of the Hotel Hermitage near Forty - left, the E -A -R, etc., following each first street and Broadway in the metropolis. other consecutively and in their proper se- The upper part of the sign does not pos- quence with respect to one another. sess any remarkable features, as may be One of the best effects obtained with this seen by carefully looking over the illustra- sign is at the close of a certain sentence tions herewith. At the bottom of the sign, when the active part of the display becomes however, as becomes noticeable in Fig. 4, is totally dark, when the letters forming the a band about 12 feet high and which extends end of the sentence appear to literally slide clear across the face of the sign. This off into the darkness of the night. band (which is stationary) is made up of It is understood that the switching con- a series of harrow strips, on which are trol of this spectacular display is arranged mounted vertical lines of electric bulbs. somewhat on the order of a player-piano, By a very ingenious flasher arrangement, with perforated paper roll, which passes due to the engineers of the O. J. Gude Co. through a special switch arrangement in a and on which it is understood patents have manner which becomes apparent to any been it is made possible to cause a electrician. A vast amount of work is issued, Ingenious Steel Jacket to Cool X -Ray Tube letter, a word or a sentence to flash across necessitated in designing, installing and op- Cathode. this normally black band from right to left, erating such a display, and this is more i. e., it is spelled out in front of the spec- clearly emphasized when we consider that tator's very eyes, the letters apparently practically every lamp in the active (spell- ise in an effort to reduce the heating in forming at the right and slowly traveling ing) part of the layout has to have a wire such tubes. across the face of the sign, each letter being brought from it to the switch- control booth This device, the new Kesselring tube. ,followed by its complement in forming a on the roof of the hotel. Most' of these comprises simply a steel jacket, as illus- wórd, etc. elaborate sign effects require a staff of sev- tration shows, which surrounds the cath- This sign has attracted greater crowds eral electrical experts to operate and care ode electrode proper. The heat produced than probably any other like advertisement for the complicated and intricate switch by the cathode is conducted through the ever erected on Broadway for many a day. gear utilized in cutting in and out the steel jacket and thence along the electrode It is so unique that it is bound to catch the proper lights. rod and so out of the tube. This device is eye of nearly every passerby, no matter The sign is in the theatrical section and, of low initial cost and much simpler than how much in a hurry he is or how intent therefore, commands nightly a vast audi- many other schemes advocated and em- on his business. ence. ployed for this purpose. www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 405 High Frequency Currents and Apparata (Concluded)

AT Fig. 7 is shown how a 16-cp. 110 - siderably wizen allowed to jump directly to that, after a few treatments of this kind. volt incandescent lamp may be the skin. In ally case, a piece of metal the blood pressure can be reduced quite lighted through the body by a should be held in the hand. No severe shock markedly, and in most cases permanent high frequency coil. A piece of cop- ns experienced in the passage of such high lowering of arterial blood pressure is ef- per wire is firmly held in the mouth frequency currents through the body a, fected. for this somewhat startling experiment and long as they are properly handled by al- This large solenoid arrangement can be it is also joined to one terminal of the in- lowing the spark to enter the body through candescent lamp. A second wire is con-. a metal electrode, as stated, and providing the frequency is high enough. Experi- ments have been conducted where half a million volts were passed through a man's body with several amperes of current. Even tvita a small high frequency set, light- ing a a9 -cp., 110-volt lamp, then one ampere of current is passing through the body. With this current, as indicated on a hot - wire ammeter (and which also has the ef- fective current value of one ampere), it is quite possible that it may have an instan- taneous maximum value of as much as 190 to 170 amperes. This is due to the very rapid discharge of the condensers in the circuit, and if large enough electrodes are used on the skin no burning effect will be felt. Rather spectacular high frequency dis- charge effects are portrayed at 8 and 9. Fig. 7. Lighting no Vt. it C.P. Lump Thru the Body by Nigh Frequency Current. These are usually produced by using an Oudin transformer giving a powerful uni- nected from the other terminal of the polar discharge at high frequency and lamp to the high frequency transformer. ultra -high potential. In the experiment at have When the 'proper adjustments been Fig. 9 a metal piece is held in the hand made the high set it will be on frequency and a flame discharge from same leaps found possible to bring the lamp up to full forth into space. The body of the man is brilliancy. The Oudin connections are in- here charged at very high voltage by con- variably employed for this class of experi- necting the high frequency terminal of the ments where lamps are lighted, sparks al- Ondin transformer to his ankles through a couple of metal ankle straps. He is best seated on a glass platform for this experi- ment, adjustments in the and all of the Fig. 9. Wonderful Brush Discharge Effect high frequency transformer circuit must be Produced by High Frequency Current. very carefully made in order to produce these fine effects, and the inductance of the used to produce spectacular high frequency {I primary exciting transformer is very im- stunts and experiments, a common one be- portant. It is quite advisable, and in fact ing to let the person inside of the wire imperative in some experiments of this cage hold a Geissler tube in his hands so nature, to use an adjustable impedance coil that the current produced in the body will in the primary of the exciting step -up pass through the tube from one hand to transformer, so as to be able to tune it the other, lighting up same in a spectacular properly with respect to the high frequency manner. If the cage is made sufficiently circuit. The wonderful effect produced at large, two or more persons may stand Fig. 8 is also an Oudin coil phenomenon. .within same and Geissler tubes placed in and a very fine spray is seen to branch out their hands so as to complete the circuit all around the top of the high frequency coil. This effect is truly marvelous and can cnly be fully appreciated when observed at first band. No photograph, and especially a half -tone as here printed, can do justice to the weird and awe -inspiring effect pro- duced in this way. In this experiment a person can approach carefully the highly charged Oudin coil and part of the spray will discharge through the head without any appreciable shock as long as the person does not come too close. In the electro -therapeutical application of high frequency currents by the medical profession there is often employed a large wire cage of sufficient size to enclose the subject's body as Fig. 10 shows. The high frequency current from an Oudin or Tesla machine is passed through this large helix and powerful currents are induced in the subject's body, and in this way are pro- duced valuable results of an electro- thera- peutical nature for various kinds of ail- Fig. io. Large Nigh Frequency Cage Used for ments and diseases. This method is one Electro -Therapeutical Treatment. Fig. 8. Another Beautiful and Spectacular Ef- of the best known to medical science for fect Produced by an Oudin Coli. lowed to jump to the hand, etc. A word the treatment of arteriosclerosis, or as i' of caution should be mentioned here, as is commonly termed, "hardening of the from one body, through a Geissler tube, to these high frequency sparks will burn con - arteries." Dr. D'Arsonval, the noted French the next body, etc., giving a very interest- scientist, lias made numerous measure- ing effect for stage and lecture purposes. Figs 7, 8 and 9, reproduced from "Electricity at High Pressures and Frequencies," by Henry L. ments in this direction and has proved by Malty other remarkable and interesting Transtrom. tests on different male and female patients (Continued on Page 419.)

www.americanradiohistory.com 406 THE ELECTRICAL EXPERIMENTER December, 1915

The Radio Transmitting Set at Arlington, Va. THE powerful Government wireless very large and are composed of hollow When a break -down occurs in such con -. telegraph station operating at Ar- copper tubing. In shifting or adjusting densers as these they possess a self -healing lington, Va., and rated at approxi- these large tuning inductances, recourse is or self -restoring dielectric characteristic, mately 100 kw., utilizes a synchronous had to a rope or a belt and countershaft and in operation it is merely necessary to rotary spark gap and a number of other which rotates the drums on which the coils keep the compressed air at so many pounds' unique apparatus especially designed to are wound. Electrical contact can be made pressure within the tanks. The metal handle such a large amount of power in with any part of _a turn as desired by tanks are of very rugged construction and the most efficient manner possible. This means of a rolling wheel or trolley. This the condenser plates within them are sus- installation was supplied by the National is noticeable, particularly on the aerial pended from the covers, which are bolted Electric Signaling Co., exploiting the pat- loading inductance observed at the extreme to the tank proper. One set of plates is ents of Prof. Fessenden, One of the right of tie photograph. grounded to the shell, while the alternat -' basic patents embodies a synchronous The rotary spark gap of heroic size ing plates are connected through a heavily rotary spark gap mounted on the end of rotates at 1,200 R.P.M. and contains two insulated terminal, as perceived from the the generatorshaft or similarly disposed so stationary spark electrodes which are fitted illustration. This plant is probably one of as to cause the spark to occur in an exact with two insulated water cooling systems to the most powerful and efficient extant to -' relation at all periods with respect to the help extinguish the spark abruptly, which, day and the wireless time- signals sent out reversal of current in the alternating cur- of course, is conducive to the most efficient at noon and 10 P. M., Eastern time, daily rent transformer (primary) circuit. This operation of any wireless transmitting set. are now received by thousands of experi- has been found essential for the best result This rotary gap is enclosed within a guard mental and commercial radio stations in any case and is always superior fo any ring of large size and in which the station- throughout the United States, and also by non -synchronous rotary spark gap. The ary electrodes of the gap are mounted in ships at sea in all parts of the Atlantic

At Left: Close -up View of Synchronous Rotary Spark Gap on loo KW. goo Cycle Radio Transmitting Set at Arlington, Va. From this Mastodon Spark Gap Is Sent Out the Radio Time Signals and Weather Reports That Spread Broadcast Over the United States and the Atlantic Ocean Daily.

Below: General View of the too KW. wireless Transmitting Set at Arlington. Tanks Below are the Compressed Air, Fessenden Type, Condensers. Water Cooling Tanks for Spark Gap are Seen Over Dynamo. Not Wire Radiation Ammeter is Observed in Foreground on Post.

l'hotos Coortiaht by Underwood & Underwood. two illustrations herewit:t depict the extra extra large insulated bushings. This form Ocean. Signals from this station have large synchronous spark gap used at Ar- of construction has many advantages, and been received under good conditions at the lington in transmitting time signals, and one in particular is that allowing the sta- Eiffel Tower radio plant at Paris, France. the other view shows the spark gap itself tionary electrodes to be moved through It has been stated a number of times that mounted on the shaft of the 500 -cycle several degrees with respect to the rotating the time signals and weather reports as alternator, together with the large -size os- spark wheel, and in this way the sparks picked up from the Arlington station are cillation transformer and aerial loading in- proper can be made to occur at practically much clearer and more easily read over ductance, as well as the compressed air any point desired in the alternating current long distances than those transmitted by condensers of the Fessenden type, which cycle passing through the step -up trans- the Eiffel Tower station at Paris, or from resemble steel boilers or tanks, as per- former which charges the condensers and, any other high -power radio station now ceived. The radiation hot -wire ammeter is likewise, this spark gap circuit. in operation. This service is of inestimable mounted on the wood post shown in the The condensers used with this set, which value to the merchant marine and also to foreground of the general view of the are, as aforementioned, of the compres -ed the naval service, enabling the chronome- transmitting set. The tuning oscillation air type, have many advantages over other ters on board ship to be correctly checked transformer and the loading inductance are types employing glass as the dielectric. twice each day. www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER -i"7 U. S. Army Field Radio Set THE photographs and diagram here- Fig. 3 as used with this set, they in general cated clearly, and the step -up transformer with show the general appearance follow regular radio engineering practise. of the resonance type, especially designed and also the connections of the As will be evident, there is employed for for this work, is air insulated. Alternating various parts making up the portable radio receiving a switch type loose coupler with current of the proper voltage and 500 pack set as used by the U. S. Signal Corps. primary and secondary windings, and sev- cycles frequency is supplied by the hand - eral unique features not commonly found, driven self -exciting generator previously on experimental radio sets at least, are described. This machine is fitted with an herewith to be noted. automatic centrifugal cut -out switch which Among these features is the inductive does not permit operating the set until the coupling of the buzzer test with the primary coil of the loose coupler. This is arranged on any receiving set very easily by simply winding a few turns of wire around the primary coil or by placing these few turns of wire at the end of the primary, so as to react on same by induction. Another fea- ture which works very nicely, and also one that is invariably used on all commercial radio sets nowadays, is the safety spark gap placed across the aerial and ground con- nections of the receiving apparatus proper. Any heavy static or lightning discharges will jump this gap in preference to passing through the high resistance and reactance of the coupler windings. This indirectly protects the sensitive and expensive head 'phones, as well as the mineral detector. Also in some cases where such protective spark gap were not used it has happened that the coupler was burned out by an extra heavy static surge through the circuit, oc- casioned by the close proximity of an elec- EE tric storm while operating the set. A simple aerial switch effects the change- Fig. Z. Showing Neat Arrangement of Complete over from to receiving set. Portable Radio Transmitting and Receiving transmitting Apparatus in Army Pack Set. Note Use The transmitting apparatus is very simple of Several "Pancake" Style Helices. and will be readily understood from the diagram. It comprises a primary coil in the proper speed is reached, and consequently oscillation transformer, and this reacts by the critical frequency produced by the Fig. L. Compact zso Watt Hand-driven soo Cycle .A. C. Generator Used to Supply Power for induction on three secondary spirals, any dynamo. This is necessary for several rea- U. S. Signal Corps Radio Pack Set. one or all of which may be joined in the sons when maximum efficiency is to be at-

The photograph Fig. 1 illustrates the hand -driven dynamo, rated at 250 watts, OS6///Ot/O/1 Trans( Antenno which can be disassembled in a few min- l utes so as to be readily packed on a mule's back. Photograph Fig. 2 shows the very Antenno compact arrangement of the transmitting Rug and receiving apparatus, including the quenched spark gap, oscillation transformer Antennabreart and loading inductance, the latter being of the flatwise wound ribbon type. These pan- cake coils forming the oscillation trans- former can be swung toward or away from one another, as they are mounted on hinges. On the shelf in the cabinet containing this apparatus is mounted the spark gap, as well as the radiation hot -wire ammeter and the transmitting key. Under the shelf there is 11111 II mounted the receiving apparatus induct- ance, and also the step -up transformer of Oueiáied&ft the sending set, as well as the high tension Resonance condensers, etc. Switching means are provided on this set /ronsf for quickly throwing the aerial and ground terminals onto the receiving or transmit- ting apparatus. All of the instruments used in the make -up of this outfit are first - class in every particular, the best possible being purchased, as becomes requisite for military requirements. The small -size hand- driven dynamo utilized in this set can be operated by two men nicely, and is especially geared up with enclosed gears as pe-ceived, so as to give the proper speed when the crank handles are turned at a fair velocity. This style of radio pack set can transmit 20 to 30 miles under average conditions, and can receive over distances of a couple of hun- dred miles or more in connection with the Fig. 3. Diagram of Connections for Transmitting and Receiving Instruments in Radio Pack Set. collapsible mast and antenna wires used in Note "Buzzer Test" Inductively Coupled. conjunction with it. The whole outfit, in- chiding the mast, can be erected in a few circuit as different wave lengths are re- tamed by such a set, and particularly due minutes' time, ready for service. quired. The quenched gap, condenser and to the utilization of the resonance type of Referring to the diagram of connections hot -wire ammeter connections are indi- transformer incorporated in this design.

www.americanradiohistory.com tog THE ELECTRICAL EXPERIMENTER December, 1915

A HUGE OIL TYPE Marconi Company Develops New 2 -KW. Radio Panel Set RADIO CONDENSER. The accompanying illustrations show, re- which move over calibrated scales marked The large oil insulated condenser here- spectively, the front and rear views of a off in wave lengths. with presented is of the non -variable type newly developed 2 -kw. radio transmitting Variation in the coupling between the and consists of a large number of zinc , set of the quenched -spark type as brought primary and secondary coils of the oscil- plates separated by glass plates. The con- out by the Marconi Wireless Telegraph Co. lation transformer is effected by the con- ducting plates are bolted together in the This set marks the latest advance in wire- trol handle and needle, which are mounted usual manner. The condenser is placed

' less outfits of this type. As will be ob- directly above the quenched -spark gap. served, all of the apparatus for both the On the lower front of the panel are primary and secondary transmitting cir- mounted the necessary motor- generator cuits are mounted behind the switchboard switches and starting solenoid, as well as panel. This conduces to the interchangea- overload relay. The usual ammeter and bility of the outfits for installation on ship- voltmeter for the primary circuit of the board, and also it permits of using short alternating- current transmitter are mounted leads for connect'ng up the apparatus, and on the front of the panel, as well as slider in this way undue losses are obviated. type rheostats for the field circuits of the

Large Size German Make Oil Type Radio Condenser.

in a container in which oil is used as a dielectric. Each condenser acts as a single unit and any number of them can be shunted across the two metal conducting tubes, as shown above the containers. Each one is properly insulated, as can be ob- served. These condensers are now extensively used in the German wireless stations, as they are very reliable. Note that hollow tubes are used to give low resistance for the high frequency currents, which, as we know, only travel on the surface of a con- ductor. PHOTOGRAPHING RADIO WAVES. Various methods have been suggested and some actually developed for recording incoming wireless waves. These were generally unsuccessful, due to the fact that the messages had to be transmitted at a slow speed. Finally a photographic re- cording scheine has been developed where- by the waves are photographed upon a moving strip of film. This apparatus here shown consists of a camera, a string gal- vanometer, mechanically-driven photo- graphic film strip and a beam of light from an incandescent electric lamp. The operation of this instrument is as follows: The galvanometer is connected to the receiving instruments in place of the regular receivers and a beam of light is set upon the mirror of the galvanometer. Now the film is passed before the reflected light of the mirror by starting the mechan- ical motor. If there are messages in the ether, the galvanometer string will oscil- late in accordance with the incoming waves and in turn deflect the reflected light on the film. After the message is finished the film is developed and fixed as in the ordinary photographic process. It will be found that the dots and dashes Front and . Rear Views of New Marconi z-KW. Radio Transmitting Panel Set.

This is a very important consideration in motor and generator. This, as will be seen, the high -potential, high -frequency circuits. forms a very desirable and compact set. The motor -generator set is seen at the readily adaptable to ship and other require- bottom of the photograph in its cylindrical ments which in most cases permit of very casing. Above it are mounted, in a special little space for the installation of the radio rack, the Leyden jar condensers. Back of apparatus. the motor -generator set is placed the step - up, high- potential alternating- current trans- FESSENDEN INVENTS SUBMA- former, which is provided with a protective RINE RADIO. spark gap fitted with ball terminals. On Professor Fessenden, of Boston, claims the upper rear section of the panel is to have invented a contrivance for sending mounted the oscillation transformer, made wireless messages from battleships to sub- Radio Signal Photographic Apparatus, up of a spiral copper strip moulded in a marines at a distance of 32 miles under Uses Film. special insulating disc, and also a large water. By experiments he hopes to in- loading inductance for the aerial circuit crease the distance very considerably. He are all connected in one continuous wavy used in transmitting long waves is incorpo- states that the appliance can also detect ine. rated in this part of the apparatus. The the sound of submarine propellers at a dis- This method of recording wireless sig- wave lengths are controlled by suitable tance of two miles, which can be increased nals is very accurate, durable, and high handles on the front of the switchboard to five miles by means of a sound- amplify- speed signals can be successfully copied. panel, as the illustrations indicate, and these ing contrivance. This, he says, would be It was found that 150 words per minute handles are fitted with indicating needles, useful in detecting enemy submarines. can be readily recorded in this '-ay. www.americanradiohistory.com V December, 1915 THE ELECTRICAL EXPERIMENTER MAR 9 9 192109

A New Vibrating Reed Radio Amplifier. 'X 1.11/.217 R By Homer Vanderbilt The greatest desire of the present wire- plating it, after which the cup is soldered ment if once set. less "bug" is to have some means of ampli- fast and a small polished carbon button is It is hoped that this may lead to further fying the incoming radio signals to such an fitted snugly into it. research on the part of other radio "bugs" intensity that he may remove his head The armature is supported by two No. along this line, as the writer's experiments 'phones and still be able to hear; also 40, or better, No. 45 B. & S. copper wires with a rather crudely made model, con- E E, which are soldered to each end of it. The free ends are fastened to an adjusting at- tachment G, which consists of II 11 II IIIIIi 11111111 i an 8 -32 threaded brass rod II1I1IIIIIIIII11II ; I II having on one end a small Upl hole for inserting the copper wire E, and the rod G slides III 'ill through a small tube N. This II tube is soldered to the bar M

, and standard F. The rod F is I giis,:" IIIIIóoö .;pilll I , oo oo supported by a square base of + _' p,III,.. i wood A, having also a small 1 umr'i, ,, wire support Q and set screw. U , The other standard K sup- ® ports the second carbon point I I by means of an 8 -32 threaded TIrC brass rod, which is used to reg- I ,,ii tl RIIIII'Ílllii ulate the pressure between the 777 carbon electrodes. NI mlluuuullu1äl11tllltl As will be noted, seven bind- fig 3 Fig. i. Photo of V,brat:ng Reed Amplifier. ing posts are employed, three of which are connected from N thereby making it possible for any inter- the electro- magnets, two from M ested friends to "listen in" at the same the high- resistance coils, while time. Many such devices have recently the other two lead from the been developed, but most of them have microphonic points I and H. proven failures, while the cost of others Fig. 5 explains the connec- is far beyond the means of the average tions of each part and, as is !se0001.10 experimenter. seen, one coil of the electro- The amplifier herewith described was de- magnet is connected in series ¡4P veloped after some research work, and with a buzzer and battery ana below is explained briefly the building of the other is hooked up directly the complete apparatus, the photo at Fig. 1 across a set of storage bat- fig. 4 being the completed instrument and Figs. 2, teries giving about 8 to 10 3, 4 and 5 depicting the construction in volts. The sensitive high -re- detail. sistance coils are connected to By referring to B in figures it will be the regular receiving apparatus noted that two electro- magnets B B are in place of the head receivers, made up from a couple of soft iron cores while the microphonic elec- % inch in diameter and 8 inches long. A trodes are wired in series with pound of No. 24 B. & S. insulated cooper a 5-ohm telephone receiver wire is wound on each. The bobbins (having its permanent magnet measure 31/2 inches between end cheeks. removed) and a small horn at- On one end of each core there are two tached to its cap. strips of soft iron L L for supporting the The operation is as follows: 1Ql coils C. These coils and their soft iron When the current is sent cores are obtained from a wireless receiver through one coil the iron ar- (having 3,000 ohms resistance), and are mature is twisted and attracted ff.'q. 2 held in place by means of two No. 8 -32 at that point. As soon as the machine screws as sh6Swn. The two large buzzer is operated Side and Top Views of Amplifier, Showing Suspension of (which pro- Reed. electro- magnets are supported on a sof t duces an alternating current in iron yoke P (see Fig. 2). the opposite coil) it starts the other end strutted as here outlined, seemed to possess of the armature vibrating. considerabke promise. Now adjust the carbon point Buzzer I by screwing the knob on INSTITUTE OF RADIO ENGINEERS i [c threaded rod J until a slight PACIFIC COAST MEETING. ia p click is heard in the receiver. At this point, without touch- On Thursday and Friday afternoons, Sept. 16 and li last, joint meetings of the 64' ing any part of the amplifier, connect the 3,000 -ohm coils to Institute of Radio Engineers and the Micraphanic American Institute of Electrical Engineers JT contact the wireless set. If there are signals in the ether, and picked were held at the Native Sons of the Golden 11 West Hall, Panama -Pacific Exposition up by the apparatus, they will grounds, San rBa/ /torn be transmitted C, Francisco. Two papers for to the coils the radio engineers were presented, one on Nigh reris /once which will cause a break in each day. Thursday afternoon Prof. Har- calf the vibration of the armature, ris J. Ryan read the results of investiga- sOhm /e%phane due to the alternating current tions on the "Sustained Radio Frequency produced in fig. 5 receirer(K the electromag- High Voltage Discharge," by Roland G. net, which consequently short- Marx and himself, taking up the flame and Fig. 5. Diagram for Amplifier. ens the contact between the brush types of discharge obtained from carbon electrodes and thereby conductors when a powerful arc The armature D, generator as we see from Fig. 4, making the "telephone circuit" com- is used to apply voltages up to 50,000 consists of a at thin strip of soft iron (about plete. This will produce a loud sound frequencies as high as 200,000 cycles per No. 34 gauge), cut as may be perceived. in the receiver. By very carefully second. On Friday Robert A small H. Marrjott, of cup H, made from brass, is now adjusting the carbon contacts the signals the United States Naval Radio Service, fastened to the armature. This is done, can be readily amplified without any read a paper first, on "Radio Development in by thoroughly cleaning the upper por- trouble. A good point about this amplifier the United States," giving special attention tion of the armature and then copper- is that it will not jar or break its adjust- to Pacific Coast conditions.

www.americanradiohistory.com 410 THE ELECTRICAL EXPERIMENTER DecrDecember, ber, f1915

THE TELEFUNKEN PERMANENT stations, with their classes of service, is length being 3,500 meters, in comparison CRYSTAL DETECTOR. here presented: with an antenna in which the spiral ar- A form of crystal detector which has Location. Service. rangement is Annapolis, Md. Official employed, the wave length been used for some [lime in the Telefunken Arlington, Va.' Official here being 5,500 meters. As will be seen, radio receiving sets as supplied to various Balboa, Canal Zone Commercial the construction is much simpler and re-e- army and navy signal corps, and also in Beaufort N. C. Official Boston, Mass. Official use in the United States Signal Corps radio Cape Blanco, Ore Commercial Cape Cod, Mass. Official Cavite, Philippine Islands Official iY. t 3500 meters Charleston, S. C Commercial Colon, Canal Zone Commercial Cordova, Alaska Commercial Darien, Panama Official Dutch Harbor, Alaska Commercial Eureka, Cal. Commercial Farallons, Colo Official Fire Island, N. Y. Official Guam, Marianne Islands Commercial Guantanamo Bay Cuba Commercial Honolulu Hawaii..... Official Jupiter Fla Official Key West, Fla. Commercial P L.5500 Kodiak, Alaska Commercial meters Mare Island, Cal. Official New Orleans, La.' Official Newport, R. I Official New York, N.Y. (Brooklyn Navy Yard) Official Norfolk, Va. Official North Head Wash.* Commercial Make -up of Telefunken "Permanent" Mineral Olongapo, Philippine Islands Official Detector. Peking, China Official Pensacola, Fla. Commercial pack sets, has more Philadelphia, Pa. Official interested undoubtedly Point Arguello, Cal Commercial Flg. z. Comparative Sizes of Spiral and than one experimenter who has seen one Portland, Me. Official Straight Types of Antennae. of them. The particular reason why this Port Royal, S. C Official detector is very little known is due to the Portsmouth, N. H Official quires considerably less space. The only Puget Sound, Wash. Official inconvenience seems to be that a spiral an- fact that once it is adjusted and made St. Augustine Fla. Commercial up in the laboratory it is sealed and is St. George, Alaska Official tenna cannot be used with damped waves not supposed to be opened by anyone, St. Paul, Alaska Commercial on account of the high tension which would even the Government operators. We pre- San Diego, Cal. Commercial be developed .ietween the horizontal con- San Juan, Porto Rico Commercial ductors. sent herewith a diagram showing how this Sitka, Alaska - Commercial crystal detector is made and besides Tatoosh, Wash Commercial up, Tutuila, Samoa Commercial being robust in construction it is also ex- Washington, D. C. Official THE RESISTANCE OF WIRELESS tremely sensitive and compares well with Yerba Buena, Cal. Official ANTENNAS. A increase the audion. Station transmits time signals and weather re. suggested explanation of of Referring to the sectional view of this ports daily. resistance of radiotelegraphic antennas detector shown herewith, A is a washer Besides these the army of the United which has been observed under certain con- serving as one terminal of the device, while States, through its Signal Corps, has sta- ditions where the wave length is increased B is a plate of sensitive mineral material, tions that are open to commercial business has been offered by L. W. Austin in a such as galena. At C is placed a thin per- at Fairbanks, Alaska Fort Mills, Philip- paper on the subject issued by the Bureau forated mica disc, while 'D is a brass, pine Islands; Fort Sit. Michael, Alaska; of Standards. graphite or other washer whose surface Kotlik, Alaska; Nome, Alaska; Petersburg, The resistance of radiotelegraphic anten- next the mica is corrugated and silvered. Alaska, and Wrangell, Alaska. nas may be divided into three parts -first, When sufficient pressure is applied to this Plans have been made for radio commu- the ohmic resistance of the wires ; second, device the corrugated surface of D comes nication between San Francisco and Ma- the so- called radiation resistance, and third, in contact with the mineral B, thus pro- nila by way of Honolulu, but work on that the so- called earth resistance. viding several rectifying parts for the re- project will not be commenced until fall. Up to the present no satisfactory theory ceived oscillations of the radio receptor and the section to 'Honolulu will not be in of ground resistance has been developed. circuit. The washer E allows the whole to operation until a year from this time. The experimental curves of antenna resist- be screwed up tightly, as perceived. No A naval station at Point Isabel, Tex., and ance, on account of the decreasing radia- auxiliary battery is necessary for this de- Great Lakes Training School Station are tion resistance, fall rapidly at first, as the tector and it is connected into circuit in under construction. wave length is increased, and then, as the the same way as the galena detectors, with wave length is further increased, remain which practically all experimenters are SPIRAL ANTENNAE FOR RADIO nearly constant, if the ground conditions familiar. Two of these detectors are PURPOSES. are good, as in the case of a ship's antenna, usually provided in the Telefunken sets M. Bethenod, in La Revue Electrique, or again rise nearly in a straight line, if and they are connected with a throw -over proposes the antenna arrangement shown the ground conditions are poor. This rise switch, so that if one should fail for some may be very rapid In the case of peculiarly reason, the second detector may be imme- poor grounds. For instance, the resistance diately switched into circuit. of the Bureau of Standard antenna rises from 13 ohms at 800 meters wave length to 38 ohms at 2,000 meters. NAVAL RADIO STATIONS. Great difficulty has been found in ex- The opening of the new naval radio sta- plaining this increase of resistance with in- tion at Darien, Isthmian Canal Zone, adds creasing wave length, but it is believed that to the facilities for the transmission of the antenna system must be looked upon Government messages, but does not extend as a condenser, the antenna itself being the the commercial service. The Navy Depart- upper plate and the ground water the lower ment, in advising the Department of Com- plate. Between the ground water and the merce of the opening of the station, offers surface there is usually a layer of semi- to transmit free all official .messages to or conducting material, which would corre- from points in the Canal Zone from or to spond to a poor dielectric in the case of an points in the United States. ordinary condenser. It is well known that Out of a total of 47 naval radio stations the dielectric losses in imperfect condensers which are now in use in various parts of generally increase in proportion to the wave the United States or possessions 21 are length of the current employed in the meas- Fig. t. Proposed Spiral Antennae for Radio= urement. It is found that by covering the open to commercial messages, while the Telegraphy. others In surface of the ground under and around are reserved for official business. antenna the Canal Zone there are two stations- in Fig. 1, in which the antenna starts from the with a wire net, thus making at Balboa and Colon -which receive com- the station building in the form of a single the lower plate of the condenser, ground mercial messages, so that the new station wire and is then arranged in the form of losses nearly disappear. need not enter that field in order to accom- a spiral, in a nearly horizontal plane, by modate the public as the facilities are al- means of supporting cables as shown in Don't nickelplate your instruments. It ready adequate. the illustration. Fig. 2 shows an ordinary increases the high frequency resistance and A list of the United States naval radio antenna consisting of 11 wires, the wave lowers the tuning efficiency.

www.americanradiohistory.com ) December, 1915 THE ELECTRICAL EXPERIMENTER 413

SOME WIRELESS KNICK- KNACKS. in the gap when seemingly :, sharp spark A CONVENIENT LIGHTNING Very few amateurs care to invest in the should be tae result, is due to these faults GROUND SWITCH. hard- rubber support necessary when build- in construction as explained above, and a "lit cases where the aerial is- perinaneat- ing efficient high- tension condensers. A change in such a small matter may make ly and effectively grounded at all times good method is to build them as in Fig. the set highly efficient. Like all other when the station is not in operation, by a 1. The plates are simply stacked one on things, a wireless set is "no better than conductor not smaller that No. 4 B. lti S. its weakest spot." gauge copper wire, run in a direct line as I called on one time to look over a possible to water pier a on Foil was at point the wireless receiving set which from all ap- s rest side of all connections to said water pearances should have given excellent results, lint which was very unsatisfactory. After testing aerial, ground circuits and G/oss insulation, l' found that tae trouble was in Porce%in fig 2 the tuning coil. \\'ith unthinking zeal and deals _ haste, characteristic of the average amateur, he had painted the coil wit.) some black enamel rich in carbon. I am not sure as to whether the turns were actually shorted, or if the trouble was due to the inductive effect. . \t any rate, when the coil was rewound with new wire, the 'set "got" long distance. Another time I "soot trouble" for an hour before the trouble narrowed down to the detector. The crystal itself was good before and after mounting, for it has been tried in the test clamps. -- The detector itself was a beautifully IIU,''I polished brass and marble affair and truly 2- _Ifll hooked tip 11 was a thing of beauty. We 1111 11 _C-C.EF the detector in series with the battery and v 'phones, and on withdrawing the point Controll'ng Out " f,..9 5 -Door L'ghtning Switch From from the crystal the 'phones still showed Inside of Building. a short. On dismantling the detector we Useful Wrinkles for the Wireless Man. pipe ru thin the premises, or to some other found -with battery and 'phones -that satisfa, tory there was an invisible vein of mineral earth connection -the switch to top of the other, using porcelain cleats for joint tl a aerial to from one post to another, running through the ground connection separators. shall not be smaller in this detector than a standard 100 - I have visited quite a few amateur radio the marble. All the holes ampere knife switch." were rebored a little larger, bushed with -From sections a and stations and it is surprising to learn how d of Rule 86 of "Rules hard 'rubber, and it has given no trouble and Requirements" many experimenters tolerate brush dis- of the ,\'ational Board of Fire Under- charges in their condensers. Some of since. writers." them paint the edge of the foil with shel- It is a good plan to bush all holes in Some radio amateurs marble bases, especially in high- tenson are not aware of lac, but this soon breaks down, due pos- the above fact and others are sadly so be- sibly to the shellac cracking when drying switches. This course is usually unneces- for cause the location of the ground switch out. sary with manufactured apparatus often indirectly locates the imperfect ones are discarded, though the apparatus in a The best plan is to dip the edges of the place which is not as well suited for it as glass plates in hot paraffine until a quarter 1 know of two instances where the pur- some chased detector "leaked," and was repaired other. To move the apparatus away of an inch of the edge of the foil is coated; from the lightning switch often increases when dry and hard, dip again quickly (to by the above method successfully. in making radial arm switches for tun- the wave length, so that to keep within 2110 make a thicker coat) and you will have no meters the amateur must shorten his aerial brush discharge. Your hot wire meter should ing coils. detectors. etc.. it is a common or practise to use simply a straight strip of use the ineffective series condenser. now show a higher reading. It is well to The only things required besides the construct a pan for coating these plates. brass or copper for the arm. with the necessary tension obtained by the use of switch are two iron angles, about two feet The size of the pan will vary with the re- of one- quarter inch round iron rod. a quirements of each amateur -a good size some form of spring, usually a spiral spring inside of the case or switch. as in round wood radiator valve handle and a measures 18 inches long, 2 inches wide and few screws Fig. 4. The arm vv:tlt this form of con- and bolts. Nearly all of these 3 inches deep. A piece of "tin" for the can be obtained from any hardware store. purpose may be obtained from a clean five - struction is never level and seldom looks well. A far better -looking, better -acting A hole large enough to allow the iron gallon gasoline or kerosene can. which, shaft to freely turn is drilled in the side when opened at the seams and bent to and much simpler plan is shown in Fig. 5. Bend the spring brass arm to the shape as of the house and the shaft put through the shape. will prove big enough for a large - hole and bent so that the end can be sized pan. in the figure at B or C. The end A will crrawed h.- cocu,,,; int.. :one frr- to the switch handle. The loca- When pasting the foil on the glass at of these screw holes is then found by belo, ? v the nu: .' : `i:: best to coat the glass with shellac, b. :.na ing the switch upon the angles with the E. will ì 1 l t s uer;"2r t, lv oil or other binder and then paste th, ío;i to screw in front of the hole in the on the glass, for if the foil is first -,ate, I kEftl'.l:'' S, and pasted the shellac forms an inerlacor fter drilling the holes and fastening the between the foil sheets where they c, -clap to the switch handle the shaft. is then (exaggerated in Fig. 2 to make at) through the hole and the switch Of course, the foil might touch in or wed fast, as shown. The control handle more places, but this is insufficient r hen fastened to the inside end of the quick discharge -a positively necess c - ft with a screw or pin and a small in- tion, since the law requires "sharp" tor put on. it may be necessary to Sometimes you will find that the ,,cn the hinge screw to have freer mo- foil is of the contacts touching the t,or, 1:' ? "used from quate, and quite often it would arc at ti, contacts, burning holes which quickly en- Contril large necessitate entire and rebuilding. tì 1 ;2- X)AIL.. These condenser contacts should in made of % or till -inch wide spring bras or copper ribbon 1/32 inch thick and bent to shape as in Fig. 3, A or B. At least they should be made of some flat metal. and even then it is an excellent plait to wrap some scrap tin -foil about the 1,ring where it comes in actual contact *Ht., t t. condenser foil; Fig. 3-,C will mal.' thi dear. Very often a "sputter spark." pi 1 v eel

www.americanradiohistory.com 414 THE ELECTRICAL EXPERIMENTER December, 1915 Laboratory Equipment for Illustrating the Principles of Electro- Magnetic, Magnetic, and Electro- Dynamic Phenomena By Harlan A. Eveleth THE amateur radio- telegraph operator core, one inch in diameter by nine inches EXPERIMENT No. 2. -To illustrate the heat- and electrical experimenter enthu- in length, is composed of a bundle of an- ing effect of Foucault or "eddy" currents. siast does not usually obtain satis- nealed, soft -iron wires. It is taped for in- Grasp the ring with a pair of tongs and faction by the mere operating of finished sulation and then, beginning at a distance hold forcibly at a point of maximum re- apparatus which has come direct to his of one inch from one of the ends, is wound pulsion. The ring, notwithstanding its hands from the display windows of the with six layers, 150 turns to a layer, of large cross -sectional area, will heat rapidly warehouse; he is -to be successful -of an No. 20 S.C.C. copper wire. The magnet inquisitive temperament and is forever is to be operated direct from the 110-volt, delving into the mysteries of the unknown A.C. 60 -cycle mains. It is suggested that in the fervent hope of discovering, by the empire cloth or other insulating fabric be "cut and try" method, some idea which interposed between the various layers, and may have escaped the observation of his that the final layer be taped to prevent contemporary "scientists." Following is a abrasion of the insulation. description of apparatus which, because of The magnet should be suspended ver- their simplicity and wide range of adapta- tically from a bracket fastened to the wall bility, will enable its possessor to investi- of the room, and a means must be devised for attaching the cord, by which it hangs, to the upper end of the core. A simple way of doing this is to turn a cylinder of wood to a diameter of about four inches and a length of three inches. Bore a hole at the center of one end of the cylinder to a depth of one inch, and of a diameter Fig. 2. Demonstrating Repulsion of Solid Cop- per from A. C. Magnet Pole. which is slightly greater than that of the Ring taped end of the core. Spread glue over and if left long enough will become red - the taped core and then force it into the hot. Care should be exercised so as not hole in the cylinder and secure it by to char the insulation of the magnet wind- wooden wedges driven in about its circum- ing. Lumps of solid iron attracted to the ference; when the glue has set the cylinder core will heat perceptibly, thus showing the will be securely fastened to the magnet. necessity of employing laminated cores in The whole can now be suspended from alternating current machinery. the bracket by a stout cord tied to a screw - EXPERIMENT No. 3. -To illustrate continuous eye set in the upper part of the cylinder. rotation from t1ectro- magnetic repulsion, or A switch of some sort should be inserted electro- magnetic attraction. in the circuit, and it may well be placed Wind a coil of wire on a form, or "pie," on the top of the cylinder near the screw - having an internal diameter of 2% inches, eye. The feed wires may be entwined about an external diameter of 514 inches and a the cord and bracket and then led to the width of % inch; the rectangular cross - power mains. The consumption of cur- section of the coil will thus measure 7/s rent will vary according to the load placed inch by 11/2 inches. About two pounds of upon the magnet, but the greater part of No. 26 S.C.C. copper wire will be re- the experiments will require but a fraction quired. Tape or bind with cord to pre- of a kilowatt. serve its form. EXPERIMENT No. 1 .-To illustrate electro- Procure two aluminum discs, 6 inches magnetic repulsion of an A.C. magnet pole. in diameter and of r inch gauge. Drill a small hole in the center of each and pivot If possible obtain a solid copper ring of so they will revolve in a horizontal plane two inches internal diameter and three - with little friction. quarters to one square inch sectional diam- Energize the magnet; then hold.the discs, eter; see Fig. 2. A satisfactory ring can be constructed by forming a coil of bare copper wire; wind the coil to the dimen- De/oil of "Pie-coil ,-6íl/uminum disc sions specified and bind by winding the 5j last few feet radially. A ring formed in this manner by the writer was wound with No. 14 bare copper wire and weighed 11 pounds. Steady the magnet with one hand and with the other grasp the copper ring and }26JC raise it vertically over the magnet. The 2 /bS. electro-magnetic repulsion is so great that 'w}gire .0IIINIII1i [P(' Fig. s. Showing Suspension of Experimental Alternating Current Electro- Magnet. gate, to a marked extent, the principles of AC coi/ electro- magnetic, magnetic and electro- dynamic phenomena. Several of the ex- Pié Coi/ periments described are exceedingly simple as viewed by the initiated, but all are guar- anteed to hold the attention cf the unin- itiated -the casual visitor to the "labora- Aluminum discs. 4/u37. disc. tory." . -A- B-

Fig. 3. Apparatus Used in A. C. Rotating Disc Experiment. partially over -lapping, one about half an inch below the other, Fig. 3 A, beneath the magnet in such a position that the end of the core is above a point on the upper disc, which is about 11/> inches back of one of the two intersections of the peripheries of the discs. The discs will rotate in oppo-

www.americanradiohistory.com Mr- December, 1915 THE ELECTRICAL EXPERIMENTER 415

site directions. If one disc is held the other will rotate with greater torque. Ingenious Instruments for Testing Electrical Machinery discs can be The rotation of one of the A new field tester, shown in the illustra- or coil in less time than it takes to lucidly by employing the coil tell shown more tion, Fig. 1, has been perfected about it. It will make a complete test 3 B. coil over for the of of wire, see Fig. Slip the special purpose of testing the field coils and any ordinary armature in less than two the core (it being understood that the armatures of the electric railway type of magnet is hanging vertically in this experi- motors. It is a quick and certain detector ment) until the bottom of the coil and end of weak fields and faults in armatures. It of the core are in the same plane, then tests the fields when in the motors or out, as hold the disc so that about three- quarters the presence of iron makes no difference. of its surface is beneath that of the coil. It is not even necessary to disconnect the The disc will rotate in an opposite direc- fields. Armatures are tested for shorts. tion-if held in the same relative position opens and grounds without raising the leads to the magnet -to that of the first case, and or disturbing the hoods. This new field will attain a speed of approximately 300 tester is very simple and easy to operate. r.p.m. The terminals of the coil should It is operated by direct current from the be short -circuited. lighting circuits by simply attaching same EXPERIMENT No. 4. -To show the shape and to a lamp socket in the car or shop. Intensity of the magnetic field around an A.C. bar magnet. When testing fields the readings are ob- tained by- sliding the pointer knob along Form a coil of 50 turns of No. 20 S.C.C. the scale to the point where two distinctly copper wire and connect terminals to a separate sounds become as one, or contin- discarded telephone receiver, as in Fig. 4. uous. The armature test is a bar -to -bar Do not use radio-telegraph receivers which receiver test with the telephone receiver are valued as such, for a strong alternat- and contact fork. ing current is to be induced in the coil, Experience shows which tends to weaken the permanent mag- that weak fields are the cause of roasted armature coils, blis- tered commutators, flash -overs, sparking brushes, arcing controllers, overloaded Fig. t. Instrument for Rapid Testing of Motor power circuits and generators. 'Hence the and Dynamo Field and Armature Coils. value of a good field tester, and especially one such as this, which is capable of accu- minutes. This device is regularly fur- - rately testing the field coils when in posi- nished with either the alternating current tion on the pole pieces. or direct current adjustable contact fork, AC.magnet coi/ Another field and armature tester, as or both, as desired. It is a handy and in- seen at Fig. 2, is about to be put on the dispensable device for power plants and market by the same company. This instru- ment was developed to supply the demand 7S°'/e%phone for testing apparatus that could be operated receiver by current from alternating circuits and which could be used in noisy places, where Exploring cod too much noise might interfere with the of use a telephone so turns N zos.c c. of receiver. It does the wire same work as the field tester above de- fig. 4 EE scribed, but instead of the telephone re- ceiver for obtaining the readings meters Fig. 4. Exploring Coil and Telephone Receiver for with pointer and dial are used. When test- Ascertaining Shape of A. C. Magnetic Field. ing field coils the readings are obtained by net. The magnetic field surrounding the sliding the pointer along the scale until alternating current magnet can be explored both meters read the same. The armature and its shape and intensity roughly de- test is a bar -to -bar meter test. The meter termined by noting the strength of sound is mounted in a convenient position right which comes from the receiver as the coil on the testing fork. is moved about the magnet. The coil should The same concern also supplies an arma- be kept in a horizontal plane throughout ture tester, as shown in the accompanying the experiment. cut, which was developed to supply the de- Another method is to employ the coil mand for a very simple little device in- used in Experiment No. 3, with its termi- tended for testing armatures only. It is nals connected to a 110 -volt lamp. Care operated in connection with either alter- should be taken not to burn the lamp out. nating current or direct current lighting The induced current from this c :;r can circuits. A hard rubber knob with also be taken through the body without knurit, age pertu;ts. rb +nginb c ...r from discomfort. one kind of current to the other. As Fig. z. Similar Device to That Shown at Fig. i, EXPERIMENT No. 6.-To illustrate the princi- is the case with the two instruments but Utilizes Meters Instead of Telephone Receivers. ples of the transformer. above described, no batteries are used. will It quickly detects and exactly locates Two coils should be wound which shorts, opens and grounds without dis- electrical repair shops of every description. slip easily over the magnet; the first of and connecting the leads or tearing off the It will test any type of motor or dynamo 10 turns of No. 4 bare, copper wire, hoods. It exactly locates a grounded bar armature. the second of a great many turns of fine, insulated, copper wire. The current in- duced in the first coil will be in the order paramagnetic, while those which are re- the influence of the field. The sheet of of several hundred amperes and the carry- pelled are termed diamagnetic. iron will shield the object from the ef- ing capacity of different sizes of wire can Place the pole of the magnet within a fect of the magnet while the sheets of be shown by bringing them across its box of iron brads, then remove the box diamagnetic substances will not affect the terminals. Relatively high voltages can from its contents. The brads will tend to transmission of force from one point to be obtained with the second coil; in fact, align themselves in the ' direction of the another, any more than an equivalent the whole will act as a fairly efficient trans- magnetic lines of force. Iron filings may thickness of air. former. be used if desired, but brads are much Magnetization may be destroyed or EXPERIMENT No. 6. -To illustrate the mag- easier to pick out of the carpet. Take weakened by an excessive rise of tempera- netic effects of an A.C. magnet pole upon dif- several of the brads and place them end ture. If an iron wire be heated to red- ferent metals. on end at different points on the magnet. ness and held beneath the pole of the mag- Obtain strips of iron, lead, copper and They will form magnetic chains and will net there will be no attraction between the aluminum and place each in turn beneath tend to assume the direction of the lines of two. At a temperature of 750 degs. C., the pole of the magnet. The iron will be force. known as the critical temperature, iron be- attracted while the other metals will be Interpose sheets of glass, aluminum, cop- comes non -magnetic, but upon cooling it slightly repelled. Substances which are at- per and iron between the pole of the mag- becomes magnetic although completely de- tracted to the poles of magnets are termed net and a paramagnetic metal held within magnetised at this stage.

www.americanradiohistory.com 416 THE ELECTRICAL EXPERIMENTER llccenlher, 1915

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How to Make an Electrolytic Rectifier By C. R. Barmckol The following are the details for the will be found very satisfactory. The ends Having procured the plates, they must construction of an electrolytic rectifier for of the box, at the top, are cut down 1% next be put in place. Their position may the experimenter who does not want the inches, making U- shaped ends for the top be seen in the drawing, the large iron plate being the central plate of the middle jar. The top board is measured off as shown !2- Step dwrnlranJ./ in drawing, the first slot (all slots 1/x% flheos/o/ inch) being placed 1% inches from edge. / One -quarter inch separates this from the Q4 next slot, and the drawings give dimensions t1 for the remainder. Having slotted the board, the plates are then fitted in their position as shown. After fitting them up as tight to the sup- porting board as is possible, bend the plates To ACJtepdorvn over as indicated. This serves to hold them in place. Binding posts from ordi- nary dry cells can be used, and are placed in the holes drilled in the plates. Having i iiiiiisiiiiiiiií.vv: zilli/iií,;i;//iii/i iïi finished this part, mount other binding - posts, two for alternating current side i and two for direct current side on the r's board, and connect as shown in drawing. Next mount the rheostat on the end of the 4a/uminum One iron box where the cover extends over. It will and z iron p /o/e /his be seen that by cutting down into the box this .size the lugs of the plates are protected. Next J The Q paraffine the inside of the box. fruit jars are placed in it as shown. The solu- tion is to be made as follows: Fill- jars /ron within inch of top with water. ( \\Tarin water is better, but not necessary) ; then dissolve a heaping teaspoonful of ordinary Parts for Making an Electrolytic baking soda into each jar of water. Rectifier. Then to each jar very slowly add about trouble of dragging numerous large jars of box. In these slots, where the box has three or four teaspoonfuls of sulphuric about and who does not care to spend been cut out. the board holding the plates acid. Although this solution can be used much money. if you have a few things rests. Its dimensions are 12x3% inches. immediately, it is better to allow it to cool around the house the cost is insignificant The containing jars are three ordinary for some time. as compared with the larger rectifiers. one -pint fruit jars. The next part is the The rectifier will be found quite efficient, With an alternating current pressure of plates. Aluminum and iron are used. The and its small size makes it very desirable. 26 volts from the secondary of a step -down necessary plates are drilled and cut as An ammeter may also be mounted on the transformer the rectifier has given as high follows: side of the box in the case of charging as 6% amperes. Of course, it cannot be Four aluminum plates 41/41x2 inches, with storage batteries. Also another improve- used for any great length of time owing to lugs 11/%x %, drilled for níá hole, 1,á inch ment may be added. You may cut a its size, but I have recharged storage bat- f rom top. r.7ctar tular hole in one side of the box. teries very successfully by charging at in- T::c ?' tA- t'4'2 inches. ''`h lugs t.. ..aking it an open window rectifier, let vats. 11/2x%, drilled for is hole, % ...cn from allowing inspect`on of the jars without re- The first thing to build is the containing top. moval. To take out plates and to renew box. The wood should be about % inch One iron plate 41/4x2 inches. with lugs solution only the wire to the rheostat needs thick, with the following dimensions: 21/4x% inches, drilled for 1/a hole. 1/2 inch to be disconnected. This rectifier utilizes 11x7x4% inches. A Mellin's Food box from top. both halves of the cycle.

EMERGENCY SPARK to the post grounded to the bell frame and wires. The lamp will light up as soon as COIL VIBRATOR. the other to the adjusting screw on the contact is made within the lamp. Having need for a spark coil vibrator. make and break contact, I secured excel- If the lead -in wires are far apart, the lent results. The batteries are connected lamp will burn best on 6 volts or more; to the bell as usual. Contributed by but if the lead -in wires are very near or JEAN J. EILER the filament extra thick, the lamp will light best on a lower voltage, as 2, 3, 4 or -..,.,.., 5 t MAKING A LOW VOLTAGE LAMP. volts. with IIIIIIIAItlIIIoIIItlIIIIIIIIIIItlIIIII Procure an ordinary mazda lamp (110, The writer has had success about 95 all the lamps thus tried. 115 or 120 volt), the vacuum of which has per cent. of not been impaired. This lamp may have These lamps burn up to 800 hours when been broken by rough handling or burned filament is new, and from 25 to 200 hours out normally. Then when filament has already been used. connect a socket by DUSKIS. (which can be placed in any position) to Contributed EPHRAIM Using Ordinary Buzzer as Spark Coil Inter- the current supply and screw in the lamp. rupter. Tap the lamp so that all or part of the Liquid Polish. - Kieselguhr, 7 lb.: and no time to construct one, I hit upon filament comes loose from the wire sup- Bath Brick (powdered), 3 lb.; Oil of the following idea: Taking an ordinary port. Now shake the lamp around, so that Lemon, 2 oz.; Lemon Juice, 1 gal.; Paraf- door -bell and connecting one primary wire the filament falls across the two lead -in fine Oil, 1 gal.; Malt Vinegar, 4 gal.

www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 417

A PERMANENT MAGNET TYPE inch from the top, which forms the front :Tread over the zinc and give it the aspect VOLTMETER. bearing. The rear bearing, as shown in of a looking- glass. A piece of wire may be Herewith I suggest how to construct a Fig. 7, is built from a flat piece of a brass soldered to the zinc (before amalgamating permanent magnet type voltmeter, which door-catch with two perforations bored it) in order to attach the mold thereto. I have made myself and found to work through it for screws, with a punch mark In the porous cup is to be placed a solution, very satisfactorily. at the center for the needle point of the of dilute sulphuric -acid, made by stirring The case (at Fig. 1) is made of any armature. one (1) part of sulphuric acid in ten (10) suitable wood that is not too thick. The No. 36 wire is wound around the arma- of water. The water must not be added base of the meter is 5x71/axy/a inches, while ture, through the slots, after first soldering to the acid, or the violent reaction might the front part of the case is 5x7x1/2 inches, one end to a needle point. About 150 turns cause an accident with serious result. A. with an egg -shaped hole 3%x2 inches are taken, after which the other end is saturated solution of copper sulphate, or blue vitro!, is to be placed in the vessel containing the porous cup. The solution must be kept saturated with the copper - salts. This can be done by placing a small basket made of wire screen in the solution and keeping it partly filled with the C;,ier; sulphate. The basket must be hung near the top of the vessel in order that the solu- tion may be diffused equally through the water. The mold is then to be made. Anything that will take the fine lines of an engrav- ing can be used. Gutta-percha and wax are the commonest materials now in use for this purpose. The wax must be warmed and worked into a ball and their pressed over the coin, Gutta -percha must by scalded. The coin should he slightly oiled before pressing on the wax, so as to pre- vent sticking. A small wire must be pressed in on one side of the wax (near the face of the coin) as in top sketch. The mold should be brushed over with pow- dered black lead (graphite) and polished. Some of the lead must be placed on the wire so as to conduct the electric current. When all is ready fasten the mold to the ' zinc -rod and place it so it is in the copper - sulphate solution. After leaving it about 12 hours the exact reproduction, or rather impression of the mold will be reproduced in the copper. This can be pried off the wax and the mold used again. The impres- sion may be coated with a thin film of solder on the back by rubbing it over with the soldering fluid, and then by placing a few small pieces of solder on it, A sol- Details and Make -up of Permanent Magnet Style Voltmeter. dering iron should be utilized to melt tie solder. In the drawing the various parts cut into it for the glass. The sides of the soldered to the remaining needle. Wires of the outfit, designated by letters, are thus is case are 1'/1x6x14 inches. Two holes 21/2 are attached to the screws that hold the explained: A the mold. B is the con- inches from the bottom are drilled for bearings and then to the binding posts on taining vessel, C is the porous pot, D is binding posts, and a piece of glass is cut the case, after which the case is screwed the zinc, and, finally, E is the little wire and fastened on inside of the case, as on by two round -head wood screws. The basket, suspended on wire from the top shown in Fig. 3, by four tacks. The scale scale is of pasteboard, glued on to the mag- of the vessel, as clearly shown. When not is of cardboard glued to the horseshoe net as shown. If the needle does not move in use the outfit may be used as an ordi- magnet, which is in this case taken from a correctly after connecting the instrument telephone magneto. to a b?`-ery, remove the wires and thus The steel magnet is supported at the top reverse the 1.11arir., F th^ ci, . by a strap as shown. This strap is either. To calibrate the instrument, connect it screwed or glued fast to the base. The up to one dry cell and indicate where the side supports are two blocks, with strips needle comes to rest by a pencil mark. of wood tacked or glued on so that they Then connect it up to two cells ; then three, overlap (see Fig. 4L The side supports and so on until the needle is at the end of are fastened to the base in the same man- the scale. The first mark signifies 1% ner as the upper block. A wooden block volts; the second 3 volts, and the third 4% turned into a cylinder, with a groove sawed volts, etc. After the marks are numbered on each side lengthwise for winding the the scale can be divided off into fractions wire in, constitutes the armature. A por- of a volt fairly accurately. tion of a sewing needle is forced into each Contributed by end, leaving the points projecting to form EARLE BELSINGER. the shaft of the armature. A hole 3/16 inch in diameter is bored into the bottom of the block, into which a small lead weight A SIMPLE, YET EFFICIENT A is placed for the purpose of bringing ELECTROPLATING APPARATUS back the armature to normal position after A novel, interesting, yet inexpensive elec- it has swung over, due to an electric charge. troplating outfit may be readily constructed from parts, be in an Into the top of the armature a straight - odd usually to found Home -made Electroplating Set. pointed aluminum or brass wire 3% inches experimenter's laboratory. long is forced. This serves as the indicating A wide- mouthed jar, of about one (1) nary battery for ringing door -bells, etc. needle. quart capacity, will serve for the cell. In by placing a piece of copper bent in a The front bearing is a piece of strip this cell is placed a porous cup, which may circle around the porous pot. brass 21/2 inches long, bent as shown in be taken from an old battery. A rod or The most pleasing and satisfactory re Fig. 6. First a/.i inch is measured off and strip of zinc is now to be placed in the sults and experiments can be carried out it bent; then it is bent again 1 inch from the porous cup and the zinc must be amal- the directions are carefully and exact!! first angle, leaving 1/2 inch for screwing on gamated by rubbing its surface, previously followed. 'Contributed by to the base. A deep center -punch mark is polished, with dilute sulphuric acid and 'made in the vertical leg of the strip 3/16 then with mercury. The mercury will WM. WARNECKE, JR.

www.americanradiohistory.com 418 THE ELECTRICAL EXPERIMENTER December, 1915 A HOME -MADE MERCURY no air present, it might be supposed that AUTOMATIC LIGHTING SWITCH. VAPOR LAMP. there would be a space quite empty left How many times have you entered a A mercury vapor lamp may be easily above the mercury. This is very nearly, dark room with your hands full and found - constructed by any experimenter with the but not exactly, true, as the mercury, like to your great perturbance that to turn the aid of a very simple apparatus, by making water, only to a much smaller extent, will light on you would have to drop everything, use of the principle of a Torricellian, or evaporate, thus filling the space above it thus losing time and also patience? To al- barometer vacuum. The above vacuum is with attenuated mercury vapor. leviate this, the following may aid you to produced when a long tube is closed at one Clamp the tube in a vertical position lose less of your patience and also to retain end, completely filled with a liquid and and attach one terminal to the mercury in your good nature: then inverted with its open end under the the dish by merely inserting a wire in it Remove the switch and place it in such a and the other to the iron wire elec- position that it will be behind the door Platinum Wire trode terminal projecting from the top. The current used may be 110 volts direct So/der Positive Electrode current, taken from the street mains, or (Iron Wire) from any other convenient source. When the power is first thrown on, no ' Tube current will flow because of the very high Mercury Vapor resistance of the space between the elec- trodes. If a spark from an inch or even C/amp Va -inch spark coil be sent across the ter- minals, it will break down this high re- sistance and pass. In doing so it will cause the formation of much more mercury vapor than before, on account of the resulting heat. The path of this spark will then have much less resistance than the space had before, on account of the greatly increased amount of vapor present Be- cause of this lowered resistance the main current is now able to pass, and in doing so will heat the vapor in its path to a blu- ish- white, dazzling light, with which the reader is familiar. Contributed by Switch Fastened to Door by Rod "C" Cuts Off ALFRED MORGENBOLD. Lights Automatically. when opened. Then procure a piece of HOW TO BUILD AN Home-made Mercury Vapor Lamp. wood (use your own judgment in select- OZONE GENERATOR. ing) ; also another piece about 4 inches by surface of more of the same liquid, as the The peculiar properties of ozone as a IX inch, and join these pieces as shown in illustration shows. Under these conditions purifier and sterilizer have made it very diagram, nailing crosspiece to door. Now the liquid, if the tube be long enough, will serviceable for use in libraries, homes, fac- bore a hole through the handle of the fall to a certain height above the lower tories, etc. An apparatus to produce ozone, switch and also in the stick nailed to the liquid level. The space above the liquid is termed Ozonator, calf be readily made and crosspiece. Put an axel from an old skate left empty, except for the small amount of advantageously employed. wheel through the holes and fasten them liquid which evaporates into it, existing as This generator should be made up of by an ordinary machine pin. Now the vapor. three distinct parts -the high -tension induc- opening and closing of the door will turn Mercury vapor lamps consist essentially tion coil. such as a two -inch spark coil; the the switch automatically on and off. of a positive electrode of iron and a nega- discharging device and the circulating fan. Contributed by tive electrode of mercury, projecting into These are treated in the following para- . ANDREW M. GALLAGHER. a vacuum saturated with mercury vapor. graphs. Minor details as to the means of starting An ordinary spark coil, having heavy over, simple in construction. may be omitted here for the sake of contact points, in order to stand continuous Two pieces of heavy sheet brass, measur- brevity. This vapor, under certain condi- work, and better still, if used on 110-volt ing 3x4 inches, are placed in a horizontal tions, is capable of carrying a current of alternating current, with its vibrator closed position, one -eighth inch apart, in grooves electricity, at the same time becoming and in series with a suitable resistance, in a fiber base. Rubber should not be used, heated and producing a dazzling, bluish - should be employed. If direct current is as it carbonizes quickly under such electric white light available an electrolytic interrupter should stresses as it would be subjected to, and The mercury vapor lamp is made as be placed in a vessel containing some water, wood has too low a dielectric strength. Be- follows: or, still better, circulating water, so as to tween the brass pieces in another groove, at Procure a glass tube about 40 inches cool the solution of the interrupter. This least one -quarter of an inch deep, should long, of about '4 -inch bore, with medium latter method of running the, c"i. will be be fitted a one-eighth-inch sheet of plate thick walls and open at .both ends. By frnm ..y ,ati :fac+m.y. Tt - " be con- glass, measuring 4x5 inches. The differ- heating very carefully and gradually. f..;t nected in the usual way. ence in potential of the two electrodes, in the.smoky flame aiy +h n in the bluish The discharging device is next to be con- which are connected to the secondary ter- flame of a rMt^^..itne torch, the walls minals of the coil, is sufficient to cause a bococ aofte..e so that they will close violet "brush" or corona discharge to form together around a piece of platinum wire in the spaces between them and the di- twisted to a piece of No. 12 iron wire, thus electric. In these spaces enough ozonized sealing it into the tube. air is produced in a short while to purify Fill the tube thus prepared with some and freshen the air in a comparatively large pure mercury, which has been boiled to re- room or hall. move all of the inclosed and dissolved air. The function of renewing the air between This boiling should take place in a glass or the electrodes and forcing the ozonized porcelain vessel. The resulting fumes. product out into the room is performed by which are very poisonous, should not be a small electric fan, operated either by inhaled. storage batteries or on a lighting circuit. The glass tube must be wholly and corn- It should be placed several inches behind pletely filled with mercury. Not even a the discharger, so that the air flows through bubble of air should be left behind, stick- the electrodes and out into the room. ing to the walls; otherwise the operation The complete ozone generator may be will be a decided failure. When absolutely mounted or cased, as the builder desires. sure that all the air has been removed, in Details of Ozone The different parts are connected the close the open end of the tube with the Generator. manner shown in diagram. thumb, and by inverting it place this end sidered. To ozonize air it is essential that Contributed by under the surface of some mercury in an a visible electrical corona or brush dis- WILLIAM AMPERE. open vessel. Then, while still under the charge be produced. This takes the form [Ed. -It is usual to employ a small 75 to surface, remove the thumb. of a violet glow and is always the index of 100 watt alternating current step -up closed ' This done, the column of mercury will an extremely high potential or voltage. core transformer for this purpose. One not completely fill the tube, but will fall to There have been many forms of dis- giving about 7,000 volts at the secondary a height of about 29 inches. In falling chargers developed, among which the one is used in several commercial ozonators of from the top of the tube, since there was herein treated is quite efficient and, more- small type.]

www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 419 10 MAKE

This department will award the following monthly prizes: FIRST PRIZE, $3.00; SECOND PRIZE, $2.00; THIRD PRIZE. $1.00. The idea of this department is to accomplish new things with old apparatus or old material, and for the most useful, practical and original idea submitted to the Editors of this department, a monthly series of prizes will be awarded. For the best ideas submitted a prize of 23.06 will be given; for the second best idea a $2.00 prize, and for the third best a prize of $1.00. The article need not be very elaborate, and rough sketches are sufficient. We will make the me- chanical drawings.

FIRST PRIZE $3.00. SECOND PRIZE $2.00. THIRD PRIZE $1.00. A USEFUL 495 WATT ELECTRIC A SIMPLY CONSTRUCTED A MAGNETIC STOVE. POLARIZED RELAY. POLARITY INDICATOR. The enclosed drawing shows a simple Many experimenters have found it im- Magnetic polarity indicators are not very way of making an excellent electric stove possible to use a polarized relay owing to well known to the average experimenter, for use on a circuit of 110 volts at 4.5 the prohibitive price which is usually and the sketch herewith shows a plan for amperes. This stove will be interesting charged for this instrument. The follow- making up one from a pair of 20 -ohm ing description, together with electro- magnets and a small permanent the Too removed Yó lhic%r po/ished accompanying drawing, steel magnet, properly motinted. While 'isn/chromeirire iron will enable one to make a Soopsmne /sturns simple yet efficient instrument 1-bale of this character with little trouble : An alternating current or t±1_ magneto bell ringer (polar- ized type) is mounted on a AP% wooden base about 4xR inches. A hole is drilled through the clapper ball to accommodate a pair of sil- ver or platinum contacts C' and C' as shown. '..djustable 6/pss 3' contact screws C and C" are beads Mounted so as to be engaged /6 /70/e 4- by the contacts in the clap- M per. A spring SP connects rlei1lafarer the clapper with a rotatable fi and slidable rod BR. which serves to hold the contacts C' and C' in a neutral posi- d.32 11111111111111111111111 /IV tion between the contacts C Magnetic Type Polarity Indicator. fE and C". Connections are made as one electro- magnet can be used in making up this device as is Practical and Useful Home -made Electric Stove. shown by heavy dotted line. at A, it best to use Upon the reception of a di- two of them as sketch shows. The small for those who like simple designs. rect current either one or the other of the permanent magnet, which can be made of The heating element is made from as- circuits will be closed, depending upon the a piece of magnetized tool steel about 1 bestos or soapstone; either one will do, as inch long by % by 1 /16 inch, is mounted it is easily cut with a hack saw. Then it on a pivoted arm C carrying an indicating is wound with No. 25 Nichrome wire (91 needle D. A paper scale is mounted suit- feet in all). After it is wound a few beads ably on the device, as at E, with a zero are slipped on the ends, so as to insulate center mark. Care must be taken in hook- them from outside objects, and fastened ing up the electro- magnets, so that by means of binding posts. when the positive pole of the circuit is The unit is supported by four screws joined to the binding post marked "plus" running through porcela'n bushings and the proper magnetic poles will be produced fastened to a slate base. When this is done in the electro- magnets to give the maxi- a cover is cut from iú -inch thick iron and mum effect or reaction on the permanent fastened to the screws. This will be use- magnet F. This can easily be ascertained f ul for heating the coffee pot, etc. by making a couple of tests with different HARAZIM. connections from the magnet coils. When Contributed by FRANK two magnet coils are used, mounted on a soft iron yoke (made of %x3á -inch stock) AN ACID -PROOF CEMENT. the two core ends facing each other will A very good acid -proof cement for ce- have to produce the same magnetic poles, menting articles exposed to acids may be so that in one air gap the magnetic action made up of a mixture of litharge (yellow between the permanent magnet and the lead) and glycerine. Mix to a stiff paste coil A will be "attractive," while in the and use quickly, as this cement sets quite opposite air gap, at magnet B, the mag- rapidly. netic effect will be "repulsive." This acts on the principle that like poles repel, while A Good Varnish for Electrical Apparatus. unlike poles attract each other. Contrib- A very good insulating varnish for metal uted by G. BARENBLATT. work on electrical instruments is black as- phaltum varnish. It has a finish like black A dime in time may save nine. A single enamel and good insulating qualities. idea gleaned from these columns may save If this finish to too glossy a varnish made i you money and time going over ground al- from orange shellac and lampblack should Polarized Relay Constructed from A. C. Tele- ready covered. be satisfactory. phone Bell. This latter is better for woodwork, while direction of the current. By the use of means of a key and a simple pole -changing the first is better for metal work. Con- this instrument either of two circuits may switch. Contributed by tributed by WALTER FRANSEEN. be closed at will over a two -wire line by HENRY B. GRAVES, JR.

r www.americanradiohistory.com 420 THE ELECTRICAL EXPERIMENTER December, i915

FASTENING CONTACT POINTS unfamiliar and remote in its efforts at im- ELECTRIC FAN HELPS DRY ONTO ALUMINUM. provement. It is only within recent periods PHOTO NEGATIVES. Sometimes it is convenient to use that it lias been made possible for most Those engaged in developing and drying aluminum as the moving element on an every individual to be provided with an photographic negatives will find an ordinary instrument such as a moving coil relay, or artificial light that is practically as good as electric desk fan of great value in quickly in wireless telegraphy when the element daylight. drying such negatives as they rest in their must necessarily have a small time period If electric light is used in a dome over drying rack. The fan is placed a few feet to prevent lag. These moving elements the library table the dome should be ar- must have contact points on them, and as ranged to take a single Mazda or tungsten it is difficult to solder them onto alumi- lamp, which should be fitted with a pris- matic or opal glass reflector, and the lamp itself should be what is called "bowl- frost- ed," i. e., have the lower part of the lamp frosted. A 60 -watt tungsten lamp will give ample light under all ordinary conditions and will use very little more current than a single 16 C. P. carbon filament bulb, which consumes about 54 watts. Desk lights should be fitted with a reflecting, or rather deflecting, shade, to prevent the direct or

Method of Securing Platinum l'oint to Alu- minum {'arts. num I hereby propose a plan which has proven successful. Electric Fan Qu ck y Dries Photo Negatives. A small rivet, made necessarily of light TI away from the negatives, and it is best that material, such as from lath or shingle Chino Shode this arrangement is so located that a good nails, can be riveted to the aluminum. Wire draught of fresh air can be drawn in Sheet platinum can then be soldered to the through the fan from an open window. The nail head, which first must be well cleaned Shield negatives will be dried very quickly in this and scraped. This will present a compara- way, and it is considered by many photog- tively large and non -oxidizing surface to Ä raphers as much superior the use of %I to the spark. By referring to the illustration Frosted Bow/ artificial cooling baths. this will be made very clear. Contributed Bulb by R. E. RYBERG. ETCHING ON STEEL. Cover the article with a film of paraffin A HANDY DRY CELL TESTER. wax (or candle grease) and with a scriber Practically the simplest and most com- write or mark on the surface whatever is monly used method in vogue for testing required, making sure to cut clean through the electrical activity of dry cells is that the wax. Sprinkle some salt over this and involving the use of an ordinary buzzer or then cover with strong nitric acid. The bell. If any number of cells worth men- etching should be continued for an hour tioning are to be tested it is rather a tedi- or so. depending upon the depth of the ous job to try out each with two wire etched part. Then clean off with hot water terminals from a buzzer. Therefore I pro- and grease the article to prevent any vide in this suggestion a very quick and rusting. efficient method of testing such batteries. Efficient Desk Lighting Scheme. and the sketch makes this idea quite clear. It consists simply of a piece of wood cut even strongly reflected light rays from Rust Preventive.-The following is a to the shape indicated; on the lower part striking the eye. A sufficient, yet soft, light good rust preventive for steel: 16 parts of it is mounted a small buzzer. The two is that which proves the least trying to the Turpentine and 1 part Caoutchouc dis- terminals of the buzzer connect by pieces eye. Indirect lighting is widely employed, solved by a gentle heat. To this add 8 of copper wire to two copper strips. as but is not universally adaptable to all re- parts Boiled Oil, stir and at the same time shown. All that is necessary is to place quirements. bring to the boiling point. Apply with a the lower part of this wood support be- brush after the manner of varnishing. tween the binding post of the dry cell so A FLASHLIGHT "BULB" This coating can be removed by the use that the two copper shoes on same make PROTECTOR. of Turpentine if desired. contact with the zinc and carbon binding Those who are troubled with the crack- posts. Contributed by MONROE MILA\l. IMPROVED BINDING POST MOUNTING.

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1 111111 a'm wwm_ r Lamp Protection for Flash -Lights. -- VIIIIIIIIIÌIIIIIIIIIÌIIIIIIIIIIIIII IIIIIIIIIINIIIII11IIIIIIIIIIIIIIIIIIIIIIII IIIIII11N4I ing or breaking fila- =`_ of flashlight bulbs and Testing Device for Battery Cells. ments will find the following device an Improved insulation for Binding Posts. antidote for these unpleasant mishaps: All that is necessary is a block of either The sketch herewith shows a method of A GOOD READING LIGHT. fiber, hard rubber or wood, backed by a using riffs inch hard rubber (or other thick- Have you a good reading light? If this copper disc. Through the center of this ness) as an insert in table or cabinet tops very important question was put to a mass block is bored a hole, large enough at one to support binding posts, spark -gaps, helix of people 99 per cent. of that mass would end to allow the base of the lamp to fit stands or other connections which carry he compelled to answer in the negative. in with ease. Just below the disc of cop- high potential or high frequency currents. \Vhy? per the hole is made smaller, with a small This results in better insulation and The reason that good lights are so un- spring attached. greater efficiency without the excessive cost common is not so easy to discover. Per- The object is to take the weight of the of using hard rubber for the entire surface. haps the best explanation may be found in battery off the lamp bulb and put it on the It is recommended for wireless receiving the well -known proclivity of the human case instead. sets also if maximum efficiency is to be mind to accept without question the things Contributed by realized from such sets. it is most familiar with, and to turn to the WATSON McALEXANDER. ' Contributed by I. L. JONES.

www.americanradiohistory.com I )ecember, 1915 THE ELECTRICAL EXPERIMENT ER 42I

A BATTERY COMPUTING TABLE. mouse is placed on the cloth, the wire net AN ELECTRIC "HOUND" CHASER. A convenient table to have at hand for placed over the mouse, and the motor set For those who are troubled with neigh- quickly calculating the power of dry cells rotating. As the motor turns around the boring dogs (hounds and such), the fol- connected tip in various ways is shown in mouse will also hurry around, being at- lowing scheme will be found efficacious in the accompanying illustration. This table tracted by the magnetism of the horse -shoe getting rid of them thoroughly and finally. magnet on the revolving shaft of the All that is required is a small spark coil motor. It is desirable that the motor which most experimenters have about their should not run too fast. by 6 7 e 9 /0 Contributed laboratory, together with a Leyden jar, a / 1 3 4 5 \V\l. \WOODHOUSE, JR. .1Y 411: 6Y 7# 9V /0/V /1Y J2Y /5 70, WINDING RESISTANCE COILS. r 2 404 \lany an experimenter has wanted to 3 604 make a resistance or perhaps an electric toaster or heater but was at a loss as to 4 B04 a S 6

7 /404

B 160,4

9 /B04 Electric Shocker for Dogs /0 china plate and a piece of string with bat- teries and a switch for sane. Direct Reading Battery Chart. The piece of string is arranged near the china plate containing milk or meat. so that is worked out for "new" dry cells only. mill when his "Riverence the Pup" strides to- Each square represents a single dry cell. ward the plate his foot engages the string Hand -Drill Used I or Rap d W ndin4 of Resist- Should a battery with an output of, say, 6 ance Coifs. which closes the battery switch and a met- volts, 60 amperes be desired, then G volts al plate or sheet under the china plate is are depicted on the top line under the (cell) winding the coils of the resistance wire. then charged with high voltage from the number 4, signifying that it takes four cells While making a resistance I hit upon the spark coil. in series to produce G volts. Sixty amperes following method of winding the coils: Needless to say, this makes the most wi,l be found on the side row opposite the The handle was removed from a hand highly seasoned dish that friend "Pup" ever figure 3, indicating that three cells in multi- drill and the drill fastened in a vise so dined on. Contributed by ple make 60 amperes. Now four cells in that the crank could revolve freely. A C. L. ROBINSON. series and three rows in multiple (4 X 3 rlo-inch rod. 5 inches long and with a = 12) give 13 cells necessary for the de- hole in one end, was fastened in sired output. Also, as each of the 12 the chuck. The wire for winding the coils A VISUAL PHOTOTELEGRAPHIC squares represents 12 cells, the arrange- was No. 22 iron (German silver would RECEIVER. ment can be readily understood. do), having been obtained from a basket A visual receiver for phototelegraphy Any combination up to 1.5 volts, 200 am- factory. The wire was cut into as many and telectroscopy, employing a special elec- peres may be obtained. Contributed by J foot lengths as coils were needed. The trolyte, has been recently invented, says L. ARTHUR R. DARLING. end of the wire was put through the hole H. Walter, in the Proceedings of the Royal in the end of the rod and the wire wound Society. The schematic sketch is herewith A MYSTERIOUS MOUSE on the rod in one closely formed layer. shown. WINDOW ATTRACTION. The end of the wire is pulled out of the It consists of luminous elements, 5,300 On the end of the motor shaft, as de- hole and the coil slipped off the rod. This in number, with independent electrical con - picted, a horse -shoe magnet of tungsten gives a coil about 4 inches long, but when nections placed in a frame, which is hardly steel is attached. This, of course, must be stretched to about G inches in length the larger than that of an ordinary camera. well magnetized. An old, weak one, will adjacent turns do not touch. 1 wound 120 The anodes s are embedded in an ebonite not do. Now, on top of the wood box, of these coils in one afternoon, using this plate e, their backs being wetted by an where the cover was removed, a cloth is method. Contributed by electrolyte which escapes from the holes fastened, by small tacks, as shown in ALBERT P. V.\XSELO \ \'. h of the pipe p and flows over the crape c. sketch. Two binding posts may be placed A voltage of 130 to 140 volts is used. The on the side of box, as will be noted. Next A CHEAP ATTACHMENT PLUG. negative pole of the circuit is connected to a mouse (of the pipe p, while the anodes s, which are -trap circular shape, prefer- Herewith I suggest a method for utilizing ably) is obtained and the entire base there- to be rendered luminous. are connected to of removed so as to leave the hollow, wire the positive pole. net only. A. little gray mouse (costing but This arrangement can be used for vari- a few cents) of plaster -paris is needed, ous applications, as it combines in a hip-

A tachment Plug Made From Wooden Rod and Lamp Base. to good advantage an old incandescent lamp base and a piece of broomstick. Empty the lamp base of everything ex- Visual Phototelegraphic Recever. cept two should be threaded wires, which ited through a hole bored in the center of a space almost an unlimited number of short stick cut from an old broom handle. elements, the surface of which can be il- The wires are then soldered firmly to a lumined or darkened hundreds of times a Magnetic Revolving Mouse Window Display. couple of flexible leads. The wooden plug second at will. The degree of luminosity may be cut down until it just fits into the can be adjusted by the voltage applied. such as are usually sold in stationery stores, brass cup and with a little glue it can be also a piece of iron :is inch thick is tacked made to hold fast. to the bottom of the mouse. The base, This completes a neat, vet very cheap Wireless communication between Scan- however, so as not to be noticed, must be and effective attachment plug for labora- dinavia and America, with an intermediate neatly trimmed off so as to fit the lines of tory requirements. Contributed '1w station in southern Greenland. has been the little creature. When all is ready the LA\VRENCEMiCHELS. proposed.

www.americanradiohistory.com 422 THE ELECTRICAL EXPERIMENTER December, 1915

A HANDY FUSE TESTER. MAKING A MOTOR IN 10 MINUTES. penpoints, and which usually come with Many electrical experimenters have cart- Anyone having some wire, a few pins Eberhard Faber's pencil sets). Two holes ridge fuses on most of their instruments. and a cork can construct this motor in less are drilled in on both ends of the case and The following diagram will show a good than 10 minutes. The armature consists posts from old batteries are fastened of a cork having a pin stuck in each end. therein. See that the pins are exactly in the cen- This is all that is necessary, and. the ter or the armature will wobble. Wind sketch plainly shows how the device is the armature with No. 30 enameled wire, operated to make a connection. as shown in Fig. 1. Stick four pins in It it invaluable for running small motors, a piece of wood as at Fig. 2. Arrange the armature, bearings, brushes and magnets, as in Fig. 3. The brushes are of No. 26 wire, bent as per sketch. Although simple, this motor will run very swiftly with one

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II, I Electric Connector Utz izing Pencil Tips , lighting automobile lamps and miniature I b>\llBla lighting systems, etc. It is merely clipped (do together, the action being the same as if a penpoint were taken out and the case closed again. Contributed by GIIIIIUIIII¡iI'Iha¡f'flqll r ALGERNON W. WRANDON.

pppllqllllllllll I I I ; eihlÌl1111117oll-l ?..ä __g Fmo1I III li SOLDERING IRREGULAR PIECES. Quick Test Board for Fuses and Lamps. IIiIAiI I111i To solder accurately irregular pieces of = metal or the parts of a broken piece, press way to test them. This apparatus can be the parts into a lump of putty, placed on used to test fuses of any kind by making a piece of tinplate. Having thus formed the block of wood to fit the length of the Simple Motor Made From Cork and a Few Pins. a mould, remove and dry the putty with fuse. Contributed by a gas jet. This burns the oil in the putty. CARL MENKE. dry cell. It also demonstrates the prin- ciple of large motors very clearly and at When the mould is ready replace the possible expense. Contributed pieces and also some solder in small pieces. the lowest Use a gas jet or blow -torch to heat same A NOVELTY AMONG by MATT JAROSZ. and do not remove the parts until quite TELEGRAPH SOUNDERS. cool. A. novel telegraph sounder of quite odd CLOSED CIRCUIT MAIL BOX proportions is described and depicted in the ALARM. following contribution: Herewith is presented a very serviceable BATTERY MOTOR ON ALTER- First two wood posts are mounted in an mail box alarm of the closed circuit type. NATING CURRENT: upright position on a base of wood, neatly Many experimenters have some small varnished. Then another wood rod is fast- battery motors which they wish to run ened on the upright ones at each end, as on alternating current. For this pur- will be seen in the sketch. In other words. pose the following directions will be found it is bridged across, from one to the other, efficacious: as drawing depicts. A pair of electro- The field windings should be connected magnets are mounted on the bottom of in series with a suitable high resistance. the wood base, as perceived. Two binding The brushes are short -circuited and then posts are fast ned to the base of the ap- adjusted to give the greatest speed and paratus, and, of course, put in circuit with power. It has been found that a 6 -volt, 4- the magnets. For . clicker an iron shaft, ampere "Knapp" motor will operate best such as door -knobs are fastened on, offers when the lower brush is at right angles itself well for this purpose. A small with the upper one. No connection what- spring to make tension is soldered to the ever is made between the field and arma- steel shaft, and the other end (of spring) ture. Contributed by is tacked to the PERCY M. ROOPE. top wood piece, which is Closed Circuit Alarm for Mail Boxes. shown in sketch clearer than words can [ED. -This is the "repulsion type" of A' is made of two light pieces of some flexible metal, and is bent, as shown, to IIIIt'i separate when a letter is dropped in the ,i7= ïi w.m box. A is of the same material, but much II heavier, and is so constructed that when a parcel or letter is placed in contact A' is opened from L. The springs should be connected in series with each other, and a pair of "crowfoot" gravity cells is then connected to a buzzer with the windings arranged as illustrated. A bell and two dry cells are connected to the vibrator con- tact and to the iron armature bar of the buzzer. When the closed circuit is broken the odor armature of the buzzer rebounds and closes =-s----_ __ the local bell circuit, thereby sounding the alarm and signifying that a letter of. parcel is in the box. Contributed by iiiiiÌìiillillllllllllllll IIIIIIIIIIIIIIIIIIP Im á- iiiilillldl I ° Operating on A. i S. F. CSOHAR. Battery Motor C. Circuit. Unique Style of Telegraph Sounder alternating For A SIMPLE CONNECTOR FROM current motor principle. describe it. After the regulation-screws PENHOLDERS. best results the iron frame should he (at the top) are properly laminated or made up of many soft iron adjusted, the in- One glance at this neat little device is together.] strument is ready for use. It may be put sufficient to disclose its simplicity, useful- sheets, firmly bolted or clamped in circuit a key, with telegraph as usual. ness and niftiness. It is constructed from A year's subscription would make an appropri- Contributed by WM. WARNECKE, JR. a simple metal penpoint case (for holding ate Xmas gift to your friend.

www.americanradiohistory.com J December, 1915 THE ELECTRICAL EXPERIMENTER 423 "SOLDER" FOR METAL, GLASS SOME USEFUL WRINKLES FOR AND PORCELAIN. THE EXPERIMENTER. A soft alloy which adheres to metal, Turpentine makes a very good lubricant glass and porcelain and can be used in the for a drill when boring thin glass. saute manner as soft solder is prepared A liberal coating of parrafine on the from powdered copper (copper dust) outside of battery jars keeps the acid from which may be obtained by stirring a solu- climbing. tion of blue vitriol with granulated tin. It is hopeless to try to restore dry cells The solution becomes considerably heated to their former strength, but after they and a fine brown powder is precipitated. have lost most of their voltage they can be Of this copper dust, 20 or 36 parts by partially restored by soaking them in a weight, according to the desired hardness solution of salt water and drilling a num- of the solder, are mixed in a cast -iron or ber of holes around the base of the bat- a porcelain mortar with sulphuric acid of tery to let the solution soak in. 1.85 specific gravity to the consistency of A very good way to intensify weak radio paste, and 70 parts of mercury added with or telephone signals when using only a EDITED BY'S.GERNSBACK constant stirring. single pole watch case receiver is to pro- Under this heading we will publish every month When the amalgam is thoroughly mixed cure a large magnet from some electrical useful information in Mechanics, Electricity and it is carefully washed with water to remove supply store. Bind one of the poles on Chemistry. We shall be pleased, of course, to have off. In oar readers send us any recipes, formulas, wrinkles, all traces of acid, and then cooled the back of the receiver where the screw new ideas eta, useful to the experimenter, which 10 or 12 hours the mass becomes very hard. that holds the bobbin protrudes (some lit- will he duly paid for, upon publication, if acceptable. When the solder is to be used it should be tle experimentation will have to be done heated to about 400 degrees Fahrenheit, in to determine the right pole), and the sig- which condition it can be kneaded like wax nals will be found to have been increased FORMULA No. 16. in an iron mortar. In this plastic state it to three and four times their previous Soaps. is applied to the broken surfaces, which strength. Transparent Soap.=Slice 6 lbs. nice Yel- are then pressed together, and when cooled Never try to tap your local telephone low Bar Soap into shavings; put into a the amalgam adheres very firmly. Con- line. The company dislikes it; in fact, so brass, tin or copper kettle, with Alcohol, tributed by DAVID KARRON. violently that they may have you arrested % gal, heating gradually over a slow fire, on a serious charge. Many an innocent stirring till all is dissolved; then add 1 oz. A DOUBLE FLAME LABORATORY experimenter has gotten himself into a lot Sassafras Essence and st :r until all is BLOW TORCH. of trouble doing this. mixed ; now pour into pans about 1% While working in a laboratory last win- Never try to make hydrogen gas with- inches deep, and when cold cut into square ter I frequently needed a blow torch for out some knowledge of safety appliances bars the length or width of the pan, as welding purposes, but as there was none to be used on the apparatus. It is about desired. in the laboratory equipment I struck upon as quick a way to put your eyes out as English Bar Soap. gal. Soft Water, a novel means of making the desired heat. there is. -Six pipe in 6 lb. good Stone !.ime, 20 lb. Sal -Soda, 4 I attached a mouth blow to a gas jet If you are using storage batteries oz. Borax, 15 lb Fat (Tallow is best), 10 your wireless set, and they fail to give lb. Pulverized :_esin and 4 oz. Beeswax; proper voltage, or get too hot, don't try put the wate, in a kettle on the fire, and to fix them yourself, as they can be very when nearl. 'oiling add the lime and soda; easily ruined. A garage man can't fix in when these are dissolved, add the borax. a day what you can "unfix" in 10 minutes. Boil gently and stir until all is dissolved; Don't light matches around storage bat- then add the fat, resin and beeswax. teries to see if they are working properly. When operating they liberate a gas which Best Soft Soap.-Mix 10 lb, Potash in 10 is at times very explosive. Use a pocket gal. Warm Soft Water over night; in the flashlight. morning boil it, adding 6 lb. Grease; then If you are disturbed by alternating cur- put all to a barrel, adding 15 gal. Soft rents interfering with your wireless re- Water. ceiving set turn your aerial in another German Yellow Soap.-Tallow and Sal- direction. It may help. Soda, of each 112 lb.; Resin, 56 lb.; Stone If you can get your wireless instruments Lime, 28 lb.; Palm Oil, 8 oz.; Soft Water, silver plated, do so by all means, as silver 28 gal. Put soda, lime and water into a is a much better conductor than nickel, kettle and boil, stirring well; then let it and high frequency currents such as are settle, and pour off the lye. In another used in wireless work travel almost en- kettle melt the tallow, resin and palm oil; tirely on the surface of switches. having it hot, the lye being also boiling hot, If you are intending to buy any instru- mix all together, stirring well, and the work ment and don't know the size, range, is done. For small quantities -Tallow and adaptability to your requirements, etc., Sal -Soda, each 1 lb.; Resin, 7 oz.; Stone don't be afraid to ask the manufacturer Lime, 4 oz.; Palm Oil, 1 oz.; Soft Water, about the instrument. Even if he does 1 qt. have a catalogue, he will be glad to give Hard Soap with Lard. -Soda and you any additional information you desire. -Sal L,iIÌ, Lard, each 6 lb.; Stone Lime, 3 lb.; Soft When experimenting with 110 -volt cur- Water, 4 gal.; dissolve the lime and soda rent always have a pair of 10 amp. fuses in in circuit. It will stop a lot of pyrotech- the water by 'boiling, stirring, settling IIIIIgIIII111 IIIIII and pouring off; then return to the kettle nics if something goes wrong. (brass or copper) and add the lard, and A Double Flame Laboratory Blow Torch Don't paint the stand that you intend to boil it till it becomes soap; then pour into mount your instruments on. Paraffine, is a dish or moulds; and, when cold, cut into by means of a rubber tube and, turning better; it don't allow so much current to bars and dry it. on the gas, held the blow pipe in the flame leak through. of a Bunsen burner. Camphor Soap. 28 lb.; The gas coming Contributed by WARD B. BABCOCK. -Curd Soap, Otto through the blow pipe had the desired of Rosemary, 1514 lb. Reduce the ef- Camphor fect upon the Bunsen flame, producing to powder, add 1 oz. Almond Oil, then sift as Rust spots on nickel can be treated with it; when the soap is melted and ready to great or greater heat than the average Grease, and after several days rubbed with turn out, add the camphor and rosemary. blow torch. a rag saturated with a few drops of Hydro- Sand Soap. -Curd Soap, 7 lb.; Marine Contributed by HARRY R. FEES. chloric Acid in Ammonia. Parts should Soap, 7 lb.; Sifted Silver Sand, 28 lb.; be thoroughly rinsed, dried and polished. Oils Thyme, Cassia, Caraway and French Shabby leather can be much improved Aluminum Polish. -An emulsion of Lavender, of each 2 oz. by either Linseed Oil or the well -beaten equal parts of Rum and Olive Oil can be Shaving Paste. -4 oz. of Naples Soap, 2 Whites of Eggs mixed with suitable color- used for cleaning aluminum. Potash Lye, oz. of Powdered Castile Soap, 1 oz. of ing matter. The surface can be brought not too strong is also effective in brighten- Hone, 5 drops each of Essencce of Am- to a gloss by the use of a soft duster. ing aluminum ; Benzol is also used. bergris, Oil of Cassia, Oil of Nutmegs. To Clean Brass. -Rub it with a mixture A good polish for aluminum consists of Melt the soap in water bath, add honey of Vinegar and Salt, or Oxalic Acid, then a paste formed of Emery and Tallow, the and when nearly cool add the oils and es- wash with Water and polish with Tripoli finish luster being obtained by the use of sence. and Sweet Oil. Rouge Powder with Oil of Turpentine.

www.americanradiohistory.com 424 THE ELECTRICAL EXPERIMENTER December, 1915

Our Amateur Radio Station Contest is open to all readers, whether subscribers or not. The photos are judged for best arrangement and efficiency of the apparatus. To increase the interest of this department we make it a rule not to publish photos of stationa'unaccompanied by that of the owner. Dark photos preferred to light toned ones. We pay each month $3.00 prize for the best photo. Make your description brief. Address the Editor.

AMATEUR RADIO STATION RADIO OUTFIT OF JACOB WEISS. G. L. LA PLANT'S RADIO STATION. CONTEST. I take this occasion to enter my station I give here a brief description and photo- Monthly Prize, $3.00. in your monthly contest. My station con- graph of my station, and would be pleased This month's pri :e winner. sists of a 1 -kw. closed -core transformer to have you publish them in your journal. (made by Queen & Co.), pancake oscilla- The receiving apparatus consists of an R. J. WIRELESS STATION AND ELEC- tion transformer, rotary gap, consisting of 5 Audion detector, Blitzen receiving trans- TRICAL LABORATORY OF motor -driven disc containing 13 studs former and rotary variable condenser; also FRANK H. BROOME. (r.p.m. 6,000), and three Murdock con- three pairs of 2,000 -ohm 'p'aones. The The accompanying photo shows the send- denser units. I use a break -in system, elim- transmitting set is composed of a Blitzen ing and receiving outfits, also the main inating the aerial switch, and a magnetic 1 -kw. transformer, rack type condenser, switchboard controlling the other labora- key. The key operates the magnetic relay, oscillation transformer and Marconi type tory and experimental apparatus, most of which in turn operates the break -in relay. discharger. As the discharger is extra which is on a slate table not shown in the My transmitter is in the basement of my photo. home and my receiving set is in the dining The wireless receiving outfit is of the room on the first floor. I use a small Pitts- burgh step -down transformer on 110 a Mr. Frank Broome is an Ardent volts to operate relay Radio and Electrical Student. type motor starter. The relay Here We See Him Surveying a fez the motor is energized by Mast Site. a small foot -plate push Below: The Radio Laboratory of mounted on the floor under Mr. Broome is Up -to -date and the table. Contains Transmitting and Re- ceiving Apparatus with Amplifier. My receiver consists of a loose coupler, primary and secondary rotary condensers and Audion amplifier, with 2,600 -ohm 'phones. There are of course the necessary bat- teries and resistances to go with the audions. I use the series -shunt system for con- denser on the primary coil. I have no trouble in getting the distant stations very well. On Oct. 18 last I heard N.A.W. very plainly. I have held com- munication with Western sta- tions regularly at such times as I h ve happened to be at home. During the winter months 1 worked 8 P.P., 8 A.M., .9 was received at a station l KW. Transmitting Set and Also Receiving Ap- semi -cabinet type, most of the instruments K.U., and paratus of G. L. La Plant's Radio Station. of which have been described by the owner in Chicago, Ill., and at Winnetka, in The Electrical Experimenter during the Ill. Also I have worked stations in Wheeling, W. Va.; Cleveland, O.; Little large I will give the dimensions for those past year. All of the instruments are of who wish to build one. It is made of a and make. and have Valley, N. Y., and 8 O.Z., Pennsylvania. the owner's design hard rubber disc 10 inches in diameter, 1/4 proved of exceptional worth. They consist I hold a certificate of the American Radio League as an official relay also inch thick, with 13 studs on the side of the of a loading coil, loose coupler. variable station; disc inch the edge. first -grade commercial license. I am a reg- placed a/4 from outer and adjustable condensers, crystal detector The motor is a Robbins & Meyers 1 /10 -hp. and 'phones. The horn was used in con- style, running at 2,400 r.p.m. The aerial nection with a receiver in receiving from consists of lour No. 14 H. D. W. P. copper WHB, NAH and other near -by stations. wires spaced 2'iá feet apart and is 80 feet The present sending set consists of a f- high and 150 feet long. It is insulated with inch coil, operated in connection with an Electrose 4 -inch insulators. electrolytic interrupter on 110 volts alter- I am a member of the Central Associa- nating current; Leyden jar condenser, tion, American Relay League and also cor- helix, hot-wire ammeter and key. Aerial responding secretary of the Hawkeye is "T" type, 40 feet high and 100 feet long. Radio Association. My call is 9.K.T. The aerial and lightning ground switch St. Anthony, Ia. G. L. LA PLANT. are both conveniently located, and can be operated from the switchboard panel. The laboratory apparatus consists of CHARLESTOWN NAVY YARD step -down transformers, rectifiers, arc RADIO CLOSED. lamps, electric furnaces, storage batteries, While the divisional radio is being se- etc., all of which are home -made. Tools cured the wireless station at the Charles- and raw material are conveniently kept town, Mass., Navy Yard will be closed and Mr. Weiss Gets Excellent Results With His all will be received at the Chelsea under the wireless table. Radio Receiving Set. messages The station is over five years old, and station. This will be for several months. during that time The Electrical Experi- ular subscriber to The Electrical Experi- The station at the navy yard has been dis- menter or its predecessor, Modern Elec- menter and find it excellent in its contents mantled and the apparatus has been set up trics, was always to be found in its library. and suggestions. at the Chelsea station. Messages received FRANK H. BROOME. JACOB WEISS, Asso. M. I. R. E. at Chelsea will be sent by "wire" to the Roselle Park, N. J. Port Washington, L. I. Charlestown station.

www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 425

boats, including the J. W. ALLEN AND HIS WIRELESS double slide tuner set, and the variable con- WCX; several lake "LAB." denser may be shunted between the aerial C. & B. boats, and numerous unidentified The illustration herewith depicts my and ground or may be switched in series stations. NAA comes in loud enough to be - 'phones. By wireless station. At the left is the receiv- with aerial. 1 have a 2,000 ohm double heard 2(i inches away from the ing set, consisting of a loose coupler, two head set and a 1,000 ohm single head set. specially designed silicon detectors, a dou- My sending outfit is a 1/4 k.w. set with a ble slide tuner, a large variable condenser Clapp -Eastham rotary gap. I have no and fixed. condenser. I have two aerials, aerial switch as 1 use a break -its system. bly receiving apparatus has a range of 11111 Mr. J. Wyman Allen, to 3,000 meters wave length. owner of the Ex- J. WYi11AN ALLEN. perimental Radio Station Shown Be- Beverly, Mass. low. Below: Well Ar- HAMMOND PROFFERS INVEN- ranged Radio Set TION TO NAVY. Mounted ron Desk. John Hays Hammond, Jr., recently laid before Secretary Daniels and ordnance ex- perts of the navy the wireless device which he has perfected to direct torpedoes dis- charged from submarines. Secretary Daniels declined to give the me- chanical make -up of the device. He said, however, it may be of incalculable advan- tage to the navy. H. LIGHTNER'S REMARKABLE POCKET RADIO SET. lfter seeing the wireless sets pictured in your Prize Contest Department 1 decided to submit a snaps;lot of a pocket wireless designed and constructed by myself. The outside dimensions of this set are one six -wire aerial 90 feet long and 60 feet 8x4x2 inches, while the weight is only two high, for sending, and one two -wire aerial . pounds without the receivers. I use one of galena detectors and 200 feet long and 60 feet high, for receiv- the E. I. Co. dime find ing. Either or both of these aerials may it extremely sensitive. My headset consists 2,000 -ohm Brandes' Superior Mr. Lightner Has Perfected an Efficient Pocket be switched on for receiving by means of of two type very good. Radio Receiving Set. the two two -point switches seen on the receivers, which are My con- front of the receiving set. The set is wired denser and coils are of my own make and using a bed spring as an aerial I have in up so that by manipulating the switches on have sufficient inductance to bring high picked up the first three stations above the front of the cabinet the hook -up may wave -length stations. mentioned. HERBERT LIGHTNER. be changed from a loose coupler to a This set is able to receive 'NAA, WSL, Alliance, O. Amateur News The Institute of Radio Engineers' Loper, president; James Stephens, vice -president; State. The following officers were elected: Presi- Robert Shults, secretary; Benedict French, chief dent, Ralph, Batelier 131 Ilyland Ave., Ames. Iowa; October Meeting. operator, and the following as members: Raymond Vice-President, W. 'P. Rathert, Cresco, Iowa; Sec- At the regular monthly meeting, held on Oct. 6, Wright, Carl Mead, Sidney Emerson, Carl Chap- retary, A. The Insti- B. Church, Lamoni, Iowa; Treasurer, at Columbia University, New York City, man, Walter Howard. Hollis Sels, 131 Ryland Ave., Ames; tute of Radio Engineers had the pleasure of hear- All should he addressed to the Training correspondence Secretary, G. L La Plante, St. Anthony, Iowa. ing a timely paper on the subject of "The secretary at 179 Main Street, Hornell. N" Y. The association bas had published a monthly bul- of the Radio Operator," by Mr. i11I. E. Packman, Tele- letin containing from one to three pages filled with professor of Radio Telegraphy at Dodge's articles of interest to the members. This will be graph, Railway and Wireless Institute, Valparaiso, Bronx Radio Club. method continued and enlarged during the next year. In- Ind. Mr. Packman's discourse covered the At the last October weekly meeting of the formation be operators, will given applicants by the officers, found best for instructing embryo radio Bronx Radio Club of New York, the election of regarding membership. We are trying to get a and covers such matters as the type of apparatus new officers was held, the result of which was as complete directory of the amateurs residing in best suited to transmit code practise signals, num- follows: M. Haber, president; J. Smith, vice- presi- re- Iowa, and the president would be glad to obtain ber of subjects to be taught, length of time dent; A. Schoy, business manager; H. Berlin, sec- any information relating to such a directory. neces- quired to thoroughly teach the operator the retary; A. Richter, treasurer. Much interest was afforded the members by a etc. sary rudiments of electricity and radio operation, A lecture was delivered by one of the members large display of the most modern types of radio ap- The point was brought out that in most cases, on "The Theory of Wireless Transmission." which loaned the occasion the paratus, was kindly for and tàking for granted that each applicant to Lectures are given at every meeting by the more by some of the well -known wireless manufacturers. school has a fairly good general education, such as advanced members of the club, dealing with timely given in grammar schools, that a finished radio topics of wireless or electrical interest. operator could be turned out in about six months. The club will be glad to communicate with other Savannah, Ga., School Wireless Licensed. About 600 students have been enrolled annually at societies and individuals desirous of having infor- Arthur Funk, amateur radio operator, who has this school and one-third of them are radio students. mation or particulars of the proceedings of this for the last two years been perfecting the station The pupil is taught typewriting and penmanship organization. he has now installed on top of the High School at as well as all necessary wireless instruction for the All communications should be addressed to the Savannah, Ga., recently received his operator's reason that most telegraphic and radio messages to- secretary, 705 Home St., Bronx, New York. license from the Government. day are copied direct on the typewriter and, of Those wishing to call on the president may do so It is a license for "Commercial, experimental and course, in any event the wireless man in charge of at his home, 670 E. 170th St., Bronx, New York. instruction purposes," and was obtained primarily a station should be a first -class penman. Geog- to enable loin to pursue research work in connec- raphy and other practical branches of study are also tion with the roblems of the station. His call gone into at this school with good results. The Ames, Iowa, Has Radio Society. letters are 4AHn practical side of the radio operating profession is The second annual convention of the Hawkeye Mr. Funk is also endeavoring to install a wire- also covered, so far as becomes possible in the Radio Association was held at Ames, Iowa, on Sept. less 'phone, working along a theory of his own, short length of time the student has at his disposal. 1 and 2. It was well attended and proved a suc- and has already begun work on the instruments. This covers matters as the routing of mes- cess in every way. The meeting on Sept. 1 was He is working independent of the lines followed such recent suc- sages, repetition of messages, the various codes and attended by wireless amateurs from all over the by experimenters in the Government modifications as well as abbreviations in use inter- cessful wireless 'phone tests. brought out that The station, which was constructed entirely at nationally, etc. The fact was miles most of the radio operators graduated are in the the High School, has a sending radius of 100 has picked up messages from Marconi service as this company controls the RADIO CLUBS ATTENTION! and the operator major portion of the radio business to -day. The Colon, Panama and the naval stations at Guanta- short-comings of young radio operators were brought namo, Cuba. Among other devices that have been suggestions recently installed is a marble switchboard, and the out and the speaker offered several We are always pleased to hear outside tending to offset these, if proper training was given lightning switch has been placed the school in the school. from young Edisons and Radio to minimize the danger from that source. Clubs. Send a write -up of your Middletown Scientific Association Holds Boston Radio Amateurs, Attention Club with photos of members and Radio amateurs located in or near Boston inter- 410th Meeting. ested in forming a wireless association with head- apparatus to -day to: Editor "Ama- The 410th meeting of the Middletown Scientific quarters and a central station will do well to in- .Association was held in the Scott Laboratory of quire for particulars at The Young Men's Chris- teur Gossip" Section, The Electri- Physics at Wesleyan University, on the evening tian Union, 48 Boylston St., Boston, Mass. cal Experimenter, 233 Fulton St., of Oct. 13 last. The address was by Professor Walter Guyton Cady, Ph.D., professor of physics Maple City Radio Club of Hornell, N. Y. New York City. in Wesleyan University, on the subject, 'Wireless on telegraphy." The lecture was illustrated with ex- The "Maple City Radio Club" was organized and slides. Oct. 2, 1915, with the following officers: Guy periments lantern www.americanradiohistory.com ['RTE5T

Flashlight for Canes and Um- lar form as perceived, is composed coherers for radio telegraphic or other very accurately adjustable owing to brellas. of strips of brass and steel soldered requirements. The inventor lays the unique construction, which em- together. This thermostat is used to great stress on the proper formation ploys a flat tension spring 28, se- (No. 1,151,114; issued to Gustav Mat- regulate a motor or other electrical of tbe spherical chamber 13, in which cured to a movable block 29. This tines and August Rehberg, Jr.) attachments for opening and closing metallic or other filings are con- block 29 can be raised or lowered This patent covers a neat arrange- dampers or doors, so as to keep tbe tained. Also he mentions that if independently by turning knob 8. ment for a small flashlight bulb, to- incubator at a practicallg constant Also the electrode 19 may be moved temperature. ajr over the face of the crystal rapidly owing to the novel construction of Arc Type Telephone Transmitter. pillar 7, which permits the whole (No. 1,150,266; issued to Walton spring arm arrangement to be swung Harrison.) from side to side. A telephone transmitter intended to be used with heavy currents, such Wireless Condenser. as for loud- talking telephone cir- (No. 1,150,895; issued to Augustus cuits, wireless telephony, etc. The Kellogg Sloan.) air waves set up by speaking into the A newly devised variable condens- horn 37 are caused to impinge er suitable for radio or other circuits _.ÿ against the arc at 27. Controlling and comprising a number of concen- electro- magnets, which aid in the trical metal tubes nested together as Q11-1111 operation of this arrangement, it is said, are shown at 15. It acts on the principle that the variable air currents, corresponding to the voice waves, will cause the arc 27 to these filings are of the proper size, change in its length and resistance, and also by utilizing a periodically gether with necessary battery of changing sweeper", or mixer, that it miniature dry cells and switch for is possible to obtain very regular and controlling the lamp circuit in a reliable results with a coherer so cane. The drawing clearly shows constructed. Again he mentions the how these parts are arranged and use of a number of such coherers on the lens of the flashlight is indicated a common circuit and each one of while the push button appears at 38. these coherers to be successively but The miniature dry cells are shown independently switched into circuit at 20. by proper means, and thus while one is decohering another one will be in Electric Apparatus Enabling the circuit to perform the regular func- Blind to Read. tion of such-asdevice. (No. 1,149.547; issued to Henry Tideman.) Electric Humidor. Intended to aid the blind to read, (No. 1,145,218; issued to Walter E. makes use in general of special books Schimmel.) containing a perforated page, whicb thereby varying the strength of the current through an induction coil 6, This type of humidor, used to pro- which is joined to a loud- speaking duce a damp vapor from water or telephone, etc. other liquid, utilizes an electric lamp Electro- Magnetic Sound Producer. (No. 1,147,016: issued to Leo Grub- man assignor to Electric Spark Appliance Co., Inc.) A novel form of electro- magnetic sound producer, intended for use illustration shows. Every other tube particularly on Ford automobiles, connects to one pole of the condens- whose magnetos yield alternating er and one set of tubes may be current. This horn has an electro- moved up and down to vary the ca-

magnet coil C, mounted in a mag- pacity by means of a special . in- netic or iron frame with pole pieces, sulated handle 34. This handle is as drawing shows. The flux from tbe threaded and the nut within same is perforations correspond to the dots pole pieces reacts telegraph on to a distinct 18, made in two halves; thus it is pos- and dashes of the Morse magnetic armature H. This, when placed in the upper part of a so code. A regular sounder (or a tele- chamber 9. In order to improve the sible to compress the nut sections phone receiver t)'pe sounder) may be operation of this device blotting pa- that the moving element can be slid used, together with battery, as shown per or some other good absorbent is up and down the threaded vertical in diagram and this circuit is opened supported in the vaporizing chamber rod rapidly. For the fine adjust- and closed by means of a metal from rods 16, and this causes the ment the handle 34 is released and stylus 3, which is moved over the .T49.1. water to be drawn up near the lamp the split threaded nut engages the perforations 7, on the page. Under and thus the vaporization is greatly screw 7, so that the plates can be ac- the page lies a metal plate, which is enhanced The moist vapor pro- curately and closely varied in their connected with the opposite side of duced in this way can then escape relative position. the circuit. Several other unique through perforations in the top of schemes are covered in this interest- .íT9.9 the containing vessel. Electric Insect Trap. ing patent. (No. 1,150,835; issued to Joseph Radio Detector Stand. Satinover.) Thermostatic Circuit -Closer for (No. 1,152,444; issued to Augustus K. It is proposed with this device to Incubators. Sloan, Jr.) (No. issued to Louis L. Another radio detector stand which 1,151,142; embodies several good features, it White.) seems, A modified form of thermostatic with respect to the spring ten- circuit closer for incubators and the sion adjustment for the "cat- whisk- like, the closing and opening er" electrode. By means of an ad- "valves" of which are easily ad- Pig -- 1- justed for, as by means of a dial 6 NM; b an' attracted forward moves the dia phragm proper ' b" naturally, and % / E..- alo in its return movement the diaphragm "D" acts resilliently on // / / / %// / the armature H. By this action the 2- inventor claims to attain tbe best results for this form of construc- electrocu e 'nsects of all kinds by ar- tion. A tuning screw t is provided ranging two sets of oppositely for properly adjusting the arma. charged wires or metallic rods to ture vibration period. No inter- a cage, as in il- rupter is used. form perceived the and handle 31 and 33 placed on the tit lustration. These oppositely charged - -- - exterior of the incubator. The 1 wires are hare, of course, and spaced handle 33 is secured to a shaft 31, Radio Telegraphic Coherer. v a short distance apart. They will which in turn connects by means of '" 1,150111; issued to Edwin a work on a 110 volts and alternating levers to the pivot 21. A therm- Gill.) lusting knob 8, the tension exerted current or direct current, the same electric element 20, which is of circu- Another advance in the design of by he metal point electrode 19 is as that supplied for lighting. COPIES OF ANY OF THE ABOVE PATENTS SUPPLIED AT 10c. EACH. 426

www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 427 Phoney Patents Under this heading are published electrical or mechanical ideas which then you haven't a smell of the Patent yet. After they have allowed our clever inventors, for reasons best known to themselves, have as yet the Patent, you must pay another Ezo.00 as a final fee. That's E10.00I I not patented. We furthermore call attention to our celebrated Phoney WE PAY YOU $3.00 and grant you a Phoney Patent In the bargain, Patent Offizz for the relief of all suffering daffy inventors in this could- so you save $43.001 I When sending in your Phoney Patent application, try as well as for the entire universe. be sure that it is as daffy as a lovesick bat. The daffier, the bet- We are revolutionizing the Patent business and OFFER YOU THREE ter. Simple sketches and a short description will help our staff of DOLLARS (83.00) FOR THE BEST PATENT. If you take your Phoney Phoney Patent examiners to Issue a Phoney Patent on your invention Patent to Washington, they charge you Ezo.00 for the initial fee and In a jiffy. PHONEY PATENT OFFIZZ PHONEY PATENT PERPETRATED BY WATT A. LUNKHED No. Px6 L;74 ELECTRO OFFICE EFFICIENCY DEVELOPER Pat. Applied Externally To all who should worry: the letter -head and starts typing. As she motor should be at least two horse -power Be it known that I, Watt A. Lunkhed, presses the keys real movies appear oli the -this is a small detail that should be care- of the City of Ohl State of Affairs, screen in front of her. The scenes appear fully attended to. have deliberately sacrificed my fortune and in perfect synchronism with the striking I or best results with this recipe for ef- last ray of sanity in devising, developing of the keys, therefore fast work is neces- ficiency it is absolutely necessary that only and perfecting this apparatus for alleviating sary so she can find out quickly how it all pure ingredients he used -thus purely emo- the troubles of all poor stenographers who ends. tional motion pictures-pure high grade are troubled with a lack of ambition. It has A touch on the spacing bar automatically chocolates, and purely sentimental music worked perfectly under all conditions. Many turns lose the Victrola with a lot of love should only be employed. girls preferring it to the effeminate atten- melodies and mushy ballads, in perfect This machine has been tested by all the tions of mushy office managers, the latter keeping with the movies. crowned heads and blockheads of Europe are not required on the payroll any longer. When the carriage is pushed back after and New Zealand, proving in every case

VIVID MOVIES CHANGING JAR OF GOOD CHOCOLATES AT CORRESPONDING RATE OF SPEED OF STENOG 1 LETTER TO A SCENE SLIDE OPERATED BY 7c LEVER

SHELF FOR CHOCOLATE. TO DROP ONTO

BALL BEARING To PREVEN¡ FRICTION SWITCH CLOSES EVER,/ TIME. PAPER IS GENERATOR CONTROLLED REMOVED FROM PLATES BY SPACING KEY

'POPULAR MUSIC OANCES ANO MUSHY LAVE ,SONGS

9

1, ARMS EXTENDING A WARM HUG CVFRY TIME LETTER IS COMPLETED AND huff ll it I ROLLED OUT OF MACHINE 110 VOLT MAIN Marvelous Elect o Office Efficiency Developer. Amid These Exhilarating Surroundings an Output of 700 Letters a Day is Common.

The results are based upon the formula each line, a system of levers (not lovers) that woman, with the aid of this machine, P. delivers a luscious chocolate to her rosy is complete in herself, does not require the E. = - where E. = efficiency P. = lips. The supply of delicacies is contained . association of males and therefore should W. in the large glass jar at the right, and if rule herself. pleasure and W. = work. By increasing the boss is of a sporting disposition he can In testimony thereof I therefore bury both factors of the fraction it is apparent offer prizes to the stenog emptying the jar here my tame seal on this day of devotion that the results will not be changed, thus first. and supplication to Woman Beautiful in doubling the work can be offset by increas- The master stroke of my invention is this City of Oful State of Affairs. ing the pleasure an equal amount, thereby found in the hugging attachment operated WATT A. LUNKHED. retaining the same efficiency, and vice versa. each time a letter is removed from the By his Attorney: The apparatus is arranged as per at- machine. The motor operated arms clasp S. A. TROMBLY, tached drawing and its operation is as fol- her firmly but tenderly around the waist fVorcester, Blass. lows: and hug her as good as any mere man Witnesses: After the stenographer has taken all the without the attendant smell of cheap to- G. WATASINCH, letters (700 a day is common when this bacco, which latter ofttimes accompany this LILL Q. Plia, machine is installed), she sits down, inserts blissful pastime. For best results this ROMEO CHEESIT.

www.americanradiohistory.com 428 THE ELECTRICAL EXPERIMENTER December, 1915 CALL BOOK. ' OFFICIAL LIST OF LICENSED RADIO AMATEURS NOT TO APPEAR IN NEW GOVERNMENT PRESERVE THIS LIST FOR FUTURE REFERENCE. Amateur Radio Stations Licensed by the Bureau o f Navigation During the Month of July, 1915. FIRST DISTRICT. SIXTH DISTRICT, Power Call Power Call of station. Location of station. Owner of station. Location of station. signal. Owner in watts. signal. in watts. -1.ßrT- Campbell, Margaret L 14 high( St., Rockport, Mass 100 6IA Griffiths, Walter M.... 1022 1st St., Napa, Cal 1,000 1.\E Durham, Wison N Oakland, MG 61K Grotzinger, Clarence E. Corona, Cal. 12 111Q Eberlein, Geo. II 15 Hastings St. Greenfield, Mass 100 GI'U Hamilton. Howard B... 1218 N. 6th St., Redlands, Cal 100 1M Entwistle Warren R 41 C St., Lowell, Mass 30 GGY Ilemenway, Walter D.. Winters Cal. 3G 1TM Jackson, Edw, A 15 School St., Newport, R. 1 180 61X Ivins, George 5102 S. Wilton Pl., Los Angeles, Cal. 220 111J_ Johnson, Edw. C., Jr 198 Randolph Ave., Milton, Mass 550 6IL Mahler, Jas. J. , Jr 233 Ifawthorne St., San Diego, Cal.. 280 Lang, Stanley W 799 Tyler St., Pittsfield, Mass 100 GIP Marsh, Hallan N 1225 W. Brookes Ave., San Diego, 1MT Lindsay, Alex. M., Jr Plymouth, Mass. 770 Cal. 330 10K Morash, Arthur F '3G Chestnut St., Cambridge, Mass.. 250 e,,GH McCarthy, John J 3913 26th St., San Francisco, Cal... 50 lI1T Oliver H. E 235 Springside Ave., Pittsfield, Mass. 100 ONS Neville, Glen 417 S. 1st St., San Jose, Cal. 30 HIS Reese,-Lauren` A 181 Woodlawn Ave., Pittsfield, Mass. 32 6í1Y Plimpton, Roe 2508% Palm Drive, Los Angeles,Cal. 330 1KL Stocker, Clarence I 65 N. Franklin St.. Lynn, Mass..... 100 6SR Shelton, R. O 3443 5th St. San Diego, Cal. 467 1TK Stiness, Samuel 260 Broad St., Central Falls, R. 1... 550 6EQ Smith, Clarence W..... 333 Naples St., San Francisco, Cal 50 lOL Swanson, Richard 13 Hale St., Rockford Mass 30 OPI_) Somers, Wm. A 2057 W. 29th St., Los Angeles. Cal.. 330 24 10G Tarr, Gertrude E 8 Iligh St., Rockport, Mass 1(111 60V Toft, Frank Mountain View, Cal. 1LJJ Taylor, Jas. W 62 Tremont St., Boston Mass 35 SEVENTH DISTRICT. 11íX Vogel, Edw. A 49 Curtis Ter.. Pittsfield, Mass 49 7KF Duncan, Andrew J..... 3919 Burke Ave., Seattle, Wash 50 1VC Zander, Joseph T 34 South St., Ansonia, Conn 25 7W11 Harrington. Wilbert I.. Y. M. C. A., Seattle. Wash. 352 SECOND DISTRICT. 71.11 Hill, Leroy C 4824 76th Sc, Portland, Ore 5(1 2:\GE Bedell, Walter R 35 [looker Ave., Poughkeepsie, N.Y. 40 7LB Mahan, LeRoy 644 Exchange St. Astoria, Ore..... 1,000 2AGM Buttner, Edwin .. 1160 Third Ave., New York, N. Y. 40 F77 Miller, Clinton 394 11th St., Portland, Ore. - 50 2SE Godley, Paul F 106 Leonia Ave., Leonia, N. J SFO 7\IF Tingstad, Anton R..... 2128 Wilkinson St., Tacoma. Wash 50 2AGO Norris, Robert P 906 Marks Ave., New York, A Y 16 EIGHTH DISTRICT. 2:\FT Ondin, C. kolger t 7 Union St., Schene tady, N. Y 1,000 SMX Cooke, Lovell ...... R.F.D. No. 3 Gobleville, Mich 120 ".\GP Ripperger, Clinton..... 147 Wisner Ave., Middletown, N. Y 12 sAF Frey, Frcd'k. E 155 Poplar St t. Mansfield, Ohio.... 330 2AGO Rosenberg, Uda P 2116 Iloneywell Ave., New York 10 nOII Harter, Raymond Spencerville, Ohio 250 2AGY Schlcckscr, Raymond R. 12 Fabyan I'1., Newark, N. J 10 SLI Hill Dormand S. 2 Taft Ave. Detroit, Mich. 440 2AGV Sievering, Harry W... 54 Navin Pl., Newark, N. J 30 nFK Hosley, Fred'k D 900 South Ave., Rochester, N. Y. .. 24 2AGN Williams, E. Malcolm. Troy High( School, Troy, N. Y 40 8L\' Krommer, Frank 811 York St., Cincinnati, Ohio. 18 2AGU Zimmermann, William.. 765 Ilunterdon St., Newark, N. J 100 SMO Magregor, James E 211 Gold Ave., Grand Rapids Mich.. 420 THIRD DISTRICT. 8RP Merrill, John l' 608 Crescent Ave., Buffalo, N. Y... 40 SMA Metzger, Milton 121 Lane St., Bucyrus, Ohio 440 s% hingee, Alex, L M... Paoli Pa. 990 sNS Moore, Allan N. 36 W. La Belle St., Grand Rapids, 3GI' Hettinger, Alfred C... 12s S. Church St., Allentown, Pa 20 Mich. 100 Mahlmeister, E., 1801 N. 13th Philadelphia, Pa 250 3IA Jr.... St., 8 ME Preece Richard, Jr..... 2124 N. 12th St., Toledo, Ohio 500 FOURTII DISTRICT. SSP Reid, (rhos A. 411 S. Limestone St., Springfield, O. 660 4AT Hall, Marvin S rc7 N Boulevard, Atlanta, Ga 327 SAC Richmond, Norman E.. 5811 Lexington Ave., leveland, O 550 4111) Pinkston, Jeter, Jr 107 Gordon St., Valdosta, Ga. 550 SHH Schaming, John P 3114 McClurg, St., Pittsburgh, Pa... 12 4A1' Sanders, Tye C 239 Woodward Ave., Atlanta, Ga 575 8DG Shiley, Charles 110 Washington St., Kalamazoo,Mich 20 4AV Stringfellow', Geo. P Ortega, Fla. 330 8CP Smith, Newell R. 525 N. Main St., Wellington, Ohio.. 550 4.\R Summers, C. Il., Jr 01 E. Main St., Gainesville, Fla 120 Sternfield, Chas. B 516 W. Cedar St., Kalamazoo, Mich., 550 4AD Walker. Jas. F . Milledgeville, Ga 1,000 SQA Struchen, Raymond S Sterrettania, Pa. 36 80V Wahl, Arthur F. Pine Ridge, Buffalo, N. Y. 550 DISTRICT. FIFTH 80\' Wahl, Wilburt C Pine Ridge, Buffalo, N. Y. 550 5CW Ansley, Hewlctte L.... 14.28 N. 12th Ave., Birmingham, Ala, 250 sACG Welty, C. W.. Pandora, Ohio 550 5CX Holland W 406 Granbury St., Cleburne, 1140 Jesse Tex.... N NTII DISTRICT. SC Z Leroy, Louis Memphis, feue. 190 5I1A Mitchell, Erwin H 1012 Government St., Mobile, `.la.. 250 9C2 Chamberlain, A. Lee... 1040 E. Sixth Ave., Des Moines, Ia. 1,000 225 5C1' Ward Robert P 233 Orchard St., Georgetown, Tex.. 5111 9UL Cheyne Thos. L. 526 West Drive, Indiana olis, Ind 5DB Wood', Ross 726 Speight St., Waco, Tex 300 .)U1 Cottrell, Hale T 1229 St. Ann St, Owensboro, Ky.... 1,000 9}I V Custer, Alfred E. 1432 S. Washington St.,Denver, Colo 2511 SIXTH DISTRICT. 913M Erickson, Edward H 627 W. Superior St., Ft. Wayne, Ind. 495 6IC Andrews, Carl 2286 Olive St., Long Beach, Cal.... 100 9JF Erskine Vernon Kennebec, Iowa. 50 6111 Bauchou, Leon J Mayfield, Cal. 24 9 K Graybill, Donald R Polo, Ind 550 6PC Bumbaugh, H. L Lemon Grove Cal. 500 9U0 Hegge Adolph Ilatton, N. Dak. 36 6J Carroll, Lionel II 427 hunter St., Stockton, Cal 100 9UIf May De Witt W 1227 Spaight St., Madison, Wis 432 8 Chase, Ralph N. R.F.D. No. 4, Santa Ana, Cal 1,000 Neumann, Adelbert G.. 1616 Wells St., Milwaukee, Wis 25(1 6FF Cosgrove, Clarence E 435 Hanover St.. East Oakland, Cal 250 1' Paetzold, William H.... 4302 Farlin Ave., St. Louis, Mo 36 6U Eddy, Myron F 1232 Alice St., Oakland, Cal 500 9UN Smith, Joe L 100 N. Highland St., Chanute, Kans. 500

Amateur Radio Stations Licensed by the Bureau of Navigation During the Month of September, 1915. FIRST DISTRICT. EIGHTH DISTRICT. Call I Owner of station. Power Call Power Signal. Location of station. in watts signal. Owner of station. Location of station. in watts. 1DJ Bishop, Donald S..... 211 Washington St., North Attle. 8ES Aber, Ernest M., Jr.... 352 W. Ferry St., Buffalo, N. Y... 30 boro, Mass. 35 SKI! Angel, Jay L R.F.U. No. 1, Bowling Green, Ohio. 50 1TX Brown, Louis 209 Blackstone St., Providence, R. I 100 Appel, Floyd 310 Short St., Erie, Pa.. 500 111 V Chutter, George A 67 Church St., Swanton, Vt. 550 8LN Butler, Harry F 456 Mahoning St., Lehighton, Pa. .. 900 1PK Eastman Damon L... Norfolk, Mass. 50 8NN Chester, Allan . 50 E. Elm St, Norwalk, Ohio 550 1PE Hardy, Jack Littleton, Mass, 500 8KU Cookman. Murray R... 118 Glasgow St., Clyde N, Y 20 1SY Hathaway, Samuel D 126 Atlantic Ave.,Marblehead, Mass 500 8LT Copp, Stanley R 5 W. Monument Ave., bayton O,.. 118 10T Ilovey. Arthur T 74 Woodcliff St., Boston. Mass 72 Cross, Blakely E 47 Burr St. Gloversville, N. Y 18 1KU Lamb, Claude M 244 Federal St. Greenfield Mass 100 8JEQ Daniels, Le Roy Litchfield, Mich. 40 1?IT Mathewson, Oliver W. 34 Corona St., Dorchester, ((lass 36 8AIC Feldstein Milton Toledo, Ohio (portable station). 40 1l'L Strattoq Rolland A 215 Federal St., Greenfield, Mass 40 8K M Guest, Wesley T. .... 13 Babcock Ave., Silver Creek, N.Y. 24 8LZ (less, Elmer 4129 Carter St., Norwood, Ohio.... 35 SECOND DISTRICT. 8AY Irvin, Daniel L Curwensville, Pa 660 2FR IEttlinger, Albert 202 W. 98d St., New York, N. Y.... 12 8SD Johnston Clarence N.. 1335 Hill St., Ann Arbor, Mich 880 ^CB Leeb, Henry Lorent 166 Ralston Ave, South Orange, N. J. 561 80H Kelly, Edward O 18 Stratford Park, Rochester, N. Y.. 825 2l)Z Tuna, Lawrence 182 Madison Ave., New York, N. Y. 24 8 B Leach, J. Gardner..... White High School, Toledo, Ohio... 900 2FL' Volke, Edgar 883 S. 19th St., Newark, N. J 15 8IA Lindsay, Percy }I ,. 172 N. Division St., Buffalo, N. Y.. 24 80C Lucas, W. Gerald 63 E. Pine St., Gloversville, N. Y.. 250 FIFTH DISTRICT (No stations licensed in 3d and 4th Districts). 8LR Magdeburg, Morris R 1306 Spruce St., Ashland. Pa 100 8QN Mann, Rolland N. 1 36 511C. (Barr, Charles S...... 1327 Parkway, Memphis, Tenn...... 1,000 53 Good Ave., Buffalo, I 8 F McCowan, Jack 906 E. 8th St., Port Huron, Mich 27 SIXTH DISTRICT. 8KN Odenkirk, Russell 332 N. Beaver St., Wooster, Ohio 20 Palmer, 500 6CD Roland F...... 470 E. Butchel St. Akron, Ohio Abbott, Clare C. 4728 S. Western Ave., Los Angeles, 80T Pancoast, Maurice H... R.F.D. No. 6, Lansing, Mich. 36 Cal. 990 80Y Peck, George W St.. Scranton, Pa 1,000 A. 1014 Vine 611L Betterly, rack 2500 Elm Ave., Long Beach, Cal 250 SFY Prince, Harmon 3214 W. 88th SL Cleveland, Ohio.. 27 6iE Bradley, John 120 Julian Ave., San Francisco, CaI 700 8GM Root, Leland B N. Y 250 Brundige, Lamont 711 Utica St., Fulton, 6VS J 114 E. [ladlepp St., Whittier, Cal 500 8RX Ryan, Theodore W.... 1458 14th Ave., Detroit[ Mich 33 Cantelow, Elbridge M 2515 Derby St.. Berkeley, Cal 250 81311 Scoville, George I. C... 518 N. Jamison Ave. Lima, Ohio 50 6FL High, Freeman K., Jr 726 W. 27th St., Los Angeles, Cal 250 811J Sherman, Fred Benton Harbor, Mich 550 61'K Latta, Paul. .. 2158 Woolman Ave., San Diego, Cal 100 8NZ Simcox, Paul C ,. Cambridge, Ohio 250 Macurda, Malcolm Ilarvard ...... 403 N. 7th St., 6MX 1714 Blvd., Los Angeles, Spindler, Raymond .... 83 Saranac St.. Rochester, N. Y 23 Cal. 500 8QSE Vickery, William 40 St., Gloversville, N. Y 18 GYM J..... Burr ltlunzig, Arthur 217 Tribune St., Redlands, Cal 500 811 V Wagner Wayne 18 East St., Ashtabula. Ohio. 440 GBR Peelle, Russell G 517 N. Washington St., Whittier, 8.031 Wing, Wills K Scott High School, Toledo, Ohio.... 550 Cal. 540 8 I Zimmerman, F. C., Jr 15 Taft Ave., Detroit, Mich...... 500 GSD Shaffer Charley L 450 W. Center St. ' omona, Cal 100 GWV Webb, Walter R 1306 W. 41st St., Los Angeles, Cal 1,000 NINTH DISTRICT. 9VU Allman, John C Crown Point, Ind 40 SEVENTH DISTRICT. 9VY Bauer, George D 2133 Weisser Park Ave., Ft. Wayne, Ind. 500 7LC Anderson, Leonard . 218 Ninth Ave., N., Seattle, Wash.. 1,000 9VP Benson, Lester A. 2706 Stoddard St., St. Louis, Mo 500 'WC Cates, Walter C 1704 Franklin St., Vancouver, Wash. 1,000 9WE Brandt Erwin TH 2314 Vliet St., Milwaukee. Wis 550 710 Hurt[, John .. 1067 E. Burnside St., Portland, Ore. 500 9WA Coats, Roscoe 820 S. Clinton St., Ft. Wayne, Ind.. 250 Penne(, }tarry R 317 Cornell Road. Portland. Ore..., 220 9VS Diffenderfer, b avis A. 2409 Harrison St., Ft. Wayne, Ind. 972 rNJR Tolmie, Jack R 1213 Columbia St.. Seattle, Wash.... 290 (To Sc concluded.)

www.americanradiohistory.com November, rqi 5 THE ELECTRICAL EXPERIMENTER t2Ì OFFICIAL CODE CHARTS GIVING INTERNATIONAL RADIO SIGNALS, CONVENTIONS AND ABBREVIATIONS.

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www.americanradiohistory.com 430 THE ELECTRICAL EXPERIMENTER December, 1915

,, ;i

'! QUE ST ION BOX

This department is for the sole benefit of the electrical experimenter. Questions will be answered here for the benefit of all, but only mat, of sufficient interest will be published. Rules under which questions will be answered: i. Only three questions can be submitted to be answered. a. Only one side of sheet to be written on; matter must be typewrit ten or else written in ink, no penciled matter considered. 3. Sketches, diagrams, etc., must be on separate sheets. Questions addressed to this department cannot be answered by mail.

MAKE AND BREAK COIL OPERA- WAVE LENGTH AND 1/4 -KW. means of a "phantom circuit." It is neces- TION. TRANSFORMER QUERIES. sary to construct two coils having a com- (368.) Montgomery Joseph, Cove, Tex., (370.) Roy Trome, Norfolk, Va., de- paratively high impedance. These coils wants information regarding: (1) The sires to know: (1) Wave length of his may be wound on a core of soft iron wire operation of "make and break" coils for aerial. (2) The dimensions and winding 6 inches long and 34 inch in diameter, and of 1/4-kw. transformer. Coi/1 S// /M9 Con /oct - A. 1. The wave length of your antenna, which is 50 feet long with a 49 -foot lead -in, p p is approximately 175 :peters. Should you 111111111111111111IIII Cod- use six wires on 18 -foot spreaders your If increased 190 w/oled wave length will be to about , tioffely 1 Ca»txt meters. A. 2. The dimensions of the sheet -iron Ora toenç/ne traiix 1eto/ 1,il'irè on core for a '4 -kw. radio transformer are en top 101/4 inches long and 61/4 inches wide, out- side measurements. The core should be Gos durner 1.4 inches square. The primary should con- sist of six layers of No. 15 D. C. C. copper gallery, wire, and the secondary should comprise 3.7 pounds of D. C. C. copper wire wound into 17 pies, each 1/4 inch thick. The secondary is wound with No. 34 wire and has 35,000 0 #36B turns. Regular transformer practise should be followed in building this transformer, Use of Phantom Coils in Sending Telegraph Fig. A -i. Hook -ups for "Wipe" Spark Gas Ig- Signals Over a Telephone Circuit. nition Coils. Fig. A-z. Connection of "Jump" paying particular attention to the insulation Spark Coil to Fence Gate. of the different windings. consist of six layers of No. 26 S. C. C. wire. ignition purposes, and (2) 't method of A tap should be taken from the third layer. ANCHOR GAP HOOK -UP. The coils are then connected across the protecting a gate or other entrance by using (371.) Menzer, Tree, high-tension induction coils. Carl Lone Ia., telephone circuit and the wire run from the wants information regarding the anchor taps on the third layer to the telegraph in- A. 1. The diagram given herewith gap in connection with a looped aerial. shows how a "make and break' spark coil is struments; the other wire from the tele- A. 1. The anchor gap is practically not used on gasoline engines or igniting gas graph set is run to the ground in the usual of used any longer in modern wireless sta- manner, as shown. burners, etc. It works on the principle it too much loss in the self -induced currents, which increases the tions, as entails transmitting set. AERIAL CONSTRUCTION. battery potential at break of the circuit. Diagram is given showing how the an- 2. gate, as A. You can protect a you chor gap is used with looped aerial, and in (373.) Harry Slater, Brooklyn, N. Y., mention, with a spark coil by simply hook- you will perceive, requires information on the usual method op- this way, as the spark particularly ing up proper switching arrangements can jump the gaps in transmitting, while in of erecting an aerial, the man- erated in the house or by action of the gate receiving this anchor gap reduces the com- ner in which the wires and spreaders are itself, and this switch should be placed in plexity of the switching scheme necessary fastened together before hoisting to the the primary circuit of the coil as the dia- tops of the poles. gram indicates. A pair of copper wires A. 1. The usual way is to lay out the secured to the gate might carry the current aerial wherever possible at full length on from the secondary of the spark coil to give the roof or on the ground, and the two the shock, or one secondary lead may be outside wires are the first ones to be se- grounded. cured to the insulators on the spreaders. It is then an easy matter to connect up SODIUM VAPOR AND SPARK the other wires between the two outer GAPS. ones, so that they will all be of approxi- (369.) Francis Feig, Jr., New York mately equal length and at equal tension City, asks: (1) How to obtain sodium when hoisted into position. vapor, and (2) the effect of lengthening the spark on the primary input to a spark STATIC ELIMINATION. coil. (374.) Glenn Decker, Ligonier, Ind., A. 1. Sodium vapor is obtained from asks us: (1) For a method of eliminating "Na" or sodium proper. The sodium is static in his wirelss receiving station. (2) usually heated, and by proper appliances Why the strength of the wireless signals the vapor is gathered from same. The va- from N.A.A. (Arlington) change. porizing point of sodium is about 95 deg. A. 1. We do not have anything particu- C. We have been unable to locate any lar to suggest regarding the elimination of definite data on the resistance of sodium Arrangement of Anchor Spark Gap and Looped static in your wireless receiving station, ex- vapor, and in this direction wish to suggest Aerial in Radio Transmitting and cepting you try one of the static preventers, that you might communicate with Dr. A. N. Receiving Set. such as that devised by Professor Fessen- Goldsmith, care of College of the City of in throwing on and off transmitting and den, and you will find complete hook -up New York, New York, who undoubtedly receiving set to the aerial. for this arrangement given in our 25 -cent can supply data on this point. book entitled "Wireless Hook -ups." A. 2. As the spark gap is reduced in PHANTOM CIRCUITS. A. 2. The change in strength of the length the primary will tend to draw more (372.) W. S. Clampitt, New Providence, wireless signals from N.A.A. is, of course, current. This is not so noticeable with an Ia., inquires for a method by which he can - experienced regularly, and this is due to ordinary spark coil excited with dry bat- transmit telegraph signals over a telephone the change in temperature, or from winter teries as becomes the case when a regular circuit without interfering with the tet_e- to summer ; the winter range of radio sta- alternating current transformer is used, phone transmission. tions is about two to three times that owing to the peculiar action resultant from A. 1. We give herewith a sketch show-. obtainable in summer. From some very the spring vibrator. ing the method of accomplishing this by (Continued on Page 432.)

www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 431 TREAD EVERY LINE Or THIS IXPERIMENIERS INTERESTING AD

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1-6 K. W. Closed Core $6.95 HERE IT IS AT LAST,! Wlrcl ass Tra nsformar.... . Electro -Set "Navy'' Loose Coupler After months of exmvrlmentinR and after making ,z,- Our Navy Loose Coupler or Receiving informer, b dozens of designs and models, we havesorm produced remarkablequalnatrumrnt . l price , is lower and in quality ,. a tM t practical formerly transformer to retail vrr It s n l Of almost any losercoupler, no matter what a t {6.96 thehe price you formerly had h pay for spark Its priee. m certainly far superiorto any we have seen at coils and batteries. anywhere scar its price. Think of being able to buy a Thousands of amateurs will welcome the advent of ire "Navy' type loose murder at a low price heaths OP/ 1 j this trament who either did not require M K, W. ,s, v following npec,ficationa usually only found in prohibitively _ powerr no did not care [o spend the money for It. 'I áriced transformers: hard rubber seeond- .¶ The transformerild fig will send m0fact -i for twenty miles end with large turned braes co rich: ` I not a wild figure, but an actual fact-if good aerial mai rubber i i4. - \ switch,,panel on the front t the E' used. circumstances it send - -` hard C ;1 Under extraordinary . Pk rbbeorsañ5i ,,pane am brass - one hundred miles. No trouble with vibrators and lb onsets: primary enclose l in a dark maho- - aa, r ctancoe or (stances. Just connect 1M Tv any finished covering on all ides; every - primary terminals to 110 volt, 60 cycle A.C. mat. . ßt1 - contact soldered, assuring perfect ronnec- a d press key. Rest silicon transformer iron k used in its construction. Don; handsome mahogany finished bso: Ìt will throw a heavy crashing spark that. with proper condenser. will all a Rap with a bolter white flame - lacquered braes posts and trimmings. The inch In diameter. Thin tom... vely email but pfowerfutnim k will send six times as lar as a 1 Inch fie, equal of tbl.. tece:ito transformer can not spark83 IL The 1.6 K. W. Transformer another ELECTRO-SET triumph. It was tented in - i :. J t be found. It is the acme of efficiency at one of the most complete electical atories In the country by competent engineers, who pronounced It moderte price. P Meet, for its size all partmukrs. you well I e dirVi with it. No. CLOSED CORE TIANSFORMERwnhoutease ,ehipiished mahogana. $6.95 10001- 6K.it'. NO. 1698 " NAVY" RECEIVING LOOSE COUPLER;aWpidn5 weight 101ba .$10.00 Ncaxobnprexateéithsullatine compound andRfimdwith fourpouts: éñpngdwightllo lbs. . 9.00 NO. 16.iß NAVY ' RECEIVING COUPLER ; ill wood construction 9.00 No. 611 Aerial Switch Type "A" Send 4c Today This instrument Is novel in The Rotary Spark Gap is without For Our ,. design and convenient in op- ,-. an equal. Made like any of the more oration. The base is dark Ina- pe, but smeller con size. ft operates in aeries with a 18 C. P. o g 0 6 y flotsam:. tampon 110 volt alternating r Ba or direct from Big New Catalogue ' - The copper lairs i its the Rotary are S Inches luny 4 is it of dozens new wire- ' irate of caacetlYru containing description of and are sawed, array aria is erteruy aces- less and experimental instruments, parts and .. p I ore. Trig rl is maanha not drawn. Posts whavybrassshara,ngwhch raw newria, are new-instruments am provided oaall navy motor which arc new catalogue every experimenter -- The to the shaft. -a contact Jaws for Therful.motor tea K.ÁÖ. aeries MUST HAVE. - connections. d A.e "AD.C.Mxhlnc small but posigned . Three rimy Type' Can, although eapei designed for our oxtK, Write Today Mists and hors are nary me K. W. transformer will readily stand any good ;t K. W. 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We Are Agents For Electro-Set ``Arlington- Tested" Crystals MARCONI USED APPARATUS Electro-Set "Famous"Famous Mineral Sets Send 5c, in stamps for new, interesting One of the most interesting Belda in wireless telegraphy i When testing outs wireless receiving installation for the ' the experimenting with varions combinations and methods first timo you want to know tbat your mineral crystal is sea- catalogueg of used Marconi Wireless Instrn of contact in detectors. We offer the following outfitespec- sitive. Then. too, w by buy minerals on a gamble. Bosura ineft5 at ridiculously low prices. We are folly designed for thin purpose and peeked ins at box. Cof results -good results. Buy our Arlington Tested" agents for this line and can ship promptly Countless Lours of interesting experimenting is offered to rystals. Every ones tested for Arlington time signals. anything from a Type "D" Tuner to a Motor the amateur with this set. It includes five different minerals Each crystal sealed in an air-tight glass phial and in Genera tor. (galena, eille.o, carborundum, bornito and molybdenum I. care( ully tested before leaving our factory. Only one crys- each parked in a neat glass bottle: one universal detector tal In 20 passes our camination. Arlington Tested - cup; three pieote to boopor-brpnze "cat whisker' wit one Crystals are the most sensitive you can procure. They are worth the price. Each one polished wood detector base: one large binding post: one bard rubber knob; oneebrass i ndividually examined and packed. rod with holderfor wire. Witb t his outfit it is possible to make many different kinds o NO. 301 ARLINGTON TESTED GALENA, individually parked and mated; postpaid .. $0.15 detectors. Itie i deal for the experimenter. NO. 302 ARLINGTON TESTED SILICON, as above 15 NO. 2100 DETECTOR MINERAL SET, as described complete. postage paid. ..51.25 NO. 303 ARLINGTON TESTED BORNITE- ZINCITE COUPLE . .40 NO. 215.) MINERALS ONLY, as above, five kinds, in bottles. posta.ie paid 50 14 EXTRA - ORDINARY BARGAINS - 1' ;#:;o/ Polarized Ringers -New, ever used. Complete Telephone Induction Coils -Never used. Wound Telephone Relay Coils -Wound to 100 Ohms with Tapped for 8-32 screw.a Worth 40. ea. new. 2 high G with resistance magnet coils wound with silk to 100 Ohms with primary and secondary coils. silk sizeci 36 eilk covered wire. Complete with soft iron Special price, r dos, (Postage Sea and a strong rerminent magnet with noner. covered wire. Excellent shocking it can be made Wire lone worth 20e. Special price, ea. Horse Shoe Magnet -3 In. long cry Aey experimenter can use one. with one. Worth 50e. ea. Specialprice ea. 09e. Ó9c. IPonmge 4c.) useful for many experiments andd for makingakin in. S nee al price, ea. 15e. (Postage 6c.Ì (Postage lc.) Connecting Blocks-Hard bber, s t in. x 1 etruments. Worth 15e. nob. price Use. Hard Rubber Koehn-Sire 19 -16 in, o Yin. Drilled Binding PostS- Handsomely nickeled 5 16 in. x 1 3 -16 in. Have 6 holes for 6 -33 mach 'screws. Postage 3c.) and Tanned fir 6 -32 screw. Handy for making ap- in. over all. Complete with nut. Worth 6c. ea. Complete with 6 screws. Worth 120. ea. Special Mertes A Dandy. Chance-We have made up para i-.. Worth 3e. a new.a Special Price. per Special price, per doz. 25e. ea. 2)5C., (Postage per p 04e. (Postage le.) umber of boxes of small odd parts of ekctr,cel doz. 10e. (Postage Sr.) doz. 5c.) Hard Rubber Handles -,4 in. x Yi in. Drilled and apparatus that every experimenter can use in his

iiri UIII fly , / fl shop. These boxeseacb contain from 40 to60pieees r'bmenters all want them. You can woke dozens with I nuts and screws with connectors. Worth with them. Worth 50e. pair. Specal artes with of odds and ends, uch as rubber knob brain óof things with them. 15e. ea. Special O5c. (Postage 2c.) yoke, per pair 09e. Postage 5e.) standards hooks, binding posta, No. 121 -Handy Assortment. Prepaid 20e. Connecting Blocks-madesCe ade of genuine hard rubber Toy Motor Parts -Consisting of on iron e screws units, with 3 handsome nickeled binding posts. Useful with polo pieces; 2 covers for same and one 3 -pole thumb puts, Coils and miscellaneous Darts. Some are 75 Ohm Receiver Coils -Never us.d. Ready to (or dozens of thin about the experimenter's sin laminated armature with shaft. All you need is new- d, but all of them are useful to have p t i any ph.. ."r to make c d s 'th. WYorth 25e. They have never been used. Special mutate bearings, and' wire to complet motor. Wound to 15 mime with silk conorct 26c. ppaa ' Äwhen to are making apparatus. Thbb a with ca. Postage 2c.) Above rte worth 40c. sot. Special price, 15c. Dot the kind of nnvenie tparta to be able to Soe al price per pan nneetora Owe RelayR or TelegraphTelex ph Magnets -in fair condition. (Postage Gr.) from for your ex ts. We've sold (Pnstape le.) Have been used but arc isP feet ham. Wound Nnle: -Commutator wire for above motor extra hchooseundreds of them m our retaildepartment. Ex- Connecting Blocks-Made of genuine hard rubber. to SO ohms resistance. Make relay or telegraph 40c. (Prepaid.) 110 THE ELECTRO -SET CO s 1874CLE ELAND, rOHIO

Yon benefit by Mentioning "The Electrical Experimenter" when writing to advertisers. www.americanradiohistory.com 432 THE ELECTRICAL EXPERIMENTER December, 1915

QUESTION BOX. Mass., sends us a sketch of a wireless tele- (Continued from page 430.) phone transmitter and wishes to know: (1) YOUR RANGE If this set would (2) exhaustive work. If not, why DEPENDS ON YOUR tests extending over a period of not? (3) Will the 6 -volt 40 -A.H. 8- a year and and more and presented in the In- volt 80 -A.H. storage cells be powerful stitute of Radio Engineers' "Proceedings" enough, and how far will it work? RECEIVERS a recent date, of this summer range has A. I and 2. To all appearances your ap- been found for ordinary ship radio stations paratus will not work because you have the of the spark type to quite regularly be only secondary of the 1 -inch spark coil inserted equivalent to one -tenth the winter range. in the high- frequency circuit, and the high REGARDING QUENCHED SPARK impedance of this coil will prevent pure GAPS. oscillations taking place. (371) Frank Zacharia, Jr., N. S., Pitts- A. 3. We cannot say whether the stor- burgh, Pa., desires to know how many pairs age batteries you are using would be power- of gap plates are required for a t/9 -kw. and ful enough for a wireless telephone, but an a 1 -kw. wireless transformer. ideal set of this type should operate on A. 1. The number of pairs of plates re- such small storage batteries. We would quired for the Telefunken gap depends like to say `here that for a satisfactory upon the discharge voltage of your con- wireless telephone it is necessary to obtain densers. The general practise is to allow undamped oscillations in the closed oscil- 1,000 volts to each gap: ^ Thus, knowing latory circuit having a frequency value of the voltage of the transformer secondary at least 30,000 per second, which is above or the discharge voltage of the condensers, audibility. It is impossible to obtain this it is very easy to calculate the number of frequency with an ordinary vibrator, and gaps required. You understand that the more power there is used the larger the Holtzer -Cabot surface must be to prevent overheat - gapg gap. Radio Receivers ELECTRO- MAGNET DESIGN. t have (376.) Charles Malcolm, Jr., Philadel- honestly phia, Pa., requires information: (1) As C earned their to relation between the size of a a t s, wire on O.T. reputation of magnet and its lifting power. (2) Data for the construction of an electro- magnet /nd.-coil being the to exert a force of one pound at a distance %N/AA/ of G inches. G - P' "Most Sensitive Receivers Made" A. 1. It makes practically no difference Other features are light weight, comfort- what size of wire is found on an electro- Q 378 6-40 able shape, durability, perfect finish. Send magnet if the voltage is in for Booklet 20 D2 for description. proper used conjunction with same. That is to say, the Proposed, But Impractical, Radiophone Hook -Up. same number THE HOLTZER - CABOT ELECTRIC CO. of ampere turns will go in a given space, roughly speaking, if the volt- for this reason spark coil sets have never BOSTON - CHICAGO age and current are properly balanced out, worked satisfactorily over very long ranges so that the coil will not overload. This. as and the enunciation in every case is very you will perceive, is merely a matter of poor. electrical design and calculation. A. 2. Your problem for designing an AURORA You electro- magnet to exert a force of one THE BOREALIS. pound at a distance of 6 inches is rather (379.) Lawrence Madison, Kingman, out of the ordinary, and it would require a Me., writes us stating that he has person- Can Get very powerful magnet coil to do this work. ally seen the Aurora Borealis from his Possibly, however, your problem can be home in Maine and that a distinct hissing solved efficiently by the use of a properly sound was noticeable. This is contrary to Results designed solenoid or suction type electro- the statements in the article entitled "The magnet. However, it does not seem prac- Aurora Borealis, or Northern Lights," with a small tical to build a regular type electro- magnet which appeared in the October issue of The Electrical Experimenter, he condenser and to exert any such pull as you mention over and wishes UNMOUNTED the range of action specified. an explanation. TRANSFORMER this transformer A. 1. It seems reasonable to suppose, INSULATION AND DETECTORS. and especially if we consider the Aurora It is a I -2 K. W. size and is built on the (377.) C. Russell, London, England. Borealis an electrical phenomenon, that same specifications as to material and asks: (1) The best dielectric or insulator there may be a noise or sound produced by workmanship, etc.. as our big central for high- frequency apparatus. (2) Several such a display. We have, however, checked up this matter quite station transformers. questions regarding the de Forest Audion carefully in preparing and Fleming valve detectors. the article, and in all cases which came to Hundreds of stations are A. 1. The best substance now available our attention and wherever this sound is that known as Bakelite Di- Electo. This theory or statement was made, it was in- now using these trans- is used by the Marconi Wireless Telegraph variably refuted by different authors and formers. This transform- Co. for its panels on wireless receiving authorities on the Aurora Borealis. One er gives you 13,200 volts. cabinets, and therefore can be considered of the best works on the subject is that by as probably one of the best substances Alfred Angot, and while many statements Let us tell you how you can do part of available at this time for the purpose in are quoted therein from various people to the work yourself and get this trans- question. the effect that they had distinctly heard former at a remarkably low cost. A. 2. The Audion detector is supplied sounds when the Aurora Borealis effect in America by the de Forest Radio Tele- took place, the authorities on this matter phone & Telegraph Co., which manages give an explanation about in line with that THE PACKARD ELECTRIC CO. practically all sales for this detector in this mentioned in the article referred to. This same idea, 555 Dana Avenue Warren, Ohio country, and it is, of course, supplied by advocating the "no various dealers. However, no independent sound" theory with regard to the Aurora companies make a detector similar to the Borealis, is concurred in by Henri Arctow- OSTON Audion insofar as we are aware. sky, a well -known authority on this phe- WIRELESS The Marconi Co. supplies the Fleming nomenon and a scientist who has passed Boston Receiving Translormer 57.50 valve, but this is said on pretty good au- many years exploring the Northern and Variable B 25 Plates 52.75 to be to the Audion. Southern Polar regions. This does not. Boston Detectors, $1.00, $1.25, $1 75, $2.25, ít.00 thority inferior Agent for Electro Importing Co. sod A. W. Bow- however, purport to infer that your ideas man Co., Manhattan and Adams Morgan Spark TELEPHONE QUES- or statements are not correct, and, as yet. Colle, Ever -ready Bash lights and batteries. WIRELESS Catalog for stamp only. TIONS. we can truthfully say that the Aurora M. MUELLER. IS Devonshire Street, BOSTON, Mass. (378.) M. A. Norgren, Springfield, (Continued on page 434.) You benefit by mentioning "The Electrical Experimenter" when writing to advertisers. www.americanradiohistory.com r, 1915 AL EXPERIMENTER 433

IN& FOR THE EXPERIMENTER"

99 IN THIS a a THE LATEST CATALOG IN AMERICA" \ "THE LIVEST CATALOG IN AMERICA" 'í'11E ELECTRO IMPORTING COMPANY CARRIES THE LARGEST STOCK OF EXPERIMENTAL, ELECTRICAL AND WIRELESS GOODS IN THE WORLD. We are the originators of the Wireless Experimental business in the U. S., selling the first w reless outfit in 1904. Our won- derful facilities enable us to give you delivery in 24 hours. WHEN ORDERING GOODS FROM THIS PAGE ENCLOSE POSTAGE ELSE GOODS MUST BE SHIPPED BY EXPRESS COLLECT. The goods shown Itere are only a small part of our entire line which is fully described in our 275 -page Cyclopedia Catalog, which weighs y lb., is 63x5% inches in size and contains 2,000 articles, 658 illustrations, 30 diagrams and fed tables, full Morse Continental and Navy Code Charts, besides "Treatise on Wireless Telegraphy," list of call letters of all U. S. Gov't and Com- a mercial ship and shore stations. This wonderful Cyclopedia sent free if you send us 4c, in stamps or coin to cover postage only. WE SELL MERCHANDISE, NOT CATALOGS, "II '5y buy Catalogs when the best is freer" Use coupon below to send for Catalog, enclosing 4c. tor pncfvwe only

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Rugby Made of 0 volte, l0 e Rheostat. Porcelain Base Xmas Tree Lighting Out- Hustler Motor. /tuns Icon - Revolver Flashlight. Ea Football. Dynamo. ohms. Pebble grain leather, lined pelvis. Very heavily built for `Pat'du. Reri Mante 10 fit. For 110 volt bouse cur- derfully on one dry cell. art model of automatic re. with duck. ):ladder oaar- auto.ltg., charging batteries. tiinuafly. Invaluiable2fnrdimm ng rent.t. Has 16 colored lamps. Will operate small toss. volver, shoots brilliant light outset' against accident, electroplating. etc. Excel_, lampa regulating small motor.. red, blue, white and green. beautifully finished and when trigger Is pressed. Con- abuse for one lent motor on 8 volte.. Turner 4'nfilZ Contrat arranged in two festoon.. very strong. A wonder for tains tungsten lamp and bat- year. power ed by V Uiacanneeb on Most owonderful value made to Inst. Size sx','_u Ìte. knob. Absolutely safe and complete the price. Size 3 x 3 x4. tery in handle. Surprise your a aide. Binding posta offered. Standard on 'sh. wt. 20 Ills, r 9.00 beer eomD. Shoat. with cord and plug Sh wt. 1 Iormnd. tr size ix2' , e17,, SI, wt . II,. .. 1.i,. tp It.,. Prie. $ .60 Ish. t.3 lb.. Prie,' 4.05 $.85 in= Sb.wt ill, Irr,,' $.95 El a

Electric Lighting Outfi, Radio Nitrogen B Dynamo. Very pou ertul. Free wireless C con - Telephone Necetver. "tresto" Hand Lamp. Fite J 8 volt 150 watt capacity. In- (tires 3 rolls and is same size gives 6 volts 6 amperes, slating of :dl lessons, total ohms. Hard rubber comp. on any dry cell and will o. 5 cell. 12 cludesdes gentor, switch dry lights. tungsten lamps. 160 cloth binder size powerful magnet. With two burn for 5041 hours. No hoard with era tees. etc., Wstandardonderfully efficient.a Made charges storage cells, runs page, receivers and no battery, danger always ï 7z101í 350 30 engine, of extra high grade materials. as a power motor, etc. Not in. with illus. u can talk 500 feet. Size ed coSl mpl without a batten.. fuse., wire shydro- to tables. Coupons for this meterandplam. so- Used for lanterns and experi- toy. Size 6x6x6 inches. inches. Shipping battery. Reflector is d- a work. '7 $. Icy 1lbs S.. mental Size.. 5.35 Sh. wt. pounds. Free Wireless Course in weight I pound. $ .g1 6í3e. ltló $74.00 2N. Sb.wt. 3 $3.70 40 75 wt. ilia. Price.. lbs. Price Price our Ctrlopeelin lotnlos. Prrice 6 aÉ' lbi'

a Upright Steam Engine. Trolley Car Outfit. Won- Pocket Ammeter. Range is Presto" Bicycle Lamp. Spark Coil. OOes 1 inch Prinasng Mress ibritluk. a Ilse water gauge, whistle. derful value, will run on dry 0.30 amperes. Pocket size. (electric). Operate. almost flaming spark on b volts. Mg). large balance wheel and will ells. Outfit consists of Dol. Finely nickel plated, ecru, 5o hours on one ,trg Celt. 2 'Bull Dog" style that's cop. it iv I"IñoÌud es.Ìon[ operate on kerosene and pe- ley car, controller, electric ate, dependable and handy. inch reflector is fully adjust- ied but never equalled. Oak of 175 characters, type ease. troleum. Tested before ship- headlight and 1515 feet of Invaluable for testing dry able. Fasten. on handle bars. frame.platlouni volute. Rub - ment. Directions included. straight and curved track. cells. Diameter 2S inches. Battery

Borealis effect is really but very little un- CRYSTALOI derstood, even by our foremost men of THE BB science. NEW DIMENSIONS OF 1/2-KW. STEP - DOWN TRANSFORMER. The New Type -BB CRYSTALOI is a SUPERSENSITIVE Detector comprising every accessory (380.) John Burkitt, Madoc, Ont., Can- and refinement in A SINGLE UNIT it consists of a highly finished African ada, asks us for the dimensions of a 1/2- mahogany case in which is located a super kw. transformer to change 220 volts to 110 sensitive Crystaloi cylinder of which the volts alternating periphery protrudes through the top making current. it accessible for rotating to secure finest A. 1. The dimensions of the % -kw. adjustment. A cohering inductance especial- transformer 220 ly calculated and calibrated to the super- for changing volts to 110 sensitive cylinder. A fixed condenser with volts are as follows : Core, outside dimen- the exact capacity for this particular cylin- sions, 14x7 inches 1.4 der. A specially wound Buzzer of which and inches square. the frequency is controlled by a knurled Primary windings consist of 625 turns of screw head mounted on the front of the No. 16 D. C. C. or enameled ease to produce a note that is best suited to wire, and the assist in cohering the alloy in the cylinder. secondary requires 312 turns of No. 13 Two of the highest grade dry batteries to wire. Three pounds of the No. 16 21/2 operate the Buzzer and a Buzzer control but- and ton which protrudes through the top of the pounds of the No. 13 will be sufficient for case for accessibility. you to wind the With this carefully designed and calibrated transformer. It can be instrument you have but to set it on the constructed in the usual manner and con- table, connect your phones and leads from nected direct to the 220 -volt mains. It will your tuning coil and you are permanently and thoroughly equipped to engage in the consume 2.5 amperes and will deliver 5 most serious wireless work of the present Dimensions 7/ z 5 4 z 3% high amperes at the secondary can be terminals. The day. Of course Variable Condensers Mailing Weight 3 Pounds, Price $12.00 iron core should be made of transformer added if desired. iron and particular attention should be paid to the insulation. Other Types of the Crystaloi - OPERATION OF ROTARY GAPS. (381.) CRYSTALOI TYPE AA, Super Sensitive Walter Franseen, Woodhull, Ill., TYPE O TWENTY -ONE HUNDRED MILES desires know: (1) CRYSTALOI IS THE LATEST CRYS- to If the "Multi -Audi- Vary Sensitive TALOI RECORD Fone" and the "Multum in Parvo" instru- ments are fully up to the claims made by CRYSTALOI the manufacturers. (2) Several points re- A PERMANENT WIRELESS DE- garding the operation of TECTOR THAT HAS MADE A a rotary spark gap. WONDERFUL RECORD A. 1. The "Multi-Audi -Fone" and the "Multum in Parvo" instruments are fully You will find wireless men on land and sea using Crystaloi Detectors in up to the advertiser's claims. The Elec- preference to any other detector trical Experimenter does not carry any made. They will not burn out or go dead and are ever ready to pick up questionable advertisements in any sense of the minutest currents that are in the the word. We do not know the patent air. They are sold under the Tur- ney guarantee and are making their number on these instruments. However, wonderful reputation on real merit. you could, no doubt, find this out by com- Send today for full description. municating directly with the United States Dimensions 21/4 x 17 in. ORDER A CRYSTALOI TODAY AND Patent Office, Washington, D. C., or with Mailing Weight 1 Pound. STOP YOUR DETECTOR Dimensions 4 z 3.A in. PRICE, $3,50, TROUBLES Weight 2 Pounds. PRICE, $4.00. the manufacturers themselves. A. 2. Your question regarding the rotary spark gap is not entirely clear, as most of the rotary gaps, to our knowledge, OUR WIRELESS ACCESSORIES are of the one type. Perhaps you refer to a gap with two breaks; the number of THE NEW TURNEY VARIABLE CONDENSER THE TURNEY ROTARY LOADING -COIL breaks has little or no bearing on the mat- This is a radical de- ter, and the only effect obtained is an in- edrform of loading-coil crease in the quenching effect. It is, of for the reason that the course, necessary to run the rotary gap so it entire coil with its switch points revolves while the sparks at the peak of each cycle of the A. switch blade remains stationary. This new C. for synchronism. This would give you f orm of construction 120 sparks per second on 60 -cycle current. makes a much neater and more compact in- Non -synchronous gaps have been used with strument, and the rotat- less ing of the coil is a much more or success, particularly the Mar- more natural movement coni type, which gives 240 sparks per sec- than turning the switch To increase a gap, Dimensions: Dimensions 3/ in. z 1 in. bladp it has a caps - ond. the tone of spark 5% z 2i4 in. Made in two capacities. city .cif 4,000 op, Type X-35 Plates. Price $3.50. Price $3.50. that is, to operate the disc at a Water speed, Mailing Weight One Pound. 0 m o Type XX -50 Plates. Priee, $5.00. oaa of 250 tmeters it is necessary to change the capacity of the ORDER ONE NOW each. When used with the ordinary loose -coupler will and see what you have been missing, give a total capacity of about 4.600 meters. The entire condenser in the closed oscillating circuit instrument is of hard-rubber composition. The blade Is for highest efficiency, the capacity being The New Turuey Variable Condenser meets all a silver alloy, which insures the maximum a'iciency. the requirements of the most exacting wireless Tofhe rotary coil has a knurled edge and is provided with a smaller the higher the spark frequency. mau inasmuch as it has more capacity for its size scale divided into sixteen equal divisions. than any condenser ever made. The great advan- CONSTANT AMPLITUDE tage lies in the fact that it is provided with round TEST BUZZER DOES A TUNER "KILL" SIGNALS? plates of a apeeial alloy 1/ in. in diameter. of Our special Constant which the entire area is available for condensing Amplitude Test Buz- (382.) "Experimenter," Georgetown, purposes. This you will find in no other variable zer contains some en- Tex., writes us inquiring how wireless sig- condenser. tirely new features nals pass through a tuner when the "curls" The New Turney Variable Condenser possesses and gives a smooth, an absolute zero. This you will find in no other even tone at all times. of the wire used in some electric connec- type of condenser. The plates are inclosed in a This is due to the ar- tions have the effect of choking the signals, flint glass tube on which the scale is engraved. rangement of the con- It is air and dnstproof and can not get ont of tact which is provided as we well know. order. The dielectric is air, therefore the efficiency with a lenient hack - A. 1. A high frequency current flowing is the greatest possible. The ends are of hard rub- CONSTANT AMPLITUDE check. T h e contact in ber composition and are highly finished. A hand- TEST BUZZER points are of pure sil- in a circuit similar to a circuit used radio somer and more valuable wireless instrument you Dimensions 2% x ins. ver, which prevents work requires that a certain amount of the never saw. 2/ burning, and the en- tire mechanism is enclosed in a non -resonant dia inductance capacity should be in that cir- lectric ease. PRICE, 75 CENTS cuit to prolong the oscillations, the turns of SEND FIVE CENTS IN STAMPS FOR Include 10 Cents extra for postage. Remit in COMPLETE CATALOG form of P. 0. or Express Money Order. wire in the tuner acting as the inductance and the elevated aerial as the capacity. 2595 Third . Avenue When these arz. properly adjusted the cir- Eugene T. Turney Company, .Inc., NEW YORK CITY cuit is in tune and the incoming wave cur- rents flowing in the circuit will be at their

You benefit by mentioning "The Electrical Experimenter" when writing to advertisers. www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 435

maximum. Should any small coils be in- serted in the connections it adds that much unnecessary inductance, which is of no use usually and the added impedance causes the current to be reduced in value, owing to the circuit being thrown out of tune, or to the Multi -Audi-Fone increase in resistance (damping). 1,500 Times The new wonder in the wireless world. It increases the Audibility HYSTERESIS IN CONDENSER. (383.) Jeter Pinkston, Valdosta, Ga., asks: (1) What is the standard formula for the solution in storage cells? (2) Is a high potential current a high voltage current? Read What Others Say (3) What does hysteresis mean when used condenser Messrs. Stickel & Stickel, of Connellsville, Pa., say: "We have given your apparatus a in the description of a variable thorough test and find that they are all that you claim them to be." that is losing energy due to hysteresis? Mr. D. L.. Irvin, of Curwensville, Pa., says: "I was surprised with the results from it. Also which is better to use in a variable Arlington and several other stations came in so loud that I could read them with the 'phones condenser, oil or air? ten feet from my head." A. 1. The standard solution used in Mr. Ralph Butcher, of Toledo, Iowa, says: "The results were even more than were storage cells is a mixture of 1 part of expected, both at the convention and by other amateurs in Des Moines, who tested the sulphuric acid to 5 parts of water. This apparatus, and other places." should be mixed in an earthenware con- Mr. John 'Pucker, Jr., of Elizabeth, N. J., says: "After a thorough trial, am astonished Don't fill cells at the results obtained Combining, as these instruments do, the greatest degree of tainer and constantly stirred. efficiency coupled with extreme compactness, they are, without doubt, the finest instruments until solution has cooled. otlered to the amateur and professional wireless field at large." is A. 2. A high potential current one W. O. Horner, of Cleveland, Tennessee, says: "I have been trying your Multi- Audi -Fone having a high voltage. out as an Amplifier . . . I was more than surprised at its sensitiveness. It is certainly A. 3. Hysteresis loss here is the loss in wonderful. . . I stood at the rear of my store, one hundred and twenty-five feet from 'phones, and copied Arlington and Key West, also Tampa, Florida. I consider that some the dielectric of the condenser. The plates amplifying for way down here on Inland." of the condenser are constantly charging and discharging; thus the stress between them is constantly changing its direction. This change of stress lias the effect of heat- FIVE OH M G0.6tOh. ing the dielectric and a small amount of the RECEIVERS Never ust mort ERE current is lost in this manner. 'TWO Cells e° ONE TEST Thon ont tel\ a` BAT For high efficiency a variable condenser CELL BUZZER dry iwNev %co in- mye used should use air as a dielectric, but oil DE T. creases the capacity and also the hysteresis h2ee _ loss somewhat, as mentioned ill your ques- tion. CRT STA E01n RADIO RECEIVING TIKKERS. PUSH DETECTOR (384.) H. P. Keiffer, Lebanon. Pa., BUTTON. EC COntOGtS , GROUND IA Dix l r To sut tl,t \Ytu\tura- C t/1,.. nYn..a Ti,Ìllottk MULTI A DI-rONE J `' -Motor ' "tt\ultl-Aväl-Tons. ADJUSTMENT BOW; SWITGNF$ Connntt 2,000 ohm TUNING HANDLE I Tttèlvtts to tests (T) (T) I1ULTI--AUDI-FONE \SRO 00 Rheostol ELIZABETii, IW. 01384 Undamped Wave "Tikker" Hook -Up. Multum in Parvo Receiver, including Crystaloi Detector and Buzzer - $20.00 asks: Is (1) it possible to receive stations Multi -Audi Fone, Including our Specially Wound Head Set - - - - $30.00 using undamped' waves with a Radioson, electrolytic, or mineral detector? (2) Can The Matchless Christmas Present. Our Complete Wireless Set, Only - - - $50.00 a copper disc be used in constructing a tikker and what is the location of the contact springs? (3) The hook -up for the tikker, using a loading inductance and tun- Talking Multi-Audi-Fone Telephone Voici Multiplier ing coil or loose coupler? A. 1. It is only possible to receive un- damped wave stations with an ordinary de- tector when the sending apparatus gets slightly out of tune, resulting in slightly damped waves. The tikker is necessary for all around work in the reception of un- damped waves. A. 2. Any metal can be used for con- structing the disc of the tikker and the two springs can lay in the groove about one -half inch apart. The disc may be 2 inches in Size, 414" x 5" x 7 ". Size, 214" x 3''/s" x 4% ". diameter, and a rheostat should be used to control the speed of the motor. The faster The amplification is so great with the Talk- The Telephone Voice Multiplier has been made ing AudiFone can be the motor is driven the higher pitched note Multi- that the signals possible by applying the principle employed in read all over the five -story building from our our MultiAudii -Font to the telepbone receiver. will be as heard in the 'phones. laboratories, which are located on the third The voice can be distinctly heard coming over A. 3. Hook -up is herewith for a floor. If the windows are opened, the signals 1,000 or even 2,000 miles of wire that would given can be heard actress the street, even wben the tikker, and no is in be indistinct coming over 100 miles eS wire. detector used the cir- trolley is passing. Buy a Multiplier and stop straining to get cuit with this instrument ordinarily. Price, Including horn - $100 sometbing you can't bear. Pelee S 1 5.0 0 IS Mt7NCHHAUSEN AT IT AGAIN? (385.) R. E. Breunig, Chicago, Ill., asks several questions regarding a peculiar phe- Send for circular to day MULTI 213 Ave. nomenon that occurred in the neighborhood Ask your dealer to- morrow -AUDI .FONE ELIZABETH, N. I. (Continued on page 437.)

www.americanradiohistory.com 430 THE ELECTRICAL EXPERIMENTER December, 1915 BUY NOW -SAVE MONEY WIRELESS XMAS SALE

BARGAIN PRICES TO PROVE the wonderful values and superior goods we give you direct from our factory. These ridiculously low prices are only made possible by our enormous output for our tremendous trade. All highest quality- beautifully made and thoroughly tested out. Save 25 % If You Act Now ...... Here is Your Opportunity to Secure the Best Navy Type Loose Coupler on the Market. Regular Price $15.00 0.00 For December Only- Reduced Sale Price - - $1 A braes lacquered 0,000 meter inductance tuner, perfect in every detail. Equipped with four point loading inductance which increases the wave length 4,000 meter over the averses Navy Type Transformers. The primary winding has 24 taps -one switoh controls the primary in groupe of ten. the other controls one turn at a time-and ie equipped with s dead end switch. Enclosed in a cabinet, the frout of which is polished hard rubber. The secondary ooil is wound with double silk covered wire and the inductance is varied by a ten point switch. With this coupler the very finest and most accurate tuning ie easily and quickly seoured. With a good sized aerial the recep- tion of wave lengths up to 6,000 meters ie possible. All Finished Parts Ready For Assembling With Full Instructions . . . $6.50

Our No. 810 Complete Sending and Receiving Station Receive The Time From Arlington Sends up to 12 miles. Regular Price $20.00 AND ALL NEWSPAPER AND SHIP REPORTS Receives up to 1,000 OUR SPECIAL TIME $8.10 SIGNAL RECEIVING OUTFIT miles. For Decem- ber Only REGULAR PRICE $10.85 -SALE PRICE Price This is our new -Sale 1915 model made of the highest Full 1 k inch coil type. Sends up to 15 miles. Receives up to 1,000 grade material ni lea under favorable conditions. o h t a ins hl e. Equipped with 2 double pole 1,000 Double slide receivers. 6 feet silk cord and coupler for close doubleu headband. Size of bass 12 tuning Is wound 16 inches, height 13 inches. weight with No. 24 only 14 pounds. green silk cover- loped and thoroughly ed wire on the "e liable onion,.n meth electric- ally perfect an ready primary the secondary - with Nothings better i tá class was ever cones No. 28. There improved are 8 points to tuning e`nabbl you divide its capac- party you mighoutdesire, ity. A 3,000 -metre loading coil placed between the coupler thus y eliminating in- and the aerial a switch that throws it In or out of the terference. The set con- by alone sists off a lit n. Spak circuit enables you to receive amateurs with the coupler l. Plate Co - and long wave stations by the addition of the loading coil. One densere "Don't Jar Out" Detector. Buzzer fixed condenser of proper capacity, Improved universal detector, Switch to tell if your one buzzer test to test your mineral, and potentiometer. This etectordand s working. on a finished oak base. All Double Slide Silk Wire instrument Is assembled highly Wound Tuner for long metal parts are heavy nickel -plated. wave station This station, with our Navy Type Loose Coupler, as Illustrated Fixed Có ser, Helix above, $15.00 complete 2.00Ób Ohm Headset.

OUR No. 401 SENDING AND RECEIVING STATION Regular Price $5.95 $4 ;95 FREE! For December Only -Sale Price - - Complete Gem Sends up to 3 miles. Receives up to 300 miles. Station % Consists of -inch coil, fluted end Receives up to 300 mile.. spark gaps, four plate secondary, one We will give absolutely free Gem Outfit to every one collapsible helix, one key, a two -slide who sends us theo coat of the tuner, fixed condenser, detector and necessary equipment for it. This equipment nougats of buzzer test to test your mineral, This 2000 Ohm Headset $3.95 16 Insulators .48 on a set is mounted highly finished 1 Ground Clamp .10 oak base with all metal parts heavy 500 Ft. of A -1 Wire 1.20 20 Ft. of Rubber Cable for lead in .90 -plated. With a good -sized aerial, nickel TOTAL $8.63 under favorable conditions, will send up Send $0 63 et once and we will include the Gem Receiving Station to 3 miles and receive up to 300 miles. Free. A splendid outfit for beginners.

Send 6c. in Stamps for Our Big 152 page Wireless and Electrical Catalog 46H -80" Containing Hundreds of Wonderful Bargains of All Kinds , ,o,'.1. F. for Big Electrical Toy Catalog. Save Money Xmas. 9 yP¢/0 H\.80

Nichols Elect. Co., 1 -3 W. Broadway, N. Y. technical ptUt,0.4\\ °JLvice on alleewireess Manufacturers of Standard Quality Goods Only ter, tonNICHOLSs ELECTRIC CO., 4ß 1 -3 West Broadway, New York.

_., üiÌÍIÌÌÌI11111111111111111111111I1lIIII11111 011 4llIIII11111 111111plpppp1pllAInI11111IlAlIIOnIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIilllllllll You benefit by mentioning "The Electrical Ertmrimenterrr when writing to advertisers, www.americanradiohistory.com Decentlf r. It)i 3 THE ELECTRICAL EXPERIMENTER 137

QUESTION BOX. (Continued from Page 435.) of Chicago from the 14th to the 18th of September last, when the wireless detector The Famous would go "dead" and no amount of adjust- ing would bring in any signals. He writes, however, that by reversing the connections to his detector it would be put into opera- DE FOREST AUDION tion again. (2) When a rheostat or potentiometer is used to regulate the bright- The Bulletin of the U. S. Bureau of ness of a lamp does the same amount of Standaids, Vol. 6, No. 4, Page 540, current flow from the battery whether the lamp burns bright or dim? (3) How does states that the DE FOREST AUDION a Radioson work? DETECTOR is fully 50 per cent. A. 1. We cannot think of any reason for MORE SENSITIVE than ANY other the peculiar action of your detector, except known form of detector. that strong static currents may have been the cause; to the best of our knowledge NO HIGHER AUTHORITY Baron Mfinchhausen had nothing to do could be quoted. with it! Further than this --A SK ANY A. 2. As the resistance in the circuit de- termines the amount of current flowing USER. through the circuit, increasing the resistance The cut illustrates the popular and will decrease the current drawn from the efficient Type RJ5 De Forest Audion battery. Type R. JS De Forest Audion Detector Detector. It remains in adjustment A. 3. The Radioson detector is con- structed on the principle of the sealed -point ALWAYS, and is guaranteed to be MORE EFFICIENT, and MORE electrolytic device of this class. This de- RELIABLE than ANY OTHER detector ever offered for private tector at one time was thought to act on use. Price, $25. the drop of resistance principle, but later researches prove it to be a pure rectifier. THE DE FOREST AU- See "Principles of Wireless Telegraphy," by Prof. George W. Pierce, where this mat- DION AMPLIFIER is used in ter is exhaustively treated upon, accom- connection with any detector, panied by actual rectifying oscillograms. preferably a De Forest Audion OPEN CORE TRANSFORMER ON Detector, to increase the intensity D. C. of received signals from 5 to 10 (386.) B. Tilden, Brookfield, Ill., writes us asking: (1) How an open core trans- times (actual, not theoretical) per former can operate on D. C., having seen step. Constant and reliable, as all one working under these conditions. (2) Forest Audion Appa- Instructions for making a closed core trans- other De former from a 2 -inch coil. ratus. Brings in stations otherwise A. 1. The fact that the transformer inaudible, operated on a D. C. generator indicates that ALWAYS. Price, the commutator on the dynamo was in very it. $65, and worth Type Pi De Forest Audion Amplifier poor condition, creating distinct breaks or bumps in the current. This would cause WARNING the transformer to operate the same as a spark coil on an interrupted primary cur- Vacuum Bulbs, having a filament and two electrodes, as well as a number rent, but the efficiency is very low. of other types, are protected under a large number of BASIC PATENTS, A. 2. A closed core transformer can be issued to Dr. Lee de Forest, and owned or controlled by this company. made from a 2 -inch coil by constructing a rectangular frame of thin transformer iron All infringers will be prosecuted to the full extent of the law. and winding on one leg three layers of No. DE FOREST AUDION APPARATUS is sold by all the large reliable 16 D. C. C. copper wire and mounting the wireless supply houses and is carried in stock by most of them. secondary of the 2 -inch coil on the other leg. The input will be about 250 watts, and ORDER FROM YOUR REGULAR DEALER, or from us if you prefer. you should place a choke coil in series with Bulletins complete descriptions sent if you stamp the primary to control the current. giving enclose ARC TRANSMITTER FOR RADIO. De & (387.) Edward D. Fitzpatrick, Wilson Forest Radio Telephone Telegraph Co. Park, Tarrytown, N. Y., requires (1) a 101 Park Avenue, New York, N. Y.

/fey, Chope Coi/ Winger's Closed Core Transformers MN . ó ABC 14,000 VOLTS Perfectly Insulated.

1.4 K.W. Sin.75 _ /te/Zr t/a K.W. 15.90 = % K.W. zn.sn Q '387 l K.W. _5.5o Designed for direct connection. Are Used for Radlophony. no volts 6o cycles without resist ance or impedance. Send 6c. for s hook -up for transmitting set using an arc. big new catalog. (2) Why does the note of a sending sta- tion become louder when the rotary gap has WingerElec.& Mfg.Co. stopped and while the last few letters are 7i1 So. Dearborn St., being sent? CHICAGO, ILL.. A. 1. The sketch herewith shows the You benefit by mentioning "The Electrical Experimenter" when writing to advertisers.

www.americanradiohistory.com 438 THE ELECTRICAL EXPERIMENTER December, 1915 method of wiring an arc for radio trans- mitting purposes. With this apparatus you will be able to cover quite a long distance, but it will be necessary to use a tikker or audion "beat" circuit at the receiving sta- tion. A. 2. The only reason we can give to explain why the note from a transmitting station increases in intensity when the rotary gap stops is as follows: The dia- It Works Fine phragm in the receiver has a certain nat- FRANCO Your keceiving Transformer certainly works fine. ural period of vibration, and this may be It brings signals in louder than any other tuning approximately tuned to the low frequency device I have ever used. N. L. (Morin, Jr., of the note when the rotary gap is stopped. FLASHLIGHTS Cagenovia, N. Y." Price only $5.00. Semi two - cent stamp for bulletin 105. Your receiver diaphragm does not vibrate fast enough to be in synchronism with the Colby's Telegraph School, Auburn, M. Y. group frequency of the transmitting set are ideal for use by electrical experi- when the gap is running, therefore it does menters. The Fibre case lights have a patented A NEW CHAMBERS COUPLER not give the loud note noticed when the wireless feature which ab- two are nearly at the same pitch. solutely prevents their short-circuit- LOOK No. 744, PRICE ONLY $4.50 ing under any conditions whatsoever. The nickel plated lights won't short- Positively un- circuit, either, and are not affected e qua led for MAGNETIZING COILS. the money. Is (388.) Young Experimenter, Buffalo, N. by oil or moisture. 6" high, 6" "Franco" flashlights are quality Y., wishes to know : Where he can .vide, and 14" (1) flashlights; equipped with our Radio over all. obtain a battery type magnetizer of the Battery they give more light than Wound with Swedish- American type? (2) If distilled any flashlight on the market. They E namele d water can be used instead of rain water in wire, and has are definitely guaranteed to give you a very unique mixing solution for silver plating, and if real satisfaction and s e r v i e e. slider. Wood- rain water is a chemical or naturally pure Among the many different styles you work mahog- solution? are sure to see the one you want. any finished. Try one, you will not be disap- Prices are very reason- pointed. A. 1. You can no doubt purchase a bat- able. Sc. in stamps brings our 64 -page illustrated cata- tery type magnetizer of the Swedish -Amer- logue, B -B -24. None otherwise. ican type from the Swedish- American Tele- See your dealer's as- sortment, or if he 2046 Arch Street phone Co,, located in Chicago, Ill. F. B. Chambers &Coe hasn't got the gen- A. 2. Rain water is condensed moisture uine Franco" from the atmosphere and contain.; no alkali, flashlights, write but has several impurities in it, such as us for an inter. "Mignon - dust and traces of various acids found in esting catalog, the air. Distilled water can be used in No. 9. System" mixing plating solutions instead of rain R Is:,e. r Pauses AFpfied for water, as they are both practically pure, but INTERSTATE a R C 2 not chemically pure. ELECTRIC Cà r.jTi(ÿ $20.00 NOVELTY CO. A Marvel in 29 Park Place ^ Selectivity and PERPETUAL MOTION. :;%ú Efficiency. NEW YORK e"410 - (389.) George Haller, St. Louis, Mo., The Last Word asks (1) any perpetual motion in RADIO - us: Has CHICAGO A PPA RATU 5, machine ever been invented that will de- a. SAN FRANCISCO Writ, J.,r Stir l'_'. x 9'. x h In,ar. liver power? (2) How do aeroplanes ob- TORONTO tain a "ground" for wireless work? MIGNON- WIRELESS CORPORATION A. 1. No one has succeeded in inventing IIIIIIIIIIIIIIIIIIIIIIII111111111111111111111111111111I11111111II11111111II11111111111111I1111111111SIMI119 k Specialists in Radio Signal Receiving Apparates a motion machine as 127 W. St.. IRA. N.Y. practical perpetual Market ELM yet, and such an invention would entirely upset all our present basic laws of physics and energy. LEARNING TELEGRAPHY rt. 2. Aeroplanes obtain a ground by "MONOTONE" QUENCHED dropping a wire 100 or 200 feet long from SPARK GAP a reel, and they use wires strung from the It is new I Wonder- tail to the wing -tips for an aerial. fully efficient. Hear - what the operator at the distant receiver WAVE LENGTH OF COUPLER. will say about your t new "spark." In $f( (390.) Nels Erlandson, Chicago, Ill., de- single units for small q ¡i I111t spark coils. Several sires: (1) A formula to calculate the wave units in series and length loose coupler. multiple for transfer- of (2) A tuning coil. Substantially (3) Whether a carborundum detector re- built of brass, electric mica and black fibre. quires a battery potentiometer. Parts nickeled. In- A. 1 and 2. A rough method of deter- troductory price only SI per unit as illustrated. Money back if this new gap mining the wave length of coupler or tun- fails to please. Send SI bill or P. O. money order today to ing coil is to calculate the length of the K. RICHARDSON, BOX 686, ERIE, P ENNA wire on the coil, primary only, in the case of the coupler, and multiply the length of this wire in feet by 1.5, which will give approximately the wave length in meters. becomes simple when your instructor is the Omnig spit Automatic Transmitter. Combined with a standard key and For further data on this we refer you to sounder or Wireless Buzzer, it ll send you telegraph mes- the September, 1914, issue of fhe Electrical sages speed, match Elrrtrirsl 6ifts the sending of an epert operator a,you become more Experimenter, in which appeared an article ficient. t Adopted by U. S. Govt. Made in 4 styles, from fur XmFts entitled "Loose Couplers and Their Wave $2.50 up, all accurate. Circular free. Lengths" ; also to the numerous publica- Omnigraph Mfg. Co., 39 L Cortlandt St., New York Lionel Electric Trains tions procurable at small cost from the Bu- Electrical Toys reau of Standards, Washington, D. C., Special Dynamos Mesco Electric Engines which give exact mathematical formulas for for Arc Lamp in calculating self and mutual inductances of Moving Picture 1 Electric Tree Lighting Outfits coils of various sizes and diameters of wire Shows. Special Dy- We carry a full line of Wireless Supplies used in practise. namos for Charging being agents of The Electro Importing Co. and radio Storage Batteries. J. H. Bunnell & Co. A. 3. For the best results with carbo- Special Dynamos for rundum detectors a critical adjustment of Incandescent Light. ing. We sell upon QUAKER LIGHT SUPPLY CO. the voltage applied to it is required and it payments of $5 and 728 Arch Street Philadelphia, Pa. will be necessary to use a potentiometer $10 per month. ^ ith battery for this purpose. Hobart Bros. Co.,Trey, O. You benefit by mentioning "The Electrical Experimenter" when writing to advertisers. www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 4, ;i,

MAGNETIC PULL. 1391.) Verne Bonnett, Birmingham, Iowa, desires a formula for calculating the pull of a magnet.at various distances from /Here's its poles. the Most Sensitive\' iv A. The pull of a magnet varie; inversely as the distance of the armature from the poles; thus, tl a certain magnet will lift 20 Head -set 1 forWirelessWork pounds inch from the pole -pieces, then 2 inches from the pole -pieces it wi'l lift one - quarter of this amount, or 5 pounds, and if 3 inches, one -ninth of this amount c r about 22 pounds. This law is known as the rule of inverse squares and is also applicable to lighting problems as well. On 10 Day ELECTRIC WIRING QUESTIONS. (392.) John Odill, Norway, Mich., asks several questions regarding the wiring of a house: (1) Is a person allowed to do ad- Free Trial ditional wiring on his premises without per- mission from the authorities? (3) Where can he obt_ìn this permission, if necessary? (3) Must the work be inspected before con- necting to the service line? A. 1 and 2. It is unnecessary to obtain permission to install additional wiring in Stromberg- Carlson Radio Head -Set the house and barn, but proper precautions THIS set is guaranteed to increase the receiving efficiency of must be taken in this work, so it will com- any radio station with which it is used, regardless of the type ply with the Fire Underwriters' rules. of A. 3. It is necessary that the wiring head -set used heretofore. should be inspected by the Fire Under- This claim is based on comparative operating tests conducted writers' before connecting to the supply at many stations. If you are skeptical, convince yourself by mains, or the fire insurance policy on the ordering a set for 10 days' free trial against all other makes. The building will be void should it burn down price is $8.25, and your money will be given back at once without from any cause. the slightest obligation if you are not satisfied. MOTOR TROUBLES. Dealers sell this Iliad -set. If you cannot get it from your dealer, write us. Write today for (393.) R. O. Shadd, Williamstown, Pa., free bulletin No. 1006. writes regarding his 1 -6 H. P. motor which sparks on the positive brush when the cur- rent is turned on, but ceases to spark when Stromberg- Carlson Telephone Mfg. Co. the motor reaches its maximum speed. Rochester, N. Y. Chicago, Ill. A. The above mentioned action may possibly be explained by the fact that the positive brush is not at the right angle of commutation and the armature, drawing more current when accelerating, will make the sparking more noticeable than when A BOUND VOLUME EOENAIME EXPERIMENTEÁ FOR running under normal speed conditions, 75C with the armature current somewhat Bound in substantial green cloth; lettered In gold. Postage on 3 lbs. is extra. A REAL BARGAIN. lower. Another cause for this may be that Book Department. EXPERIMENTER PUBLISHING COMPANY, Inc., 233 Fulton Street, New York. one of the wires in the armature is ground- ed, causing an excess flow of current. When the motor reaches full speed centrif- ugal force might throw the wire away from M r. the armature, thereby destroying the ground. King rose from are RADIO CONNECTIONS. Newsboy to (394.) Henry E. Davies, Jr., Vineyard Meter needed Haven, Mass., writes us asking for a hook- Engineer up for the Mignon cabinet style radio re- NOW AS METER ENGINEER Get the big job. Earn the big salary. Get Into the new profession where high salaried positions are seeking the men. Train yourself to fill one of these big jobs. There is one or more in every Electric Light Plant. The demand is growing daily for Meter Engineers. We have trained hundreds of others and placed tbem in big jobs. We can do tbe same for you. fern $1,200 to S3,CCO a Year Just a few short months at borne during spare time. You learn while you earn. Course Is interesting, concise, thorough. You learn all about meters and instruments. No problem will stump you. Step into an Electric Light Plant as Meter Engineer at a - salary of $1,200 to a year. r- course prepares $3,000 Our Our Money-Back Guarantee you for every emerg- we guarantee to furnish you with our complete ency, course of instruction to Eleetneel Meter Engm- 'ng nd train you Without Marge, other than as apeed in ourEnronment un- Mr. King's Rise to Meter Engineer 1 `°'ilon g 1 tll >ou r OVahaed to aetepl a position pa,ine from $75 to $300 a month. Furthermore. we His e% p erience is no different from bun- I guarantee to aasiar POU in securing a high grade dreds of our students. He wanted after rou reeeine a Diploma. If ahter the big l eeeiá,n g an piss and-Instructions to which job and trained for it. He has a fine entitled. all sition -at a big salary. His training makes 1:geeme y arednó Perfecb;; e him Indispensable to his employer. His w remna lac fwl amount of >our tuition. job is sure tbe year round. FR EE -Full Information -Use Coupon. / Ft. Wayne Correspondence School Get the School Literature story / Ft. Wayne, Ind. Dept. 352 Hook -Up for Mignon Radio Cabinet Receptor. of Mr. Ring's rise, terms, testimony from and graduates, outline of course, J Gentlemen: -Send me absolutelyly free ceiving coupler, together with variable con- duties of Meter Engineer-all absolutely and prepaid your new literature on Meter denser. tree. Write to -day, NOW." Use coupon. Engineering. A. We show in the diagram connec- Name tions for the Mignon cabinet style radio Fort Wayne Correspondence School receiving coupler, together with variable con- Dept. 352 Fort Wayne, Indiana/ Address denser, fixed condenser, detector and 'phones. i You benefit by mentioning "The Electrical Experimenter" when writing to advertisers.

www.americanradiohistory.com 440 THE ELECTRICAL EXPERIMENTER December, 1915 THE RADIO PIONEERS. boys- aCsluW- In a recent communication to the New ASK DAD York Times Dr. Alfred N. Goldsmith, di- FOR THIS cricLi TRAIN rector of the radio laboratory at the Col- lege of the City of .New York, said: "I have read the highly interesting re- Your Ho ports which have appeared in the Times Uni- Lectric lighting plant gen- the radio (wireless) telephonic erates standard 11.1 -volt direct describing current; operates from one to 50 experiments carried on over great distances lights, electric motor, electric iron, by the American Telephone & Telegraph vacuum cleaner, electric toaster, one force pump, churn, washing machine, Write Quickly for Our New Catalog Co., using for the transmitting station etc. telling how you'll have barrels of fun with belonging to the United States navy (Ar- a Lionel electric locomotive, Pullmans, lington, Va.). Without desiring to dis- No Batteries -No Switch -Board freight cars, switches, semaphores, electric parage in the least the undoubtedly earnest and a better machine for less money. nigh lights, track, etc. Make the trains scoot. imeed gasoline motor, generator auto- Run 'em on batteries or a Lionel Multivolt and intelligent engineering work which has matic governor, all complete in one small, com- transformer which saves batteries. (See resulted ill the accomplishment of this par- pact unit. Uses standard lamps and fixtures. cut below.) Simple. easily installed, dependahle, economi- 250,000 hoys own them -Join us. Lionel ticular achievement, I feel strongly that cal. Costs less than other syyst:.me to buy and Electric Trains are safe-no shocks. less than due credit has been given to the to operate They're steel -not Cast Iron -and won't many and eminent radio engineers who Waterman Motor Company have done previous research work in this 112 ELLIOTT AVENUE field, and without whose work the results MT. LIOflfL iiign/C just obtained would have been completely DETROIT, MICH. V t_i unattainable. Write to -day for If Your House full description ;Uni - Lectrice break. Not high priced. "I have been creditably informed that 601.eo ttacvac Has Electricity and low price. Unconditionally guaranteed. BuyThisTrens- what are known as oscillating gas valves LIGHTING SYSTEM Finished handsomely In former colon and gold. have been used for generating and con- BOYS' BIG trolling the power used in this work. While CATALOG I cannot hope to gauge the relative impor- FREE tance of the contributions of all the pre- Written s p e- vious inventors, I certainly believe that the eially for much TOO, crammed following gentlemen are entitled to full of pic- more than a curt dismissal of their claims, tures. have contributed Section of Li- and ignoring of all they onel Rail Free. to our knowledge of the oscillating gas Most toy dealers, electrical stores and de- valves. I to Edwin Armstrong, of partment stores sell Lionel Toys. Go to your refer Toy Dealer, find out if he sells Lionel Columbia University; Dr. Lee De Forest Trains, tell me when you write for catalog (under some of whose patents the Ameri- PORCELAIN -then l'll Include a special section of rail- free. can Telephone & Telegraph Co. is already "THAT'S OUR BUSINESS" J. Lionel Cowen, A Friend of Boys, President ; Fleming, of London licensed) Professor Standard and Special Shapes, Regardless 48 L East 71 Street University (one of the early workers in THE LIONEL MFG. CO NewYork City el How Difficult r this field) ; Peter Cooper Hewitt, Dr. Irving Langmuir, of the General Electric We illustrate one hard shape we make. Co.; Dr. Meissner, of the Telefunken Co.; A pair of roils 734" long and 134" in Harvard Uni- diameter with 8 holes on ends and middle. BOY Professor George Pierce. of They must be perfectly straight and we ELECTRICS versity; H. J. Round, of the English Mar- make them so. It's hard but not for us. We can make your difficult; designs also. coni Co.; Dr. Reisz and his associate, von Send us blue print for quotations. Knapp Marvelectric Lieben, the Co., and Mr. THE GREATEST of Telefunken Weagant, of the American Marconi Co. Union Electrical Porcelain Works Three of these gentlemen, Messrs. De For- est, Armstrong and Langmuir, have in the TRENTON, N. J. order named made the results of their re- searches public in the 'Proceedings of the Institute of Radio Engineers,' and the in- Auto Throttle Governed teresting and important information which Engine for Every Work they gave has thus become available. H.P. Thera is no other four - Cycle engine with auto- "It is impossible for me to apportion maticauto type of throttle achievement suitably governor on the market credit for the present near the price. Unlike among all the gentlemen mentioned, but it ordinary low priced e EXPERIMENTS NUMBERLESS ei nes it is not bit- oncein. is quite certain that their united contribu- a- governed with ir- More fun. more information than a hundred hooks. regular Finished as shown. Demonstrates Magnetism, Sole- tions to radio telephony have made the speed and wanted noids, Resistance, gasoline. Motors, Dynamos. Arlington- Hawaii transmission possible. It It fires every shot with Price speed regulated by exclusive auto -throttle $3.75 is their due to receive credit for what they govenor which ea s even Live dealers everywhere. Order direct, or ask your economical power. dealer have done. It is not just that the commer- It will operate electric light plant. pump water. u to show you the Knapp Line and insist o n separator, churn or.,the free,err, chop feed. operate machim getting Knapp Goods. organizations involved should receive e yy, In fact. it is ensue for every work." Dealers not already handling the cial H pper ceded complete for Knapp Line should ask prices. full public credit and the originating engi- fnlyy$36. Direct to you Catalogue illustrating many specialties on request. rnm the factory. write neers be hidden by enforced anonymity. It for catalog. KNAPP ELECTRIC & NOVELTY CO. is certainly to be loped and expected that C. Benninghofen a Sons 523 West 51st St. N. Y. CITY they will receive at least the mention which Dept. 110, Hamilton, 0. they have earned." This Complete, Efficient Wireless Receiving Set TOY RECEIVES 1500 MILES TRANSFORMERS This stati on io equipped with a two -elide loose With 80 ohm double pole receiver, coupler. The primary is ound with No. 20 head hand and cord. care wire,a secondary woend with No. 30 silk 9 Different Voltages covered wire and is divided off in e. to taps which are brought out on the end piece. contact being $4.45 50 Watt . . . $3.00 made by phosphor hrons rotary switch with loo . . . . hard rubber knurled knob. Our new, specially Watt $4.50 much will not jar out and allows a 200 Watt r. . . $6.00 much finer adjustmentst nt than condenser of exaot;.ce- Wireless, Bell and PeeitY, specially constructed far this loose affords extra efficiency. An extra other transformers pair of binding ports Is provided to which a variable condenser may he connected. All parts en of solid oak and mounted on Send for Folders e solid oakbase. The set ishe.utifullyfinish- ed throughout and is fully guaranteed in every particular. DISCOUNT TO DEALERS Send stagy Dip Wireless Catall000g "E" and free a hart made of unbreakable fibre. A. R. DARLING 19 E. .2 Street All "Universal" sets are sold with 10- 1532 N. Capitol Ave. Universal day trial privilege and money - back Wireless Co. N. Y. CITY guarantee. Prompt shipment guaranteed. Indianapolis, Ind. You benefit by mentioning "Tice Electrical Experimenter" when writing to advertisers. www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 447 SUBSCRIBE TO

C IINEIYTIO11 THE NATIONAL HELPMATE OF INVENTORS Edited by H. GERNSBACK REPORTS:- Patent OIBer news and decisions, and r..,,lit pit b,u(s. l'a tent successes, market op In this Department we will publish such matter as is of interest to inventors port uni li ev nod methods. PUBLISHES:- Valunble articles on successful and particularly to those who are in doubt as to certain Patent Phases. Questions inventors pied their methods: the Mistakes of In- addressed to "Patent Advice" cannot be answered by mail. Sketches and descrip- ventors. helpful mechanics and manufacturing. tions must be clear and explicit. Only one side of sheet should be written on.

FOOLPROOF ELECTRIC SWITCH. upon it, but we would advise our corre- (33.)Wilmer J. Slifer, Quakertown, Pa., spondent to be cautious and he should try MAINTAINS I Itnr au of Fed,. al Protection. which s.eun5 s rung, T did PO tents, and sound submits a sketch of a novel electric switch to have a search made in the Patent Of- trade -marks and copyrights In the United Slates which he terms "foolproof" for the reason fice before going ahead with the patent. and in all eon nt i,s at n reduced cost to aiili that it is necessary to use a key in connec- This is the best we can suggest in the conte. tion BEFORE SPENDING MONEY ON PATENTS with it. He wants to know if this absence of the actual model. CONSULT INVENTION and the ]Sureau of Fed switch can be patented, and if such an eral Prutvetion. article is in demand. SELENIUM WIRELESS RELAY PATENTS secured through this Bureau adver A. After looking over the drawing and ELECTRIC REGISTERING - tised free in INVENTION. the description, we have come to the con- Send sketch, drawing. and description. or mod. THERMOMETER. el. for report and w t oit bh advice, Certificate of clusion a could conception pn tests nove, tors. scut nu request. that patent not be obtained (37.) Isaiah Rosin, Cincinnati, Ohio, on device, at least, have SPECIAL OFFER! INTENTION sent for one this we our doubts submits to us a drawing a selenium about it. In a actually of half year for 25c. Adda sit case patent was wireless relay which is supposed to work obtained, we do not think it would be of by very much value as switches means of a selenium cell and a telephone of this kind receiver and by its vibrating diaphragm are not very well liked by the trade. and amplifying relaying arrangement. He MUM wishes to know if a patent can be obtained 215 McGILL BLDG. - WASHINGTON. D. C. ELECTRIC RAIN AND t WIND upon this device. He also has bruitted an SIGNAL. idea on a registering thermometer which (34.) Martin Hoeft, Minonk, Ill., claims is intended to be used in registering tem- PATENTS THAT PAY" to have a new device for electric rain ;mid peratures at a distance. He wishes to D E K wind signals, but fails to submit dia.v- know if this device is novel and whether it OVER $600,0R B Y CLIENTS ings to explain the idea. In the .absence_ can be patented. 00 of these we cannot give any advice on the A. We find that the first idea is en- PATENTABILITY TWO WONDERFUL merit invention. _ of the tirely impractical and it will not work the REPORT BOOKS FREE: way it has been submitted to us. A relay INSULATOR AND AERIAL. CON- Send sketch or model of Entitled "Inventor. does not work on alternating current and your Invention for free Guide" (I S6 panel and NECTOR. the idea of lighting a lamp as outlined in arch of the "What and How to In. (35.) Bernard Russell, Colorado Springs, the drawing to operate a second selenium Office R and re. vent -Proof of Fortune Colo., has sent in a drawing of a new in- cell is not practical and will not work. Dort es to patentability. in Patents" (127 eases/ sulator on which he desires to have some As to the electric registering thermom- advice. He also submits an aerial con- eter, this is quite a clever idea and deserves Highest Referesleet, toe uding 100 menu( nector and wants to know if the latter is being looked into. We think that if this PROMPTNESS ASSURED patentable. He inquires device to be further if there is were worked out carefully Across the Street from the U. S. Patent Office a market for these two articles. He fur- from its present crude state a valuable thermore wishes to know if an article can patent might be obtained upon it. We E. E. VROOMAN & CO., WnshiStreet. D C. be patented by using Electrose instead of would advise our correspondent to get in porcelain for insulation without the con- touch with a patent attorney. sent of the company. REGISTERED PATENT ATTORNEYS A. The insulator presents no novel ROTARY SPARK GAP. PATENTS A ARKS ideas and we do not think it is practical; (38.) William Boyle, Brooklyn, N. Y., we doubt whether a patent could be ob- submits a drawing of a new rotary spark tained on it. gap in which two separate motors are The connector, -however, has some very used and the spark points being arranged LgNCAS1Eßfâ, ALINE novel features, and this is an article that in a novel manner. probably will be 252 Ouray Bldg. °C- Washington, D. C. welcomed by many wire- A. While the idea of using two motors Free less Book " Inventions-Patenting and Promoting " people. You should by all means try on a rotary spark gap is not novel, the ar- Improvements wanted -Send for free bulletins & advice to obtain a patent on this connector, and rangement of the spark points seems to we think this can be done without much have some merit. at least we have never trouble. seen anything quite like it. Concerning the last inquiry, you cannot We think the best way is to get in touch PATENTS obtain a patent by simply changing one with some of the patent attorneys and THAT PROTECT AND PAY material to another. In other words, if you have a search made in the Patent Office constructed (let us assume) a screw- Books and Advice Free to find out what has been done before in Send sk.teh or model for search. Highest References. driver made of aluminum, you could not this line. If you find that nothing similar Best Results. Promptness Assured. obtain a patent on this screw -driver simply exists so far, you stand a good chance of WATSON E. COLEMAN, Patent Lawyer because it was made of aluminum. The obtaining a patent. 624 F. Street, N. W. Washington, D. C. mere substitution of materials does not entitle anyone to a patent. TEMPORARY WIRING INSULA- PATENTS WANTED Write for List of Patent Buyers who TOR. desire to purchase patents and What To Invent with valuable list of Inventions Wanted. $1,000,000 in prizes offered for inven- (36.) Walter Franseen, Woodhull, Ill., tions. Send model or sketch for Free Opinion as to patentability. We have a has submitted to us a new idea showing Special Department devoted to Electrical Inventions and are in a position to assist how to run temporary wiring on walls and advise inventors in this field in the development of their inventions. which have been papered, by using a special appliance. He wishes to know if MODERATE FEES -WE ASSIST INVENTORS TO SELL THEIR PATENTS the idea is good enough to warrant ob- Write To -Day for our Five Books sent free to any address. (See attached coupon:) taining a patent on it, and whether the idea has any merit. ------FREE COUPON!... - - -- A.. Inasmuch as no sample had been I VICTOR J. EVANS & CO., Patent Attorneys I submitted to this department, we are not I NEW YORK OFFICES: 189-191 Broadway PHILADELPHIA OFFICES: 1429 Chestnut St. quite sure that the device will do every- I Main Offices: 779 9th Street, N. W., WASHINGTON, D.C. I thing which our correspondent claims for GENTLE'SEN: Please send me FREE OF CHARGE your FIVE Books as per offer. it. As far as we can see, the idea is novel 1 and ADDRESS we think a patent might be obtained LNAS!E -= You benefit by mentioning "The Electrical Experimenter" when writing to advertiçer.r. www.americanradiohistory.com 442 THE ELECTRICAL EXPERIMENTER December, 1915

ELECTRICAL WAY TO FATTEN jl! SHEEP. Electric lighting of pens at night causes WIN HEALTH sheep to eat frequently and accordingly NEWEST FORM OF ELECTRICITY grow fat for the markets in record time. FOR YOUR OWN PERSONAL USE The tour made through the ranch section The VIOLETTA HIGH - of Oregon by Samuel Galland, a Spokane FREQUENCY GENERATOR is used and endorsed by thou - financier, resulted in the discovery that the ands of physician.. It gene- Oregon rates the Violet -Ray High- sheep growers are using electricity Frequency Current which is extensively for both light and power. used with wonderfully quick reeulte for facial, ecalp, and Besides being applied for pumping in irri- body treatments. gation districts and for doing nearly all Compact. operates al ei orr ir t' adand the ranch work, electricity has been wired absolutely d«and maarvel construction. MILLERS FALLS into the sheep pens. The light is turned Write now for our limited special TO LS on at 4 o'clock in the afternoon in winter 10 day FREE TRIAL offer. and burns until 9 o'clock. The ranchers AGENTS RESPOND find that sheep will eat during off periods Bleadon -Dunn Co 208 N. 5th Ave., Chicago, Ill. when the light is turned on. At 4 o'clock For the Home, Shop in the morning lights are switched on BUILD again and the sheep again begin to feed. YOUR OWN or Laboratory Frequent feedings encourage the animals Grandfather's THE experimenter is usually a to eat so much that they are quickly fat- particular man who is particular tened for the market. Clock about his tools. WITH OUR HELP calls BARON We furnish blue prints, Experimental work for accurate MÜNCHHAUSEN'S NEW finishing material and in- tools and not the least of these SCIENTIFIC ADVENTURES. structions. Buy the works, should be a good reliable bit brace. (Continued from page 388.) dial, weights and pendu- lum from us at surpris- The next time you visit a hardware r ingly low prices. You store for any purpose remem- have been in Flitternix's mind too, for make a fine profit build- just ing artistic clocks f o r ber to ask to see presently he set his chronometer to noon, your friends. which, of course, was a ridiculous thing Complete works, 16.00. MILLERS Others with chimes at all FALLS to do, for we did not know if the Mar- prices. Bit Brace No.732 tians divided their day into 24 hours or Ask for attractive free Ball bearing head. P r o t e c t e d into 100 hours. offer. Ratchet. Free acting sweep handle, jaws "We were now floating some 1,500 feet Clock Company chuck permit accurate centering up over what we knew to be 1661 Ruffner M. and hold bit with a bull dog grip. afterward PHILADELPHIA, PA. Nickeled steel parts and fine pol- the Martian National Capital, the 'city' of ished wood handles. Send for handy pocket the Ruler. It is located in the elliptical catalogue of complete line. spot which terrestrial astronomers have MILLERS FALLS CO. marked as 'Solis Locus' on their Martian Armature Discs "Toolmaker to Master Mechanics" maps.* AT FACTORY PRICES Millers-Fa Ile, Mass. if Any size from 234 inches "As our host had divined our inner- to 14 inches in diam'eter. most wishes, we soon passed over the Best grade material with capital and approached the waterway japanned insulation on one side. Send stamp which you will find in your Martian map for circular, i under the name of 'Nectar.' FRED. R. HEILMAN "The Martian Canals! At last we be- 444 Niagara St. Buffalo, N. Y. BUILD AN held one of them at a distance of less than 2.000 feet! The riddle of terrestrial as- AEROPLANE tronomers for over a century! The cause oExperimental and Model Work of one of the most heated controversies ELECTRICAL INSTRUMENTS AND "Ideal" Nieuport on Earth! And now we saw them close FINE MACHINERY We'll Sb ow You How Monoplane. Complete by with our own eyes! outfit, all parts, ready Inventions developed. Special Toole, Dice, to assemble. $5. "The 'Canal' proper, which is termed Gear Cutting, Etc. Thousands of American Boye, and grownups, too. are building and racing aeroplanes. It's the 'Nectar' by astronomers on Earth, is about HENRY ZUHR great new American Sport. 6 miles wide. It runs in a perfectly 3244 Frankfort Street New York City By means of our simple, easily understood plans straight line for over 500 miles and is and instructions we'll show you how to build an about 20 feet deep. Like all other Mar- EXACT 3 ft. WAR MODEL tian waterways, it is lined with the Uni- EXPERIMENTERS -INVENTORS Let u develop your inventions and make Guaranteed to Fly versal Martian material termed TOS, your working modele. Not a toy, but a wonderfully interesting real which looks like glass, yet is not glass. Our well equipped shop and staff of expe- miniature flying machine with which you can rienced model builds are st your servio .. have The Tos in this instance is waterproof, is We carry complete stock of mere. intensely fascinating and instructive sport. Shipment made came day order reoeived. We make war models of all the well -known an electrical conductor on one side and an Send 40 In stamps for booklet Inventor.' types of aeroplanes. An especially popular knock- insulator on the other. Yet it is a solid Supplies down model is the body and much harder and tougher than UNION MODEL WORKS, Established 1882 "IDEAL" 3ft. TAUBE MONOPLANE steel. The conducting side is turned 119 S. Clark St., Chicago Duplicating exactly toward the water, and when a certain cur- the famous German rent of ION is sent through the Tos, the BRASS GEARS cut by an aeroplanes used in the entirely new p Tb. EUROPEAN W A R. water near it loses all weight because the most accurate made and at priose Complete with plans. gravitational attraction of Mars is neu- that cannot be equalled by others. simple directions Every gear has a hub, outer and all parts, in- tralized thereby. It becomes now an easy cluding rubber -tired disc wheels, ball -bearing matter to move the tremendous masses of true, highest gradegrade red hrtes, rand propeller shaft, hand nob heavier than others. We carved wooden propellor, water, a problem which your earthly carry the largest stook in the etc. Guaranteed to rise from the ground world, and every gear listed is by its OWn power and fly. De- scientists could never solve. always shipped on date of order. livered, ready to assemble, all \' SEND FOR CATALOGUE charges paid I "At each bank of the vast waterway 2,000 feet CHICAGO STOCK GEAR WORKS Scale Drawings with building and flying in- we saw immense towers about 20a So. Filth Ave. :: Chicago structious sold separately at following prices: high. These towers are spaced about 5 Curtiss Flying Bast...25c Bleriot Monoplane ...15e miles apart and follow the entire course Corti., Military Tractor 2Sc Taabe Monoplane - 25c Hydroseroplane.35e Wright Biplane 25e of every canal. Their purpose is as fol- Experimental Work at Reasonable Prices Nieuport Monoplane.. 25e Cecil Pooh Racer 25a lows: TOOLS AND DIES BUILD A FLEET. Race one type against the other. immense Get a complete set of above 8 plans for $1.60. "At the top of each tower is an Light Machinery Designed and Built. Auto- There's a dealer near you who sells parts and 'pyramid,' made of a certain variety of matic Machine. Cams Cut Exactly to Templet plans for Ideal" Aeroplanes. If you can't Tos. The sides of these pyramids are And him, write us, GEO. SCHWARZ & CO. formed of thousands of small black cells, Write to -day for our 50 -page Aeroplane Book 123 Liberty Street NEW YORK containing full information, prices for parts, which, when exposed to the Sun's rays, Send sketch or blue print for estimate complete models, etc., postpaid 5c. IDEAL AEROPLANE & SUPPLY CO. See accompanying map of Mars. Solis Lacus is located about 30° latitude and 90° longitude. the Classified Advertisements In thl 76 -82 West Broadway New York City at Issue. They are small but contain Nectar runs from the eastern (left) edge of Solis big and opportunities. Lacus, due east. READ bargains

You benefit by mentioning "The Electrical Experimenter" when writing to advertisers. www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 443

absorb the heat of the latter. As the surface of these pyra- mids is very large, a propor- WANTED tionally large amount of heat is received. This heat is di- rectly transformed into ION Railway Mail Clerks and stored within the pyra- mid. The latter turns on its $900 to $1800 a Year axis, so, as to present the larg- ($75 to $150 a month) Pleasant Work- COntlnually Traveling est possible surface to the Rapid advancement to higher Government Petitions. "No lay- Franklin Institute (The Pathway to Plenty), Dept.DII1, Roches'er N.Y. Sun from sunrise until sunset ; offs" because of STIl I K ES. WARS, FINANCIAL FLURRIES or TThls coupon filled out a. directed, entities the sender to frees ilTfi;n aue,nio al' a the WIII MS OF SOME PETTY BOSS. TIIE POSITION 15 free rare 1 our kink, l; nt l' it on d Hpw to t Thom. ' het of also as more power is gen- Government k. d to conddorauo0 for Free Coaching fee Yontsidry residents ts city residents stand the same chance for h bnnpon her checked COUPON erated than needed during the immediate appointment. Common -sonso education sufficient. Bookke Mail Cbrk.$900 to $1800 ...Customs p .. a.S800 to $1500 NOT -Bookkeeper 800 to 1800 ...Stenographer .. , BOO to 1500 daytime the excess is used Political influenee REQUIRED. ...POStoface Clerk 800 to 1200 ...InternalR 700 to 1800 Write Immediately for schedule showing Cho places and dates of hce Canter, 500 t0 1200 ...Clerk In the Departments during the night. TIIE COMINO GOVT examinations. Don' t delay. Every day ...Rural MauffeCarrier . 500 to 1200 Wa.hln ton. y00 to 3500 you lose means the of t so much coaching before the ...Auto Chauffa0r ...Canadiant Gov't Poa dons "Now, then, from the top of ansi exam oo j us Name the pyramid a gigantic Ema- FRANKLIN INSTITUTE, Dept. D 113, Rochester, N.Y. Address 0113 nation Ray bursts forth, fed Use this before bee tow it. Wrier plainly, from the stored ION, origi- nally secured from the Sun's heat. 'This ray is made to fall over the entire width of the waterway, and it is directed on the latter at an ang'e. The ray striking the water, which does not resist, as it has no weight, as explained to you, must naturally move away from the direction of the ray. The applications of electricity are increasing This it does, the Emanation every day. The man who has an exact knowledge of electrical Ray 'pushing' the water at a science has ever growing opportunity for profit. Ten years ago rate of about 23/4 miles an practically all machines in use were run by steam engine and countershaft. Statistics now show that most of the machines used are now operated by the hour. If it was not for the electric drive. A generation ago gas was the only known means for lighting ray the water would, of and cooking. Now almost every modern house is lighted by electricity, and course, be entirely motionless, electric cooking utensils are coming more and more in use. Even the steam locomotive, that great achievement of the twentieth century, is being gradu- for the Martian waterways ally replaced by electric power. Whether it be for driving machines, for are exactly level, there being railway transportation, for lighting for heating. for cooking, for a thousand no 'fall''to them. daily necessities, the watchword of the age is " Do It Electrically." "As each tower assists in moving the water over a cer- tain distance the water gradu- Hawkins Electrical Guides ally acquires momentum and flows slowly but steadily. Be- fore the momentum has been Will Show You How expended, the next tower is Electrical knowledge means money to you and these books will show reached, which pushes the you how to get it. Hawkins Electrical Guides are the standard works on Electricity. They water on to the next one, and cover every single phase of the subject and they are written in a way you can understand. so on The text matter is arranged in questions and answers, and contains several thousand illustrations. No more through the entire for a solution of your electrical problem. You find the answer at once, clearly and concisely. length of the Canal. You will groping naturally understand that these towers must work nights as A Most Complete Library of Electricity well as during the day, else 1 the water would not flow dur- at the Lowest Cost ing the night. The stored Look at the titles and convince yourself that Hawkins Electrical Guides tell surplus power during the day, you everything you want to know in Electricity. 4MN - illiNEl of course, makes this possible. They are a complete course in Electrical engin- VIAL lltwae Ill Ana ' 6 Furthermore, the towers work eering. written especially for the ambitious man 1uDew. 6 Lunn Liu LtDaDt 'Dilatt' who is training himself for advancement,for the CUIDE GIIDE `GUIDE -iG`IJ. QUE !GUIDE to full and wide awake man who ie likely to he called in for their efficiency un- work outside of his regular line, for the man who interruptedly year in and year needs at his elbow, for ready reference, an accu- 1,4P6 rate up-to -date work on electricity. An examin- 1 out, for there are no clouds to ation of these books will convince ou of their 11.. Itratty7 volume. They hide the Sun on Mars, as it is value instantly. They cost It per vuva .. they are ,.,!' me ,war well known; consequently, the are a wonderful buy at this price, and ,nit w.IVg w the beet electrical hooka at any price. Don't take our word for their merits. Fill out the coupon pyramids are never without today and the books will he sent you ahsolutely power, except nights. FREE for your own examination. You have seven days full use hefore you pay a cent. i, "You realize that all the towers must throw their rays The binding is ine flexible black leather NM In Handy Separate Volumes with gold edgesand urable and attractive. in the same direction, which, The books are easy to handle and easy to read. They fit your pocket and youryou pocket -book as well. of course, they do; thus, if the FREE water is to, be moved in one COUPON season from North to South, to You 0 the rays face the South. Dur- Shipped FREE Theo.Audel & Co. ing the next season Send no money. Examine the books first. Decide for yourself that ® when the they are the most complete library of electricity ever Published, and that you cannot 72 Fifth Avenue flow of the water must needs afford to be them. Every book is complete in itself. She price is only Rl per copy, NEW YORK but ppwithout bargain. Settlement can he made at only Sl per month. Please he reversed, as explained to NUMBERS ARE READY.t gain. ® submit me for exam- you yesterday, the Emanation ination Hawkins Electrical one. $1 eafrs. Ship Rays will all point northward. Easy Payments at once, prepaid, the first eight A FEW OF THE SUBJECTS numbers ; if satisfactory Thus one of the great prob- Magnetism-Induction-Experimentsnettem- Induction -Ez erments -DDynamos Accept this greatreatoffernow- I agree to lems Each page send you MOO each month Until paid. on Mars has been solved. tune Windings-Installing of Dynamos-Electri- --every illustra- cal Instrument Testing a tical Management tion will convince you o the big But who does the work? The Dynamos and Motors-Distribution Systems - value we are offering. See the Wof lnng- Wirinngg Diagrams -Sign Flashers-Stor- books Bret. then decide. If you all dominating Sun. of Alternating Current. decide to keep them you Signature andage Alternators -Alternating Current Motora- "And who moves the waters Tranefarmers- Converters -Rectifier.-Altemat- make settlement at only @hr' ins Current Syatema -Circuit Breakers-Measur- monthly until paid for. on Earth? Who, condenses ing instruments-Switch Boards -Wiring -Power Occupation the waters Stations - Installing -Telephone -Telegraph- from the oceans Wirelese- Bell.- LigVhting -Rnllw . Also many aal Mail Coupon, and lifts up myriads of tons Ready Reference Index of the ioElectricityme of water year in and .year out, Today Business Address to form clouds, which latter produce the 72 Avenue Residence rains, without THEO. AUDEL & CO.CO NEWW ftO . , which your rivers would run dry within four weeks? The ' Reference You benefit by mentioning "The Electrical Experimenter' when writing to advertisers. www.americanradiohistory.com 444 THE ELECTRICAL EXPERIMENTER December,. 1915

Sun, of course! "Only on Earth the Sun does it in a Learn Electricity! natural manner; here on Mars, the Sun works just the same, but without the in- termediary of the clouds," * * * * There was the familiar snapping sound in my receivers, a low click and everything was quiet. I knew that the telegraphone wire on the Moon must have been filled to capacity, and that I would not hear again from Münchhausen till the next evening. (To be continued.) "I'll PayYou$I75to$300 SUBMARINE F -BOATS ALL UN- That's what many su- Per Morrill!" perintendents and man SAFE, NAVAL BOARD FINDS agere have said to OUR GRADUATES. That's investigation into the what one will say to YOU. It's not out of the The preliminary ordinary. In fact it Is Just what can happen cause of the sinking of the submarine F-4 if you become a COYNE trained man. It means on March 25 last at the entrance of Hono- success for you for life. Any man between the ages of 15 and 50 who has ambition, no mat- lulu Harbor has resulted in a report to the ter how little education, can learn this big Navy Department, which asserts that all paying trade in our schools in a short time and at small expense. four of the submarines of the F class, in- cluding the F-4, had inherent faults, and were difficult to keep in repair and that COYNE NATIONAL serious trouble was experienced with their MIR N. Y. ELECTRICAL SCHOOL is the pioneer and premier school of the Learn by Doing" method. TRADE SCHOOLS propelling engines, electric motors and When you have completed this Course you shall be fully storage batteries; in short, that they were qualified to handle ALL branches of Electricalindustry. on long The equipment of this School is unequalled and up-to-the- Largest and best equipped trade school in America. in a dangerous condition for use minute. No preparation needed to become a "learner" in For 15 years we have sent hundreds of mon out annu- dives like the one on which the F-4 met this school. You can start to learn on any day of any ally as skilled mechanics to help supply the rapidly week throughout the whole year. Send for catalogue. increasing demand. Let us train you for one of these with the accident which wiped out the lives big fobs. Our employment bureau places graduates of her officers and crew. into big paying positions free of charge. New York Electrical School The Board of Inquiry found that the 29 West 17th Street New York City Men Wanted For These Trades storage batteries of the F-4 were always in a state of being more or less electrically "grounded," due to leakage of electrolyte, Electricity and that these "grounds" have been of Plumbing sufficient intensity to cause flame and the fusing of electrical connections, also that LET SAM BROWN Bricklaying these faults obtained in all four of the boats of the F class, of which there are TEACH YOU THE Motion Pic. Opr. three remaining, the F -1, F -2 and F-3. The Mech. Drafting F-4's storage batteries evolved excessive Our Own Building quantities of hydrogen gas. The fumes of AUTOMOBILE We teach all these big paying trades under actual hydrogen and acid were noticeable inside working conditions. Wo do not have classes, do not use books, do not teach by correspondence. Each man is the F -4 on long dives and on March 6 last, instructed individually rightin our hig shops. Drafting. some before F-4 was lost, there BUSINESS Estimating and Plan Reading included IN A LL courses. days the We charge a small tuition fee which can he made in was a hydrogen explosion in that sub- He'll fit you for a good Job as chauffeur, test- easy payments if desired. All tools., equipment and and er, repair man, salesman, etc., In 3 to 5 weeks. material is furnished by the school FREE. Our insti- marine which damaged the battery deck Sam teaches you personally -is right on the tution is open Day and Evening. Many of ourstu- broke several separators of the cells. The lob every minute. Established six years. dents earn a part or all of their expenses whileattend- ing. Our employment bureau is always ready to report just received by the Navy Depart- gist a man to earn expenses, without charge. ment asserts that the "conditions under Earn $75 to $300 a Month SEND COUPON FOR FREE BOOK which an explosion of hydrogen is always Good Jobs everywhere are waiting for good men. possible in F Complete equipment to work on; 4, 6 and 8 Be a man of action. Send obtain all the boats of the today for our class." cylinder cars for students' work. No theory. Ham 1s practical. Short on lectures -long on FREE COUPON -fully illustrhated.o It costs nothing actual, practical work. When you finish you W. r you and showse. how eoonE, Manager you can earn more money, RADIO LINKS TWO PRESIDENTS. are ready to tackle any auto problem. You're COYNE NATIONAL make a bigger success as good as the hest. Sam does a good Job. It was announced at the Navy Depart- Learn from a practical mechanic. I have a fine IRA DE SCHOOLS than y uyuver. dreams ment recently that congratulatory messages 3 story building, at 1518 -21 Prospect Ave., and Dept. 1598 ro o m e over and go 1520-26 Brownwell Court. Welding and Bronz- 3951 E, Illinois St., IL through o u r shops were exchanged between the President of ing Depts.; large, well equipped machine CHICAGO. - ILL. visitors a r e always the United States and the President of shop; Radiator, Fender and Tire Depts. Start Without any obligations on welcome. m at once. Drop in and see me, or write -Sam me whatsoever, please send : Guatemala in celebration of the opening of Brown. e your book of trades and B. W. COOKE, Manager a new high -power radio station erected in Lull Dartioulam -ALL PItEE. : COYNE NATIONAL Guatemala City, Guatemala. Ohio Auto School TRADE SCHOOLS The naval station at Arlington, Va., han- Dept. 1598 Dept. 212, 1521 Prospect Ave. Name 39.51E. Illinois St. dled the American messages. CLEVELAND. O. CHICAGO,ILL. Address NEW ELECTRIC AIR WARMERS. The approach of cool weather is direct- Learn INT NoWyCARDS/ ing attention to the subject of convenient ió To teach electrical means for warming rooms. S'NCBPersonally l by mail. LEARN the the now avail- to years' successful teach variety of these equipments Big field for men and able there has been added recently a new omen. Yo. can AUTO EARN SIB TO S45 A WEEK line of electric portable and fireplace heat- Weaver Canada, saveYour course increased is a BUSINESS ers, which made by Western manu- Write forfullpnrticulare. See what's in It for you. r facturer. DETROIT SCHOOL OF LETTERING Earn a Splendid Chao. d. Strong, Founder Dept. 3712, Detroit Salary or Have a A complete assortment of these is on Business of Your AVA 1; display in the Manufacturers' Building at Own the Panama- Pacific International Exposi- The Auto hnslnesa is growing by leaps and tion. You May Learn Theory, Code and h Hinds; there are better opportunities now than Laws of Radio Communication These heaters are all of unique construc- or at Your Home, ever before, for properly trained men as Chauf- heating The In Our School feurs, Demonstrators, Mechanical Experts, etc. tion, with one or more units. fitting you for positions paying good sal Over 3,000 of our graduates are making good one shown in Fig. 1 resembles an enlarged area with wonder( ul chance to travel sae money. Most Up- to-Date -12 Years of Success. one heating world over. It's the most interesting pro- Latest equipment including 8 and 12 cyl. cars; latest types motors desk telephone stand, and has fession known and the demand for skilled and lighting and starting systems. unit consuming 615 watts. It is made of Operator. is increasing. Send stamp for gals Individual Instruction. Tuition and Board reasonable. Write at once. alog ich gives full information. brass, highly nickeled. The height of the U St SCHOOL NATIONAL RADIO SCHOOL. 1405 CLEVELAND AUTOMOBILE outfit is 16 inches, base is 6.5 inches Washington. D. C. 2343 Euclid Ave. CLEVELAND, O. and the in diameter. The weight is about five You benefit by mentioning "The Electrical Experimenter" when writing to advertiser.'. www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 445

pounds, making this a very handy device We We Solely readily placed where desired. that can' be .roa- Guarantee ' Teach The reflector behind the heating unit directs ABRAHAM LINCOLN First Grade and the heat to the point where it is needed. 7wi// study and got 14 The heater, or rather stove, shown at ready and maybe Commercial r y^` Specialize Fig. 2, will take the place of a small coal my chance will come:' Operators' 1 i on Radio or oil stove, and it stands 28 inches in Licenses Telegraphy height. It weighs 13 pounds and has two heating units which consume 960 watts. LEARN WIRELESS SEE THE WORLD AND GET PAID FOR DOING IT YOUR Chance

Last year every one of our graduates success- Will Come fully passed his required commercial Govern- ment Examination upon the first trial. These results speak for themselves. Send a stamp for Born in a log cabin, Abraham new fall prospectus. Fall classes now forming. Lincoln had little chance to Eastern Radio Institute acquire an education. But 899 B. Boylston St., Boston, Mass. he was determined to succeed. "Some day," he said, "my START NOW chance will come." So he Fig. 1. Small Size Electric Neater studied and got ready. And of New Type. , TELEGRAPHY his chance DID come. 1 Body and guard are finished in white or and WIRELESS black enamel, the balance of the heater be- ing highly nickeled. Your chance will come. Some ( ff Studen s who start now reap the ad- This form of heater will give a great day you'll be considered for 'Il vantages of the wonderful opportuni- ties created by the war and which will deal more satisfaction to the user than promotion or for a good job in multiply when peace is declared. any electric heater yet placed on the mar- some other line of work. If ket, High efficiency is /1r Our book on "Telegraphy and Wire - say the builders. you are ready, you'll go up. "Il less as an Occupation" sent on re- obtained by operating the heating units at ceipt of IOc. It gives much necessary a high temperature, thus increasing the re- and valuable information.', sistance and decreasing the operating cost. And you CAN get ready. No They can produce heat comparing with matter if your schooling was BOSTON SCHOOL OF TELEGRAPHY other radiators at approximately 20 per limited-if you do have to work 18 Boylston St., Boston, Mass. cent. lower amperage. long hours. you really want They do not depend solely on the wire If a better job, the International I WILL TEACH YOU ENGINEERING TECHNICAL WORK temperature for radiation, and the high E temperature surrounding the unit is not Correspondence Schools can ACHINE DESIGN c affected by outside atmospheric conditions train you for it at home during This is the hest course ever publicly as readily as the comparative low temper- offered. It includes work and draw- your spare time. ings made by me for the past 27 years ature produced by other heaters; in other for U. S. and Foreign Govern- words, it is a more permanent heat. ments. It constitute. a complete More than Five Thousand I.C.S. study of all branches of machine de- sign. mechanical drawing and real ' =kléiy.sï Students every year take the shop system. None of the usual Cor- respondence School out and dried ma- trouble to report promotions or terial. It starts at the hegioning.takea throughu h salary increases due to I.C.S. help. Poblhermos nd advancs until you have a thorough training In What the I.C.S. have done for Machine Design and a fair knowl- edge of U. Sand Foreign patentlaws. these men they can do for YOU. MAIL A POSTAL FOR FREE LESSON. Pay as you learn. Terns arranged to suit yourself. Mark the Coupon NOW CONSULTING ENGINEER, 57é Bldg. Bridgeport,Gt. Just mark the osition or occupa- tion you prefer and mail the Meet Your Personal Needs coupon today. Finding out costs If you want to specialize in some form of electrical nothing. education suited to your needs, for a longer or shorter time, there is one place giving you boundless oppor- tunity. High school not required for this work. Also, usual s urses to degrees. Open nearly all the year. Stat almost any time. Expert faculty. Cost low now. Write for information to International Correspondence Schools HIGHLAND PARK COLLEGE Box 1071 -T, Scranton, Pa. president, George P. Magill, A. M., D.D. Please explain, without ob !gating me. how I can qualify for the position. trade or profession before which I have Des Moines, Iowa marked X. ELECTRICAL ENG. MECHANICAL ENG. Electric Lighting Mechaninl Draftsmen Electrician Shop Pracdn Interior Wiring Cu Engineer Electric Car Running ARCHITECT Telephone Engineer Builder & Contractor Telegraph Engineer Structural Draftsman STEAM ENGINEER Plumbing and Headng Mining Engineer CIVIL ENGINEER Thereisaneverincreas- Chemist Surveyor Learn Wireless Telegraphy. rag demand for compe- BOOKKEEPER Railroad Construcdon tent operators-this profession offers steady employment. Higher Accounting CONCRETE ENG. eta good eelary= wireless operators t ravel all over the world. Shorthand &Typewn'g Textile Manufacturing The PAINE Uptown BUSINESS SCHOOL Good Eng. for Evr'yone ILLUSTRATOR 1931 Broadway, (65th) New York. Bendier Catalog E Fig. 2. Electric Stove of Neat Pattern. CIVIL SERVICE WindowTrimmer Consumes goo Watts. Railway Mail Clerk Show -Card Writer SALESMANSHIP Agriculture AND Superior durability for the heating unit ADVERTISING AUTO. RUNNING TELEGRAPHYPHY is claimed and from the thermal point of Name Taught by retired railway officer. Railway wires in view in regard to durability, the individual advanced ro Expenses earned. All .graduates operated on Street and No. placed direct in the telegraph service. parts of the units are being City Starr Send for Folders and Rates an average of 30 per cent, below fusing and this allows for any condition Occupation Pelear School of Telegraphy, Madison, Wis. Point. in - Americas arising which may cause trouble case Employed by _ Scientific Railway Traininafehoot of an excessive voltage. You benefit by mentioning "The Electrical E.rperimenter" when writi tg to advertisers. www.americanradiohistory.com q.}6 THE ELECTRICAL EXPERIMENTER December, 1915

SquareDea] TO BREAK FOGS BY ELECTRICAL Miller WAVES. SELF -SHARPENER sy, « 191, Shipping men in New York are interest- FOR SAFETY RAZORS ; ed in an announcement from San Francisco that experiments are to be made there in an Insert safety blade - l,loáol.r (any but Durham effort to dispel fog by the use of electrical Duplex), turn handle waves. The problem of clearing such in- few times. Hones iYolr and sharpens one land waters as New York Harbor from the operation; keen cut- Ready/ dense mists that often interfere with navi- ting edge like new. gation has engaged the attention of ex- Sent anywhere for $3. Money back guaran- perts for many years, but no scheme within tee. AGENTS reasonable cost has yet been brought for- WANTED. ward. Recently oil has been suggested. The CIRCULAR EE ON Hydrographic Office of the navy is tenta- REQUEST. tively considering this subject. The news from San Francisco is to the IN.MFG. CO., 1 W. Broadway, New York effect that Government scientists have con- Waltham structed a giant electrical machine with H air which experiments are to be carried on in Grows Hamilton the harbor. The machine is a giant electri- When properly nourished. Our VACUUM CAP used a Howard cal transformer, the largest one ever built. few minutes each day draws It can take a current of 1,000 kilowatts at the blood to the hair roots. Elgin The blood is nature's nourish- 2,300 volts and "step" it up to 1,000,000 ment and when properly sap - volts. This charge is expected to produce plied, It promotes hair growth. 'Illinois- Rockford stops falling hair, and dan- a broad, continuous flash of lightning 100 druff disappears. Our cap Is feet long. Experts believe the result of used by Physicians, and men Alt 1916 Models. who know It to he the Scien- I amthe first mm In the country offer rvO this electrical disturbance will be to clear tific method of promoting s 2,5 the New 191e Model& of America's nu."w up a fog or mist for some distance; that "Hair Growth." We send best known watches. 1 have them all, - our Vacuum Cap on 60 days' the latest products of the world nT SPECIAL is, in comparatively inclosed waters. The tree Write for our moat famous factories. You can get N ^AI trial. too,the latest mountings forDlemonda experiments will be watched with great in- booklet on "Hair and Its and the most uptredste Jewelry, at the right priese. Growth" testimonials, and ap- terest by steamship men and navy officers. pllcatlon blanks, sent sealed Peter Cooper Hewitt, a recognized expert in a plain envelope free. No Money Down in matters electrical, in expressing his in by Me The ModernVaceum;Cap Co. Express Prepaid Advance views as to the efficacy of this method, 470 Barclay, Denver, Colo. You take no chances with me. I am 'Square Deal" Miller said: "I have not gone into the question, and I trust the people. That is why 1 am doing the great- est credit Watch, Diamond and Jewelry business In the so I am unable to properly discuss it, but country. Suppose you want a watch. New 1919 Model, a brand new up to date one, Name any one. 1 I see nothing improbable in its efficiency. have it for you. No money down, Express prepaid. It might work in small inclosed spaces and A full month to carry it in your pocket; and the easiest of Long Time Payments. T hat's the test that tells. All these under proper conditions. As I recollect, Watches Guaranteed for 25 Years. somewhat similar experiments were con- ducted several years ago on the Thames at I Smash the Terms London to clear the deck spaces of the NO REFERENCES DEMANDED My term, will surely suit you. You get unlimited credit, fogs. The results were said to be of a sat- with no red tape, notes or collectors isfactory character, but what has been done An "Open Charge,* Account since then, if there has been any continu- the same kind of credit you get from your grocer. No f matter where you live or what your income might be, you ance of the work, I am not informed." can now own the finest of watches a beautiful diamond .3)0,41+ Throw Away or any rare jewelry and never miss the money. REVIEWS. 1916 Catalog FREE s roam: BOOK Ye car Worn Tres and address so I ran maul you Free end postpaid. the most ALTERNATING- CURRENT ELECTRICITY AND ITS beautiful catalog of Its kind ever printed I want you to have this book. ft's a gem. It illustrates all makes of val- APPLICATION TO INDUSTRY. (First You can get 5,000 miles MORE uable Watches, Elegant Genuine Diamonds and a vast service from them assortment of Beautiful Jewelry, all on the easiest and Course.) By W. H. Timbie and H. H. must liberal terms. write for book today and get letter Higbee. Cloth covers; 534 pages; 51/4x8 from me that will make y friend from the start. For over three years European Motorists Square DealUMILLER, Pres. inches; 370 illustrations. Price, $2.00. have been getting from 10,000 to 15,000 Miller -Hoofer Co., 515 Miller Bldg., Detroit, Mich. Pub:ished by John Wiley & Sons, N. Y. miles out of their tires by "half -soling" them City. with Steel Studded Treads, just as we half -sole our shoes when the first sole gets thin. This book is planned to meet the requirements understood In the past 8 months over 20,000 American THE BOYS' OWN LABORATORY for a work r simple enough to be readily to form Motorists have followed their example and ara by the beginners, yet sufficiently advanced saving $50.00 to $200.00 a year in tire expense. a basis for engineering calculations and practical CHEMCRAFT A. C. work. A Complete Outfit of Power transmission, fundamental ideas of A. C. Guaranteed 5,000 Miles without Puncture CHEMICALS - (39 Chemical Reagents) currents, different arrangements of circuits, power APPARATUS (All Necessary Apparatus) Absolute freedom from tire worry -blowouts, factors, reactance and construction of single and punctures, rimcuts and rutwear eliminated-no INSTRUCTIONS (The Chemcraft Book) polyphase generators, are among the subjects cov- matter whether your tires are old or new you for performing over 50 Different Experiments. Each ered. should put on Durable Treads at once-they experiment can be repeated many times. The text is well illustrated with many clear an- cover your tires from rim to rim-nothing can Under the heading "Chemistry and Its Applica- alogies and photos of actual apparatus. The sub- work in between -that's why we guarantee them tion to the Industries" are many experiments in ject is covered in a rather broad manner to give as we 'do. which the products of our great chemical industries the reader a clear grasp on alternating current are really manufactured on a small scale. Every- We Deliver Free- prepay the express and theory and practise, while the authors promise allow to he the judge. Durable Treads thing is explained in a clear interesting way. another course, soon to be ready, which will cover you Chemcraft also contains 30 mysterious experi- are easily applied in your own garage in 30 the subject more in detail, as to the characteristics minutes without extra tools. ments in Chemical Magic. It's great fun to show and operation of commercial types of machines and these to your friends. appliances. Special Discount to motorists in new terri- If your dealer does not have Chemcraft we will tory on first shipment direct from the factory. send yours direct. Price $1.50 postpaid. Descrip- APPLIED ELECTRO-CHEMISTRY AND WELD- Mail the coupon today and we'll send you full tive literature sent on request. ING. By Charles F. Burgess, E.E., and information, sample, and copy of signed guar- THE PORTER CHEMICAL CO., Hagerstown, Md. George W. Cravens. Cloth covers; 140 antee without any obligation to you. pages ; 135 illustrations; 5%x81/2. inches. Published by American Technical So------Mail This Today - - ---, ciety, Chicago, 1915. Price, $1.50. COLORADO TIRE & LEATHER CO. I A practical treatise, written in a clear, readable 129 Tread Bldg., Denver. Colo. EXPERIMENTERS style, that is sure to increase the interest in practi- 1.9 Transportation Bldg., Chicago, Ill. We have what you want. Samarskite, cal applications of electrolysis and welding. 912 Woolworth Bldg., New York. The first part covers the subject of electrolysis, Gentlemen: radio-active mineral,based uponUran :um. electro-plating, decomposition, high tension genera- Please send me, without any obligation, full 100 lbs. contain 1.75 milligrams tion of ozone and the method of nitrogen fixation information, sample copy of signed guarantee I Radium. in an impressive and nontechnical manner. for 5,000 miles, and Special Discount Terms. Price per pound $4.20; large discounts on The remainder treats of electric welding in all its forms. The various application of electrical, Name I orders of 5 pounds and over. 1 oz. sample gas and chemical welding, are discussed at length. Address I sent for 60 cts. cash. This book is worthy of perusal by every worker in the above.mentioned field, who will find his time Le -Bar Chem. Co., MineralctProd, vatio., Md. well repaid by such reading. My Tire Sizes are ELECTRICAL INSTRUMENTS. By W. H. F.

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Murdock, B.Sc., and U. A. A'schwald, The newest ideas Gold girafes case. My $3.00 Exerciser B.A. Cloth covers ; 5%x71 inchés ; 366 $100 pages; 164 illustrations. Published by Gt cases are yours Guaranteed for Reduced to Macmillan Co., New York City. Price, to choose front. 25 years. $2.75. Until further notice I In this work the writers have endeavored to will send one complete create a work suitable for the advanced "meter- man" and have succeeded admirably. In the historical summary, they show early forms Muscle Builder of measuring instruments and then take up each type, going on to explain carefully and at length Outfit with many formulae, the theory, as well as the practical details of each instrument up to and in- to any reader of supply meters. Electrical Experi- cluding various forms of demand menter upon Closing with chapters on magnetic permeability receipt of meters and a discussion of the post office box and $1.09 -just one -third the well bal- regular price. I will also slide wire bridges, the chapters form a include a complete body- anced and symmetrical whole. This book will no building course of in- doubt find a place with all specialists on meter structions containing 24 work, desiring to keep in touch with the best prac- selected exercises. The tise. MUSCLE BUILDER will meet the requirements ELECTRICAL MEASUREMENTS AND METER of any person-weak or TESTING. By David P. Moreton, B.S., strong -man, woman or E.E. 'Cloth covers; 4%x6% inches; 266 child. Can be pages; 191 illustrations. Published by A Chest used to exer- '. cise any muscle Frederick J. Drake & Co., Chicago. The Burlington Expander Also in the body. Price, $1.00. In this work the author has succeeded in combin- with each ontft, I ing great clearness with conciseness and accuracy. will give an extra The fundamentals are handled in a manner not handle, without charge, by surpassed by his treatment of higher and more which the Muscle Builder technical alternating current measurements. Many Smashes can instantly be converted analogies, combined with profuse illustrations, tend into a most effective \\ to make the work invaluable, alike to the layman All Watch Competition Chest Expander to be search of knowledge on used for developing the and practical electrician in chest and lungs. Take ad- the subject of electrical measurements. vantage of this opportu- Starting with the idea of giving the reader a nity while it lasts. Send good grasp on the principles of electricity, the author carries him forward in short steps to a full Look ! your order today. knowledge of all methods of measuring electricity, 19 Ruby and Sapphire Jewels - Prof. Anthony Barker making in all, a book worthy of a position in every Adjusted to positions- Studio 28,110 W. 42d St., N. Y. electrician's bookcase. Adjusted to temperature Adjusted to isocllroniam-- ELECTRICITY FOR THE FARM. By Frederick 25 -year gold strata case - Irving Anderson. Cloth covers; 5%x7 %; Genuine Montgomery Railroad Dial - BRAIN vs. BODY New Ideas in Thin Cases. IN THE 266 pages; 50 illustrations. Published RACE FOR SUCCESS by Macmillan Co. Price, $1.25. All you fellows wbo are de- Taking a really difficult subject, the author has voting every bit of your time treated it in an exceptionally clear manner. Start- Only and attention to the cultiva- ing off more like fiction than a technical treatise, tion of mental efficiency, do And all 50 you ever he shows the great changes on the farm made pos- sible by a small electric plant. He proceeds with of this for $2.50- S T O P an elaborate treatment of water -wheel installations, only $2.50 a and ask yourself what It will leading up to the electrical equipment, which is for A avail you if you neglect your treated at some length. month the body r You think the brain ie masterpiece of Month the all important essential in The final chapters deal with gas engine and wind the race for your goal. Is it r power as applied to electric generators. With this watch manufacture- direct to you - pos- Will your brain live longer book at hand, the farmer can start to install an itively the exact price that the wholesale than your hodyr Will your electric plant with full confidence of success. brain live up to its training dealer would have to pay. We do not care and do good work if it has to be eontinuallY flashing mes- How TO PASS U. S. GOVERNMENT WIRELESS to quote these prices here, but write - sages from a neglected body. LICENSE EXAMINATIONS. By E. E. write before you buy. Think of the high -grade, dor registering proteste from a guaranteed watch we offer here at such a i organised Marano ht Will Bucher; 70 pages ; 37 illustrations ; size, remarkable price. Indeed, the days the brain of a crooked, of exhor- w y dyspeptic, or eak. 9x5% inches; paper bound. Price, 50 bitant watch prices have passed. Write today. puny.undeveloped man justify cents. Published by Marconi Publishing the training it has had r Or will a brain weakened by -Corporation, New York City. youthful be 100 This book, arranged in the form of a catechism, The Newest Cases Der cent, efcient?ens My book "Intelligence In fills a long -telt need. Answering as it does 118 In our new watch book, that we will send Physical and Health Cul- questions of actual bearing on the subject, it is an to you free and prepaid, you will see illustrated ture" will answer these Ques- invaluable help to the radio amateur who desires to the newest ideas in watch cases. The latest tions in way that will in- pass the U. S. Government wireless license exam- triumphs of the master goldsmiths. Notice terest and surprise you. Send inations. four Cents In stamps to Cover especially the Inlay Enamel Monograms. Block Postage on a copy. Do it nowt The questions are answered in a clear, easily un- and Ribbon Monograms, Lodge Emblems and LIONEL STRONGFORT derstood, manner not untouched with a certain Diamond Set Cases. All offered direct to you Health and Strength Institute amount of technical terms. The book treats of on this startling offer. Send the coupon today. Dpt. C125. Atlantic City, N.J. the different parts of a radio installation in order and covers each quite thoroughly. It gives numerous formulas for the calculation of the various currents and apparatus. The book ap- See First! pears to been written in a very hurried man- It iU,tPl°_ have Be a DOCTOR of ner as the errata is rather large, and in fact it con- You don't pay a cent to anybody until tains a minor mistake in itself. However, this you see the watch. We won't let you buy a Bur- CHIROPRACTIC ä-;t1- book should find a large demand with students of lington watch without seeing it. Hold it in your radio phenomena who desire a better grasp on the hand and admire it. Notice the design, hand- $75 TO $100 WEEKL Yl;- subject in a practical way. somely shaped -aristocratic in every line. Then The need now for Doctors of Chiroprac- -ND., look at the works! There you ace the pinnacle of tic is tremendous -your opportunities are YEAR BOOK OF WIRELESS TELEGRAPHY AND awaketothewonder- watch-making. You understand how this won- e foladvanfa RR atoeir a yearorcalr 1. TELEPHONY FOR 1915. Published by Mar- der timepiece is adjusted to the very b'oe. to earn $10.1300 fed is "emcee are second! bers. There'sTbere'e room for you-the te md°oDrn, rla coni Publishing Corporation, New York Learn Home in spare tir°' H° at eureomplet e City. Size, 8Ysx6 inches ; 1,000 pages ; 32 sly earn rercomplete colors. tad Book course complete cet free eM1arte Free Watch and of Ìrfe -like colora. illustrations ; cloth bound. Price, $1.50. 5 Lesson Sections FREE oeóió ;'mäá The year book for 1915 has just made its ap- Get the Burlington Watch r He t offer ever made. Write now for free facts. it 1914 both In Book by sending this cou- Burlington Watch Co pearance and surpasses the edition will Illustrated Book Free "om°e h oy a t size and quality of its contents. It contains as pon now. You know 19th St and Marshall M. Chiropractic-tells about Dle comymeceas[ee fu tietrratm ed. a lot more about watch / ypheed know robe Q usual the complete list of ship and land stations of n 3389 Lhlmgo, ILL prosperous profession. alr- bgfe iochiedignified.offer is limited. the world and the laws and regulations of the va- buying when you read please it. You will be able to send me (with - American University, Dept, 441, 162 N. Dearborn St. Chicago. rious countries on radio -communication. out obligations and pre- It also contains numerous formulas and tables in- - steer clear" of the double - priced paid) your free book on valuable to the commercial operator as well as to watches which are watches with full explana- the amateur and deserves a position on every ex- tion of your cash -shelf. no better. Send or $2.50 perimenter's book the coupon to- a month offer on the Bur - The chapter on wireless telephony is very brief for lington Watch. and treats of the various s stemd in a general way day Typewnter prieessmashedlUnderwoode. and our offer. Flemington,. Royale L. C. Smiths. Yom. going into few details. However, it treats of the etc.-your choice of any standard factory entire history of wireless telegraphy in some detail, Burlington e Name rebuilt machine at a bargain. Everyone .- ...... __,. melodi and repairs.'ethroe as to discoveries of the various experimenters in W atch Co. eYecir- this line, etc. cular tell° how to an 40 per cent to in Matrefell find. GO Percent on each machine. The various articles by prominent men the Marano3e0 Address field of radio- communication are of special interest . Write for it. C. E. GAERTE, President and timely. They deal with the effects of wireless Chicago EARSOIIN TYPEWRITER EXCHANGE. DEPT. 626, CHICAGO, ILLINOIS telegraphy on the present European conflict and You benefit by mentioning "The Electrical Experimenter" when writing to advertisers. www.americanradiohistory.com 448 THE ELECTRICAL EXPERIMENTER December, 1915

Here's YOUR Chance to Learn the latest developments in long- distance wireless communication. The adaptation of wireless teleg- raphy to meteorology and surveying are treated on in an interesting manner. DRAFTING The book likewise contains lists of radio societies. NEW BOOKS wireless telegraph companies, the latest books and This Complete $15 Drawing periodicals available on the subject, a glossary and Outfit and Full Instructions dictionary of technical terms, etc. in Mechanical Drawing FREE Presenting in one volume the entire history of wireless telegraphy as well as the latest advances in HIGH FREQUENCY the art it fulfils its mission as a year book in a satisfactory manner. APPARATUS THE WIRELESS TELEGRAPHIST'S POCKET Boox by Dr. J. A. Fleming. Red leather Its Construction and covers, gilt edges, 348 pages; 39 illustra- Application tions; 41/ax71 inches. Published by the Practical Wireless Press, London, England, 1915. By Thomas Stanley Curtis Price $1.50. Price $2.00 postpaid This is a much desired pocket size volume of tells you all about extreme value to the radio operator and engineer, This new book whether for theoretical or practical consideration. Electricity in Stagecraft. There's The author is one of the best known writers and Electricity in Horticulture, Etc., agood job waiting for you. scientists in the wireless field, and has here pre- The country is facing greater sented a general clean -up on the necessary meas- and shows you how to make and use urements and calculations occurring in wireless the apparatus for these experiments. prosperity than telegraph and telephone engineering. Sufficient dia- grams and illustrations are incorporated to make it has everbefore the book of great practical value. The section covering the different losses and FREE. TECHNICAL ADVICE experienced.Far - over-all dimensions as well as the efficiency of the individual apparatus making up a complete wireless seeing men are transmitting set, is of extreme value and has not getting ready for been covered heretofore in most text -books, which /11 When you order an electrica' presume to deal thoroughly with the subject Some NI or a mechanical book, do you boom times. Get of the subjects covered include a considerable always get just the treatment of the amount of mathematics up to Calculus, and this this training now section ends with electrical and other units, dimen- subject that you desire? We main- and in sions, etc. This is followed by chapters on high fre- tain a Department of Technical Ad- share the quency and voltage measurements; capacity calcu- vice to aid you in the selection of the by coming prosper - lations and absolute measurements the bridge a given purpose. CHARLES W. MOREY method; frequency and cymometer measurements; right boot¿ for Presidenl.t the ems... aerial and etheric wave radiation, covering the Heed of a Large Chicago ity. We make Fidrm of Civil, Meehaniad calculation and determination of radiation resist- /I[ The service is free; will you tel ou i Fi.ci rieaf acte'seern nod the way plain. ance and decrement; transmission and transmitting "u us what subjects interest you and a,otraciors, circuits, as well as receiving circuits, with a final section covering routine station practise for radio let us help you to select a library, operators. The book contains an appendix of one book at a time if you wish? valuable mathematical tables, including logarithms, Men Wanted circle dimensions, etc. A Stamp brings our literature promptly. All in all, this neat volume appears to possess great merit and it should find a ready sale among AT BIG SALARIES all radio men who wish to have at their fingers This is a rare chance for a few wide -awake young men. end the latest concise data on this important branch of science. TECHNICAL PRESS ASSOCIATION On account of the rapidly increasing demand There are several sections of the book which for trained draftsmen Pres. Morey has issued NEW YORK orders that instructions be furnished to a seem as though they might have been made larger, 836 -C Aeolian Hall, limited number of young men who are inclined even if other sections had to be cut down some- along engineering or architectural lines. what. This pertains particularly to the opening Read about this great offer below -then mark chapters, which deal with mathematics. Manifestly and mail the coupon. it is impossible to cover the subject of mathematics in a few pages, and while to many users of this HOME spare handbook the mathematical notes will be found THE PANDICULATOR STUDY AT hours for a short m useful, it would be just as well to have left them only and learn this profitable and pleasant out or made them cover less ground, as those who profession, and get in the class drawing the big are interested sufficiently can procure numerous pay envelope. Hundreds of men are in daily treatises at a nominal cost, covering mathematics attendance at this old established college. In very thoroughly and completely. your own home you can do the same work these men are doing. and the same experts that teach them will guide you toward the big Job. These BY WIRELESS PHONE FROM AR- well -known engineers prepare your instruc- TO PARIS. tion matter. Your work is examined and ap- LINGTON This University discovery is the most im- proved by them. They know exactly the (Continued front page 393.) portant health invention of the century. It re- practical training you need and they train you. makes and rejuvenates the Human Body. It No books to sell. Live, up-to -date blue prints produces normal spines. It frees impinged and of work in actual construction. In your own Paris and also in Honolulu. irritated nerves, corrects contracted muscles, home you work with plans of machinery, build- "We have now heard from all our expe- shortened ligaments; eliminates congestion, im- ings, steel works,etc., actually being construct- is note that proves circulation and drainage of the body. IT ed in Chicago, New York and other largecities. ditions, and it interesting to LENGTH. the circle of the area covered by these WILL INCREASE THE BODY'S Electrical Drafting and Design expeditions was about 10,000 miles in diam- THE PANDICULATOR CO. No other similar correspondence course In America has eter. Never in history was such an expe- a resident college of National reputation back of it, nor Cleveland, O. a faculty of active experts actually engaged In muni- dition ever undertaken as was this one." cipal and corporation engineering work. These men know exactly the kind of training you need because "How long was it before Webb in Ar- they are in constant charge of big work. lington was able to establish communication price OYS,Beal Boy's Magazine In the werideliho with Shreeve in Paris, and what test words 1 J DO YOU LIKE RATTLING GOOD STORIES t was asked. Are you Interested In baeeba" and slide. were used ?" Mr. Carty tics, $45 COURSE FREE "Owing to the very limited time at their carpentry, Stampe and coin coldpetg,collecting, necessary to cable the exact amateu are ltem,gardtntng and pets IN disposal, it was If you are sit down right now and send MECHANICAL DRAWING minute during which the Eiffel Tower plant oarterfora cane enbecrlptfon to Boys' This College has set aside a limited number of Free Comma.. s large 32 page boys Scholarships and will give the regular $45 Coors In was available," he replied, "and in those monthly magazine. It IS chock.10chock I I of the Mechanical Drawing Free with any one of the Home few seconds Webb did his talking. Signals verye s' Study Courses named In the coupon below -this to In lollof life and action, and has reg- addition to the complete $15 Drawing Outfit which is had been previously arranged, first by num- nlar departments every month on all the also furnished to students free. Take advantage of this above sabieete besides unusually liberal offer today, as It will be withdrawn bers, and then followed by words. Shreeve great Interest to boy . ALLHOPS ti ANT I when the allotted number of Free Scholarships has If you will send 26 note at once for was to cable what he got after each test- mal been awarded. It costs you nothing to get full Infor- you mation. No obligation on you. that is, provided he got anything-and, as copy'of Connie Macke news Rootlet "The Score of Success in ACT NOW -FILL OUT COUPON TODAY you know, the signals were heard on three One seer 25 cents. nail year 15 nuts,uts, Three of 10 each. different nights. Owing to the fact that Boys' Companion, 104 South La Salle Street, Chleago, 114 -Electrical Drafting -Builders' Conne is in existence only one set of M achloe Drafting -Plan Reading there now A rchltectnral Drafting -Estimating transmitting instruments, and that at Ar- -Strnctaral Drafting -Sheet Metal Drafting Show Card Writers Earn $80.00 to $200 -Cisti Engineering (1080) -Surveying lington, the talk, of necessity, as was the Name case with San Diego, Honolulu and the a Month -LEARN FREE Ad other places reached by the expedition, had We will furnish a thorough course in Show Card Writing and Lettering Town...... State...... to be one -sided." absolutely free to introduce our College or Home Study Course ...... [Editor's Note. details and illus- colors, if you will purchase an assort- -For ment of Alpha Colors to use while trations of apparatus used at Arlington in practicing. Particulars for stamp. CHICAGO TECHNICAL COLLEGE Honolulu talk, see November, 1915, issue ALPHA COLOR COMPANY, Inc. 1060 LAKE VIEW BLDG. CHICAGO, ILL. of The Electrical Experimenter.] Dept. T, 81 E. 125th St., New York You benefit by mentioning "The Electrical Erperintenter" when writing to advertisers. www.americanradiohistory.com December, 1915 THE ELECTRICAL EXPERIMENTER 449

HIGH FREQUENCY CURRENTS AND APPARATA. J')) (Continued from page 405.) experiments with high frequency currents í . b will be found described in the series of many excellent books listed at the end of this discourse. It can also be said that we '14'4 of to -day know very little about these high frequency currents and their possibilities. Nikola Tesla has done more in this direction 1w. than any other person, as can be readily judg- ed from the fact that over 15 years ago he successfully produced sparks 100 feet long 4.. resembling in volume and sound the light- ning discharges we have all seen in nature (not imitation ones). It is hoped that this ..,. article may serve to kindle the spirit of research along these lines in the young ex- perimenter's mind, and he surely will be 0`/\ amply rewarded for any discoveries he may make in this little -understood branch of electrical science, which bids fair to unlock the door to a future electrical era of which our generation has no reasonable concep- tion at this time.

BIBLIOGRAPHY. ABEyour services in demand today. Have you the training Books Recommended. The Theory and Design of Induction that equips you to hold a position paying $1 25 to $300 a month? Coils. By H. Armagnat. Have you the same knowledge as the man who gets the fat pay envelope? If you are ambitious -send the eoupen below and find out about the opportunities that await you 'High Frequency Currents (Electro- In the profession of Signal Engineering. Salaries are paid to men who know. You can get just the therapeutical). By Dr. Frederick Finch kind of training you need to accept one of the big jobs, right in your own home- during your stare Strong. time. We need men. Do not delay. Send the coupon today for the book that tells you all about it. Experiments with Alternating (Currents of High Potential and Frequency. By Be a Signal Engineer We Need Men Two Big Nikola Tesla. Be the man who gets the fat pay envelope. The pro - The profession of Signal En- Outfits Fre- fession of Signal Engineering Is only in its infancy. There gineering is calling to ambitious Electricity at High Pressures and are thousands of miles of block signal° to be installed. men. Our ranks are not over- FREE quencies. By Henry L. Transtrom. SignalEngineera.suprvi.aors inspectors and foremen are crowded. Then are opportu- Complete Sig- required to superintend this Installation. Hundred. of maintainer nities- golden ones. awaiting nal Engineer's Wireless Telegraphy and High Frequency and better) men are needed to maintain the system already la use. the men who answer the call. OutStandcom- Electricity. By Prof. H. ,LaV. Twining. Your duties 'may take you .from coast to coast. Block signal systemeare no long- plete Draft-s. Railroad men fortunate travel erin the experimental stage. All min's Outfit Telegraphy. (Covers Tesla's end o freet a Is libereellyawará giveú away Wireless can accept where will be located eteadi le at one over the country they are being position you I installed. Some h ab tely free wireless transmission of power patents.) place States eve legis. our fatpay eyon loöemó b soon.. Send coupon i r free Signal Book. lated to compel the railroads to to students By Charles Henry Sewall. install systems immediately. In our profession you will have the Articles Published in Back Numbers of Nance you have been looking $125 to $300 a Month for, We are calling you. Take e' Electrical Experimenter. That Is an ordinary salary for Signalmen-many immediate advantage of this Department A Vs-kw. Tesla Coil. Page 73, Septem- Sgnal Engineers make much more. In the Signal Depart- wonderful opportunity. ee of Signaling relent, supervisors. Inepeeton tainere battery men. poet Don't fail to send the con- Ream 3389 ber, 1913. one of authority p ying from $75 000 a month up. elie to the n today big free men who beve bad the kind of training you an g-t rightin for our a 1810 Wilson Avenue Currents of Utra -High Frequency and hums. Even while you learning roe may hold one of Signal Book end foil par - R wood Station poeitione a the Siena/ der Signal Engineer. tiulars. Do it NOW. a Chicago, Page 151, February, 1914. lilinols Potential. Gentlemen: -Please send -Inch - A Tesla Transformer for One Big New . me absolutely free and pre Spark Coils. Page 187, April, 1914. Send Coupon for Book .ae S,urnai yEngineeeriing. Also full Electro- therapeutics and High Frequency Put your name and address on the coupon or on a letter particulars about your great or a post card now. and send us. no obligations spal free outfit otter. It is dis- Apparatus. Pages 20 -23, June, 1914. it to Absolutely sesame of any kind. We will send you our !Agnew Book absolutely free, e no any kinds Some Experiments with High Frequency and prepaid. Read about this fascinating profession. Read Currents (in two parts). Page 24, June, about the opportunities that await you. The book is free. Send e the coupon for It now -it's the first step toward the realiza- Name 1914 ; page 119, December, 1914. tion of your ambition. Get your name and address in at once. e' High Frequency Currents -Explanation and Apparatus (in two parts). Page 68, Department of Signaling / Address September, 1914; page 84, October, 1914. Room 3389, 1010 Wilson Avenue, Ravenswood Station, Chicago / A Miniature High Frequency Outfit. Age Occupation (Construction details given.) Page 123, December, 1914. Cuts the toughest wire with the least strain 'Spectacular Discharges and Large Tesla "RED DEVIL" NIPPER No. 542 -6 Coils (36 -inch spark apparatus. Construc- I lb. handle pressure gives zo lbs. cutting pressure. tion details given). Pages 54-55, June, Hand -honed. "stay sharp" cutting edges, slip -proof, 1915. scientifically shaped handles. Sample 85c postpaid. MECHANIC'S TOOL BOOK FREE ISN "HOME ELECTRICAL" WINS SMITH & HEMENWAY CO., loc. Sh rkClty`> AWARDS AT WORLD'S FAIR. The 900.000 persons who have inspected the "Home Electrical" display at the Pan- The Newest Thing in ama- Pacific International Exposition will be interested to know that the General Flashlights Electric Co.'s exhibit has been awarded two Your watch gold medals by the international jury of on one end of your awards. One of the gold medals was chain, your WATCHLITE on awarded for the high educational value of the other. the display, while the completeness of the Not merely a novelty, exhibit and its drawing power as an at- but a use- traction carried off the ott.er gold prize. ful, serviceable flashlight. The "Home Electrical" presents a full - sized model home of Spanish -California Bright Star Battery Co. bungalow design, in which world's fair Factory and Main Office: visitors see a practical demonstration of NEW YORK how electric energy performs all the house- Branches: hold labors and adds to the comforts of CHICAGO MONTREAL "WATCHLITE" living.

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TO FOIL SUBMARINES WITH surfaces, and is the inventor of a stepped UNDERSEA SEARCHLIGHTS. aeroplane that is the lightest machine so (Continued front page 392.) far built, it is said. From the realm of mining engineering this end the inventors make use of an ob- the Naval Advisory Board has been hap- servation tube. This can be any of the pily favored with the selection of two emi- well -known devices for seeing beneath the nent specialists nominated by the Ameri- surface, but they prefer the rttariscopc, can Institute of Mining Engineers, These shown at 16, arranged adjacent to the tube gentlemen are William Lawrence Saunders 10 and being curved at right angles 17 and and Benjamin Bowditch Thayer, both of 18 lens 19 is at top and bottom. A pro- New York City. Mr. Saunders is a min- vided at the lower extremity of the tube. ing engineer of great prominence and was and opposite this is an inclined mirror 20, born in Columbus, Ga., in 18:.6. He grad- with another above. 21. at the upper end of uated from the University of Pennsylvania the tube; from this the rays are refracted and for some time was in charge of the to the sight hole 22, at the end of the tube hydrographic work of the National Storage 17, appears so that when any object in the Co. He is serving at this tame as presi- least a illutttinated field its image, or at dent of the Ingersoll -Sargeant Drill Co., shadow of it, will be caught by the mari- Big Money the Imperial Tool Co., and the Ingersoll - scope and seen in the sight opening 22. Rand Co., and at one time he was editor means As soon as they had devised a of of The Compressed Air Magazine. He is locating in a in an object the path of vessel a specialist in the design of compressed air to be destroyed the inventors next foresaw inach:nery and has invented many impor- the necessity at for having some means tant devices in this field. Mr: Thayer was hand of attaining They devised, Electricity this end. born in San Francisco and graduated from therefore, a torpedo tube 23 at the bow of Harvard University. He is a well -known the vessel and means for electrical industries offer won- adjacent to the mining engineer and is president The locating object. of the the Our illustration here- American Institute of Mining Engineers, derful opportunities for boys with with shows a torpedo being discharged. The and, industrially, he is president the a liking for electricity. The sala- inventors would have it understood, how- of Anaconda Mining Co. ever, that their invention does not lie in any ries paid to trained men are large This brilliant staff includes detail of the torpedo tube or of its loca- of specialists -promotion comes rapidly, and, two all- around men of science, as selected tion, but that any means of discharging a best all, the profession is not by the American the of torpedo or other missile from the bow or Chemical Society, in persons of Dr. Leo H. Baekeland, of Yon- overcrowded. from the submerged part of a vessel can be kers, N. Y., and Professor William R. employed in connection with their means of Whitney, of Schenectady, N. Y. As a The opening of new lines, from locatng the object to be destroyed and time to time, (such as wireless tel-. invention chemist of repute Dr. Baekeland is well their of an electrical device for known. He exploding a discharged torpedo when it hits has also produced several im- egraphy and telephony), promise portant industrial productions based on attractive and paying fields to those or reaches the vicinity of the object to be destroyed. chemical affinity. He was born at Ghent, who wish to Belgium, in 1863 and the specialize. The will As illustrated, the torpedo 24 has con- graduated from Ghent, where he served to do and Special Training will necting wires 25 with any usual or pre- University of later as Professor and the Associate bring success to you. ferred sparking device, wound into a cable Assistant Professor of Chemistry. He also has been 26, which is carried on a reel 27. The ter- The International Correspondence minals 29 on board the vessel are connected Professor of Chemistry in the higher Nor- mal School at Bruges. He is also the in- Schools by means of two wires with a source of of Scranton can help to the -known supply of electricity provided with a con- ventor of well Velox gaslight make you an expert in electrical so trolling key 30. When it is seen that the paper widely used by amateur and pro- work. Hundreds of boys have torpedo is in the immediate vicinity of the fessional photographers, and besides in- already won success through submarine, mine or other object it can be vented the famous Bakelite used very ex- I. C. S. help. You can do the immediately exploded by closing the circuit. tensively for all kinds of electrical and other insulating requirements. Professor same. Everything is made so clear "We have shown our apparatus attached to the bow of a vessel." said Professor Whitney was born at Jamestown, N. Y., in that you can learn in your spare Parker, "but it is obvious that it can be ap- 1868 and graduated from the Massachu- time, regardless of where you live plied to any other part as well, and thus setts Institute of Technology, where he or what you do. No books to provide a certain means of defense. As a served afterward as Instructor, Assistant buy. means of offense the importance of the in- Professor and finally rs Professor of vention will be readily seen, and it will also Chemistry. The greatest electric corpora- be noticed that if several vessels equipped tion in the world -the Gener1 Electric Co. as of its most val- There's big money in electricity. Get with the helioscope and mariscope were ap- -now counts him one he the re- after it by marking and mailing the proaching abreast a mine field or fleet of ued men, and is the directjr of attached coupon today. Finding out submarines a very extensive field would be search laboratory of that immense indus- costs you nothing. illuminated and placed under observation, trial and scientific organization, which has so that the object of danger could easily be solved more problems of an electrical and Mark the Coupon -NOW destroyed. Furthermore, it is apparent that other nature than probably any other in- where the objects of danger are readily lo- dustrial concern of similar age. cated a surface vessel, because of its greater . From the field of electro- chemistry there INTERNATIONAL CORRESPONDENCE SCHOOLS, speed and mobility, can easily avoid such has been contributed to the Board two able objects, even if it cannot destroy them." authorities: viz., Professor Joseph William Box 1071 B, SCRANTON, PA. Richards, of South Bethlehem. Pa., and Explain, without obligation to me, how I can ELECTRIC Lawrence Addicks, of Chrome, N. J. Pro- Qualify for the position before which I mark X. BRANDING IRON. For branding hams, bacon and other fessor Richards is the instructor in metal- Automobile Running tenog. &Typewrit'g packinghouse products, a new electrically lurgy and mineralogy at Lehigh University. Motor Boat Running Bookkeeping heated iron has been invented, which re- He was born at Oldbury, England, in 1864 Electrical Engin'er's R. R. Accounting Electric Lighting Good English for Ev'yone' ceives its current from an ordinary lamp and his early education war obtained in the Electric Railways Civil Service socket at a cost of but one- fourth of a public schools of Philadelphia. He was Dynamo Running Architecture cent an hour. with degrees from Lehigh Univer- Telep. & Teleg. Eng. Contracting & Build. honored Mechanical Eng'r'g Structural Engin'g sity and later spent considerable time in Mechanical Drafting Plumb'g & Heat`g THE UNITED STATES ADVISORY advanced study at Heidelberg, Germany. Shop Practice Civil Engineering on Steam Engineering Salesmanship BOARD AND ITS PERSONNEL. Mr. Addicks is considered an authority Mine Fore. & Supt. Advertising (Continued front page 399.) the metallurgy of copper, and acts in the Chemistry _IAgriculhire capacity of superintendent of the plant of Co. at Name Society of America. He is also a member the United States Metal Refining of other scientific societies, including the Chrome, N. J. He was born at Philadel- Street and No Aerodynamic Commission of the Aero Club phia in 1878 and graduated from the Mas- of America. Besides his other numerous sachusetts Institute of Technology with the City Sta ' activities in the realm of flying machines degree of Bachelor of Science in mechani- engineering. He has held Prese=to= upa =c= and allied devices, he has investigated the cal and electrical _J determination of air pressure on arched important positions as consulting engineer www.americanradiohistory.com T)cccfnbcr, 1915 THE ELECTRICAL EXPERIMENTER 451 and is very well known in his chosen line of work as a man of great ability and re- source. HOW THE "WIRELESS WIZ" CELEBRATED XMAS. (Continued from page 397.) Complete Set of run out again should the current be fed Drawing Instruments to the third rail of the side -track. The track switch is pulled into the straightaway yrs.! will give you this complete set 10. of drawing instrutments absolutely by operating the switch The express free. They are regular working in- train will then continue to run around and struments -the kind I use myself and they may be reversed and backed into its sta- do not cost you a penny, And besides the instruments in this exquisite plush lined tion, 'B.' The freight train can br backed leather case. I wall give you absolutely off the siding by closing the switch 3, and free a 20x25 inch drawing board, a 24 by means of the current reverser, X', can inch T- square, a 12 in rule, a suraly of drawing paper, two triangles, a French be made to go around the track. It is curve, pencils, erasers, thumb tacks, etc.. understood that by properly manipulating etc. A complete draftsman's working outfit. And I give it to the men who get these switches and working the rheostat my personal instruction absolutely free, R that some quite effective situations may be ereated. "An eleetrie whistle was mounted in one of the stations, and this was operated by a push button before the train was started. magnetic stops made as Be "The electro- arc a Draftsman! depicted in sketch C. and consist merely of a bent strip of brass or small wood Draw $125.00 to $175.00 Per Month box supporting an electro- magnet, to which is pivoted an arm, 1, which is raised into There is an urgent demand for skilled draftsmen. Companies are posi.ion by the electrie eurrent in the coil. issuing calls every day for men to fill positions paying from $125.00 to throw the current reverser on the train to $175.00 per month. Work is light, pleasant and profitable. ill the usual manner. "The Christmas tree was supported from the eeiling by means of a turnbuckle, and Will Instruct on the bottom of the trunk were mounted ef Draftsman You Personally two large wooden pulleys, as in this figure, Ch D. A friction drive from the motor, M, I am Chief Draftsman of a large and well known firm. I have been doing and the pulley, G, gave sufficient reduetion Pay as YouWish! the highest paying expert drafting work hr a qaarter of a century and 1 know the kind of training that is demanded from the men who get the gearing, so that the tree would run very want is the night big salaries. I will give you personal instruction deal individually with WHATIkind of en. Don't working as slowly. I had concealed about two dozen pother about the expense. you and give you up -to -date. practical plans just your ability 1 by giving tiny lamps in foliage of I charge a very small fee for and advancement require. train you you actual work - the the trees, training you to be an expe- practical work. the kind that you must be able to do in order to hold which were fed through a eommutator rienced draftsroan.Youscan big paying positions.: will give you my individual instruction. pay the small cost as (see D), arranged as detailed, to cause nits Ifpermanent.f your work is right, I will advance you rapidly. If it is wrong, 1 will show you best. you where, make you do do all I can make an ex- expert draftsmen. and it right, and to you the lamps to flash; furthermore, some of develop pert draftsman and designer in a short time. Write today without fail. the trimmings were coated with ealcium sulphide, which glowed in the dark after the lights were shut off. Send Coupon For Chief Draftsman Dobe "The second pulley, H. by means of a Engineer's Equipment Co., Inc. belt -drove pulley, I, in the reverse direc- My Big New Book Div. 3389 Chicago, Illinois tion to that of the tree. The shaft of this Put your name and address on the free coupon or Without any obligation on me pulley was fastened to the drum in the a letter or a post card and send it to me today. I whatsoever please mail your book lighthouse, on which was mounted colored will send you absolutely free and prepaid my new Successful Draftsmanship' and book "Successful Draftsmanship. and the great full particulars of your liberei Per- sheets of eelluloid. The body of the light- special offer that I am now making on which you sonal Instruction offer to a few house was made of stiff cardboard, and get the $15.00 Draftsman's Working Outfit abso- students. It is understood that I in was high lutely free. You assume no obligations of any am obligated in no way whatever. the top mounted a candle- kind in sending in the coupon. Get in line now power tungsten lamp. The wires from this for a big paying position. Getting the book and lamp and the revolving cylinder were ar- full particulars of the special offer is the first step. ranged as in sketch E. The rocks scattered Chief Draftsman Dobe Name_ around the scene eonsisted of `willemite' Engineer's Equipment Co., Inc. that glowed under the effects of the ultra- Div. 3389 Chicago, Illinois violet light. This light was generated by Address .._.._..._...... _.._,. means of an are lamp (made as in Fig F) and hung behind the rear screen, which had a half -moon shaped hole eut in it and secure the best in FLASHLIGHTS cheesecloth pas.ed over it. The sea was and BATTERIES by insisting that made of thin, blue cloth on which was You Can Only laid strips of cotton batting. A rotating this trade -mark fan underneath the platform caused up- is on flash- Beacon Flash- heavals of the cloth, and the cotton roll- ing back and forth gave the effect of roll- light -case and lights and ers breaking on the rocks. The scenery battery. If Batteries are was made from ordinary sheets, and the your dealer made in a wide mountains, ete., marked in with chareoal." "I suppose you used the old scheme of cannot supply variety of the microphone to open the doors," I broke you with our product styles and shapes but in. write directly to us only one quality "Yes," he replied, "the same old thing, - except that the relay, after once closing, for Catalogue A2. THE BEST. kept the contacts closed and supplied cur- rent to the motor until the door was fully opened, when the circuit was broken by NE IDEAL m`P`Oz LiIIPIMIIlIt3t611- means of two springs; here's the hook-up. )qTStPT2.] 1914 -y-, OTHERS vEXaln6 I'll mark "Cigarette" si= - it Fig. G." "Ideal Fountain Light." "Well, I'll never forget that scene," I re- marked as I was leaving. 118-20 "Yes, and I'll never forget the job I'll Beacon Electric Works of National Carbon Co., NEW YORK iï have in cleaning up in time for the New BRANCHES : Year's party," grunted the "Wiz." CHICAGO, SAN FRANCISCO Yon benefit by in ntinp ing "The Electrical Experimenter" :rhea writing to advertisers. www.americanradiohistory.com 452 THE ELECTRICAL EXPERIMENTER December, 1915 SLICING

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WIRELESS TOP FOR AN AUTO- telephone receiver, and holding it to his SEEING A BASEBALL GAME BY MOBILE. ear was dumfounded when he could WIRE. A report from Belgium tells of the most plainly hear a message coming from no- (Continued from page 400.) extraordinary use of an automobile top. It where in particular. seems that a British patrol succeeded in The top skeleton formed the receiving produced that the spectator really thinks capturing a German touring car in which wires of a wireless station, and the mes- he is at the actual field. Every movement two officers were seated. The motor had sage came from the nearest headquarters of made at the regular ball ground is shown (broken down, and the officers were made the army corps to which the officers be- instantaneously at the miniature one here prisoners. longed. shown. This is accomplished by means of In glancing over the car one of the patrol an operator situated on the field, who tele- noticed a wire connection to the metallic The companies constructing the new steel graphs each movement that occurs on the "skeleton" of the raised top. Following barges that will ply the Mississippi River whole field; even if the players are prac- the wire, he pulled from under the seat a use electricity to insure absolute safety tising or the mascot lifting the bat off from fire for their cotton and other inflam- the ground, etc. All this is carefully and exactly shown on the screen. Dykes Book -FREE mable cargoes. Electric energy is now used to operate the motor -driven cranes for The entire scheme is based on the re- iotereelinr, instructive -tells you versed how to Item AUTO TRADE. how loading and discharging cargoes and for motion picture theory; instead of to become a chauffeur and repair- the film moving from one eeetitik man-SEND FOR IT-T.-d" -n..I cooking and heating in the officers' and another &L.OIRE :32 Rs* 81d0.8t. LDnls,Mo crews' cabins. in front of a light, the light mZifol& behind a fixed transparent film. This film or transparent screen, to be more exact. is a solid mass of miniature baseball figures. anyone of which becomes animated with Handy Binder the switching on of an electric light in the rear. Each figure is carefully con- for THE ELECTRICAL EXPERIMENTER cealed in a light -tight box, and when a play is about to be enacted, the operator Holds and preserves 12 issues, each of which can be moves his light along a line of the figures, inserted or removed at will, without tools. Will keep each becoming successively illuminated and Ti3f= your magazines perfectly for all time or just preserve instilled with life in due course. them like new till you bind them permanently. Made of The players run bases, sliding head or heavy material, extra strongly reinforced feet first, jump into the air for the ball ELECTRICAL at the back and covered with handsome and in exactly the same way as the player green cloth, suitably lettered in gold IENTER OC does in real life. Also, as the photograph EXpE Shipping weight 2 lbs. Add sufficient postage, other- shows, a miniature bleacher crowd is placed wise we will have to send binder by express. in front of the screen, and at either side of same are mounted complete score Order a Binder To -day and Preserve Your Magazines. boards, which give the names of the play- Experimenter Pub. Co., Inc., 233 Fulton St., N. Y. ers, their position on the team, the "runs," Book Dep't. "hits" and "errors." "Outs," "bar's" and "strikes" are duly recorded instantly by electric bulbs, placed alongside these terms, and which appear in the illustration. This wondrful device is the outcome of three years of continuous labor and in- genuity on the part of George S. Coleman. Photograph by courtesy of I. Stein, of Life -Like Baseball Player Co.

WITH THE AD MAN, Will you take a 20 lesson Wireless Course ab- The service as rendered by some so'utely FREE-even postage charge prepaid? magazines to their readers is Just something like "clam digging," as you A course that telle you everything you can possibly which is "neither fishing nor farm- will receive it, ant to know about "wireless' starting off in Lesson ho. 1 by explaining the Principles of Electricity. The Second ing," and always hard to define. cloth bound, and Third Lessons are devoted to m netiem. motors; The new service we are trying to size 7 1014 generators and wiring. And tben, by simple easy stages x this wonderful Course Luken you into "Wireless The rive to. readers of the Electrical ins., 160 pages, mysteries of "Wireless iol led to you by the use of ysuch simple language soskudfully used. that of necessity Experimenter will not be an in- 20 lessons, 350 ou must understand every word. l'ho subject i not definite something, but always illus., 30 tables, treated eupenicially, however, for the-e is as whole lesson devoted to the Theory and hlathemm lies of this epoch definite, and really valuable. with every bit of marking subject. To lend charm to the Course, the last Lesson (No. 20) is devoted to a bistory of Wireless and the How many times have you information on men wbo developed it. The wireless course positively wanted to make some particular Wireless you can can not be bought, but will be a et absolutely f ree with a l yearn subscription (12 numbers) of the 1-lectrieal article or piece of apparatus, and possibly want, be- Experimenter at $1.00. It's the biggest dollar's worth completed sides you can ever buy anywhere at any tine. Send for it found when one -half valuable in- to- day enclosiae 81.00. Send nov before you forget. you were unable to obtain some formation on Elec- The coupon below is a convenient way. But do It I art or ma`erial which was atlso- tricity, Magnetism lutely essential? Most frequently, as 1 Theory of them THE EXPERIMENTER PUB. CO., Inc. when that happened, you had to -and it's FREE as Publisher "The Electrical Experimenter Magazine." let matters rest, until by accident explained. or by Io 1g search you located the manufacturer or dealer of the article you wanted. EXPERIMENTER With our wonderfully large re- PUB. CO., 233 Fulton St., New York search fa:ilitirs we can al ost al- Gentlemen: ways place you in immediate touch On your absolute 'guarantee that your 20 Lesson Wireless Course is just as with the manufacturer or dealer described by you, you may send me sane FREE. You are to send me this Course of just the article you want. at once, all charges paid, and enter my name for a full year's subscription to the This service will be free of Electrical Experimenter, 13 numbers, for which I enclose *$1.00, the price of the charge to you, and we know you Electrical Experimenter alone. will appreciate it. (If a 2 -year subscription is desired, enclose $1.85.) Address your letter to the Ad- vertising Dept.. and I will see that My naine is every endeavor is made to supply you with the information you de- My address is sire. MILTON HVIES. (12) *Canada and Foreign Countries, $1.50 -2 years, $2.85.

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