PT. OVER T S. LLECTRICAL ILLUST. ;XPERIMENTER. CIENCE AND INVENTION

_LASSOING AEROPLANES WITH FLAME AND BOMB SEE PAGE 300

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Use this "Free Outfit" Coupon ACT PROMPTLY CHIEF ENG. CòO4E;-D- '.t. 2¢ Get the full benefit of this great offer. Send the 441 Cass St., CHICAGO, ILL. Coupon or a postal for free information without delay. Do SIR: Send at e.q.cytilly prepä0 and entirely free -complete it ,wu' -- before my free offers and guarantee are withdrawn. particulars of .vourgrèkf ôJfe-r Ñi- this month. CHIEF ENGINEER COOKE .Nome .9ddress Chicago Engineering Works DEPT. 29 441 Casa Street CHICAGO, ILL.

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www.americanradiohistory.com September, I918 ELECTRICAL EXPERIMENTER 289 1111111011111111111M111111111111111111111

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MODEL TWO -STORY STRUCTURE IDEALLY LIGHTED DRAFTING AND COMPLETE SEVENPOLE TRANSMISSION FUR WIRINIi PRACTICE OESIGNING ROOM LINE ILLUSTRATING THREE OF THE 10 DEPARTMENTS OF PRACTICAL ELECTRICAL EDUCATION, TRAINING, DEVELOPMENT 383 Electrical Experiments for Each Student ONE SUPERIOR WAY BY WHICH THIS SCHOOL MAKES ELECTRICIANS AND ENGINEERS HREE hundred and eighty -three demands and recognizes, and for which high salaries of thorough practical education. training and de- are paid. And your school life bere will he so fas- velopment experiments a year -for you to be best and most cinating the 12 months will the FOR GRADUATES. work out yourself! And the most profitable of your life. No matter what your past POSITIONS modern electrical appliances, appa- education you can enter the electrician class here. This school enjoys the highest regard of electrical Mail the coupon now for details. Industries, and those employing master electricians ratus. machines, laboratory and work -shop and engineers because of the ability of its gradu- materials with which to work, by which to B. S. ANO E. E. DEGREES IN 3 YEARS. ates, due to the practical and thorough Instruction, learn from actual experience! Also, a This school teaches Electrical Engineering also - training and development given here, in accordance and gires Bachelor of Science and Electrical Engi- with the electrical world's requirements. And large series of practical lectures, and just the neer's Degrees of recognized standing under the concerna look to this school for their bigger electri- necessary text book instruction! All laws of Wisconsin -in 3 years (36 months). This cal men. Consequently, this school can insure under the guidance of an able faculty com- substantiates this school's standing and ability and splendid positions to Its graduates. So that your posed of practical, electrical men chosen the higher. recognized electrical education you can success is certain If you enroll here -your success obtain here in a short time. begins the moment you enroll. Soon as you graduate from high positions in the actual field of Young men with High School diploma, or the equiva- you can have a position and be accepted by the electrical practice. That is what you can lent are accepted in the Electrical Engineering De- electrical world as an electrical man of ability - get at this school, and that is what you partment. Others who finish the Electricians' not a boy just out of school. ('nurse with diploma can enter Electrical Engineer- YOU EARN WHILE YOU LEARN. need to succeed. And isn't that ideal ing class -and receive degrees referred to in 3 CAN system of electrical education just what years. Mail the coupon and get complete Informa- In addition to the practical Instruction, training and you want? Jlail the coupon now for com- tion about Electrical Engineering bere and Degrees derelopmeut given at this school. an arrangement given. exists with large companies whereby students of this plete details about this school and all its school can have employment one -half day and at- advantages. ONE SUBJECT -ALL ITS BRANCHES. tend classes, lectures and laboratory tests one -half Electricity only in all Its branches -(see coupon day. receiving pay for their outside work which can ELECTRICIAN DIPLOMA IN I YEAR. lower left) Is taught here. Consequently the in- go toward helping to pay living expenses, etc., bere. 11.-re you can obtain a recognized Electrician Diplo- struction. training and development you will receive And besides the money thus received students ob- ma In one year- Itwelve months) ; and with the here will be more thorough ; you will learn more to tain actual business or technical experience, which practical method of thorough Instruction. training a shorter time and at less expense by enrolling is of extreme value for their future. Prospectus and development here (as referred to above) you here. This is not a school of many different sub- outlines this "Earn While You Learn" plan-mall will crado to with that ability the electrical world jects: nor Is it n little school. This Is an institution the coupon. SCHOOL OF ENGINEERING OF MILWAUKEE

CLIP THIS COUPON AND MAIL NOW Any Boy or Young Man Next Term Starts Can Enter This School SCHOOL OF ENGINEERING OF MILWAUKEE September 2 59--373 Broadway. Milwaukee. Wn. No Matter What His Without ,.l,ntai ng Inc :lease , n.I ,,. , r ir.nrrn, and vidi 1Ìrw,al Inl.rn rrinr Ili, f .il.,,lnal II'I.it; u1,lr,1, u,..r..te.l Prepare to Enroll on That Day In. \Iail'rI Education ' September sooner if you Ìan M START here Jnl;o,.;'>';;r''I ( i THERE Is the proper starting place here -or Pr,r, q,o.e unÌb.r I, , for every young man whatever his past like -and start at once to get the superior, ( le e Pr.ellral leo I ,.I. , 12 ytl_ E cml fa,.lri education The main re- thorough. practical electrical education. IFr r ihr.. , rrr n: , or present ability. is the training and development this school glves. F:IMIr1e.l r:. : cu;',I 1 .alrem, -nt for entrance In this school Special Short Courses. ambition to succeed, and the will to work. Start tow -and graduate the sooner. Instead I e r and later. I:4,Ir4 Tr. Uhler and LICen wh I 1:.. r Metern an whatever your age mr education you can enroll of waiting until later, graduating L1- n )Inter I:.;a marl II EIrrrÌ..rlc w'Irnnan ( once. Special here- you'll be advanced as your ability Begin your life's success at Ti]-: h.nr Trwlhle a d Iterfa6 a n Ur:.l . i.a n( I privileges granted to those subject to draft this Wirt 17..vf al F:ugl'..e, Iv"Itrve t o- arrants. This Is all electrical sehnoi for all ul Tl.r t year or Inter- explained in prospectus. Mall n -lent rival lY ambitious young men- -and all S'Ay1F.. ... ,de,Iri,ally ambitious ynm'g men should enroll the coupon at the left. Get all the Informa- ADr,ltFS. 1,e, nor rile nnr.plalled advantages and bene- tion NOW. lis they and the world veil( Prepare to enroll September 2 -Your Success TTY 1\TF; mince elr,trical drriv.. Starting Day. -

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www.americanradiohistory.com ERectricai Experimenter 233 FULTON STREET, NEW YORK Publisbt by Experimenter Publishing Company, Inc. (H. Gernsback, President; S. Gernsback, Treasurer;) 233 Fulton Street, New York

Vol. VI Whole No. 65 SEPTEMBER, 1918 No. 5

LASSOING AEROPLANES WITH BOMB AND FLAMEyE Front Cover POPULAR ASTRONOMY-THE SUN AND HIS SATELLITES. eorge Wall THIRD PAPER. HOW THE ELECTRIC "SEA TANKS"AIDEDnPOLA R By Isabel M. Lewis, of the U. S. Naval Observatory 310 By H. Winfield Secor 293 THE GYRO ELECTRIC DESTROYER -ONCE MORE. SHALL THE BALLOON MICROPHONES TO WARN OF AIR RAIDS 295 READERS OF THE "E. E." BUILD ONE? 312 AMERICAN AVIATOR ESCAPES UNDER HUN ELECTRIFIED THE PHENOMENA OF ELECTRICAL CONDUCTION IN GASES. 296 PART FIVE. By Rogers D. Rusk, M.A. 314 MAKÌNGFE SYNTHETIC GEMS IN THE ELECTRICyy FURNACE. , EXPERIMENTAL PHYSICS, LESSON 15, CURRENT ELEC. Holmes 2998 TRICITY (Continued) By John J. Furia, A.B., M.A. 315 TEST DIVING MACHINE TO UNDO U.BOATS' WORK U. S. SIGNAL CORPS RADIO OUTFIT IN FRANCE 316 ELECTRICITY AND RADIO AS USED BY 'MOVIE" SPIES 299 THE EINTHOVEN STRING GALVANOMETER-ITS THEORY, LASSOING AEROPLANES WITH BOMB AND FLAME. OPERATION AND CONSTRUCTION By Samuel D. Cohen 318 By H. Gernsback 300 A GRAPH FOR SOLVING WAVE LENGTH, FREQUENCY INDUC- NEW ELECTRICAL IDEAS ON SUBMARINES AND TORPEDOES 302 TANCE AND CAPACITY By E. M. T. (Radio Engineer) 320 POPULAR DEMONSTRATION OF THOUGHT-TRANSFERENCE HOW TO BUILD A HAND MILLING MACHINE..By Thomas Reed 322 AND OTHER PHENOMENA. GLASS BLOWING IN THE EXPERIMENTAL LABORATORY. By Albert Abrams, A.M., M.D., LLD. 304 By Prof. Herbert Metcalf 324 "OVER THERE " -A MINIATURE WAR PANORAMA. By George Holmes 305 EXPERIMENTAL MECHANICS -METAL TURNING. THE BLIND NOW TAPE ELECTRIC COILS 307 LESSON 6 By Samuel D. Cohen 326 NEW ELECTRIC FUSE LIGHTER FOR BLASTINC 308 EXPERIMENTAL CHEMISTRY-28th LESSON. MAKING ELECTRICIANS OVER NIGHT 309 By Albert W. Wilsdon 328

COLD FROMOo M ELECTRECITY F we pass an electrical current thru a more dyspepsia than all the other causes combined. metallic wire, the latter becomes heated. Water cheaply to cooled near the freezing point is what r g The thinner the wire and the larger the we need, so our doctors tell us. When will we see the current, the greater the heat in the wire. first direct electrically cooled carafe, with its wire - All of our incandescent lamps work on covered net work, and a plug connecting it with the this principle, as do our electric irons, chandelier above the dining table? toasters, water heaters, etc. And where is the still greater benefactor who will But few people know that electricity can and does increase our working capacity one hundred per cent produce cold direct, merely by passing from one cer- when the thermometer stands over 90°. During torrid tain metal to another. Nor is it a recent discovery. spells, even in moderately hot weather, the entire world The device, termed "Peltier's Cross" after its French slows down. You simply can't work your best during inventor, Peltier, was demonstrated in the middle of the dog days, even if you happen to sit in a bathtub the last century. Briefly, the apparatus consists of two full of cold water, as I am doing just now, trying to LO bars of metal, one being Antimony, the other Bismuth. write this Editorial! (The heat, by the way, furnished The two bars are soldered together at right angles form- the idea for it!) ing a cross. If we now pass a current thru the cross From late spring to early winter, millions of radia- by connecting the positive pole of a battery to the Bis- tors stand idle all over the world. Why have we not muth bar, and the negative pole to the Antimony bar, sufficient intelligence to turn these perfectly good heat- the point of junction between the two metals becomes ing plants into cooling plants? The system is in the Lc21 rapidly cooled. If we drill a shallow hole into the top house and waiting, but we are too stupid to circulate o bar and fill it with water, it soon turns into ice, prov- freezing water tltru it, and thus reduce the room tem- ing the experiment. perature to 70° or less. A visitor from Mars would This phenomenon is of course well -known to the laugh his head off while walking into our offices where electrical man, but the very surprising fact is that it the already hot air is made still hotter by fans n lias never been turned into practical use during all these which do not cool by the way, but increase the tem-- years. Of course, it goes without saying, that the perature. (Put your hand on a running fan -if it is original Peltier's Cross is not an efficient apparatus - not too hot -and you will know why fans do not cool it would be decidedly expensive in time as well as money a room.) Our visitor could not possibly understand to freeze ice cream this way! why our radiators were hot instead of cold. But the principle is certainly there, and it is pretty But we will not always be children. Some day we'll well understood by the scientist; all it needs is im- grow up and then we will know enough how to keep provement. And right here lies a wonderful gold mine cool in summer, be it in the office, the house, or in the for the man who turns out an economical electrical subway. But when that day comes, be prepared to shut apparatus to produce cold commercially. Think of all all doors and windows, just as you do in the win- the ice -less refrigerators, ice -less ice chests, ice -less ice ter. If you don't your room will become hot just cream freezers and what -not, for which we are eagerly as it becomes cold in the winter, should you leave the waiting. Where is the benefactor who will lift the door open. Yes, and great American curse-ice water? Ice water is re- then we'll all have summer colds, to be sure I sponsible for more ruined American stomachs, and for H. GERNSBACK.

l IV-1 The ELECTRICAL EXPERIMENTER is publleht w the 15th of each month at 733 canna, "u.l unieas full postage bee be n Includ d. ALL accepted cootribu- Fulton Street. New York. There are 12 numbers per year. Subscription price a $1.50 a tlons are paid c for su on publication. A special rate I paid or novel experiments; good Year In O. S. and posessalooa. Canada and foreign countries. 72.00 a year. U. S. coin as photogrephs accompanying them are highly desirable well as U. B. stamps accepted (no tordre coins or stamps). Single copies. 15 cents each. ELECTRICAL. EXPERLIIE \'rER. Monthly. Ente rd as second -clue matter at the A sample copy will ha sent gratis on request. Checks and money orders should he drawn New York Post OM, under Act of Congress of March 3. 1819 Tille registered U. S. to order of EXPERIMENTER PUBLISHING CO.. INC. U you change your address Patent Office. Cot, 1918. he E P. Co.. In ., New York, The Contenta of this notify us promptly, In order that copies are not miscarried or lost. A preen wrapper In- magazine are copyrighted and must not be reproduced without giving full credit to the dicates expiration. Ne copies sent after expiration. publication. All communications and contributions to tide Journal should he address to: Editor. The ELECTRICAL EXPERIMENTER Is for sale at all newsstands In the United States ELECTRICAL EXPERIMENTER. 233 Fulton Street. New York. Unaccepted contrihu- end Canada . aka ai Strentanis, 3; avenue de t'Opere. I'es. 291 www.americanradiohistory.com 292 ELECTRICAL EXPERIMENTER September, I 9 1 8 `LEARN BY DOING' The Only Way to Learn Electricity

The only way you can become an expert is trical Contracting, together with the skill to by doing the very work under competent in- install, operate and maintain all systems for structors, which you will be called upon to do producing, transmitting and using electricity. later on. In other words, learn by doing. That A school for Old and Young. Individual in- is the method of the New York Electrical struction. School. No previous knowledge of electricity, me- chanics or mathematics is necessary to take minutes of actual properly Five practice this electrical course. You can begin the to a man than years directed is worth more course now and by steady application prepare and of book Indeed, Actual Prac- years study. yourself in a short time. You will be taught tice is the only training of value, and gradu- experts with actual ap- School have by practical electrical ates of New York Electrical paratus, under actual conditions. s,000 of our to the only men that are proved themselves be students are today successful electricians. to demand of fully qualified satisfy EVERY Come in and read their enthusiastic letters. the Electrical Profession. Let us explain this course to you in person. If At this "Learn by Doing" School a man you can't call, send now for 64-page book - acquires the art of Electrical Drafting; the it's FREE to you. best business method and experience in Elec- SCHOOL OPEN ALL SUMMER. Unusual Facilities for Providing Roam and Board at Low Rates

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Vol. VI. Whole No. 65 SEPTEMBER, 1918 Number 5 How the Electric "Sea Tanks" Raided Pola By H. WINFIELD SECOR

very latest war -time animal is barbs or knives which can cut their way their way thru the heavy steel nets span- the electric "Sea Tank" as used by thru nets and other obstacles just like their ning the navigable approaches to the port, the Italians in a recent naval raid on prototypes, the land tanks, first used so ef- within which there lay at anchor Austria's TliEPola, Austria's famous naval base. fectively by the British. This under -water fighting fleet, and that a mighty Austrian From the information available on demon is provided with several torpedo battle -ship of the Virubus Unitis type of this latest hybrid among war -time offensive tubes at the bow, and from all accounts, it about twenty thousand tons displacement devices, it is learned that the Sea Tanks seems that the device was crewless, and was torpedoed. measure about forty feet in length and six operated by means of electrical control The detail illustration herewith shows feet in width, and that they are propelled currents sent thru a flexible insulated cable the probable arrangement of the interior of

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Copyright. 1918, by E. P. C The Italian Navy Recently Carried Out a Remarkable Attack On Pola, Austria's Famous Naval Base, In Which the Latest Engine of Wa , The Electric "Sea Tank," Played the Leading Rôle. These Monsters with Their Net -Cutting Knives and Controlled by Electricity from a Mother Shlp, Past Thru All the Harbor Barriers and Blew Up a 20,000 Ton Battleship. by electricity. Further, as our illustration connecting with a war vessel, which latter the Italian Under -water Tank, also the ar- herewith shows, these Sea Tanks are pro- nosed its way up to within a few miles of rangement whereby the steel belts carrying vided with an endless rotary chain, running the steel nets guarding the harbor of ¡'ola. the net -cutting knives or barbs are driven lengthwise around the vessel, these rapidly The account of the attack on ¡'ola by the by powerful electric motors, which obtain moving chains being fitted with sharp steel Italian Sea Tanks states that they bored current from a storage battery carried in 293

www.americanradiohistory.com 94 ELECTRICAL EXPERIMENTER September, 1918 OBTAINING ELECTRICITY DIRECT FROM COAL GAS. How Artillery Observation Electricity direct from coal gas is pro- claimed as a possibility. According to the claims of a prominent New York engineer, Balloons `Phone to Earth the new process involves an electrolytic cell used as follows : The method is to dissolve When the artillery observers of our army man of keen sight and quick perception to in an electrolyte of fused borax the oxid in France, go up in balloons for the purpose fulfil the duties of an observation officer, as of a metal such as manganese, which forms of spotting the shell two or more oxides of hits and correcting the different degrees of ranges, they must have oxidation, and passes a positive and sure from a lower to a means of communicat- higher degree of oxi- ing with the artillery dation when in contact officers on the ground. with air, and from a The photograph here- higher to a lower when with shows a telephone in contact with a reduc- dug -out in France with ing agent, such as fuel two United States sol- gas. When the solu- diers. who are in direct tions of a higher and a telephonic communica- lower oxid are brought tion with the aerial ob- into liquid contact at server above by virtue any point a difference of a thin copper wire of electrical potential which runs up to the results, and if an appro- balloon basket. T h e priate electrode is im- work of the aerial bal- mersed in each of the loon observer is more solutions a current of or less hazardous, and electricity will pass in a it not infrequently hap- conductor joining them, pens that the observer's so long as the differ- balloon is shot down by ence of oxidation re- an enemy shell, in spectively in the two which case he must use solutions is maintained. his wits and endeavor The current is about to make a safe landing one volt, and front 15 with his parachute. On amperes upward the other hand, it has often been remarked by Madrid gets its elec- had tricity for lighting and officers who have t,ro n to' Commits, e n PIN le Information see- power from a hydro- the opportunity of This Photograph Shows Two American Telephone Men in a Dug -Out In France, ing service near the Eu- Carrying on Communication With an Aerial Observer in a Balloon. These Men electric plant 120 miles ropean battle - fronts, Perform a Most Important Service in That They Control the Fire of the Artillery. from the city. that these observation balloons will sometimes remain aloft and the changes in range in some cases have to An electrically equipt tremolo attach- unscathed for days at a time. The work be made very quickly in order to bring ment for stringed instruments has been is extremely interesting and plenty of vol- about a certain military maneuver. \Ve may invented which produces the desired effects unteers are always available. It takes a safely entrust this task to Pershing's boys. when buttons are prest. the undersea craft, or from electric energy Pola may seem all the more practical and "Sea Tank" while it is submerged. By supplied thru the cable connected with it. possible to the layman when it is considered means of a sensitive microphone installed The electrical control cable in such devices that the entire Gulf of Venice is very in the vessel, it would be possible to ascer- as this, and where it is of any considerable shallow -about 120 feet at greatest depth- tain when the Tank had chewed its way length. is invariably coiled up and stored and such an underwater fighting monster thru the enemy nets, and it could then be in the tank or torpedo, as otherwise the might crawl even along the bed of the Gulf caused to approach the surface again if so device would have to be extremely power- of Venice and tackle the steel nets and mines desired. It is not however, imperative that ful in order to pull the constantly increas- protecting Pola, much in the same manner the vessel be made to come to the surface ing length of cable thru the water if it were as a gigantic turtle would crawl along the so as to show the signal light, for by means stored in a magazine on the tender ship. bed of a lake. in fact, some engineers of the position indicating apparatus just de- It is entirely feasible for a device of this venture the opinion that with the proper scribed, its exact position at any moment kind to be controlled by a warship of the design of the moving caterpillar belts and could be known and torpedoes discharged destroyer class at a distance of seven miles barbs, that the Tank could be made self - from it at an enemy war vessel swinging or even eight to ten miles or more. With propelling in the same manner as just men- at anchor within the netted area. ingenuity and the proper design of the tioned. device of the type here under discussion, It is most probable however, that the U. S. PATENT OFFICE NEEDS and also in consideration of the undoubted Italian Sea Tank as now used is fitted with EXAMINERS. and proven cleverness of the Italian en- powerful propellers the same as the sub- The U. S. Patent Office announces a need gineers, there is no doubt but what such a marine, and also that it has a suitable rudder for technically trained persons for the ex- device could be sent out and steered so as for the purpose of steering it. To prevent amining corps of the Patent Office. Men to he submerged when it neared the steel the cable from becoming fouled in the or women are desired who have a scientific nets and to bore its way thru them, and propeller blades, the latter are encased in education, particularly in higher mathema- then to rise again; also at this juncture the substantial steel cages. The pilot light or tics, chemistry, physics, and French or Ger- observation officer on the war vessel look- lights are provided with shields at the front. man, and who are not subject to the draft ing thru his night glasses, could press the so as to throw intermittent signal flashes for military service. Engineering or teach- proper electric control button and cause one sternward, and by arranging this on a tele- ing experience in addition to the above is or more torpedoes to be discharged at an scopic mast the officer in charge can, by valued. The entrance salary is $1,500. enemy war vessel in the manner described simply pressing the uroper button, cause Examinations for the position of assistant in the report from Rome, and which now them to rise ten to fifteen feet above the examiner are held frequently by the Civil forms a part of Italian naval history. hack of the Sca Tank while it is progressing Service Commission at many points in the In any event, the Sca Tank would appear thrti the water near its objective. When United States. One is announced for to prove an invulnerable antagonist against the Tank has progrest sufficiently near the August 21 and 22, 1918. Details of the ex- such war measures as harbor nets and the net or other obstruction it is to burrow thru, amination, places of holding the same, etc., like,' and it is conceivable that when dc- the proper electrical impulses are sent over may be had upon application to the Civil signed to carry a crew, and providing the the electrical control cable which starts up Service Commission, Washington, D. C., or craft k equipt with powerful under -water the water- ballast tank motor, and by filling to this office. searchlights. such a machine should prove the tanks, the craft is caused to submerge Should the necessity therefor arise tem- highly effective in clearing out mine fields. It is a simple matter and one which has been porary appointments of qualified persons and particularly such mine -infested waters used heretofore to provide a suitable elec- may be made pending their taking the Civil as those leading up to the great German trical position indicating arrangement, Service examination. Application for such naval base at Heligoland. This maneuver whereby it becomes possible to know at any appointment should be made to the Com- by the Italian Sea Tanks in their attack on instant the direction and location of the missioner of Patents, Washington, D. C.

www.americanradiohistory.com September, 1918 ELECTRICAL EXPERIMENTER 295 Balloon Microphones to Warn of Air Raids By LEE À. COLLINS

IN the scheme of aerial raid warning here Military Committee reports as one of the Allies had thus gained some information proposed balloons are sent up and held greatest scientific achievements of the war, in a way which had long puzzled the Ger- secure by means of a strong rope or the telephone arrangement whereby the po- mans. cable. Sensitive electric microphones are sition of enemy guns is determined. A fastened to the under -harness of the bal- portion of General Bell's statement follows: MARCONI 11,000 K. W. BUENOS loon. All of the sound detectors are in All armies now employ scientific methods AYRES RADIO PLANT. is to erect the series with a telephone receiver and a of locating guns which have never been The Marconi Company near source of electric current by means of two employed in warfare before. One is known largest wireless station in the world J. Nally, vice wires which lead down by the cable. as the sound- ranging method. Briefly, they Buenos Ayres. Edward

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A Numberof French Cities Are Equipt With a- Specially Sensitive Microphone "Listening- Posts" Placed On High Buildings or Other Elevated' Structures, for the Purpose of Detecting the Approach of Enemy Aircraft. An American Inventor Here Proposes a Very Simple and Feasible Plan for Giving Aerial Alarm .Frotectioq' to Our Towns and Cities. The Scheme Is Simple, Involving the Use of Small Bal- loons Which Carry a Series of Horns Pointing in Various Directions, Each Horn Being Connected With a Super -Sensitive Microphone; Each Microphone Is Connected By Its Wire to Earth. Where a Selective Switch and a Pair of Listening 'Phones Enable the Operator to Quickly Ascertain Which Microphone Is Being Actuated, and Thus Also From Exactly What Direction the Enemy Aeroplane Squadron Is Approaching. These Microphones Will Indicate the Approach of Aircraft Several Miles Away.

Balloons can be sent up all along our have observers scattered along a curved line, president and general manager of the com- coasts or cities at suitable distances apart. which has been accurately measured, and pany, has just closed a contract for the in- In case an enemy aeroplane attempts to all of these observers, of whom there are stallation. The power of the new station, bomb our cities, the sounds of his aeroplane usually six, utilize electric sound -ranging it is announced, will be 11,000 kilowatts, and engine are caught by the sensitive micro- apparatus by which they report instantane- three towers will be erected, each the size phone detectors and are heard thru the ously the moment they hear the sound of of Eiffel Tower. telephone receivers. One central listener a gun èxplosion. At a central point another could keep the receivers fastened to his electric apparatus records these sounds from ears and receive the alarm from all of the the six different stations, and by a scientific IMPROVE NAUEN WIRELESS detectors, or a listener could be kept for method they combine the knowledge gained PLANT. each district that the balloons were guard- from these six points and succeed in locat- The German wireless station at Nauen ing. A galvanometer indicator can be used ing with a remarkable degree of accuracy has been greatly improved since the out- instead of the receivers to give a signal of the position of the gun that made the ex- break of the war, according to the Frank- approaching enemy aeroplanes. The range plosion when it was fired. furter Zcihutg. Instead of a single trans- of detection will probably be greater than Each side has a type of telephone which mission tower 300 feet high, it now has ten most people estimate, as tests made with is able to hear distinctly over very consider- towers ranging in height from 890 feet to microphones in locating pieces of artillery able distances conversations not intended 360 feet, while the distance thru which have proved. ' for the listener, and for a long time the messages can be transmitted has been ex- Allies employed this system of gaining in- tended to 6.200 miles. The Frankfurter SOUND -RANGE TELEPHONES TO formation without the knowledge of the paper is quoted as saying that the Nauen LOCATE GUNS. enemy; but the Germans captured one of services have proved invaluable for instruct- Upon his return recently from the battle these instruments and discovered that their ing cruisers and U -boats and that both the front in France, Major- General J. Franklin conversation in the trenches had been Gocben and Breslau received thru Nauen Bell in supplying information to the Senate listened to for quite a while and that the instructions to steam into the Bosphorus.

www.americanradiohistory.com tí ELECTRICAL EXPERIMENTER September, 1918 American Aviator Escapes Under Hun Electrified Fence HOW would you like to be captured Another idea which he unsuccessfully and his liberty. He kneeled down and offered by the Teutons, and after escaping tried out was a ladder which could be thanks to his Maker for his miraculous .from your captors, not to mention placed against one of the fence posts, and escape, and a few minutes later he past sleeping in swamps and woods by this he built from small twigs and boughs safely between the strands of the final day. and subsisting on fruits and which hé found in the woods near the fence barbed wire into Holland. raw vegetables, finally reach the border line and bound them together with flexible twigs which meant your liberty, only to find that and strips from his underclothes. GENIUS AND ULTRA VIOLET a deadly electrified wire fence stared you Eventually Lieutenant O'Brien hit upon RAYS.. square in the face? Such was the experi- the idea which finally saved his life and By J. Marchetti ence of an American flier, Lieutenant gave him his liberty, and his plan is shown In a back number of the E. E. there ap- Patrick O'Brien, member of the Royal Fly- in the accompanying illustration. This was peared an article entitled "The Effect of ing Corps of England, who managed not nothing else than to burrow under the elec- Ultra Violet Rays on Milk and Other only to escape from his German captors, trified wire fence. However, this was not Aspects," by Dr. Humbert Bizzoni. In this after having landed on Teutonic soil with as easy as it may seem at first thought. he says that "the cerebral substance is de- his flying machine, but succeeded eventually The electrified fence measured about ten composed by ultra violet rays causing sun- in getting past the highly charged electric feet high and the charged wires were spaced stroke, when the rays of the sun are suffi- fence which guards every foot of the about ten inches apart while the lowest ciently powerful to react on the body." He border land between Belgium and Holland. charged strand was but two inches from shows that it is not the heat that causes This fence serves three purposes. First, the ground. This is not all, for when our this, for we never hear of heat prostration it prevents the Belgians from escaping into brave Lieutenant had dug a considerable "among workers in foundries, glass and Holland; secondly, it keeps enemies from quantity of the soil away with nothing but pottery factories, etc., where a high tern - perature prevails. Yet these same men may BARBEO WIRE be taken with a sun- FENCE stroke upon exposure to the sun." BARBED [ Still it is a matter of surprise when we :_NCE read in the memoirs and confessions of de- 10-12h ceased geniuses that they accomplished bet- ter work in the intense sunlight. In fact some of them could not work unless the sun's rays fell on their bare heads. No doubt, the ques- tion has often pre- sented itself to many, why many men of 1'4' ,, w.NEAwilt genius have preferred ,'l'RLNCN wntEn114R,a,r SOLDIER CRAWLED or had to compose in 111011 TENSION EaCCrR,C FENCE the scorching rays of the sun. But may we not find an answer in One of the Most Thrilling Experl- Dr. Bizzoni's discov- entes of the War Is the Tale of ery. And when we an American Aviator- Lleut. Pat- rick O'Brien of the R. F. C.. see that genius and Who Being Captured by the Ger. madness grows in mans. Finally Made HI. Escape the Thru the Highly Electrified Fence same pot, according Between Belgium end Holland. He Succeeded In Digging 'a Tun to C. Lombroso, and net Under the Charged Wires. that post -mortem ex- aminations have f shown degenerations of cerebral matter of making their way to freedom; and thirdly, his bare hands, lie discovered a heavy un- many great men of this type the conjecture it prevents desertions on the part of Ger- derground wire about six inches below the becomes more convincing. As the sunlight man soldiers themselves. surface of the ground. He had great diffi- is rich in violet rays and they are capable of The accompanying illustration shows one culty in digging the earth away without decomposing the cerebral substance, conse- of the most remarkable experiences ever being discovered by the sentry who walked quently they acted for such melt as stimu- enacted by a war- tortured human being. up and down periodically along the German lants. We all know that many famous men \ \'hen Lieutenant O'Brien finally emerged side of the fence, and again, the under - have resorted to narcotics and other stimu- from his last hiding spot in the woods near ground wire, which was as thick as a man's lants in aiding them in their creative works. the Holland border, he nearly ran into this finger, would not give. So for these individuals the ultra violet rays electrified barbed wire barrier before he But Yankee pluck and courage finally won, acted as creative aiders by effecting chemi- knew it, altho he had previous knowledge of and by tugging at this wire, which did not cal changes akin to narcotic stimulants. it. carry any charge but served merely as a Also, light vibration acts therapeutically The hero of our story first thought of guard wire against just such an escape as this, by its penetration. But in the case of these trying to make a grand pole vault over the he caused the underground wire to give at men the dissolving power of the ultra violet whole three fences including the central several points along the fence. He then rays was of greater consequence. electrically charged one, but this idea was proceeded with extreme caution to crawl Among such "Sun Fiends" we find finally dropt as the triple fence covered a feet first and on his stomach thru the trench Rousseau, Lesage, Giordani, etc. Rousseau span of at least twelve feet, and in order which lie had dug with his hands. His said that the action of the sun in the dog - to safely clear the last barbed wire barrier nerves were none too good, but he knew days aided him to compose and he allowed he would have had to vault at least ten feet that one false move of even one inch, would the rays of the mid -day sun to fall on his high and fourteen feet across. With the mean certain death, and in a few moments head. The striking fact is that Rousseau's possibility that if the pole ever slipt he he successfully made the passage under the brain showed, after death, a marked de- might be thrown on the charged wire and heavily charged wires and emerged into the generation of one of the lobes. Lesage, immediately electrocuted when in falling his final space between the central electrified in his old age, became animated as the sun body would establish the circuit between fence and the final barbed wire which was advanced to the meridian, gradually gaining fence and ground. the only remaining barrier between himself (Continued on page 351)

www.americanradiohistory.com September, I 9 1 8 ELECTRICAL EXPERIMENTER 297 Making Synthetic Gems in the Electric Furnace By GEORGE HOLMES, Asso. A. I. E. E. THE history of jewels and the thrill- in India the Rajahs gave the privilege of fallen in Arizona and was shipt immediate- ing part they have played in the mining to their subjects with the proviso ly to the University of Paris for examina- world's history would make the that all gems above a certain size were to tion. Out of the discoveries of the pure "Grimm's Fairy Tales" fade away be sent to the Rajahs themselves. As a re- carbon or diamond crystals that the meteor into oblivion. Kings, Queens, Sul- sult, whenever a large stone was found it contained conclusions were formed that it tans and entire Kingdoms have been wreck- was broken by the miners. only an occa- was chiefly a continuation of heat and pres- ed thru the many intrigues and mysteries sional one being sent to the Rajah to insure sure that made jewels. that have been connected with famous the continuation of the mining franchise. Dr. Aisen at this point became deeply jewels of ancient times. There was Caesar, At that time jewels were cut and polished interested in gem making; and analysis of Anthony and Nero and the havoc they by rubbing them against each other. It the component minerals in various jewels

SMALL GEMS IN GLASSLIKE MASS AS THEY COME. PROM THE ELECTRIC FURNACE

GEM ROUGHED GEM CUT TO OUT SIZE

FINISHED SYNTHETIC ,JEWEL AFTER POLISHING

a Gem In the Fierce Heat of Manufacturing Precious Stones in the Electric Furnace: 1 -Dr. Maurice Aisen at Work Making Synthetic 2-One View of the "Gem Making" Laboratory. 3- Another View of Dr. Alsen's the Electric Arc -the Greatest Heat Known to Science. Are Turned Out by the Workshop, and 4-a Close-Up Glimpse of a "Battery" of Electric Furnaces in Which Rubles and Emeralds These Synthetic Jewels Is Illustrated by the Small Border Views. They Hundred for the Jewelry and Allied Trades. The Evolution of Furnace, But the are "Roughed Out," Ground and Polished the Same as Regular Gems. Diamonds Have Been Made in the Electric Synthetic Diamond Cannot Be Manufactured Economically Just Vet. wrought on Rome and the splendid cities was not until the fifteenth century that the followed, including various tests as to the of the far famed east; not to mention Cleo- present rotating wheel method of polishing proper application of heat and pressure. In patra, the charming Queen of the Nile, who them was introduced. his laboratories Dr. Aisen has formulas put the skids under a number of happy In the olden days the manufacture of a which can produce almost all known jewels rulers just because she was the best drest perfect stone was a long and tedious opera- and semi -precious stones, the only excep- woman in Egypt and changed her jewels tion. To -day it is a fact that jewels can tion being so far the diamond. seven times a day. he analyzed, the component minerals found, After a gem has been analyzed and its For centuries it was necessary to mine then the same proportion of ingredients component minerals found, the same pro- these wonderful gems, by the sweat of the assembled and synthetic jewels actually portion of ingredients are assembled and brow; but now all this is changed for to -day manufactured, which equal Nature's own put into crucibles where they are raised to in the very heart of New York City, an product. the required temperature and then are sud- expert electro-chemist in the person of Dr. Some of the earliest experiments in arti- denly cooled. There are a number of meth- Maurice Aisen is making precious stones ficial or synthetic jewel making were per- ods used to obtain the desired high tem- with the aid of the electrical furnace that formed in Dr. Aisen's student days in the perature necessary in this marvelous bid fair to rival all those of ancient times. University of Paris. One day Prof. Henri twentieth century work. Among the first There are more large and beautiful dia- Moissan, his instructor and world famed is the oxygen- hydrogen flame. Various monds in the world today than rubies and chemist, found diamond crystals in the types of electric furnaces are now used and this has a curious explanation. Ages ago meteor. The meteor was one which had (Continued on page 354)

www.americanradiohistory.com 298 ELECTRICAL EXPERIMENTER September, I 9 I 8 Test Diving Machine to Undo U- Boats' Work

ADEEP sea diving machine designed phone communication established with the the project is capable of a development of for use in raising torpedoed vessels barge. The telephone operator on the barge 225,000 k. w. was tested in Long Island Sound manipulates the necessary switches. HE DUCKED THE LIGHTNINGIIt off New Rochelle, X. Y., recently. Olympia, \ \'ash., is sonic speedy place - Its inventor, \V. D. Sisson, has ELECTRICAL RESISTANCES AT lf you don't believe it read this! asked for a Government trial. LOW TEMPERATURES "Lightning struck in the same place twice The machine, propelled by an electric By Harry E.'Dey, E. E. in 30 years when it destroyed the home of motor. went down ninety -eight feet, bored The resistance of all pure metals to the Mrs. D. G. Parker, on Eastside street," says holes in a steel plate, inserted riveted and flow of electricity decreases in proportion a "special" dispatch to a local paper of that brought the plate to the surface. It was with the temperature, until at the absolute city. manipulated by two men inside. The cur- zero, (minus 273 Centigrade) there is no 'A neighbor climbing down an Adjoining rent was furnished from a barge. Its in- resistance. If it were possible to extend cherry tree managed to duck the flash. ventor asserts that the machine can be used wires to the space beyond our atmosphere, Fire followed that burned the Parker house. to fasten water tilled pontoons to sunken which is supposed to have a temperature of Mrs. Parker escaped without being ships. Then. when the pontoons are emp- absolute zero, unlimited power could be stunned." Well! \Veil ! tied, the ships will be brought to the surface. transmitted from any one portion of the Propellers on the bottom for moving up earth to the farthest point away on the filmi- NEW MEXICO RADIO STATION and down and two on the side for propul- est of wires and without loss, excepting on There has been establisht a new Mexican

This Deep Sea Diving Machine, Intended for Use In Raising Torpedoed Vessels, Was Tested In Long Island Sound, New York, Recently With Success. The Device, Propelled By An Electric Motor, Went Down Ninety -Eight Feet, Bored Holes in a Steel Plate, Inserted Rivets and Brought the Plate to the Surface. Its Crew Is In Constant Telephonic Connection With the Salvage Crew on the Barge. At Left - Examining the Drills and Electro- Magnets. Top Right -Going "Over the Top." Lower Right -Hand View- Lights On and Going Down. sion forward and backward, make the ma- that portion passing thru the air which is Wireless Station on the island of Lobos, chine easy to maneuver. It is nine feet estimated to extend about 45 miles above off the coast of Tampico, erected mainly long, seven feet, six inches in diameter and the earth. From New York to the moon for the purpose of affording facilities to the weighs nine tons. would waste much less power than is now various petroleum companies for com- Powerful magnets on the outside hold lost between New York and Buffalo. municating with their vessels over great the machine against the ship into which distances at sea. This station is said to be rivet holes are bored. Small glass port- RECORD -BREAKING HIGH VOLT- provided with some of the most powerful holes permit the machine crew to see what AGE POWER LINE. apparatus available, and is expected to they are doing. Strong electric lamps light The Big Creek system of the Southern establish communication with the Wireless the water for them. There is equipment California Edison Company transmitting Stations at Mexico City, Tuxpan, Tampico, for expelling exhausted air and pumping electrical energy at 150,000 volts into Los \'era Cruz, Progresso, Frontera, Mazatlan, tvater from the ballast tanks. Communica- Angeles, a distance of 275 miles, represents Santa Rosalia, La Paz. Queretaro, Monter- tion with the barge was maintained by a world's record in power supply. This rey, Saltillo. Torreon, and by way of telephone. One of the photos shows the splendid system has two steel tower lines. Havana with various stations in the United inventor and a member of the crew in- It receives its energy thru single phase States. specting magnets and drills. A second transformers weighing 81 tons -the largest photo illustrates the diving and salvaging yet built. Energy is generated from two With wireless stations powerful enough machine ready for a plunge beneath the power plants, one dropping the water 1,900 to reach vessels in all of its vvaters, the waves. while the third photo shows the ma- feet and the other 2,100 feet. The present Chinese government will establish a typhoon chine going down, with lights lit and tele- installed capacity is 64,000 k.w. Ultimately warning service.

www.americanradiohistory.com September, 1918 ELECTRICAL EXPERIMENTER 299 Electricity and Radio as Used by "Movie" Spies By GEORGE HOLMES

motion picture dramas seem to tires to shadow him. At the time the the infamous Imperial German Government. be filled with scientific features United States and Germany were maintain- And listening in on the wire which had now -a -days, especially in connec- ing friendly relations, sincere on the part carried the summons to Heinrich von Lertz T HEtion with German spy plots. To be- of the Washington Government, but ab- was - gin with we have the big patriotic solutely hypocritical as far as the Kaiser's Miss Dixie Mason of the Secret Service. film serial "The Eagle's Eye," from which representatives were concerned. That explains why that just at the mo- we show photos of three episodes. The So the operatives assigned to Dr. Albert ment when the Hun spies had started to first is the adventure of "The Brown Port- merely watched him, noted his visitors and raise the aerials on the wireless mounted folio." The greatest single discovery which his daily routine. Everywhere he went on an automobile on a lonely road in Long has been made in connection with the in- there was an indistinguishable shadow Island, that a high powered automobile vestigation of the Imperial German Gov- always with him. Dr. Albert lost his port- loaded with Secret Service operatives should ernment's spies and plots in America, came folio because he was aroused from a doze appear. The agents of the Kaiser fled, but

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F g. 1.-Von Papen's Traveling Auto Wireless Meets %Llth Disaster On Long island and Wolf Von Igel is Seriously Wounded. Fig. 2.- Harrl- son Grant. President of the Criminology Club and Head of the Secret Service Discovers Dixie Mason at the Power Plant Switchboard with Her Arm Caught in the Switch and Herself In a Dead Faint. Fig. 3. -Dixie Mason is Surprised at the Wireless Room of the U.53. Fig. 4.- Guy Empey's "Over the Top" -The German Count and His Accomplice, at the Switchboard of a Tall Office Building Somewhere In Downtown New York, Ready to Throw the Switch at Midnight Which Will Light a Signal on Top of the Tower. Thus Notifying the Other Spies on the Jersey Shore That It Is Time to Begin Blowing Up Munition Factories and Ships.

thru the persistence with which opera- by hearing his station called by a guard on their automobile proved unfaithful and a tives of the United States Secret Service the elevated train on which he was a pas- skid in rounding a corner wrecked the ma- kept on the assignment of watching Dr. senger. He forgot the bag for a moment, chine against a bridge (see Fig 1). Heinrich Albert. Day after day, and night and his "shadow" got possession of it. Next we have the big "\lunitions Scan- after night, they followed him thru a "Doctor, if thru your carelessness those dal." French soldiers on the first line in daily routine which seldom varied. They papers have fallen into the hands of the France were saved from a merciless as- took nothing for granted and the result Secret Service." the German Ambassador sault from mast German troops at a time was that one afternoon, Dr. Albert became exclaimed, "then steps will have been taken when the French artillery would have been drowsy when taking his daily trip from his to warn the ships which are already upon useless, by the alertness of the U. S. office to the German Club. His doze cost the ocean, on which bombs have been Secret Service. Members of the Kaiser's him the possession of a brown portfolio, placed. Arrange to have wireless warnings spy army in America had successfully the contents of which was the first verifica- intercepted." started on a plan which would have made tion of suspicions that had long been held The Ambassador walked from the room a large shipment of artillery shells of every by Chief William J. Flynn, of the Secret to his own private suite. Dr. Albert seized calibre for the French artillery useless be- Service, that the Imperial German Govern- the telephone. almost distraught. He called cause it would have been of a size which ment, itself, was backing the Hun propa- Captain Boy -Ed. A second call appraised would fit only German guns. The speci- ganda in America. Captain von Papen of the disaster. A third fications for the manufacture of the shells Chief Flynn became curious about the telephone number and Heinrich von Lertz had been changed, when a trivial matter contents of a brown portfolio which Dr. had been summoned to do the bidding of of the name of the ring- leader in the plot Albert always carried and assigned opera- the arch spy -the accredited Ambassador of (Continued on page 356)

www.americanradiohistory.com 300 ELECTRICAL EXPERIMENTER September, 1918 Lassoing Aeroplanes with Bomb and Flame By II. GERNSBACK

STOPPING an aerial raid by means of fire of the boche protecting anti- aircraft erratic flight of such a device made it ex- anti -aircraft guns is a notoriously im- guns below. tremely inefficient, it was soon given up and possible undertaking. While the Nevertheless our pilots brave his barrage came into disuse. aeroplane itself is now, and probably and fly right thru it. They "slip," nose -spin, In the present device the writer proposes will always be the most trustworthy loop -the -loop or "pancake," making it al- the use of a "mother- shell" containing means two of combating enemy bombing planes, most impossible for the gunners to get the explosive bombs, as well as two "liquid - there has been felt for some time the want range. If the pilot knows his business he fire" bombs. Each one of these bombs has of other means to bring down the raider. returns invariably to his airdrome, barring a smaller companion-a heavy lead ball, the We must not lose sight of the fact that a few holes in his wings or in the fuselage purpose of which is explained later. a large city like Paris or London requires of his machine. For be it known, there is All of the bombs and balls are normally hundreds of the very best fliers as well as no greater disgrace for a flier than to be housed in the metal mother -shell which need machines to safeguard these cities. These shot down by land guns. not be very heavy, as it does not contain fliers could be used to a tremendously better If we had a positive means to bring down any explosive charge itself. All the bombs

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A new "Lasso Shell" which can be shot from a cannon and used to combat enemy aeroplane attacks. It Is fitted with a time fuse so as to "explode" at a certain height, liberating the explosive and flame bombs, attached by piano wires as Illustrated. If these do not finish the enemy 'plane there are still the flying lead balls to be conjured with.

purpose at the front hunting down Hun a raiding flying machine without utilizing are kept in their respective places by means planes, while the former are kept locked up our own or our Allies' aeroplanes, we of a casing composed of eight pieces of rea- indefinitely to ward off enemy bombing would, of course, have the enemy at a great sonably thin steel. These pieces are re- squadrons. disadvantage. leased from the mother -shell, and fly off as Anti- aircraft guns firing shrapnel do not Bearing these things in mind, the writer soon as the time mechanism located at the bother an intrepid flier in the least nowa- advances a plan which to a certain degree apex of the mother -shell permits this. This days. It frequently happens that a pilot accomplishes such a result. The principle time mechanism works on the principle of must fly as low as 2,000 feet in order to suc- itself is very old and well known, the appli- the one used on shrapnel, the purpose of the cessfully set into flames a boche "Drachen," cation and the various refinements only present device being to keep the mother - as the German observation balloons are being new. shell intact till it comes within a few hun- called "Over There." These aerial sausages In short the idea centers itself upon dred feet of the aeroplane under attack. are fired upon at close range by the Allied the time -worn "chain- shot," which was This, of course, makes for great accuracy, pilots, who use incendiary "phosphoric" bul- nothing else but chaining several cannon as the mother -shell can be accurately timed, lets to accomplish the purpose. To do so they balls together and shooting them at the and being a self -contained shell like any must fly low which immediately draws the enemy with devastating results. As the other, its flight will naturally be true.

www.americanradiohistory.com September, 1918 ELECTRICAL EXPERIMENTER 301

The mother -shell in addition is "rifled," To prevent the aerial lasso from causing What then is it that we feel when we exactly like other big shells. A rifled shell widespread damage thru fire or explosion, are moved rapidly by an aeroplane? The while still in the cannon is made to turn on should it miss an aeroplane, the four bombs answer is the illusion of speed, inspired by its axis by following a corkscrew path cut can be equipt with time fuses, exploding a summation of sensations which we have into the inner walls of the cannon. This them before they reach the earth. Of the habit of associating with rapid motion. imparts a spinning action to the shell which course, the four lead balls might cause This illusion can easily be induced without it maintains during its entire flight. So damage, but certainly not more than the moving the man, and it has often been done, while the shell flies over its course with its myriad of shrapnel balls and shell frag- for example, at one of the Earl's Court ex- nose pointed at its target, it also spins like ments, crashing to the ground during an hibitions a passenger trolley on a few feet a top. This spinning action, it has been aerial barrage. of rails was arranged at the centre of a found, keeps the shell better on its course The aerial lasso built on a smaller scale large room of which the walls and ceilings than if it did not spin. could, of course, be used between combating were mounted so as to be bodily rotated In the case of the rifled mother -shell, an- aeroplanes. If our planes were equipt with round the trolley. The trolley was given a other distinct advantage is had. Aside them, as well as the necessary guns to fire little jerk to convey the impression of a from keeping the shell on a true course as them, the Boche planes certainly would be starting acceleration, and then as the trolley soon as the time mechanism acts, the pieces at a terrible disadvantage. became stationary the room was made to of the casing are thrown violently outward turn at an increasing speed round the ex- by centrifugal action. The same is the perimenters, who suffered from the con- case of the four bombs which are hurled viction that they were traveling on smooth outwardly as shown in our cover illustra- rails at a high speed. tion. Each set of bombs and balls are at- NOTICE Our impression of speed is derived largely tached to a central steel ring by means of a from the optical effect, due to adjacent ob- thin, but tremendously strong steel piano With the September issue nearly jects flitting by, and is increased by a sur- wire. Each wire may be from two hundred every magazine which heretofore sold face or skin effect due to the wind which to three hundred feet long as desired. But for 15e goes to 20e. This includes brushes past us and cools and presses on as the mother -shell and the various bombs every prominent scientific and tech- to our persons. These two effects are suf- still have their rotary (spinning) motion, it nical magazine. The price of the ficient, but the impression is heightened by follows that the entire device will continue "Electrical Experimenter" for the going a little further. Our past experience to revolve not unlike a miniature planetary present remains at of most mechanical and animal means by system. The four piano wires will be which we have borrowed speed has shown straight and taut, and as they cut the air us that they are rarely if ever perfectly at a great rate of speed, they will probably smooth in their action. After the change "sing with a weird as well as a shrill note. of speed due to the starting operation there If you ever swung a stone attached to a 15c are slight irregular changes of speed and string over your head, you will know what changes in the direction of the movement. we mean. Altho tremendous pressure is being These are always associated with rapid have an aerial lasso excel- exerted upon us from all sides, due traveling; we call them jolts and jars if We now par will not raise lence, covering a circular space of from to soaring prices, we they are severe, and we wrongly - regard four hundred to six hundred feet, all de- the price of this magazine at present. them as part of the sensation of speed, dio pending upon the length of the piano wires. Paper alone has advanced from 4c per they are pure accidentals. They ought Woe to the enemy aeroplane flying into it, pound three years ago, to llc a pound properly to be called accelerations, and the now, with printing, postage, engrav- act of starting is the only acceleration which or which is overtaken by it I There can be no escape. If either of the two contact - ings, art work and labor increased is in fact necessary to obtain speed. Yet a exploding bombs touch the aeroplane, it will proportionally. fourth factor can be detected in many of be wrecked by the terrific ensuing ex- No other scientific Journal gives as our impressions of speed. I allude to noise, plosion. If either of the contact -flame much for 15e as the "Experimenter." whether of whistling wind or of beating bombs touch, liquid fire will be sprayed over All other magazines in this class print hoofs or of moving machinery. These wings or fuselage, setting the plane on fire. their pages in ten point type. Ours is things no more constitute a sensation of But let us suppose that neither type of printed in eight point type: speed than the bristles constitute a hedge- bomb were effective, or touched only non - hog. They are merely excrescences and vital parts of the enemy plane. Here it is This is ten point type. causes of independent sensation. At one where the lead balls take up their deadly This is eight point type. time or another an aeroplane flight gives work. Suppose all the four bombs had rise to all these sensations to an acute de- been exploded. If it were not for the four Note the difference. "Experimenter" gree, and super -adds one novelty, that of lead balls, the four piano wires would simply pages contain 30 per cent more matter, the point of view. go limp and the fight would be over. But space for space, than the other maga- The following comparative table of speed having these lead balls spaced about ten zines. Your 15e spent on this Journal is of interest: feet from the explosive bombs, they will not really buys more than two 20e maga- 1. Light and the electric telegraph, 186,000 be affected at all after the former have been zines. And we believe the quality of m.p.s. set of. The planetary system broadly our matter is much above the average. 2. Shell near the muzzle of 6 -in. gun, 2,500 speaking, still remains intact, altho now we Won't you show your friend this feet per second. have only four "moons" left. But suppose copy, or tell him about it? 3. Shell from 75 mm. gun, 1,600 f.p.s. only one of them manages to get entangled -The Publishers. 4. Sound, 1,100 f.p.s. in the trusswork of the enemy plane. Im- 5. Revolver bullet near the muzzle, 500 -800 mediately the flight of the entire system is ti f.p.s. stopt abruptly and the three other balls come 6. Tip of the blade of an airscrew, 600 whizzing around, snarling up the entire WHAT IS HIGH SPEED? f.p.s., or 400 m.p.h. plane and breaking the wings, fuselage or One of the first questions the layman asks 7. A fast aeroplane through the air, 150 tail as they come crashing down at a terrific the aviator is, "How does it feel to fly ?" by m.p.h. speed. You have read of the terrible Mexi- which is generally meant, what is the sen- 8. A fast aeroplane with a high wind, 200 can lasso, the Bolas, which is a lasso with sation of speeding thru the air at the rate m.p.h. lead balls. It works on the same principle made possible by the aeroplane. The fol- 9. A fast car, 120 m.p.h. as our aerial lasso, only the latter having lowing abstract from an article appearing 0. An express train, 80 m.p.h. lead balls weighing several pounds apiece, in Flight should be enlightening: 1. A fast steamship, 40 m.p.h. will cause correspondingly greater havoc, An analysis of sensation is always inter- 2. A bicycle (pedaled), 32 m.p.h. especially on a comparatively fragile aero- esting and might be expected to be excep- 3. A race horse, 30 m.p.h. plane. tionally so in the case of speed, yet para- 4. A man skating (for a mile), 24 m.p.h. Perhaps you have read accounts of aerial doxically enough there is no such thing as 5. A man running (100 yards), 20 m.p.h. fliers and their dread to intercept the a sensation of speed. There are many 6. A man running a mile, 13 m.p.h. course of even the smallest bird. It is a proofs of this, but I will adduce for one, 7. A man walking, 4 m.p.h. well known fact that an aeroplane pro- that the early centuries of human existence peller revolving at its great speed, will be man, tho he has since been proved to be French electrical works have arranged to instantly shattered if a bird as small as a moving thru space at the prodigious speed employ men who have been blinded in the sparrow flies into it. Therefore it may be of some thousands of miles per hour, war to wind armatures after the system of imagined what a large lead ball, or a power- thought himself to be living on the immo- Dr. Schuyler Wheeler of New York. It is ful piano wire will do to a propeller, should bile hub of a rotating dome of the moving also understood the system will be intro- either come in contact with it. planets and stars. duced in England.

AMONG the hundreds of new devices and appliances publisht monthly in the Electrical Experimenter, there are several, as a rule, which interest you. Full information on these subjects, as well as the name of the manufacturer, will be gladly fur - nisht to you, free of charge, by addressing our Technical Information Bureau.

www.americanradiohistory.com 302 ELECTRICAL EXPERIMENTER September, I 9 I 8 New Electrical Ideas on Submarines and Torpedoes

THE busy war inventors have been Jr. Mr. Seymour provides considerable shears. When in action these steel blades bombarding the Patent Officc at food for thought in his novel invention are rapidly oscillated in the same manner as Washington with hundreds and even which comprises a cigar- shaped steel hull, a pair of scissors, by means of an electric thousands of more or less ingenious the interior of which is subdivided into a motor located within the submarine. The ideas on improvements in submarine number of separate chambers, each one of motor is connected to a shaft attached to warfare. Some of the latest endeavors of which is adapted to house the various .elec- the cam actuating the shear blades thru a Yankee inventors in this branch of naval trical and other apparatus necessary for con- water -tight stuffing box. science are here illustrated and described. trolling the torpedo. This steel hull is As the mine cables are cut and the mines The first idea represents what its inventor normally submerged beneath the surface of float to the surface, they can be picked up -August S. Trautman -prefers to call "a the water, and supported at this depth by by any vessel adapted for the purpose, and submarine safety and observation device." means of a surface float which carries working in conjunction with the submarine His invention purports to provide a corn - visible identifying means, such as colored or submarines. The operation is best carried bined life -saving and observation .chamber flags or disks in the day time, and signal out at night of course. The ends of the which is normally housed within a suitable lights flashed intermittently at night. cable shear guide -horns are provided with compartment on board the submarine. When In brief, Mr. Seymour's electrically con- electric lights to enable the operator to the submarine happens to become disabled trolled dirigible torpedo is of the self -pro- guide his boat more quickly in the proper thru a naval engagement or otherwise, or pelled type, being provided with a special direction to encircle the cable and cut it. in the event that the commanding officer internal combustion engine adapted to run The operator is provided with loud should want to ascertain whether any enemy on a fuel consisting of hydrogen and speaking telephone equipment, signal lamps, war vessels were in the immediate neigh- oxygen. The engine is provided with an etc., as well as electric controller for the borhood before rising to the surface, it electric self- starter, and the motor for this shear motor, so that he has very accurate then becomes possible to have an obser- apparatus may operate when the torpedo is control of the apparatus, and also the move- vation officer enter the buoy chamber under way as a dynamo. supplying current ments of the underwater craft. He can shown, thru suitable water -tight doors; for charging storage batteries, etc. Fuel thus instantly give orders to the helmsman when the buoy chamber is opened to the for operating the engine is contained in a to change the direction of the submarine, water the buoy then rises to the surface. suitable storage tank in the torpedo hull, etc. The cable- cutting shears are designed The buoy is at all times under control by and also the supply of gases ready for mix- by the inventor, so that they can be readily the submarine by means of a steel cable at- ture to produce the fuel for the engine. bolted to the bow of the submarine and tached at one end to the bottom of the This dirigible torpedo is intended to be quickly removed as soon as the cable -cutting buoyant chamber and at the other end to a controlled thru a fine electric cable con- operations are completed. motor -driven windlass on board the sub- necting it with a war vessel operating in the marine. A telephone and electric light vicinity. The cable being of small size is WHY THE ELECTRIC GUN WILL cable is also unreeled with the buoy as it stored in the hull of the torpedo, and is NEVER BE A SUCCESS. rises to the surface, so that the observation wound in an ingenious manner so as to be By Harry A. Dey, E. E. officer can at all times communicate directly released rapidly and easily and without with the submarine commander below. danger of knotting. The inventor's design Every few years a new inventor springs As the inventor points out, his device can enables a very small insulated electric cable upon the public our old acquaintance, the be made large enough to hold several men to be used for this purpose (with its con- electric gun, which has so many good talk- instead of but one, for the purpose of sav- sequent high electrical resistance) for the ing points. An electrical engineer of our ing the crew's lives, and it is not at all reason that he uses a sensitive galvanometer acquaintance, was one of the inventors. difficult to arrange the apparatus so that the relay, which can be actuated by relatively He did not, however, place it before the life- saving buoy could be hauled down to weak electric currents coming thru the public. He went ahead and spent a few of the submarine several times in order to re- cable. The front end of the torpedo hull his own dollars, and soon became con- move all of the crew in case of disaster. contains the high explosive gun- cotton or vinced of its impracticability. This was The buoy could be designed sufficiently other charge, which can be detonated at any nearly thirty years ago when the dynamite strong and provided with a sufficient length desired moment by simply pressing a but- gun ship VESUVIUS was first constructed. of cable to enable it to rise thru a depth of ton on the torpedo boat destroyer or other Our electrical friend got to thinking how water of two hundred to three hundred feet. vessel controlling the torpedo. It may be a nicely electricity, by means of a long sole- As the illustration shows, the observation surprise to the reader to learn that this noid barrel, could throw that charge of buoy is fitted with telephone and electric small yet destructive war device may have dynamite without danger of the shock blow- light as well as one or more rapid firing a field of action as great as ten to twenty ing up the gun. He made some experi- guns, photograph apparatus, binoculars, etc. miles, this being the radius over which the ments, actually building one of one inch The floating compartment is provided with torpedo can be sent, and a sufficient length bore, and followed this up by experimenting suitable gyroscopic apparatus driven by an of patrol cable carried therein for the pur- with the pulling power of solenoids. If the electric motor for the purpose of stabiliz- pose, the inventor claims. When the torpedo solenoid experiments had been made first, ing it, and there is also provided a means is placed over the side of the war vessel, the gun would not have been built; for he whereby the center of gravity of the buoy the engine self- starter motor is set in found that 25 pounds per square inch was can be changed by shifting a weight when- motion by means of a pull cable running up about the best pull that he could expect, and ever the gyroscope might prove inactive. to the top float and fastened to a button the VESUVIUS required 600 pounds per There is furthermore a propelling mechan- thereon. square inch to toss its bomb a mile or two over the hills. He threw up his hands in ism driven by a motor and so designed as The third electrical idea is an interesting disgust at himself for not beginning his to cause the buoy with its occupant to be Cable- Culling Shears, intended to be mount- propelled a experiments at the other end of the line. in body of 'water and beneath ed on the bow of a submarine or similar If he had started out by investigating the the surface thereof, and to be guided ac- vessel. As is well known, it is a slow on the VESUVIUS he cording to the desires of the operator. The -sweepers power required job for mint to trawl along thru gone no further, for he well cover of the buoy may be camouflaged so as considerable areas, feeling their way and would have this was from 3 to 4 times as not to become readily detected by the cutting loose the submerged but firmly knew that as electro- magnet would pull when enemy. anchored mines. The contrivance here sug- much an in contact, which is impossible in any An oxygen tank is fitted within the buoy gested by Mr. Johan E. Johannessen would actual device; the pulling power dropping for the purpose of supplying the observer seem to offer some worthwhile ideas in this moving very rapidly upon the insertion of any air with oxygen during the time that he is con- direction. His electrically operated mine - gap. The best that could be expected from fined therein, and also a reserve tank is cable shears are intended to be secured to any gun of this type, even if made of an im- provided in the container whereby air from the bow of a submarine, and also the vessel practical length, would be to use as a sub- the outside may he collected and accumu- so fitted with this device is provided with stitute for hand throwing of bombs from lated. A motor -driven pump is provided to a observation port window and suitable or to trench when they are within a operate the auxiliary air apparatus. The an adjustable and powerful electric trench fairly female baseball pitcher's range. buoy can be made to describe a circular path searchlight as in the illustration. In this by means of a suitable rudder provided at way the submarine can make considerable the base of the structure. speed in cutting the submerged mine -cables, An electric magnet weighing only seven The second idea here illustrated is that and the shears are provided with large pounds that will lift fifteen times its own of an electrically operated Dirigible Tor- horn -shaped guides which serve to force the weight has recently been invented. It is pedo, its inventor being James M. Seymour, cables toward the cutting blades of the intended for use in machine shops.

www.americanradiohistory.com September, 1918 ELECTRICAL EXPERIMENTER 303

NEW ELECTRICAL IDEAS ON SU1t\IARINES AND TORPEDOES

CAMERA

AUAILIARY ENTRANCE AIR CONTAINER 1 FOR

PAE ICING WELLA

AIR PUMP WATERTIGHT AIR PUN'F MOTOR OOORS

ENTRANCE LOOR TABILIZING TO BU EY PROFILEER GYROSEOPES

RU OOER ti

VISUAL SIGNAI

ELELSIARTER GAS ENGINE BUOYANT MOTOR POOLLINE SUPPLY PULL CL OAT LINE

"SAIITT PIN" LIKE \ PL GLINE 1 ELECTRICALLY fIEC.CONTROI EXPLOSIV E GAS ENGINE LOXIROLLED CABLE FINE ENOUGH GAS FUEL R000ER CONCUSSION TO GIVE 20 E1. TANKS STORAGE RANGE EIRING Pill BATTERY

1 PROPELLER WI/r FLUE ' Of ORATOR 2C M.OFELEC. GALVANOMETER RuEEER1 (ABLE TORRE REIAYS.EIC. GASKET O 1A I

MINE COLLECTING BOAT

l'oll'n40 . VAS. by E. V. CO. Tor full description see opposite page'

www.americanradiohistory.com 304 ELECTRICAL EXPERIMENTER September, 1918

Popular Demonstration of Thought - Transference and Other Phenomena By ALBERT ABRA\IS, A. M., M. D., LL. D. Professor, Cooper Medical College (Medical Dept., Stanford University, 1893- 1898.) DETAILED reference to this sub - TELEPATHY.- Derived from tele, at a dis- hand dependent from the side of the table ject -(natter may be found in my tance and pathos, feeling, it signifies that (Fig. 2). book, "NEW CONCEPTS IN DIAGNO- one mind (agent) can influence another EXPERIMENT 1.-Solving the mystery of SIS AND TREATMENT" where atten- mind (percipient) without the agency of tion was first directed to the the recognized organs of sense. demonstration of these phenomena by ap- BRAIN -WAVES are an actuality and like light and the impulses of "wireless" are conveyed by the ether. The ELECTRON THEORY shows that the ultimate constituents of matter are elec- trons or charges of electricity and that RADIO- ACTIVITY is dependent on ethereal disturbances by a change in motions of the electrons. ANIMAL REFLEXES. -When the pupil of the eye contracts to light it is a REFLEX and involuntary. The reflexes surpass in sensi- tivity any instrument devised by science and show that RADIATION is a universal property of matter. The perceptive struc- ture of the eye (Retina) is 3,000 times as sensitive as the most rapid photographic plate and the nerve of vision (optic), 2/5 of an inch in diameter contains 500,000 to S00,000 insulated fibers. The electro- magnetic waves in "wireless" demand an exciter, but the sensitive human Fig. 2. Once You Have the Straw "De- reflexes first utilized by the writer in de- tector" Rigged Up on the "Percipient's" Fig. 3. Arrangement of "Percipient" to Wrist, Then the Shadow or Even the Move- tecting energy make an exciter unneces- Show the Electrical Effect Created By Con- ment of the Straw Itself Can Now Be sary: the revolutions of the electrons alone centration of Mind By the "Agent,' Even Watched Closely In Front of a Square -Ruled substitute the exciter. Tho He (or She) Be Situated Forty Mlles Paper. This Is Your "Thought Wave" De- Away. A Wire Connects the "Percipient" tector and Indicator. THE HEART.-The writer employs this mus- With the House Electrolier. cular organ among other reflexes for con- pantos not available to the laity. Telep- verting energy waves into a sensible form. nand acting upon mind by brain waves athy is in disrepute and the scientifically It is coincidently a receiving station and traversing the ether. minded psychologist Prove that the brain doesn't believe it. Science wave -theory is correct de- that, telepa- demands that phenomena We anticipate that this article will spite the fact should be objective, cap- create a sensation in scientific thic effects unlike other circles, as well as with laymen, and we present it for what it is worth. energy do able of reproduction at all We have not made any of Dr. Abrams' forms of radiant times and demonstrable tests, and we print the article with not vary in intensity ac- an open mind -neither endorsing nor condemning it. We say with Shake- The by instruments' of preci- speare: "THERE ARE MORE THINGS IN HEAVEN AND EARTH, cording to distance. sion. HORATIO, THAN ARE DREAMT OF IN moment a person (agent) The scientific YOUR PHILOSOPHY." WILLS FORCIBLY (not mere simple Dr. Abrams is well known as a scientist; he has made this interesting method which I shall pre- thought) there is a slight subject his life work, and his views are endorsed by many prominent hesitancy or retardation of sent shows that spiritistic doctors and scientists. He is the author of numerous works, amongst phenomena are independ- them an elaborate the straw. Close observa- book: -"New Concepts in Diagnosis and Treatment." a slight extra ent of disembodied spirits Will our readers please advise us should they be successful with Dr. tion shows and referable to human Abrams' experiments? Editors. kick of the latter followed energy: that it will serve -The by a transitory stop (in- as a means of disocculting hibition). Each time the the occult and will enlist agent wills in the direc- the genius of the multitude in corroborat- also a detector of etheric thought waves. tion of the percipient (irrespective of ing my original investigations. TECHNIQUE.. -The percipient must have a distance), the pulse effects may ,be noted. regular and comparatively large pulse and Before each act of willing by the agent, at must be seated in a comfortable chair fac- least 10 seconds must elapse to permit the ing the geographical West. Colored wear- percipient's heart to recover from the ex- ing apparel must be avoided by agent and cited reflex. The latter is easily exhausted percipient : the latter's eyes must be closed by too much experimentation on the same to avoid distraction, breathing regular and subject. If several persons are present, mind abstracted during all observations. Experiments should be executed primarily in daylight. All reference to the pulse, re- fers to the movements of the straw con- nected to the percipient's pulse. Find the 1) and its latter (Fig. indicate location with . .111P a pencil. , Cut a very small piece of adhesive plaster / wir and roll it so that the roll presents an ad- hesive surface on both sides. Fig. 1. -X indicates the site of the wrist - pulse. Fix it parallel to the pulse. To the plaster attach one end of a very fine straw (from a broom), 6% inches long. Place the straw at an angle so that it will approximate a sheet of ruled paper (vertical lines). Fig. 2.- Position of arm with straw Fig. 1. The Mark "X" Indicates the Site of attached to the pulse. the Maximum Wrist Pulse, and At This Point Observe the swing of the straw directly Dr. Abrams Affixes a Small Piece of Adhesive or a shadow. Plaster, and One End of a Very Fine Straw. Fig. 4. On Either Side of the Wind -Pipe in as In the latter event, if the the Neck, As the Two Black Marks Show, light is from the South use the right and if their minds should be passive so that the There Are Located the Right and Left from the North, the left pulse. waves front the agent alone will act. Note Pneumogastric Nerves. When These Nerves Note that the greatest amplitude of by effects on Are Stimulated, the Needle Movements Show the the the pulse that some are Less Amplitude: and When They Are De- straw is secured by the arm resting com- able to will more forcibly than others. prest the Movements Are Greater. fortably on a book or cushion with the (Continued on page 345) www.americanradiohistory.com September, 1918 ELECTRICAL EXPERIMENTER 305

"Over There " -A Miniature War Panorama By GEORGE HOLMES REALISTIC and beautiful is the pre- senting it spells its success and from all ac- formative and therefore educational. No sentation of a great Spectacle or counts it bids fair to equal in fame if not matter what the impelling idea of the Panorama in the miniature, when exceed the original battle panorama of "The author, whether purely for commercial correctly staged. This field presents Battle of Waterloo," done by Robert amusement purposes or not, he eventually a wonderful opportunity for the Barker, or our own "Battle of Gettys- proceeds to inform and spread knowledge. real genius and creative mind to bring forth burg." The creator of "Over There" To many, the fact that the panorama has

Electric Nestor Switch "nuns the Whole Show."

Out Front" and "Behind the Scenes" of Coney Island's Latest Success-"Over There " -a Complete Living Picture In Miniature of the European Battle - Fields. It Took a Real Genius To Produce the Thousand and One Details So That the Audience Could See What "Shell - Fire" Does to a Peaceful Little French Village. truly enchanting effects of color, scene and is Mr. Hugh Thomas, for years associated a serious history away from its uses as action. A splendid example of this fascin- with the big Coney amusement resort, pro- an amusement proposition will come as ating art may be witnest in the new and jector of the "Submarine Battle," and other news. Yet its initiation is connected with timely panorama "Over There" now being mammoth indoor spectacles. no less a personage than Sir Joshua presented at "Luna Park" -the far -famed There is a value about the panorama Reynolds. The invention, for it was origin- heart of Coney Island, New York City's which cannot be denied. First of all, it ally patented as such, came from the brain pleasure ground. To say that Luna is pre- lends itself only to subjects which are in- (Continued on page 353)

PUSH BUTTON- DYNAMO SPINS - Several years ago a similar dynamo flash- LAMP LIGHTS! light intended to be operated by the pres- Flashlights are now used by the million sure of the hand or fingers was brought all over the world-practically every well out in Europe, but due to the war condi- equipt soldier in the Allied as well as in the tions which followed soon after its intro- German armies, not to mention the navies, duction, it has never reached the United carries an electric flashlight. Think what States. The type of dynamo flashlight here it would mean if overnight a modern illustrated was invented by a Yankee genius Aladdin should wave his magic wand and and the model was thoroly demonstrated decree that the flashlight could stay but that before the editors. the batteries must go. Such will be the magical change which will overtake us one of these fine days when the invention il- WONDERS NEVER CEASE lustrated herewith is successfully exploited "The Office Dog" conducts a full page and made cheap enough to be available to feature in the amiable Ladies' Home Com- every man, woman and child who have any panion. It is usually a very bright page and use for flashlights. you can learn a lot from it. We like it. The model of the push- button dynamo Dogs, however, are notoriously shy of elec- flashlight shown herewith is somewhat large tricity, as any boy who has a spark coil as it is the first model constructed by its AND a dog will readily testify. Dogs and inventor. The principles on which it is de- electricity never mix. "'l'he Office Dog" signed are, however, correct, and it is only is no exception to that rule. He is shy on a matter of refining the details of its make- electricity too! Witness the' following up in order to reduce its size and weight. blossom plucked from its May, 1918, page: As herewith illustrated, the trigger which Walking in a thunder storm under an is placed on the handle and resembling that umbrella with the modern metal rod of a revolver, is successively pulled toward is now said to be about the most dan- the handle by a natural gripping action of gerous of practices, since the metal is the hand, and this trigger works a quick - an almost certain conductor of elec- acting worm or screw similar to that found tricity. on the well -known ratchet screw -driver. The italics are ours. It was a new dis- The other end of this trigger actuated covery to us, that a metal could be an almost ratchet is mechanically connected with a certain conductor. Will the "Office Dog" small alternating current dynamo or mag- please send us at once a sample of that re- neto, which supplies the necessary current markable metal for analysis? Will gladly to light the flashlight bulb. The bulb is send him in return an almost certain soup - The Latest in Flashlights -the "Push Button to mounted in the usual reflector and fur- Dynamo Light." A Small Dynamo Does the bone, guaranteed give almost certain nished with a suitable lens. Trick. food for thought!

www.americanradiohistory.com 306 ELECTRICAL EXPERIMENTER September, 1918

U. S. X -RAY STATION ON WHEELS. For operating between the field hospitals The Man Who Stayed at Home and the firing lines, a Chicago electrical genius, Mr. C. L. Fits, lias developed the At last' A war play without "fire -works." of his sweetheart, which further adds to all complete X -ray equipment illustrated. It is To say the least, our American audiences the troubles. mounted on an automobile and derives its power from a specially designed direct cur- rent generator, driven by the engine. This generator is equipt to deliver 2 K. W. alter- nating current. 'l'Ite transformer will deliver a spark from 10 to 12 inches long. The transformer and synchronous motor are mounted rigidly in a cabinet. The X -ray machine is of the in- terrupterless type, which is superior to or- dinary machines which rectify their own current in the X -ray tube. The marble switchboard has all necessary instruments such as a time switch, pole indicator, rheostat, pilot lamps, fuses,'and switch ; also a volt -ampere meter for the low tension side of the transformer. On top of the cabinet is mounted a milli - ampermetcr for measuring the current which passes thru the X -ray tube. The Radiographic table is full size and can be tilted 90 degrees. It is equipt with one X -ray tube under the table for Fluoro- scopic work and one above for Radiographic work. The lower tube moves in a longi- tud'nal direction, while the upper one moves both longitudinally and vertically. The table has an automatic tray and cassetts (plate holders) into which the plates can be inserted from the side. As the cabinet is built in sections locked together, it is very easily taken apart and set up with the radiograph table together in a room or inside a house. In this case the automobile would be the power station and a cable would make the connection A Critical Moment from the Timely Play '.The Man Who Stayed At Home." The Photo from the dynamo to the transformer. Shows Mr. Brown and Miss Kaelred In the Act of Intercepting a Submarine Message and In the left corner of the compartment is Falsifying a Reply That Led the German U -Boat Astray and to Capture by the British an instrument cabinet. In the bottom of Sea-Dogs. this cabinet is a lead -lined cabinet for un- exposed X -ray plates. Between the X -ray have been bombarded with a class of pro- Nevertheless, and in a truly melodramatic cabinet and the instrument cabinet is a dark ductions and films that tended more to the style, he discovers the Hun's secret wire- room chamber which enables the operator "flag- waving" and "patriotic airs" variety, less outfit in the fireplace and turns it to to load the cassetts and to develop the than to any real semblance of plot, story his own advantage and then wrecks it. negatives. or genuine interest; which would in a Further thrills are experienced in the at- On the left side opposite the radiographic moderate way serve to amuse, thrill and tempted burning of the house and his almost table is a leather upholstered seat which most of all, go a long way in the moulding untimely end in which he puts one over on folds hack into the wall. Occasionally it of opinion and stir one to real conscienti- the Kaiser's spies and their final round -up. may be used as a berth. The room is ous and patriotic thought. Whereupon he wins his "lady- fair" and the lighted with white and blue electric lights. The production in mind was presented glory of the whole household, even to Dad's When the doors are closed it makes a very originally under the title of "The \\'hite profuse blessings! desirable dark room for Fluoroscopic work. Feather," by Mr. William A. Brady, at the Comedy Theatre in February, 1915. This was of course before we Americans had begun to think of a war with Germany or the intrigues that were taking place daily right in our very midst. Naturally tinder such circumstances, the most part of us, self -centered, failed to see the moral in the piece and like many other unfortu- nate plays it was relegated to the store- house. The story of the piece has had some ma- terial changes made in it, in that now it is the American troops and their transports which must he protected from the under -sea sniper the "Hun Submarine." The action takes place in an English coast town. Mrs. Sanderson and her son are running a hoarding house as a blind, being actively engaged in spying for the Imperial German Government. Christopher Brent, an Englishman of dense or "Silly - Ass" type, is a . boarder. Everyone up- braids him for being a slacker; even his best girl is doubtful of him. Naturally he feel. very hurt but can offer no defense on his behalf for his seeming idleness because -S- S -S -H, he is a spy in the employ of the $ritish Government ! With him at the .same house is his "cryptic" and beautiful Miriam The Latest Design of Portable X -Ray Ambulance for U. S. Army. It Derives Its Power, female aid in the person of Miss About Two Kilowatts, from a Special Dynamo Driven by the Engine. It Includes Plate 1Lre, His being so much with the afore- Developing Facilities, Complete Switch -Board for Controlling X -Ray Bulbs, and Other said personage raises rebellion in the heart Necessary Conveniences.

www.americanradiohistory.com September, 1918 ELECTRICAL EXPERIMENTER 307

The Blind _ ow Tape Electric Coils

ASHORT time ago the question of se- As this was an entirely new line of work Naturally, as this is new work, the speed curing some help from the blind was for them, it was decided to have a repre- is not so great as with those who can see, taken up by the Westinghouse people sentative of the Association go to East but this will increase as they become more with the Pennsylvania Association, a branch Pittsburgh to become familiar with the proficient, and also the number employed of which is located in Pittsburgh, and a work so as to he in a position to instruct will he very materially increased.

It Has Been Found That Blind Persons Can Wind and Some Idea of the Work Done by the Blind May Be Judged Tape Electric Coils Quickly and Accurately. Taping Arma- from This View, Where All Sorts of Intricate Coils Are ture Coils. Wound and Taped. sample lot of motor coils to be taped was those assigned to do he work. The repre- One of the employes engaged in this sent to the Association in order that the sentative selected for this training was the work and shown in accompanying left -hand employes might be given a chance to show wife of a former Westinghouse employe, photograph is Carrol Moore, formerly what they could do. When the coils were who was deprived of his sight last summer, an employe of the Westinghouse concern. returned, it was very evident that this work and who is now employed at the Associa- Deprived of his sight, because of his pre- could be done in an entirely satisfactory tion. She went to East Pittsburgh and was vious familiarity with electrical apparatus, who have employed until such time as the manage- he now finds it easy to adapt himself to manner by those been deprived ment felt that she was sufficiently pro- taping coils. of their sight. Accordingly, arrangements ficient in the taping of coils to teach the Some idea of the broad scope of the or- were made with the management of the As- blind and to inspect their work. ganization may be obtained from the fact sociation to allow some of their employes At the present time seven persons are that last year the sales from the products to do this work, payment to be made on a employed and their efforts have been very of the blind employes amounted to over piece -work basis. satisfactory, insofar as quality is concerned. $40,000.

THAT ODD PHOTO!!! IS IT AN veloped at the point of contact due to the ELECTRON? high resistance of the iron or steel. The can controlled by means I was a of etching depth be taking picture the Mess Hall used, it is said, at the New Trier High School, Winnetka, of a rheostat. The pencil Ill., with the aid of a flash -light, writes Mr. Lytton Calrow, who submits this very inter- esting photo in the monthly "Odd Photo Contest." At first we thought Mr. Calrow had really photographed a wild electron shooting thru a more or less tame molecule. But we were in for a bump. Listen to what the contributor has to say: - The flash -light powder was placed a little in front of a line with the lens and the results are noticed. I have seen several well known instructors in Physics and Chemistry and Optics and none could give me a definite answer as to what the reason for the lines and perfect elliptical figures were. They must be either grains of pow- der or light waves, it seems to me.

THE ETCHOGRAPH MARKS DESIGNS ON STEEL. A small portable electric outfit, which can Marking Tools with the Electric Etchograph. be used to mark small tools and for mark- ing on any steel surface, has recently been can he handled with the same facility as perfected. The outfit consists of an electric an ordinary pen or pencil, and script writ- pencil or "etchograph" and a step -down ing or any other type of lettering can be transformer which can be connected to any used. The outfit is made to operate on 110 - lighting socket. To operate the device, the volt 60 -cycle circuit, or can be used on electric pencil is drawn over the steel sur- 110 -volt direct current with .a small rotary Can You Guess What This Photo Represents? face of the work, when great heat is de- converter.

www.americanradiohistory.com 308 ELECTRICAL EXPERIMENTER September, I9 I8 New Electric Fuse Lighter for Blasting 14,000 kva., 60 A California inventor, Mr. Albert S. Cole, sand tons of coal, on a basis of one year's These units are rated at have a 25 cent has devised a clever and very useful form time, is 2.78 men. cycles, and since they per on electricity sup- On the average, 1,000 tons of coal in the overload rating they are practically 17,500 of fuse lighter operating fac- plied from a battery. Where considerable United States produce 125 h.p. for a year kva. (kilowatts at 100 per cent power of time; 35,- tor), maximum rated transformers. These 000.000 water transformers tvill operate at the high trans- horsepower de- mission voltage of 150,000 volts. veloped and in These transformer units will form one commission 42,000 kva. bank, which, together with a would save the spare unit will make the preliminary in- necessity of stallation to step up the voltage from 13,200 mining 280,000,- -that of the water -wheel generator. Power 000 tons of coal will be transmitted about 25 miles to an per annum. As industrial plant where it will be stept down regards labor, by means of a number of 7,000 kva. single - this vast ton- phase transformers of similar character- nage requires istics. for its produc- Owing to the large size of the units them- tion, transpor- selves and the great amount of generating tation and con- capacity which will ultimately be concen- sumption 280,- trated behind these transformers and their 000 x 2.78 men, need to be able to withstand the effects of or 778,000 la- momentary short -circuits the shell type of borers of one transformer with special end frames and kind and an- bracing arrangements was selected. Struc- other. The tural steel for these parts was used thruout, amount of la- because the strength of the various members bor required to can be depended upon to a much greater operate this 35,- degree of certainty than with castings. The 000,000 w a t e r top and bottom ends of the coils are held horsepower against distortion by two heavy steel plates may be put con- each re- enforced by four lengths of angle servatively a t iron riveted to them and held together by four heavy tie -rods. tL,nrl-+%ITtR 40,000 men. Therefore t h e The tanks are made of heavy boiler plate, > net saving in all seams being welded by means of the oxy- the way of la- acetylene process. bor alone by Some idea of the physical size of these the installation units may be gained from the fact that the of this water height measured 23 feet 6 inches over the horsepower high tension terminals and the units weighed would be ap- complete with oil and fittings around 110,000 proximately pounds. Note the relative size of the man 740,000 m e n standing beside one of these gigantic trans- available for formers. other industries Hydro -elec- SparKGap tric power is A New Electric Fuse Igniter for Blasting. It Produces a Shower of the real effi- Sparks Between the Ignition Electrodes Whenever the Button Is De- cient energy of prest. The Batteries and Spark Coll Are Carried in a Small Case to- morrow. Slung Over the Shoulder blasting is to be done, it would seem that this ELECTRICITY CAUSES FEW apparatus would find extensive favor. The ACCIDENTS. complete electric fuse igniter can be con- While serious accidents to linemen of veniently carried by a coal miner or other public utility companies are often caused person, the battery, spark coil and so forth by electric current, it has recently been being enclosed in a small leather carrying found from an analysis of nearly 6,000 ac- case, somewhat resembling those in which cidents among this class of employes that binoculars are carried. With this apparatus less than 12 per cent of the total number of a stream of electric sparks is obtained be- serious accidents is caused by electricity, tween the two metal points protruding from and that a very large proportion are the re- the hand electrode, whenever the battery sult of carelessness. The following is a circuit is closed by pushing the small switch detailed analysis of 6,000 accidents occur- button attached to this hand member in the ring to linemen only. Accidents due to manner illustrated. electric current are given as 11.4 per cent: The spark coil may be one giving a Ys Per cent. to 1 inch spark. The battery is made up of Striking or struck by material 18.8 two or more dry cells, or several flashlight Electric current 11.4 batterics can be employed instead. The \\'ire, glass, sharp edges 10.0 stream of sparks obtained with this device Handling tools 9.4 serves to ignite the regular blasting fuse in Struck by falling bodies 9.4 the place of a match. It is possible to build Lifting or moving material 9.4 the apparatus at small cost, and it possesses Falls from pole 7.3 several unique features, one of them being Acid, solder, or compounds 6.0 that it is just as efficient on rainy or stormy Fall from elevation (other than poles) 6.0 days as it is on clear dry days, which is Fall on level over material 5.4 not the case when matches or other sources Injured by spurs 4.0 of ignition are employed. Fall from vehicle 2.0 Run down by vehicle 0.7 Injured by animal 0.7 HYDRO -ELECTRIC POWER VERSUS COAL. THE WORLD'S LARGEST TRANS- The services of half a man are required FORMER. in central steam stations for every thousand Four of the largest single -phase trans- The World's Largest Transformer -Rated at 14,000 Kilowatts Normal or 17,500 Kilowatts tons of coal used. Therefore the total labor formers ever built were recently completed at 25 Per Cent Overload. Compare with Fig- required for the consumption of every thou- by a large American electrical concern. ure of Man.

www.americanradiohistory.com September, 1918 ELECTRICAL EXPERIMENTER 309 Making Electricians Over :Night

THE war has changed many things. walk out thru the school door ready to Besides teaching electricity the school If we were a speedy nation before tackle any electrical job anywhere at a min - also teaches practical draftsmanship, and the war, our national speed certainly ute's notice! there are also plumbing and brick laying de- lias increased to a surprising extent This seems hard to believe when one partments. Photographs Courtesy Chicago ever since we entered the struggle. stops to think how many things the student Coyne Trade and Engineering Schools. Years ago a German writer called Amer- must learn before he can call ica The land of unlimited possibilities." himself an accomplished elec- His brothers are now finding out this truth trician. His knowledge not to their hearts' content. Indeed, it seems only lies in the theoretical as if there is no end to what we can accom- learning, but he must know plish, but if we are to win this war we how to do things with his own must husband all our forces, not only in hands. While the fundamen- materials, but in human efforts as well. tal knowledge can be readily War economies are not only effected in obtained from books, the wheat, beef or coal, but the saving of human accomplished electrician neces- time is an enormous factor if we are to sarily must know how to do win this war. It will not do alone to things out of his own experi- turn out 91 ships in one day or sending a ence, and unless he has the million men to France six months ahead equipment to do it with it of the schedule. It is the man behind the usually proves a long and man behind the gun who helps just as much tedious job. to win the war. The concentrated instruction If we can save a great amount of time necessary to turn out a modern for our workers we save just that much electrician is being practised in dollars and relieve just so many more and it is quite amazing to see workers for other endeavors which we how quickly students become could otherwise not do. experts in nearly everything Time was when it took from three to electrical in this school. In four years to turn out an accomplished walking thru the instruction electrician who could be entrusted with any rooms we find students rang- job that came along. Only a few years ago ing from eighteen to fifty busy it used to cost thousands of dollars to at work-practical work -in make an accomplished electrician, which every conceivable branch of amount was made up in expensive tuition, electricity. In one room we find a The Way to Learn Motor and Dynamo Winding Is to board, etc., as well as money lost in non- large number of students Actually Do the Work With Your Own Hands, As This production while the student was learning. getting instruction in wire Student is Doing. Hundreds of thousands of dollars were splicing. An instructor stand- lost in this manner because the student, ing among them shows them just how it STATIC ELECTRICITY AND GASO- seldom, if ever, is a producer while study- is done, explaining everything necessary, LINE EXPLOSIONS. ing. This means a tremendous loss to the and then the pupils are taught how to splice Sometime ago there was much discussion nation, as a minute's reflection will readily the wire themselves. Here also they do by several authorities on whether static show. soldering, testing motors and generators, electricity resulting from pouring gasoline However, nothing amazes us any longer while in other rooms we find them wiring thru chamois could ignite gasoline or not. in these stirring days. We are indeed doing lamps, telephone systems, lighting systems, In connection with this an inquiry has arisen the impossible in all branches of human as well as electrical sign systems. Next we from a reader regarding static electricity endeavor. While we say today: "It can't see them at work operating a motor flasher, when filling tanks, especially motor cars, be done," along comes a chap who has while another class is studying switch cir- with gasoline says a contemporary publica- already done it and thinks it commonplace. cuits. There are also classes handling tion. This has been the cause of fires. In Out in Chicago in the "I Will" city, they every kind of installation work. reply thereto, a Canadian Insurance In- The writer on a trip thru spector reports as follows: this institution watched stu- "The fire danger inherent in static elec- dents at work on meters, test- tricity is present only when the chamois ing motors, transformers, alter- skin is used as a lining for the funnel or nators, induction motors, etc. other filling apparatus. The use of chamois He watched them winding skin suggests itself because of the prop- stators, repairing arc lamps erty of chamois to pass gasoline but to re- and doing all sorts of every tain water. day routine work on starting, "It has been found that when gasoline lighting and ignition systems. runs thru a metal funnel with chamois skin, static electricity is released which in a In still another room are few cases on record has generated a spark seen students working on spark and ignited the contents of the tank. It coils as well as operating all has been demonstrated experimentally that kinds of motor control appa- a spark is generated only when the fun - ratus, testing watt meters and nel is held in midair, without making con- building switchboards. tact with the metallic gasoline tank itself. It is quite surprising to find "Since electricity seeks the shortest path, what a huge equipment is col- it is advisable to ground the chamois -lined lected under the roof of a funnel, by permitting it to make contact school of this kind, but on the with the metal walls of the gasoline tank. other hand a minute's reflection This way all danger is avoided." will reveal that unless such a A case in point of the effect of the haz- tremendous equipment was pro- ard of static electricity occurred on July vided the practical instruction 2nd when an auto truck of the Imperial would of necessity be faulty. The Most Practical and Resourceful Electrician 1s the One Oil Company at its filling plant in Van- Who Has Actually Made the Test On a Dynamo or Motor As a matter of fact, if the stu- couver, took fire. The wagon was being Himself. dents are bright and alert at filled from the tank and the driver had not all, they will themselves de- made the proper ground connection, the now have a big machine (which isn't pat- mand to see as well as do work upon tank being insulated by the automobile tires. ented, either), where they feed raw, lanky almost any imaginable sort of electrical During the. process of filling, static elec- youths in thru a hopper at the top of the devices. Hence, it did not surprise the writer tricity was generated, making a small ex- roof and three months later full fledged to find that there was even an electrical loco- plosion which ignited the liquid in the tank electricians, with diplomas in their hands. motive upon which the students worked! truck.

www.americanradiohistory.com 310 ELECTRICAL EXPERIMENTER September, I9 I8 Popular Astronomy THE SUN AND HIS SATELLITES -THIRD PAPER By ISABEL M. LEWIS Of the U. S. Naval Observatory

OCR sun is but a star traveling thru Our planet earth has one satellite, the tries for every day that the planet is visible. the universe at the rate of thir- moon, that has the distinction of being the The five remaining moons have all been dis- teen miles in a second. It largest moon in proportion to the size of covered in modern times. They are ex- is accompanied in this journey the mother planet. Jupiter and Saturn have tremely small bodies visible only in large to unknown parts of space, that moons that surpass our moon in actual size, telescopes. Satellite V is the nearest of lie in the general direction of the constel- in fact, two of the moons of the outer all the moons to Jupiter. The other four are at great distances from the planet. The planet Saturn has nine moons. Titan, the largest, is nearly equal in size to Jupiter's largest moon and is therefore r larger than Mercury, four of the other moons have diameters between one thou- sand and two thousand miles in extent. Since Saturn is nearly twice as far from the sun as Jupiter his moons are much more 4 difficult to observe, tho the two largest are visible in small telescopes. Saturn is unique in the solar system in possessing in addition to his nine satellites a most wonderful ring sytem composed of swarms of minute moonlets, each pursuing its individual path around the mother Venus In Different Parts of Her Orbit as Seen From the Earth. The Direction to the planet. It is this unusual ring system that Earth Is Toward the Bottom of the Page. The Planet Mercury Shows These Same makes Saturn the most interesting to Phases. Neither Planet Can Be Seen When in Line or Nearly In Line With the observe telescopically of all the planets. Earth, Except on the Rare Occasions When They Transit the Sun or Pass Directly Between the Earth and Sun, When They Appear as Black Dots Projected on the Sun's The planet Uranus has four satellites and Disk. Usually They Pass Just Above or Below the Sun and Are then Invisible, Due Neptune one. Neither of these planets nor to the Glaring Light. Mercury is Never More Than 29 Degrees or Venus More Than any their be 47 Degrees From the Sun. of satellites can well observed on account of their great distance from the earth. The indistinctness of surface mark- lation Hercules, by an extensive family of planets are actually larger than the smallest ings makes it impossible to determine the minor bodies, the eight major planets and major planet Mercury but they are very period of rotation of these two outer their encircling moons, twenty -six in num- small in proportion to the size of the planets on their axes. It is believed to be ber, one thousand or more asteroids, and planets around which they revolve. Mars, very rapid, however, as is the case with the numberless comets and meteors, all mov- other outer planets Jupiter and Saturn. All ing in prescribed paths around their ruler the planets in the solar system fall natur- whose intense light and treat are the result ally into two groups. Jupiter, Saturn, of his comparative nearness. Seen from Uranus, and Neptune, the members of the the distance of the stars he would be only outer group, have on the average, diameters one star among the hundreds of millions ten times as large and therefore volumes of stars that form the visible universe. The most important members of the sun's family are the major planets, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. named in the order of their distance outward from the sun. Saturn and Its Three Concentric Rings Com- We hear occasionally of the possibility posed of Swarms of Moonlets In Revolution ix of the existence of inter-Mercurial and Around the Planet. Note Divisions in the Ifa. '.'' trans- Xeptunian planets and some day Rings and Also Belts on the Planet Paral- tel to Its Equator. an additional planet may be discovered within the orbit of Mercury or beyond the the next planet beyond the earth, the nearest orbit of Neptune. The gravitational power of the superior or outer planets, has two of the sun extends far beyond the orbit of tiny moons that bear the names of Deimos Neptune and there seems to be some evi- and Phobos. They are both less than ten dence pointing to the possible existence of miles in diameter and revolve very near to two planets on the outskirts of the solar iv :47 . the surface of Mars. They can only be venus system. The question of the existence of seen in very powerful telescopes. The inner a planet within the orbit of Mercury is now, moon Phobos is unique in the -solar system after long continued and diligent search, for it makes three trips around Mars while considered to be settled in the negative. the planet is turning on its axis or ex- Were it possible to view the sun from periencing one day and night. the distance of the nearest star with the aid Jupiter the next planet outward from the r (AIMS y of the greatest telescope on earth all the sun is almost a sun himself in the eyes of -4ti u . members of his family would he hopelessly his extensive family of nine moons. Four invisible. So, also. We cannot tell as we of these were first seen about three hundred point our powerful telescopes at the stars years ago when Galileo pointed his first whether these other suns are attended by crude telescope at the heavens and any one planet families. \\'e may only argue that can now see them with the aid of an opera it is very unlikely that there should be but glass. One of the four is equal in size to one star among hundreds of millions that our own moon; the others surpass it in is attended by a group of comparatively size. These moons are most interesting Diagram II. Relative Sizes of the Major small dark bodies that shine by the reflected little bodies to observe and they have figured Satellites of the Sun, and the Earth's Satel- lieht from the star they encircle. lite, the Moon. The Distance of the Moon in some important astronomical discoveries From the Earth Is Sixty Times the Earth's With the exception of the two planets, as well. Their eclipses in the shadow of Radius and Is therefore Not Drawn to Scale. Mercury and Venus, spoken of as the in- Jupiter, occultations or disappearances be- The Scale of the Diameters of the Planets Is Twenty Thousand Miles to One -half Centi- ferior planets, since their paths lie between hind his disk, and the transits of their meter. Note the Comparative Sizes of the the earth and the sun, all the major planets shadows as well as the bodies themselves Terrestrial Planets on the Left and the have moons or satellites of their own that in front of the planet are all phenomena of Outer Planets on the Right. Roman Numer. ais to the Right of Each Planet Represent encircle the mother planet just as the importance to astronomers and are there- the Number of Its Moons Discovered to mother planet encircles the sun. fore puhlisht in the almanacs of all coun- Date.

www.americanradiohistory.com September, I9 I8 ELECTRICAL EXPERIMENTER 311 one thousand times as great as Mercury, Our own moon always keeps the Venus, Earth and Afars, the members of the same face turned toward the inner or terrestrial group. earth and the evidence seems to The terrestrial planets are the pigmies of be that some of the satellites of the solar system, the outer planets are the Jupiter and Saturn rotate in the giants. The density of the planets Mercury, saine way. The length of the Venus, Earth and Mars averages nearly day on Mars is known very ac- five times that of water. One, at least, of curately on account of the rare- these planets supports many varied forms ness of its atmosphere which of life. enables us to see some of its The existence of life on Mercury is made surface markings. Its length impossible by the absence of an atmosphere. is about 24% hours and its sea- Venus and Mars both have atmospheres sonal changes strongly resemble and there is a strong possibility that both our own. of these planets may support life. Mars Life on any one of the outer has probably been the most discust of all planets is impossible. The the planets tho Venus is the Earth's density of these planets aver- twin planet ini size. mass, density, and sur- ages about the same as the face gravity just as Uranus and Neptune density of the sun which is a are the twins of the outer group. It is now little higher than the density of believed that water and vegetation exist on water. The density of Saturn Mars. The reddish color of this planet is is even less than water. In other supposed to be due to its extensive desert words, Saturn would float in tracts. The existence or non -existence of water and it is the lightest of certain surface markings on this planet, the all the planets. It is assumed "canals," still continues to be a matter of from these facts that the four dispute. It is reasonably certain, tho, since 'outer planets are largely in a air, water and vegetation exist on Mars gaseous condition. They all that some form of animal life also exists possess dense atmospheres and The Planet "Mars " -After a Drawing By Alfred Rordame, there. in spite of their huge size Made December 3, 1911. Note the Canal Lines, Which in The question of life on Venus depends rotate on their axes with great the Larger Telescopes, Are Plainly Discernible. largely upon the length of its rotation rapidity. The two whose rota- period which is still uncertain since no de- tion periods are known, Jupiter and may represent the material of the primitive finite surface markings can be found on Saturn, turn on their axes in about ten solar nebula that was not swept up when this planet. So dense is the atmosphere of hours. On account of this rapid rotation the larger planets were formed. Venus that it appears to be always hidden and their gaseous condition both Jupiter With few exceptions the asteroids are from view beneath a canopy of clouds. It is the general belief that Venus, as well as only to be seen in large telescopes and then Mercury, rotates on its axis in the same only as star -like points of light. Most of time that it takes to make a revolution them are simply huge rocks and all are around the sun. In this case the same side necessarily devoid of life since such small of the planet would always be turned bodies have not sufficient gravitational force toward the sun and under such circum- to hold an atmosphere. stances life on Venus would be very difficult Law and order prevail among the differ- heat due to great extremes of and cold. ent members of the solar system. The revo- This peculiar form of rotation is by lution of the planets around the sun and of no means unknown in the solar system. the satellites of the planets around the primary planets are performed according to known laws that make it possible to fore- tell the positions of these bodies years in advance. Asteroids and comets also obey the laws of the solar system and after three observations of the positions of one of these bodies have been obtained their future movements can be followed. There is, moreover, a uniformity in the form and motions of the planets and their moons that is considered significant in connection with Jupiter and His Belts. Photographed By E. C. Slipher of the Lowell Observatory, the origin of the solar system. All the Flagstaff, Ariz. Generally Considered the planets and their satellites are nearly per- Best Photograph of Jupiter Ever Made. fect spheres. They all, with few exceptions, rotate on their axis and revolve around the and Saturn are noticeably flattened at the sun or, in the case of moons around their poles. Both of these planets have a number primaries in the same direction from west of dark belts parallel to their equators and to east. When the noted nebular hypothesis faint belts have also been seen on the planet was advanced to explain the origin of the Uranus. According to one explanation solar system the exceptions were unknown. these belts are fissures in the planets' upper They are now considered to make doubtful atmospheres thru which the lower denser the truth of the hypothesis. These exceptions atmospheres are seen. The rotation of the are the two outermost satellites of Jupiter, planets on their axes would cause these the outermost satellite of Saturn, and the openings to lie parallel to the equator. satellites of Uranus and Neptune. All these The terrestrial planets are separated from bodies retrograde or travel in their orbits a wide gap. the outer group by Within this in a direction opposite to that of all the space be found or are to the asteroid other planets and satellites. planetoid group. There are known to be over nine hundred and fifty of these minor The paths of all the planets around the bodies whose diameters range from five sun are nearly circular and they all lie in Diagram 1. Relative Positions of the Orbits of the Eight Major Planets. The Three hundred miles for the largest to three or nearly the same plane. The asteroids have Inner Circles Represent the Orbits of Mer- four miles for the smallest. There are orbits that are more flattened or elliptical cury, Venus and Earth, Named In Order of only four asteroids whose diameters exceed and these orbits are in some instances Their Distances Outward From the Sun. The Orbits of the Planets Are Ellipses, Not one hundred miles and the majority have highly inclined to the planetary orbits. The Circles, but They Cannot Be Distingulsht diameters of less than twenty miles. The comets have orbits that are usually very From Circles In a Drawing of This Size. total mass of the asteroids is much less than elongated ellipses or parabolas. Some of Within the Asteroid Belt Are Found the smallest planets. Majority of the Asteroids, but Not All of that of the of the major the comets may he only temporary mem- Revolution of Planets It was believed at one time that these small Them. The All the bers of our solar system tho astronomers and Asteroids Is in the Direction of the bodies were fragments of a shattered planet Arrow, From West to East. On the Scale The generally believe that they are all perman- of This Diagram the Nearest Star Would but this view is no longer held. Be Distant Four fifths of a Mile. asteroids as well as the comets and meteors (Continued on page 340)

www.americanradiohistory.com 312 ELECTRICAL EXPERIMENTER September. 1918 The Gyro -Electric Destroyer -Once More The Pro and Con of Mr. Gernsback's Idea of Winning the War with the Gyroscope

read with a good deal of tions have had to give way to the power he impossible for the Hun to set foot on a interest and thought Mr. Gems- of the big guns, the Tanks offer no defense bit of safe ground. With all the talk of back's articles in recent issues of at all, for any purpose. When steel tur- the Allies devoting their efforts to building fJAVIXGthe ELECTRICAL E\PERtMENTER in reted forts like those along the Belgian a large fleet of planes, it appears that very regard to winning the war by frontier suffered such damage and were little has been accomplished in this direc- building 45 -foot monsters called Gyro - practically blown out of the ground, what tion. Because if they had how was it pos- scopics, which would spread defeat and possible defense could a Tank or even a sible for Germany to assemble the im- consternation in the ranks of the Hun mense forces and materials on the I beg to take issue with him on the Western front for the past spring feasibility of this plan, regardless of d rives. its astounding features: According to the Tank and Gyro- In the May issue, he says editori- scopic' defense idea, we wait until the ally: enemy has assembled all his forces "This war, more so than any and munitions for the drive before other, is a machine war. A stereo- they are called on for action. On the nevertheless, a typed phrase. but, other hand, the bombing plane checks very true one. When we speak of the enemy while he is trying to as- a machine war, we usually have in mind artillery of all calibres, semble his supplies, by hunting out the from machine guns upwards to most vulnerable points of attack. I 42 cm. guns, and larger. \Ve be- can say without fear of contradiction lieve that we will not be contra- that a suitable supply of bombing dicted when we state that vast planes would make a big offensive im- bodies of infantry can not move possible, by bombing everything above forward nowadays without the ground. Nothing can escape these support of protecting artillery bombs ; they are everywhere at once from the rear. Logically, the con- carried by swiftly moving planes, clusion follows that if we can an- capable of returning to a base for nihilate the enemy's artillery, he more and resuming the havoc. The must fall back. Even trench sys- Tank and Gyroscopic could attain no tems without artillery support such speed or return for supplies. from the rear can not be held for Once in the work they must go on un- any length of time by the enemy. til their supply of ammunition is used If our artillery is intact, but if the tip and become the prey of the enemy. enemy is deprived of his, even tho \ \'hile it is evident that this is a his infantry should outnumber The Gyro -Electric Destroyer, Here Illustrated, Was Fully machine war, and the Tank has been ours ten to one, he would have to Described In Our February, 1918, Issue. This 45 -Foot tried and the Gyroscopic suggested, retreat just the same. These, of Monster Is Steered By a Large Gyroscope Wheel. Shift- I am confident that the need will be ing the Latter Either to the Right or the Left. The accomplished course, are very obvious facts." Wheel Made of Lattice Steel -Work Is Practically Proof with men, munitions and According to reports from the fight- Against Stray Shell Shots. The Destroyer Runs at a bombing planes. Men and munitions, ing fronts this is true enough without Speed of From 40 to 60 Mlles an Hour and Due to Its of course, are everything, but in addi- Huge Diameter It Rolls With Ease Over Trenches and the endorsement of the General Staff. Other Obstacles. tion to these, the Practical value of the In the next paragraph he writes: bombing plane has been proved over "The British now engaged in the Gyroscopic put up in the face of such a fire, the Tank and Gyroscope, and they will \Western war theater realized this truth with their limited crew and supply of am- bring results unless some inventive genius very early and set about to rectify it. munition, especially when the batteries of brings forth some new type of land battle- The result was their present Tanks. the enemy are capable of plowing up every ship, which must necessarily come, because These machines fulfill several pur- foot of ground. A few well directed shells men alone cannot stand the awful havoc of poses; they are used to batter down of the 42 ctn. type would be sufficient to put battleship guns, now used for the first time the barbed wire entanglements pro- them hors de combat without further ado. on land. Inasmuch as no modern forts, tecting front line trenches: secondly, Mr. Gernsback states: Tanks or Gyroscopics can withstand them, they raise havoc among the enemy's "In other words, the large and speedy other means, one of which is the bombing men by flank fire once across his lines, machine obviously is the thing in this plane, must be found to overcome them. but most important of all the Tanks war. In former articles we have shown LOUIS LEON. are supposed to annihilate the enemy's that it is perfectly feasible to run mon- - Director. artillery either by putting the artiller- ster machines over land at speeds from Rochester, N. Y. ists out of action by gun fire from the twenty miles upward." Leon Telegraph & Wireless School, Di- Tank or by climbing right over the Possibly, but how could it he done in the rector Wireless Telegraphy, Mechanics In- enemy's guns. thus putting them hors mud of Flanders? The Gyroscopic with its stitute. de co,nbot. For the first two purposes heavy bulk would sink axle deep in the

: depend dry the Tanks are ideal for the latter they mud. Its success would upon Mr. Leon's criticism is taken, but Even well I have ,ignally tailed. The reason is ground and smooth ground at that. regret that I cannot agree with him. Quite very simple. The Tank is an extremely if it could succeed in passing the enemy's the contrary. slow -moving vehicle in the open field- barrage and run down first line trench hat - My answer resolves into the one five to eight miles an hour at the most teries and machine guns. it would still have itself word : SPEED. In my in Feb- is its speed. Even if camouflaged a high power guns several miles back to con- article the ruary 1918 issue of the ELECTRICAL EXPERI- Tank makes a shining mark for the tend with as well as guns at a much nearer MENTER I stated explicitly: enemy gunner:, who find little trouble range, and would he practically blown to in getting the range of the slowly pieces before it could over -run them. "As we have pointed out before, what is crawling tractor. One or two shells By this reasoning we are able to see that wanted is a machine, not necessarily soon puts the most ambitious Tank out no machine of the Tank or Gyroscopic type monstrous and weighing many thousand ,. tons, of Lusines: can expect to achieve a decision in this hut one that need not weigh more Another truth. and he might have added, war. It is in the air that we should look than the present Tank, and that can cover ground so the Tanks have any real military value for results. Swiftly moving bombing rapidly, that it becomes almost if impossible for where are they in the past hie (Allied) planes which offer little target to the enemy the enemy to get the range." drive? One would expect to read in the can he depended upon to put the enemy's I furthermore said: news disoatchcs where the Tanks like bits batteries out of business. no matter where "It should also he noted that only a very of Gibraltar stood out in the open and they are located. As many military experts moderate speed of the motors is necessary. stemmed the advance, but such has not been have stated the decision N.vill be in the air. inasmuch as the diameter of the wheel -45 the case. It has been proven that in a The side that controls the air will have the feet -is so large that it will move at the warfare where nothing can live above the advantat'e. With thousands of bombing rate of from forty to sixty miles an hour ground, and even steel and concrete projec- planes covering the Western front it would with the motors running at very slow speed."

www.americanradiohistory.com September, 1918 ELECTRICAL EXPERIMENTER 313

Now if Mr. Leon knows of any method Exactly as the Hun submarine is help- Nowhere in my articles did I mention to train a large calibre gun and score a less against our fast moving destroyers - that the Gyro -Destroyer could or would win the war, but i did say: hit on an object 45 feet high and less than for it can not get the range quickly enough express -so the Hun gunner is helpless against " \ \'e are quite confident that a machine 20 feet wide running at more than our Gyro- Destroyer. And just as our boys of this kind should do as good work as a hear it. Always re- speed, I'd like to of in blue drop a depth charge on the prowl- thousand men in the field, and, perhaps, member that a Gyro- Electric Destroyer un- ing U -Boat, so will our boys in Khaki drop better." der fire would run at all times a slightly a bomb on the German Gun. I still maintain that I am right, until erratic course; (let us say, a steep zig -zag). Mr. Leon says: "How could the Gyro - actual experience with such a machine Under such conditions a direct shelf hit is Destroyer run thru the Flanders mud ?" proves me wrong, and that I firmly believe impossible, and any artillerist will tell you The answer is simple: It doesn't! \Vhy won't happen. so. The enemy simply can not get the s * s * s range of the swift moving monster. It i000luumummmimuumiuluuuuuumumMimmuuuiuuuummmnmuuniuuuuh In connection with the above a curious could only be hit by a very remote chance. THAT "OCTOBER "ELECTRICAL R thing is happening of late. i am in receipt The zig -zag tactics coupled with the high EXPERIMENTER of many letters from "Experimenter" read- speed of the destroyer have their true ers, and I reproduce a few below. These So,rreth:ag sew -an automatic bul- fair samples of the many that counterpart in the modern battleplane, fly- P let- proof. steel plated electric soldier letters are come to my desk, but I will let them speak ing thru a heavy barrage of anti- aircraft -that will hold the front line fire. An aeroplane pilot caught in the midst trenches against all odds. for themselves: of a barrage (providing he flies low Electricity -the nerve -force behind Editor Electrical Experimenter: enough) immediately begins to "pancake," the artillery barrage -101 things In reference to your May Editorial or else to loop, dive or climb. He never P about barrages you probably never S. and some of the preceding ones. i Ea in sym- at the 10 even dreomed about. wish to state that I am totally stays same level for more than far this "Monster seconds, and consequently the Tesla's New Lightning Rod -It up- pathy with you as as gunners s Land Battleship" is concerned. I am below never get his range. He simply vets all the old theories regarding such devices. Do you think it should well acquainted with the details of it, laughs at them, while he zig -zags vertically. as I have read your recent magazines Indeed, there is no greater for have a sharp point? Read Dr. Tesla's dishonor statements. as well as some of a few years ago a modern air- fighter than to be shot down Electric Power from the Ocean -A where you have also presented a ma- by anti- aircraft guns. It is very seldom new idea in this field of science by chine of that kind but of a different done nowadays, the real battles being fought E. D. Stodder. construction. I am also with the same in the air between the contending flyers. The Lotest Electrical and Wireless opinion in reference to the "Tanks" for I front the American Front. I have seen one and its clumsiness. therefore insist that no large' calibre ä Photos may not ap- can possibly put Destroyer The Telephone Girls with Pershing Now in order that you gun the Gyro- peal in your Editorials without results out of business. As to calibre Overseas. small guns, I would suggest, that, being your cir- let them shoot at it. They will do as much Spectroscopic Methods and the to culation reached the 100,000 mark, and damage as a machine gun does to a Tank. Production of Spectra -A sequel the article "How to Build a Spectro- naturally all those who read the ELEC- The armor of the Destroyer will not mind scope,' in the August number, by TRICAL EXPERIMENTER cannot but be it any more than a rhinoceros minds buck- interested, should patriotically contri- Donald S. Binnington. i= shot. The Revolving Mirror -How to bute $1.00 to the Editor, and the Editor Regarding the large guns, our Destroyer photograph an oscillating spark dis- should dispose of all such money by by Prof. building. and perfecting one of those simply runs over them or runs them charge. popularly explained 0 its into the ground. Or the crew may elect Lindley Pyle. Giants and prove to the Government effectiveness. to slow down when approaching one of the The Burnt -Out Lamp Price Contest -Second Spasm. For the Government at the present large guns. Then from one of the side time is overburdened with the enormity turrets a few small are dropt on Ohm's Law and the Alternating bombs Article Every of its war tasks and it hardly has time or under that gun, wrecking it in a W. Current Circuit. An few Radio and Electrical Student Must for experimentation. seconds. Then on to the next gun. á I personally would be more than will- Read, by Arno A. Kluge, Instructor and As for the bombing planes, I am just as in Radio. University of Nebraska. - ing to make such a contribution great a believer in them as Mr. Leon. \Ve Glass Blotting in the Experimental would urge it upon all those whom 1 certainly do need them, and if we can only Laboratory. It Tells You the How _ know to be readers of your magazine. make them fast enough to get them "over and Why. Part II. By Prof. Her- JOSEPH SEAR, bort E. Metcalf. No. 422 South Fourth St.. there" it will surely help to drive the Huns = Philadelphia. Pa. from the air and bring our day of victory - Besides One Hundred Other Live. LA * s * s s nearer. But bombing planes alone will !fide -Awake, and Timely Articles on Electricity, Physics, Radio, Chem - Editor Electrical Experimenter: never win the war any more than Gyro- The Gyro -Electric Destroyer which Destroyers alone can win it. But both will istry, Mechanics. and Astronomy; and All the Usual Departments. adorns the cover of the February, 1918. unquestionably prove of great help. issue of the "E. E." is a mighty inter-

Of what good are Mr. Leon's bombing II monster, and, if practical, l0d11 . 411111 [111, tl IISIMIV111@IIIIOC10; esting looking planes against large calibre guns, well IDUnum1EM1DU1V1111111111 would no doubt give an account of camouflaged, and invisible from above. shoidd it? Guns cannot advance thru mud itself on the battle field. \Vhat good are the bombing planes against either, nor does an army as a rule. Both I suppose the Government, deluged an intrenched enemy? What good are they contending forces, if mud separates them, with ideas of all sorts, and over- against a Hun division sneaking up under are deadlocked. But we can run over dry whelmed with the expense of carrying cover of night? Mind you, I am not at- land, and there is always plenty of that out its army building and army moving tempting to minimize the tremendous im- somewhere, and rte can then take the enemy programme. does not care to invest in portance of the bombing plane, but by itself from the rear and destroy his guns, before anything that departs so far from the it will not win the war. Germany did not he knows what is up. Then if our infantry usual. win the war, and she has thousands of follows the Destroyer there will be an end Nevertheless, looking at the thing on bombing planes. So have we and our Allies, to the deadlock in that section behind the paper, and dreaming of its possibilities but they have not won the war for us. Flanders, or any other mud field. if it would work. makes one very anx- Again I say, the ious to see it tried. enemy must retreat Therefore,this let- if he has no guns to ter and suggestion. put down a barrage Editor Electrical Experimenter: Why not get every with which to pre- I enclose herewith $ as niy contribution towards building a srodei "E. E" reader, and vent us from getting of your Gyro- Electric -Destroyer all others possible. at him. Destroy his You are to build as large a model as the funds will permit and the money is to donate one dollar guns, and he must to be used for the sole purpose of building this war machine. You agree to publish to defray the ex- fall back. And the an exact account of all funds spent and all contributions are to be acknowledged pense of building Gyro - Electric De- thru the columns of the Electrical Experimenter. one of these craft stroyer can and will and trying it out? You pledge yourself to construct the machine as quickly as possible and you do all this with com- upon its completion. if it works. turn it parative ease. And will turn it over to the U. S. Government immediately ''ver to Uncle Sam. by its help the lives Name If it doesn't. the loss of thousands of our is ours, and we won't splendid boys will be Address holler.

1111/1111 111 1111111 (Cont. on page 347) saved. 4111111111111 llllllllllll $$$$$$$ 1 llllllll 11111111 1111 lllllll 11 1111.1111 111 lll 11 l 1111 Pli llllllll

www.americanradiohistory.com 314 ELECTRICAL EXPERIMENTER September, 1918 The Phenomena of Electrical Conduction in Gases PART V- \VEIGIII \G AN ION By ROGERS D. RUSIi, M. A.

S large as the earth is it has been m tity m divided by e, then solve for in the weighed, and as small as the small- The simplest method of measuring - is mass. est ion is it also has been weighed, e The first step then is to measure e, the and measured many times. We are called tite energy method of J. J. Thomson. charge on an ion, and this like other similar accustomed to think of one as in- It is a well known fact that the energy of processes can be accomplisltt in several finitely small, and yet in this great universe any moving body is % m v', and if this be ways, but practically all methods for meas- .f ours the earth may be hardly an atom of the energy of one electron the total energy uring e, which have been developed so far of N electrons is: depend on the fact that drops of water can N % in y` - \V,- which may be measured be made to condense about ions and if in terms of the amount of heat generated sufficient ions are present a cloud is formed. when these rays fall on a metal plate. But It had been suspected for some time that the number of electrons N, is equal to the the presence of dust particles in the air was total charge Q, divided by the charge on one of the causes which made moisture each electron e, and the equation becomes collect in drops and fall as rain. In 1897. Q C. T. R Wilson made the discovery that in nt v' _ W or transposing ternis; dust free air clouds would form if electri- e fied particles or ions were present. This m 2W discovery was immediately followed up by -= So when the heat W. H. A. Wilson, J. J. Thomson and others. e - who made use of the new fact to enable Qv' the quantity of electricity Q in the gas, and them to determine the charge e, on an ion. the velocity v, are measured it is an easy As is well known the complete or total charge. in an electrified gas can be readily The Way Ions Are Deflected By a Magnetic by Field. A Pretty Experiment Easily Made measured driving these ions by means of With Simple Apparatus. an electric field to a plate connected with an electroscope or electrometer. If the the whole, and beyond the electron there number of ions were known it would be a may be SUB -ELECTRONS, divisible again and simple process to divide the total charge by again. Scientific investigation extends both the number of ions, and obtain the charge toward the ultra -great and toward the ultra - on each ion. Up until Wilson's discovery small but to the student of electricity the the counting of such minute particles as latter field is the more interesting, because ions had been an utter impossibility. Now it leads us on toward the solutions of the assuming by the laws of probability that problems as to what electricity and matter only a negligible number of drops would really are. forni about two or more ions at the same In previous papers it has been shown time it was only left to count the drops and how the velocity of an ion may be measured, take this as the correct number of ions. the methods of production have been men- Its order to insure as great accuracy as pos- tioned, and the causes of disappearance The Expansion Chamber By Which An Elec- sible very small drops were used, and in- have been explained. All these quantities tric Cloud is Formed. stead of being visibly counted their num- can be very definitely measured. but more ber was estimated in the following manner: than that the weight of an ion can be meas- m -A single drop was observed in a micro- ured. also its electric charge and its size or scope and its weight calculated from its volume. matter to calculate the ratio of -. e diameter. Then the whole cloud was When it was first attempted to obtain the There are many other ways of measuring weighed and this total weight divided by weight of an ion. or more technically speak- chief among which is a the weight of a single drop. This gave the ing the mass. something was discovered of the same quantity method depending on the fact that positive number of drops. The total charge was startling significance to the scientist and then measured as suggested above and di- which may revolutionize all of our scientific vided by the number of drops. This then views. Matter of any kind had always was the charge on the ion, and two birds been described as that which possest mass were killed with one stone for now the mass and this property had always been con- could be gotten from the various values sidered the most unfailing and unvarying which had been obtained for ratio of the attribute of all matter. In fact, it was the mass and charge. one quality by which matter was defined A typical apparatus for producing such a and distinguished from non- matter, but cloud is shown in Fig. 2. A is the expan- when in weighing the ion it was discovered sion chamber and P is the pump by which that seemed to be a new wave this untrue, a known expansion can be obtained; E, E of scientific thought developed which is A, The Field About a Stationary, Electric are the electrodes. When the piston is gathering force as it goes, and bids fair to Charge; B, The Way a Field Resists Motion. pulled down the air in A suddenly expands change completely many of our present Or Its Inertia. and very rapid evaporation takes place ideas. on For a long time scientists were unable (Continued page 355) to measure either the mass of an ion or or negative ions may be bent by a magnetic its charge by any direct meliod so that in force. As the magnetic force on the ion order to obtain some idea of the magnitude depends on the charge on the ion, and as the _-'c-- of these two quantities it was customary to amount the rays are bent will vary inverse- m ly as the mass of the ion, it is readily seen ,^` `..__ *. _ measure the quantity - -, or the mass divided that the amount of bending can be measured e in terms of these quantities and set equal '-i,--ti by the charge. This quantity was easily e m -1-- ` attainable because it occurred in many equa- to - or the reciprocal of -. Fig. I repre- -}¡,'. tions concerning ions, and if the charges m e were considered the same on all ions, it scuts the deflection of ions by magnetism, gave the relative masses: or if the masses in a tube similar to that used for measur- ing the velocities of ions. were considered the same. it gave the rela- r tive charges. On account of the fact that Now to measure the mass of an ion or all univalent ions in solutions carry the to weigh an ion all that is necessary is to same charge it has been customary to apply fined the quantity of electricity carried by The Complete Field of a Rapidly Moving Elec- the same notion to ions in gases. each ion and substitute it for e, in the quan- tric Charge.

www.americanradiohistory.com September. I 9 1 8 ELECTRICAL EXPERIMENTER 315 Experimental Physics By JOHN J. FURIA, A. B., DI. A., (Columbia University) LESSON FIFTEEN

Two Basic Experiments of intense Interest to Every Lover of Electro- " Electro- Plating" Experiment Which Proves Very Interesting and Physics. Fig. 79-The Electrolytic Decomposition of Water and Fig. Educational. The Electric Current From a Battery or Small Dynamo SO-Forming Water From Its Constituent Gases, Hydrogen and Causes the Metal Ions to Deposit on Spoons, Keys, Etc., Resulting Oxygen. in What is Known as "Plating." CURRENT ELECTRICITY ing is the simplest in which to secure and the current thru, (b), (d) and (f) become (Continued) mix the elements in the correct proportions. copper -plated, the speed of the action de- Experiment 87. (See Fig. 80). The jar contains dilute pending on the current. In a similar man- PLACE a few drops of sulfuric acid sulfuric acid. Electrodes, thistle tube T, ner by using silver instead of copper and a in a small vessel of water (see and J -tube, are connected thru a tightly silver salt instead of copper sulfate we Fig. 79). Fill two test tubes with fitting rubber stopper. MAKE SURE can silver -plate articles suspended on the this dilute solution of sulfuric acid THAT THE THISTLE TUBE ACTU- negative wire. Using nickel and a nickel and invert them in the vessel as ALLY IS IMMERSED AT LEAST salt we nickel- plate, and with gold and a shown. Lead current from storage battery HALF AN INCH IN THE SOLUTION: gold salt we gold -plate. CARE SHOULD or other sources of at least ten volts to THAT THE ELECTRODES A R E BE TAKEN TO CLEAN WELL THE platinum electrodes P and P' (steel nails TOTALLY IMMERSED AND THAT ARTICLES TO BE PLATED. The ex- will do fairly well if platinum is not avail- THE "J" (TOP) TUBE IS NOT IM- planation is similar to that of electrolysis of able). Bubbles of gas will appear rapidly, MERSED. The other end of the J- water. The dissolving of the salt in the the negative electrode filling its test tube tube is immersed in a porcelain cru- water causes the salt to dissociate into the twice as rapidly as the positive. On testing cible or china cup containing a soap positive metal ion (copper, nickel, silver, we find that the gas at the negative elec- solution such as one uses for making gold, etc.) and into the negative ion (sul- trode burns with a blue flame (a test for good soap bubbles. When the current is fate, chlorid, etc.). The positive metal ion HYDROGEN). The gas at the positive elec- turned on the solution in the jar breaks up is attracted to the negative electrode be- trode does not burn; but a glowing splinter into two parts Hydrogen and one part cause of the electrical field established, when placed in the gas burns brightly, i. e., Oxygen, as in the previous experiment. The loses its charge and deposits itself (or the gas supports combustion a test for gases mix in these proportions in the space plates). The negative ion passes to the OXYGEN). CARE MUST BE TAKEN above the solution and pass out thru the positive electrode, gives up its charge and WHEN MAKING THESE TESTS TO tube into the soap solution forming bubbles combines with the metal to form more salt KEEP THE TEST TUBES INVERTED; of Hydrogen and Oxygen, each bubble con- which in turn dissolves (the sulfate ion OTHERWISE, THESE GASES, BOTH taining two parts Hydrogen to one part loses its charge and combines with the BEING LIGHTER THAN AIR, WILL Oxygen. The first few bubbles contain the copper to form copper sulfate, which goes ESCAPE. Modern theory explains this air of the space above the solution and into solution). Thus the strength of the phenomenon, electrolysis, as follows: should be blown away. Then touch the solution is maintained and the metal at the When the sulfuric acid is dissolved in bubbles with a lighted match. A loud but positive wire is eaten up. the water. it breaks up into positively harmless explosion will result (harmless be- EXPERIMENT 90- Electrotyping is an im- charged Hydrogen ions and negatively cause it is an inward explosion rather than portant application of electroplating. Set charged sulfate ions. The current causes an outburst) and water is formed. The use up in common type the page to be electro- an electric field to be established in the of the thistle tube is obvious. Should the typed. Stamp it in wax or other compound solution between the electrodes. The hydro- pressure of the gas in the jar become large prepared for taking moulds. Coat the wax gen positively charged ions are attracted by because the gas is not escaping thru the impression of the type with grafite powder the negative electrode and repelled by the J -tube as rapidly as it is generated, there to make it a conductor of electricity. Sus- positive electrode. On reaching the elec- would be danger of an explosion and of pend this at the negative electrode of a trode their charges are neutralized and the the jar bursting. Instead, as the pressure copper -plating outfit as described in Ex- ions combine and form Hydrogen gas. The increases some of the solution is forced up periment 89. \Vhen a sheet of copper about negative ions move to the positive elec- the thistle tube, making more room for the 1/75 of an inch thick has been deposited on trode, their charges are neutralized, they gas and also causing less surface of the the wax mould, remove it from the solution react with the water liberating Oxygen and electrodes to come into contact with the and peel off the wax and replace it with forming additional sulfuric acid. The fact solution. This principle is extensively molten type -metal backing to give strength that we find that two parts of Hydrogen used in gas generators to avoid accidents. to the copper facsimile. From such an are given off to one of Oxygen is one of EXPERIMENT 89 -Place a solution of electrotype many thousand impressions can the reasons for believing that each Molecule copper sulfate in a vessel (See Fig. 81) AB be made. of water is composed of two atoms of and CD are heavy copper wires insulated EXPERIMENT 91 -1it the last lesson we Hydrogen and one atom of Oxygen. from each other and connected to a battery learned that electricity in motion is always EXPERIMENT 88 -Just as water can be de- of at least ten volts (D.C. house current is accompanied by a magnetic effect (Oersted's composed into its elements Hydrogen and very good for this experiment). To the experiment) and we learned the rule for Oxygen, the elements in their right propor- positive wire connect some pennies or other determining the direction of the magnetic tions can be mixed and water formed. Any pieces of copper (a), (c) and (e) ; to the field knowing the direction of the current. of the methods can be used for securing negative connect a key% (b) a spoon (d) Let us look into this effect a little further. the Hydrogen and Oxygen but the follow- and a coin (f) (no copper). On passing (Continued on page 350) r -!- , a -it-

, Mercury /roughs

o' S "Y N Fig. B2

Demonstrating the Rudiments of the Magnetic Circuit and Its Rela- These Diagrams Show the Direction of Current Flowing Thru a Helix tion to the Electric Current Producing the Magnetic Field. A basic or Magnet Coll to Produce a N. and S. Pole. Also How the "Right - Rule Everyone Should Know. Hand Rule" Is Applied to Magnets.

www.americanradiohistory.com ELECTRICAL EXPERIMENTER September, I9 I8

Notice to All Radio Readers As most of our radio readers are undoubtedly aware, the U. S. Government has decreed that all Amateur Wireless Sta- tions, whether licensed or !unlicensed, or equip! for receiving or transmitting, shall be closed. Titis is a very important consideration, especially to those who are readers of the ELECTRICAL EXPERIMENTER, for the reason that we desire to continue to publish valuable articles on the wireless art from time to time, and which may treat on both transmitting and receiving apparatus. In the first place, there are a great many students among our readers who will demand and expect a continuation of the usual class of Radio subjects, which we have publisht in the past four years, and secondly. !here will be hundreds and even thousands of new radio pupils in the various uaval and civilian schools thruout the country who will be benefited by up -to -date wireless articles treating on both the transmitting as well as receiving equipment. Remember that you must not connect up radio apparatus to any form of o nfenna.-The Editors. U. S. Signal Corps Radio Outfit in France

THE Radio Division of the U. S. Signal QUICK TRANSMISSION OF TELE- would be written "ston, lin, lim, practic, etc." Corps has been wonderfully enlarged GRAPH OR RADIO MESSAGES. 3rd Proposal: In such words as "Experi- since our entrance into the great menter, longer, water, writer, seeker, feeler, world war. and thousands of portable Altho there are 26 letters in the English stronger, quicker, etc.," I would eliminate wireless outfits are being assembled and alphabet only 23 are used frequently, the the "e" before the final "r," and the words shipt to Europe at this time. The ac- ones very seldom used are "X, V, Z." As would then be written as follows: "Ex- companying photo- perimentr, longr, graph shows one watr, seekr, feelr, of the Signal strongr, and Corps R a d i o quickr." "Also the Squads on duty in "e" before "d" as France. A collaps- "stored" = 'stord." ible telescopic mast 4th Proposal : is usually supplied "X" at the end of with this apparatus a word would in- so that the antenna dicate "shun" as in can be raised or "Induction, fiction, taken down at a traction, fashion." moment's notice. The above would \\'lien the troops be written as "In- are entrenched in ducx, ficx, tracx, dugouts, then the and fax." T h e radio men install "shun" in centers their apparatus in of words can also a well protected be written "Fax - underground cav- able." "Z" at the ern and lead their end of a w o r d antenna wires would indicate from the apparatu. "able." "Disabled, up thrtt dark pas- fahle, table, etc.," sageways and out would therefore be to the aerial itself written "Dzzd, fz, In trench warfare tz, etc." the antenna is a 5 t h Proposal: low affair not ex- "Z" at the begin- tending over three ning would indi- to four feet above cate "st" as in the trenches. The ` "stick, stayed, antenna u n d e r stem, steamer, etc. these conditions is They would h e given a fairly good written as follows: length to make up ,'Into Con) right by Committee on Public Information. "zick, zayd, zem, Corps Squads Operating a Portable for the low alti- One of Pershing's Signal Radio Outfit In France. and zeamr, etc." tude. Contributed by When the army makes a rapid advance, "V" is used more than the other two we "One of your Radio Bugs." then the radio crews move forward with trill discard it. \\'e then take "X" and "Z." E. LAUFER. the troops and carry their wireless ap- 1st Proposal: "X" alone indicates the paratus and aerial paraphernalia on mules word "the." "Z" alone indicates the word horses, "is." "X" may also indicate "a" or "an." Four working parties building a railroad or or still more often nowadays, on across Australia keep in touch with one an- auto trucks, some of which are assigned to If you were to write "they" just write "xy." the radio divisions for the purpose. There 'Writing the word "and" write "xd." In other by wireless telegraphy. are also a large number of portable wire- writing the sentence "The boy is good and less outfits mounted in auto trucks which he will go with them," all you write is "X American naval officers are installing a can travel over the field very rapidly, and boy z good xd he will go with xm." If you wireless telegraph station in France. which can be put into operation in less than were to write "his" just write "hz." "Busi- The Temps announces that the station a minute's time. These wireless trucks ness" would be written "bzness." will be ready for Ilse in August to corres- carry a telescopic aerial mast made of steel 2nd Proposal: To eliminate, wherever pond with the station in Annapolis. It will tubing. and are provided with special means practicable, all final "e's," such as "stone, cost $2,500,000. After the war the station for quickly raising and lowering the mast. line. lime, practice, etc." The above words will be taken over by the French.

www.americanradiohistory.com September, I 9 1 8 ELECTRICAL EXPERIMENTER 317

YOUNG ROCKEFELLER LEARNS The line connection is used only in cases along these lines, and constitutes one of the RADIO. where it is desired to receive thru head re- hest equipt laboratories of its kind available There is hardly a wealthy family in the ceivers, in which cases the head receivers today. country that does not have its boys in the are connected by plugging into this service; and, in the draft, the New York socket. In the event that more than district where the fewest exemptions were one pair of head receivers is to be claimed was the district in which the richest used at a time, they may be plugged into a connecting cord and in turn connected to the line connection in the set. This set has incorporated in it i ballast resistance which makes it possible to connect any number of head receivers without in- terfering with the sound of the buzzer. The set shown herewith is furnished complete with two three -foot cords for connection to the Battery and Omnigraph, but does not include Battery, Omni - graph or Head Receivers.

UNCLE SAM PAYS $1,600,000 FOR POUL- SEN PLANT. Tite Poulsen Wireless Telegraph & Telephone Company has sold its wireless rights and plant in the United States and dependencies to the U. S. Government for $1,600,000. This payment has already been made, while important deals are said to be pend- ing for the sale of Poulsen rights for use in other Photo by Paul Thungn 1 countries. Private W. A. Rockefeller of the U. S. Aerial Naval Patrol, Studying Wireless Telegraphy. SWEDISH RADIO families live. Private \V. A. Rockefeller, TALKS TO PALES- of the U. S. Aerial Naval Patrol, if com- TINE. missioned, as he hopes to be, believes he Sweden's most powerful radio can see his way clear to station, situated at Karlsborg, has Photo- Courtesy. The Oscillator' outfitting himself Cruft High Tension Laboratory at Cambridge, Mass.. completely -provided, of course, the dealers been put into operation. Regular Where Some Remarkable Experiments Have Been give him reasonable time. He is the son of communication is now being con- Conducted. the late William G. Rockefeller and grand- ducted with Dutch Altenburg in nephew of John D. He is here seen prac- Austria, and also Tsarskoe -Selo. Messages A CONSTANT TONE RADIO ticing the wireless code with an Omnigraph, have also been exchanged with Spanish sta- BUZZER AT LAST the standard code machine used by the tions and Constaninople. Word has been For a hundred and one purposes the radio Army and Navy schools. received that the Karlsborg station's mes- man daily finds that he needs a constant sages have been read by a little station in tone test buzzer. For all accurate measure- A COMPACT CODE TEACHING Damascus, Palestine, altho the Damascus ments of wave lengths and decrement such INSTRUMENT. station's plant is too weak to reach Karls- a buzzer is absolutely essential. It has re- As can be seen in the accompanying borg. mained for a well known English concern photo this new code teaching set consists to bring out such a buzzer, which sells for of a wooden base on which are mounted CRUFT HIGH TENSION RADIO something like nine dollars, but it is worth a sending key, a buzzer, a battery switch, LABORATORY. it. and three connection sockets. These sock- The accompanying photograph shows the This instrument, the result of exhaustive ets are marked "Bat," "Omni.," and "Line," excellent building and lofty latticed -steel experiments, will operate continuously at and are used respectively for connection to aerial masts at the Cruft High Tension and constant amplitude without changing its the Battery, the Omnigraph, and the Line. Radio Laboratory at Cambridge, Mass. periodicity, and the note is instantly vari- The Omnigraph connection may or may not This laboratory which was built several able by the movement of a cam, say its be used, as desired, but is included in case years ago, was used as a special research sponsors. A pure musical note with a range the student desires to practise receiving laboratory prior to the declaration of war of three octaves can he obtained. Sparking from an outside source. by the United States. It was formerly used at the contact points is entirely eliminated by the U. S. Naval Radio School at Cam- bridge, but it is not now directly used by this school. The Cruft Laboratory was built to carry on high class wireless and allied high ten- sion research work. including such measure- ments as the quantitative and qualitative tests of radio signals, the determination of the operating characteristics of radio trans- mitting as well as receiving apparatus, wire- less telephone experiments and tests. etc. Considerable work has been done at this laboratory in the short time it has heen in operation including a large number of ex- periments on the wireless telephone of Prof. New Constant Tone Radio Buzzer. Chaffee. The laboratory is fitted up with a com- b a small grafite rod Which can be shunted A Code Teaching Instrument Provided With plete equipment of the various measuring either across the coil or the platinum con- Plug Switch for Battery and Omnigraph. instruments necessary for conducting tests tacts, and if desired cut out entirely.

www.americanradiohistory.com 318 ELECTRICAL EXPERIMENTER September, 1918 The Einthoven Galvanometer Its Theory, operation and Construction By SAMUEL D. COHEN

THE electrical measuring instrument is a delicate and sensitive electrical instru- radio received currents from distant trans- is the most important asset to the ment used for measuring very small electric mitting stations. electrical and radio experimenter, currents. To the radio experimenter and A commercial form of Einthoven gal- and it would be impossible for him to engineer, the galvanometer is found to be vanometer is shown at Fig. 1. Here A rep- study the actual characteristics of most useful, insofar as unimaginably small resents the powerful magnetic poles excited any electrical piece of apparatus without the currents are dealt with, especially in the by the huge electro- magnets, B. B. The radio receiving circuit where currents of case, E, contains the fine wire carrying the one- thousandth part down to a few mill- current to be measured. Fig. 2 shows ionths of an ampere flow. schematically the arrangement of the Practically all galvanometers with which suspension for the tine wire E, which the student is familiar consist of two main parts, a coil of wire thru which the current can flow to be measured, and a permanent steel magnet constituting the field. This is the moving coil type. In other forms of ,this instrument, the coil is comparatively large and is rigidly fixt to the frame of the instrument, while the magnet is a small piece of steel suspended lightly by a fiber of untwisted silk or quartz. In other gal- vanometers the arrangement is reversed, and the coil or part carrying the current is made as light as possible and placed in a very powerful magnetic field produced by a large electro- magnet, which usually forms the body of the instrument. The latter type of instrument is the one in which we are interested, as it has proven to be the most sensitive of them all. Even in this class of galvanometer, there Fig. 1A. A Special Form of Einthoven String Galvanometer Used in a New York City Hos- pital In Recording the Beat of the Human Heart. This Galvanometer Is So Extraor- illl;i!l'i' li illliil!;I.1I1 dinarily Sensitive That the Minute Electric 1 Fig. 3. II. Currents Generated at Every Beat of the Einthoven Galvanometer As Built Heart Actually Cause the Instrument to By the Author and Shows a High De- Which Register a Deflection on a Moving Photo- gree of Sensibility. This Type of Galvano- graphic meter Is One of the Simplest to Build, and It Film. Is Suitable for Use in Recording Radio sig- nals and Other Extremely 'Minute Currents. must be as fine as possible. Platinum, The Construction Cost Is Very Small. silver or aluminum can be used, but it was found that even a smaller diameter can be aid of it. Voltmeters, ammeters and watt- Record Obtained With the Einthoven Gal obtained by using quartz or glass fibers, meters are the ones used to the greatest vanometer Showing "Make and Break" these being platinized or silvered. The ends Curve of a Current of 1.3 Micro- Amperes. extent by the engineer. However, the most The Average Radio Signal Has a Strength of of the wire are soldered to T- shaped mem- important of them all is the ammeter, espe- Forty Micro- Amperes. The Time Interval bers, which are held by two set screws cially when it is used to measure a minute Between the Vertical Lines is .055 Second. placed at the ends. Adjusting the tension quantity of electricity flowing thru a given of the wire is a close operation and it is circuit. This instrument in its finer term are two types, the one developed by Prof. carried out by mounting the upper wire is called a galvanometer. A galvanometer Korn, who utilizes two, fine parallel wires carrier upon a rod having a cam at the suspended in a pow- upper end, the rod being normally pushed N erful magnetic field, up by a spring. With this arrangement a very and a second form fine adjustment of the wire is secured, con- devised by Prof. nection being made to the ends of the wire. Einthoven, who uses The method of noting the displacement of a fine, single silvered the wire when carrying a current in the quartz wire placed magnetic field is shown in Fig. 2. An eye- in an extremely piece. AE, is inserted in a hole in one of powerful magnetic field. The latter was found to be far more sensitive than the former, and this type of galvanom- eter will therefore be described in this article. Several years ago the author con- structed a very sim- pie Einthoven gal- vanometer. A l t ho not as sensitive as the commercial ones, it gives fairly ac- c curate results in experiments Fig. 1. A Commercl.tl Type of Einthoven Calvanometer Which Has which Been Extensively Used In Making Quantiative Radio- Telegraphic he conducted in ra- Measurements Such As the Strength of Rec ?ived Signals, Etc. The dio Fig. 2. Diagrammatic view Thru the Eint- Holder or receiving Carrier Supporting the Galvanometer Thread Between circuits. The instru- hoven Galvanometer Magnet - Poles, Showing the Powerful Magnetic Poles Is Removable for the Replacing of the How Deflections of the Filament or String Filament. The Observer Looks Thru the Po'e- Pieces and Sees the ment was sensitive "C C" In the Direction of the Arrow "a," Deflections of the Filament By Means of a Te escope Shown at D, D. enough to record Are Viewed Thru the Telescope.

www.americanradiohistory.com September, I918 ELECTRICAL EXPERIMENTER 3 I 9

the magnet poles, and the light is projected To determine the period The wire is of the string by actual by the tube C and the lens F. i? stretched between the points CC, and with measurement is a difficult the in the direction in- problem. However, the the flow of current /o dicated by the arrows, a deflection is ob- following may be found of tained as shown by the horizontal arrow interest, especially to the "a." which is at right angles to the mag- more advanced student of B netic field NS. Even a minute movement electricity. If a short cur- by the wire is greatly magnified by the tele- rent be sent thru the string scope. For projecting on a screen, the eye- by means of suddenly tap- piece is removed and by sending a power- ping a key connected with 9 ful light ray thru C, we see the image of the string, it is given a jerk the middle part of the wire on the screen. and is displaced thru a The screen is placed one meter away from distance d (at the center). the wire, inasmuch as the deflection will It then swings back to vary with the distance. The instrument may zero and then past the zero be calibrated to note the amount of current point, due to the slight mo- necessary to produce a deflection of one ment of inertia which it millimeter division at one meter distance. possesses. Calling this This is a standard of calibrating all types distance X, the point is thus d -X from it, where of galvanometers. I/ It was found from actual experiments in d -X is less than d. If a determining the sensitiveness, that the string damped oscillation is sent s s will be displaced one millimeter for currents thru the wire, the string 1 does not actually come to as small as 10-" ampere ( rest for a definite time. 1,000,000,000,000 During this time there may or one one- trillionth of an ampere). Sev- be a complete vibration eral millimeters or even centimeters of de- from which the natural flection can be obtained with the aid of the period t/n can be ascer- optical instrument and with currents of tained. If the string be values of 30 to 40 micro -amperes, (one made to cast a shadow micro- ampere = one one -millionth ampere). over an illuminated slit It is thus seen that the instrument is ex- thru which the light passes tremely sensitive. when it is displaced, and Some of the most valuable features of this light falls on a rap- this instrument are :-its quick action, its idly traveling band of a dead beat, and its quick period of swing, this highly sensitive photog- being due to the almost negligible weight of raphic film, and a tap be the moving part, its moment of inertia be- then given with a key or ing extremely small. Also it possesses prac- switch, a record of the tically no self -induction or capacity. It was movement of the string is found that with a wire of standard length obtained. If the rate at and thickness which is one -thousandth of an which the film travels is fig. 4A inch thick, that the period of the wire is known, is a simple mat- it Fig. 4. Assembled View of the Home -Made Ein- 1 ter to calculate the period thoven String Galvanometer, Showing Field - of a second. This is small enough of the string of the galvan- Magnet Coils and Adjusting Screws As Well As 1,200 ometer. Base Suspension Block for the "String." The Telescope Members Are Screwed Fast to the Pole - for practically all speeds of code reception The string has a shorter Pieces By Blocks at 6, 6. used by commercial radio companies. period if its length be shortened or its tension increased, and 1-r/ro/es the damping of the oscillation can be ef- fectually increased if a twist be given to one end of it. It is thus seen from the above discussion :}r¿ that the character of the string, its material and manner of suspension has a great deal -- to do with the sensitivity of the instrument. fibre Also the intensity of the magnetic field . ende i.. i7. 114.4 wherein it is placed has considerable to do with its sensitiveness. The table below fig. gives an excellent idea of the period of the 7 string, its resistances, etc. a// /o /es 1/8 dril/ This will suffice for the discussion on its r-'^1 631 !Op operation. Let us now turn our attention to the more important topic for the construc- tor, namely giving the reader complete di- mensioned details on the construction of a sensitive Einthoven galvanometer, which the f:L author built several years ago. Fig. 4 is a photograph of the completed instrument. fig. 6 This galvanometer was used for experi- 1.~, :;;1 mental work in radio -communication and y.8 its sensitiveness was found to be three -hun- fig. S /e3? dredths of a milliampere for one millimeter z pie Ori%/ /op deflection at one meter distance from the ISOM screen. This was found to be sensitive enough for practically all kinds of work where small currents were dealt with. Detail assembly of the galvanometer is .}_i- fig /0 given in Fig. 4-A. The base 1, is made from three- quarter inch bard wood stock, and the drilling lay -out is given in Fig. 5. All holes are to be drilled with a No. 18 twist drill. The magnetic field is derived from two electro- magnets 2, 2, and their construction is shown in Fig. 6. The core irr /qo acef is a piece of wrought iron one -half inch diameter. The fig./2 fig /3 El in ends are machined down to four and one -quarter inches. Two fiber Working Drawing Giving Dimensions of the Principal Parts of the Einthoven String bobbin checks are placed on each end. Two Galvanometer Here Described. All of the Parts Are of Very Simple Design, and Can made Be Made With a Little Care By Any Amateur Mechanic Without the Aid of Any holes are in the lower end with a Elaborate Machine Tools at Ail. (Continued on page 345)

www.americanradiohistory.com 320 ELECTRICAL EXPERIMENTER September, 1918 A Graph for Solving Wave Length Frequency Inductance and Capacity By E. M. T. (RADIO ENGINEER)

THIS graph gives a comprehensive The scale starts at the bottom with one diagonal of the upper right -hand rectangle. view of the relation between reso- centimeter of inductance. The next main If the work is accurately donc, long nant frequency and concentrated division is for 10 centimeters, and from the straight lines in any direction will intersect capacity and inductance over a range starting point the following main division neatly the corners of the main rectangles. somewhat more extensive than is at is for 100 centimeters. As the scale extends Now note this property of the double present covered by wireless telegraphy. In to 10" centimeters or 10° times the first main rectangular logarithmic scales so produced: fact, the graph is equivalent in length to division, which is about one -inch long, it If a straight diagonal line is drawn thru 16,000 miles. may be quite readily estimated that 10° the corners of the main divisions from left In order to do this logarithmic to right in the downward direction, scales must be employed for in no the product of the values of the verti- other way can the enormous ranges cal and horizontal lines at the inter- of values be suitably shown. Loga- sections is constant. This may be rithmic scales are quite simple and noted by inspection. The same is true their use should not deter anyone, not for any other parallel line and the familiar with logarithms, from under- Rqs:,.:NM logarithmic subdivisions. standing and using the graph. It is Now, for a constant resonant fre- suggested, however, that the definition KLN quency, the product of the values of of logarithms be reviewed in the un- capacity and inductance must be con- abridged dictionary. stant. Therefore for any constant In many ways this graph is superior Le04.,kvklb. value of this product the frequency to the tables for a similar purpose as is constant and is a straight line rela- given in Zenneck's book, and in the tion to the scales, which is much sim- Smithsonian book of Physical Con- pler than a curved line relation. stants or to the Graphs in the Eccle's m% itt The graph is so simple that it may Hand -book. be easily expanded to any extent in As an example in the use of this any direction or any given section may chart let it he required to determine h'IL.%&N be enlarged to any extent if greater E is the resonant capacity to be used with range or accuracy desired. an inductance of 10' centimeters, in an Having constructed the scales for oscillatory circuit to vibrate at 600 capacity and inductance it remains to meters wave length. First locate the Num. El draw in the diagonal lines for fre- point in the right -hand column of the quency or wave length. chart corresponding to 10' (100,000) This may be done from the familiar cms. Follow the horizontal line across formula : 6:1MWS X (wave length in meters) until it intersects the diagonal line labeled with the desired wave length, 1.8851IL(Itenrys) X C(Farads) X 10° in this case 600 meters or frequency Inti which changed to the logarithmic of 500.000 Where these two lines `:bMUli(l6YlY. MEE form, for convenience in calculations, intersect drop the down along vertical and making C 0.000000001 farad or line to the = bottom of the chart, where 0.001 microfarad and expressing the it is ascertained that .001 m. is f. the IIMEN inductance in as centimeters so to right capacity to be used with the in- =w,° avoid small decimals we have: ductance chosen. With 10,000 cms. of ^ log L (centimeter's) 2 IogX = (meters) -0.5506 inductance. and 600 meters wave I - In order not to complicate the graph length, the capacity reads .01 m. f. 'VERO too much, only a few frequency and Any other capacity, inductance, wave wave length lines are drawn. The length or frequency can be found in Here's the Radio Computation Chart You Have Been Looking For. Solves Your Inductance, Capacity and lettered wave lengths used by the U. this manner. Wave Length Problems Instantly. Larger Printed Proof S. Navy are included. The amateur The following description is partly of Chart, 71/4 by 10 Inches, Sent Free Upon Request. may easily add lines for any desired for the object of assisting the amateur Blue -Print of Chart Measuring 19 by 25 Sent Postpaid wave length. to construct his own graphs to a on Receipt of 25 Cents to Interested Readers. The relation between the Navy larger scale after similar methods to wave lengths are as 1: those here employed in constructing the inches is equivalent to nearly 16,000 miles, :: 11 4 present chart. illustrating the enormous range covered. 112 or as 1 : 1.25992 : 1.58740. The scale at the top covers the range 10" The small subdivisions of the scales must The calculated values of the wave lengths to 10' farads and at the bottom are the cor- necessarily follow the same law as the main shown and the inductance in centimeters at responding values in micro- farads, the prac- divisions and for convenience, their values, 0.001 micro -farad are as follows : ' which may be obtained from any table of Wave Frequency Inductance Log tical unit of capacity. Just below the micro - Length Cycles Per Centimeters Induct farad scale are the equivalent capacities in common logarithms, are here given as a Meters fiecnnd ance electro- static units, sometimes employed to percentage of the main divisions. 2 150,000.000 1.125 .0515 5.96 50,400,000 10 1 express small 1 very capacities. The value 0.00 6 77.81 18.85 15,900,000 100 2 0.001 micro- farad. that of a popular ama- 2 30.10 7 84.51 so 6,000.000 703.6 2.8473 teur variable condenser, is near the middle 3 47.71 8 90.30 100 3.000,000 2,814 3.4494 200 1,500,000 11,250 4.0515 of the chart. To the right. values extend 4 60.20 9 95.42 300 1,000,000 25,300 4.4036 to 1.000 times this and to the left to 1 /10,000, 5 69.89 10 100.00 378 794,000 40,210 4.6043 which is quite small. smaller 476 63t,000 63,520 4.8050 If subdivisions are desired for 600 500,000 101,300 5.0057 It may he noted here that one electro- greater accuracy they may be obtained from 756 397,000 160,800 5.2064 static unit of capacity is the capacity of a logarithmic tables. 052 315,000 255,300 5.4071 sphere of one centimeter radius. far re- A convenient graphical' method mak- 1.200 250.000 405,300 5.6078 of 1,512 198.000 643,300 5.8084 moved from other conductors. One -thou- ing the subdivisions is by means of a slide - 1,905 157,500 1,021,000 6.0091 sandth micro -farad is equivalent to 900.000 rule scale. Drawn from the upper right - 2,400 125,000 1,621,000 6.2098 electro- static units. hand corner the longer line is made equal 3.024 99,200 2,573,000 6.4106 3,810 78,800 4,055,000 6.6112 The right -hand vertical scale gives the to the 1 to 10 scale of a slide -rule and the 4,800 62,500 6,484,000 6 811' inductance in C. G. S. electro- magnetic units horizontal lines are drawn thru the unit 6,048 40,700 10,300.000 7.0126 or centimeters and the left -hand scale the divisions of the rule. By transferring the 7.620 39,400 16,340,000 7.2133 9.600 31,250 25.940,000 7.4139 corresponding values in practical units or lengths from the slide -rule with a pair of 12,095 24,800 41,180,000 7.614, Henrys, exprest both in decimals and ex- sharp dividers quite accurate scales may be 15.239 19.700 Henrys 7.8151 ponentially, so that those who only occa- constructed. The vertical subdivisions are 10.200 15,600 .104 11.01ry use 50,000 6.000 .704 8.84/3 sionally such notations will here find then drawn thru the intersections of the 100.000 3,000 2.815 9.44'.4 the correct equivalents. horizontal subdivisions and the resulting 600,000 500 101.3 11.0(.57

www.americanradiohistory.com September, I 9 1 8 ELECTRICAL EXPERIMENTER 321

CLOCK -SPRING HEAD BAND. UNIQUE SCHEME FOR LEARNING ondary, and therefore none liable to cross In the ordinary watch -case receiver the THE CODE. or get tangled with the support rods. loop for hanging on the hook is placed as in The writer some time ago decided to Contributed by Fig. 1. An idea occurred to me thru an learn the code, and it occurred to him that ALBERT W. \\IILSDON. accident which happened to the receiver I as he had an "I. C. S." language phono- was examining. 1 dropt it, breaking the graph, it might be used to advantage in this connection. At first a buzzer and tele- graph key were rigged up, the recorder and a blank record was placed on the machine, and a few dots and dashes were recorded. When reproduced, the results were not entirely satisfactory as the sounds were rather weak and ragged. Then the follow- ing scheme was tried out and the results were good clear tones somewhat similar to a 500 cycle station. A telegraph key, five dry cells, the primary of a local battery induction coil and a telephone transmitter were connected in series. Two 75 ohm bi -polar receivers were connected in multiple, across the sec- ondary of the induction coil. One of these receivers was supported so as to face the transmitter and be tight up against the mouth -piece. This produced the ordinary well -known "howler" effect, whenever the telegraph key was closed. This Home -Made HeadBand Constructed A Clever Way In Which to Secure and Bring from a Piece of Old Clock Spring Proves EHI One of my indulgent commercial tele- Out the Tap Leads On the Inside of Loose caclous In an Emergency. graph operator friends having become in- Coupler Secondaries. They Are Fastened in terested, volunteered to make me some Place With Sealing Wax. records. loop off. When I picked it up I noticed The phonograph was adjusted to the placement of the loop and an idea came a speed of about 100 R.P.M., a blank record A MINIATURE RADIO BUZZER. put on and the second receiver held in to me. I thought of getting a clock spring The base of the buzzer should be made of -inch wide and bending placing front of the speaking tube of the phono- g it and it graph, while some tough wood or fiber, the dimensions in as the loop had been and so forming a my friend tapt off the Con- being mostly tinental code, running thru the alphabet at left to the maker. The sin- head band. I procured an old clock spring gle electro- magnet core consists of a soft from a discarded clock and bent it to fit the rate of about 8 to 10 words per minute iron and repeating each letter four times. rivet or brad similar to boiler rivets, my head. I then bent it as in Fig. I to fit Next but much smaller, the one needed here some reading matter was recorded on an- being the hole in the receiver. I put the spring about -inch in diameter and I inch in other record at a slow rate of speed. When g into place and put the piece of rubber back, length. A hole is bored in the base and and heating a large nail I ran it over the the rivet forced thru with the head set cracks left between the piece and the re- Te% /rey loc. bot Ind coil flush with the under side, as shown. Wind ceiver. I then emeried the surface until it the projecting end of the core with at least was smooth. In this way a fair head -band four layers of No. 30 B. & S. silk -covered can be made for and by the amateur. Mo wire. Now, connect the ends of the coil to Bending the free end of the spring out as wiry cells two consecutive binding posts, three having at Fig. 2 will avoid scratching the face. been erected as near the edge of the base Contributed by FREI) ELLENBERGER. as possible. lronsm The armature or vibrator is made of a - corset spring or something similar. The corset A "VEST POCKET" RADIO SET. Phonograph recorder spring must be heated to a cherry red and then bent into the desired shape. Bend I give herewith a sketch and details of a the spring as shown, so that it will stay small pocket receiving I know that set. flexible soeof»g tobe about 4 -inch above the magnet when many of your readers would like to make mounted as shown. A hole is then punched one. I have tried mine out on the big Phonograph cylinder n in the spring and a short piece of silver antenna at NAH, where I am an operator, A Novel Scheme for Producing a 500 Cycle wire riveted into it. This is one contact and found that I can get quite a range of Tone by the Reaction Between a Microphone point. A wire is now led from the armature wave -lengths on it. The secondary is wound and a Receiver for Recording Code Practise to the remaining binding post. Signals on a Phonograph. with No. 32: the primary with No. 36, silk - The current is conveyed to the armature covered magnet wire, 20 turns to a contact thru a stiff copper wire bent double and 10 contacts to both secondary and primary. the reproducer and horn were placed on hammered together at the contact. it has a A fixt condenser is shunted across the the machine and the records run off, they piece of silver wire or platinum soldered to 'phone terminals; it is made of thin tin- turned out excellent and could be read it at the contact point. This wire is con- foil, about sixteen square inches, wrapt in anywhere in the room. nected to the middle binding post and then waxed paper. The detector is galena. All A few records made in this manner act bent over so as to barely touch the contact parts are nickel plated and mounted on as a constant guide to the beginner and on the armature. hard rubber. The coupling is fixt. QST enable him to rapidly learn what good This buzzer could no doubt be reduced from NAA could be heard faintly. Waves signals should be like, assuming of course. in size until the hand could be closed over from 300 to 1,200 could be heard gold. that the records were made by a good it ;. yet it does its work as well as one twice Contributed by operator. or three times as large, and it can be used AUDLEY V. H. WALSH. Contributed by L. A. GARY. HINTS ON SECONDARY TAP LEADS. In making taps from the secondary of a loose coupler or on a primary switch, many readers undoubtedly have a great deal of trouble. A little wrinkle which I found, eliminates all the bother caused by these taps. First the taps should be taken thru the tube in the manner shown in the illus- tration. apply After the wire is past thru the tube, A Useful Radio Buzzer of Small Size Which a small speck of sealing wax, a little away Any "Bug" Can Make for a Few Cents, and from the hole thru which the tap is brought. in a Few Minutes' Time. A little more wax is placed on the wire after it has been straightened, near the ends, to an advantage in a portable wireless set An Extremely Small "Vest- Pocket" Radio or for learning code, cetera. Set Which Has Accomplisht Wonderfu which will contain the switch. By this the et Results. method there are no loose wires in the sec- Contributed by HAROLD LEWIS.

www.americanradiohistory.com ,2 ELECTRICAL EXPERIMENTER September, I 9 I 8

A Simple Hand Milling Machine By THOMAS REED HONEST, I'm sorry about that dent except for the fact that in operation correctly, is sure to "come out right." "Arabian alarm -clock." Bugs. I the machine is held firmly in the vise, C, The holes in the index plate should be know you were just beginning to which gives all the stability required. spaced off and drilled as accurately as pos- feel, whenever you saw my name The soul of the machine is the index - sible, but errors tend to eliminate them- attached to an article, that you plate, D. This is a disc of thin metal, per- selves, from the fact that the diameter of were assured of a sober, dependable ex- forated with rings of small holes; the num- the index -plate is so much greater than ber of holes being dif- that of the work. If you drill the plate ferent in each ring, anything like near enough to satisfy you, but dividing the circle you will be surprised at the apparently per- l',./70 )& drill into equal spaces-60, fect regularity of the work. ga des 72. or whatever the It is best to make the index plate from case may be. 1/16 inch- stock, hut thin sheet iron will do. If . The index -plate is we must (which is my delight) draw on our fastened immovably household resources, I should think the bot- to the shaft E by the tom of a tomato -can, carefully unsoldered nut F; (see Fig. 2) by rotating over a gas -flame, would make and as the plate and an excellent plate. And don't forget the in- shaft turn, they carry valuable pic tin. with them the work The guides, Q, Q, which hold the file P, G, held on by the nut should of course, be made out of steel, mid H. Long pieces of hardened. The pivots R, R, are eccentric work can be steadied with the shaft E, so that the file may ap- by the back -center S. proach the work at different angles. fg 4 While the work is Fig. 3 shows a hack -saw guide. The disc being operated on- turns eccentrically at T, forming a variable Nock say while the ratchet - bottom -stop for the saw. SOW tooth J is being filed Fig. 4 shows two forms of punch- guide, guide out - the index -plate where pegs are desired to be set at regular is held in a fixt posi- intervals, as in making rotary spark -gaps. er tion by the spring- After marking the work, the punch U can 5 lever K; a peg, L, on be withdrawn from the sleeve \V, and the the end of hole drilled with a hand -drill. This peg - fI enters one of the holes setting is illustrated in Figs. 9 and 13. in the plate . The Of the various forms shown in Figs. 5 lever, with its peg, is to 13, Fig. 5 is done by a drill and hack- placed in line with any saw ; Fig. 6 by two hack -saw blades in the of the circles of holes same handle; Fig. 7 by a knife -file, Fig. 8 by loosening the by a flat file, Fig. 10 by a half -round, Fig. wing -nut M, on the 11 by very small flat file, and Fig. 12 by a b o It of which the round file. Among the many- shaped files, lever K is pivoted. and one or more hack -saw blades, you ought The ratchet -tooth J to conte pretty near producing any figure Fig. 1. General View of the Hand Milling Machine Which Every Experimental Machinist Will Want to Build. Not Only Is It An Extremely Serviceable Device. But It Gives the Fundamental Ideas of the Larger Milling Machines. This Device, Altho Quite Simple, Is Capable of a Surprisingly Large Variety of Work. position of demonstrated fact; and that being finished, it is fake bing -clock must have jolted your con- desired to rotate the fidence worse than it did the "Sheik's" work into position for slumbers. the next tooth. Say Well, to commence the long, up -hill fight you are cutting a 30- to regain my reputation as a purveyor of tooth wheel', and your "Frozen Truth" exclusively, I'll present you outer index c i r c l e with a little hand milling machine, de- contains 60 holes. By signed so you can make it yourselves, for pulling on the small the production of milled objects, such as handle N, the spring - those in Figs. 5 to 13. lever K bends, and The germ of this idea was a machine the peg L is with- which our crowd made years ago, following drawn from the hole. one said to be used by the old Swiss hand Be careful now, and watchmakers. That tool, however, em- don't lose your place. ployed a revolving cutter, and, you had to Rotate the index -plate make a separate cutter for each piece of in the direction of the work. The present, greatly simplified ma- arrow, count off two chine makes use of files of various shapes, holes, and let the peg hack -saws, drills, etc.. requiring only a slip hack into the sec- special guide for each class of tool. ond hole. Now your Referring to Figs. 1 and 2, the frame, work is held for the A, A. A. would, in a manufactured article, next cut just 1/30 of be a casting; but I have designed it from 3 a revolution ahead. pieces of heavy flat wrought -iron, bent into and so on around Fig. 2. A Side View of the Hand Milling Machine With a File Being shape and held together by the screws B, B. you r ratchet -wheel, Used In the Guides. The Machine Is Held in a Substantial Bench The -e screws would probably not he suffi- which. if you count Vise.

www.americanradiohistory.com September, 1918 ELECTRICAL EXPERIMENTER 323 ON TO that even the wild requirements of a "Bug" A MERCURY FIRE ALARM. KEEP YOUR STRAW HAT may find essential to his happiness! Here is a drawing and a description of an AVOID SHOCKS. Oh. -as the numbers of the holes in the automatic fire alarm which I believe will be An engineer suggests in a recent issue of index- plate; a ring of 60 holes gives you of interest to your readers. Safety First the wearing of straw hats the following equal divisions: 2. 3, 4, 5, The device makes use of the expansion with stiff brims for those employed around 6, 10, 12, 15, 20 and 30. Another ring of 56 of mercury when heated. It can be quickly electrical stations. It seems that the straw adjusted and requires hat is far superior to a felt hat from the no re-setting. The fire safety standpoint ; for should the head come detecting mechanism accidentally in contact with live wires, the is clearly shown in rim of the hat or the crown prevents injury, figure. and gives the necessary warning. The same It consists first of holds good when working around steam a glass (or brass) pipes. In a recent accident, where a man tube about 2" tong unconsciously came in contact with a 13,- and having a bore of 000 -volt line, he would have been protected vs" or a trifle more. had he worn a straw instead of a felt hat. The lower electrode o has a short piece of is some- The singing of telegraph wires fyS Fig 6 Fig. 7 copper wire soldered times regarded as a weather prognostic, to it 4" long. The though opinions differ as to the kind of rod is fitted into the weather it foretells. There has been much tube as shown and discussion as to the cause of this sound. then the end of the Probably it is simply the Aeolian harp effect, tube is filled with and its occurrence depends chiefly upon the the sealing wax. The direction of the wind in relation to the di- rod should not fit rection in which the wires run. Variations too tight or its ex- in the pitch of the sound depend upon pansion will break the changes in the tension of the wires with Fig d fig /0 tube. varying temperature. Electricity, contrary A small rubber cork to popular belief, has absolutely nothing to that fits the tube do with the singing. tightly has a needle run thru it to form the upper electrode. A SIMPLE BUT POWERFUL HAND- A short length of FED ARC -LIGHT. wire should be sol- The arc -light shown can be made from dered to this needle odds and ends at a very small cost and can. as shown in the draw- be used for wide variety of purposes. A ing. piece of wood for the base, some strips of The tube is fastened brass, a few battery binding posts, screws. Fig /2 Fig iS fe to the base, measur- drop cord and plug. and two battery carbons ing 1/" by 3" by in a fruit jar, with a small piece of fiber Figures S to 13 Illustrate the Great Variety of Work Which Can Be means a brass insulation are all the articles needed to Turned Out on the Hand - Milling Machine Here Illustrated and of strip Described. This Is. However. Only a Partial Number of the Differ- and two small screws. construct the arc. The fruit -jar resistance ent Shaped Parts Which Can Be Made With the Aid of This Hand - Binding posts are is one novel feature. Two ordinary battery Miller, and With a Little Ingenuity on the Part of the Building carbons are held at a fixt distance from each Machinist, Many Other Useful and Intricate Parts Can Be Con- mounted on the same ceived and Executed. base and the wires other by two strips of fiber, the bottoms connected to them. being about IVg of an inch and the tops about holes would give you 7, 8, 14, and 28. This A few drops of mercury are put in the h of an inch apart. Rubber insulation cut covers most of the desirable low numbers, tube and the rubbe r cork and the needle in- from an old tire may be used for handles at and shows how easily you can figure for sertcd as shown i n figure. By regulating the end of the strips holding the arc car- yourselves any other factors you need. bons. By moving these handles the arc may be raised or lowered or fed together. After THE PRODUCTION OF RADIUM the wiring is completed fill jar g full of FROM U. S. CARNOTITE ORES. water. add a little salt. and connect the As one of the results of an agreement plug with a regular 110 volt house light between the National Radium Institute and socket. This will make it necessary to put the Bureau of Mines, Department of the heavier fuses in the fuse block. This arc Interior, to develop a more efficient process will melt any substance placed between the for the manufacture of radium out of the carbons, as it will give from '4 to 1" flame. carnotite ores of Colorado and Utah. the If a housing is placed over the base, as Bureau of Mines now has as its share more shown in dotted lines, and a reflector used than $180.000 worth of radium for use in with a common reading glass in the sleeve, the sciences. This was procured for an the arc will cast a powerful beam for a expenditure of less than $38.000. In addi- distance of a mile. tion, under the agreement, the bureau has Contributed by CARLYLE \ \'ALTS. turned over to the National Radium In- stitute about 64 grams of radium; and has given the country a method of producing pure radium compound from the ore for one -third the current price of radium. Baffery.4 ,. When the Bureau of Mines began this work in 1912, it found that the precious An Electric Fire Alarm Is something Every one Will Want to Experiment With. Here's carnotite ore, constituting the largest known a Home -made One Which Can Be Con supply of radium ore in the world, was strutted in Dozen Lots at Very Small Cost. going to Europe, mainly to Germany. where it was being turned into radium and sold the distance between the needle and the sur- back to the United States at fabulous prices. face of the mercury, the temperature at which the alarm is given can be regulated. A good method of adjusting this appa- AUTHORS!!! ratus is to connect a bell and battery to All matter intended for publica- the terminals. Place the instrument and the an oven or a sand bath and tion -not only by us, but by any thermometer in adjust the needle so the bell just rings when other magazine or newspaper as the thermometer registers 110 degrees well -should be written on one side Fahrenheit. of the paper only and in ink. If it \Vith such a system an annunciator may isn't, somebody else must copy part be used to indicate from where the alarm came. of it off on another sheet before it by This device has been used the writer Easily Made Form of Electric Arc -Light is given to the printer. for the past two years with success. Suitable for Use In Stereoptican or Home Contributed by \\'ALTER L. MILLER. "Movie" Machine.

www.americanradiohistory.com 324 ELECTRICAL EXPERIMENTER September, 1918 The Manipulation of Glass Tubing in the Experimental Laboratory By Prof. HERBERT E. METCALF

I'ART I. necessary to duplicate the article. Its func- eral feet of rubber tubing of various sizes, IC the experimental laboratory there is tion is the standard, and if the home -made a generous stick of sealing wax, and a always a demand for small pieces of machine will do as good work, that is all sharp three - cornered file fits us out. apparatus which are made out of glass, that is necessary. Now that we have assembled before us and yet are usually too high in price THE KIND OF GLASS TUBING TO USE. all our materials ; the glass tubing of the to be purchased on the market. Again, To begin with, the glass tubing MUST be fresh. The experimenter can- not expect good results from I I, ,:I In ,I glass tubing which has been ly- I.II 41! II illli IIIi,;pl !I ing around his laboratory since the year one. That is why such I Í I i í qíii poor success is attendant upon many efforts in this direction. He will have to go directly to the largest supply house in his city and demand fresh ;oft glass tubing suitable for bend- ing. To get hard glass such as boiler gloss tubing will spell failure immediately. If there is no supply house close at hand f then write an order to the near- est large supply house, in all Fig. 1. How, Making a This Shows After File Mark on cases specifying explicitly that Fig. 3. This Illustration Shows the Vari- a Piece of Glass Tubing, It Is Broken By Grasping the ous Gone in Tube at Both Ends. One on Each Side of the Cut With the tubing is to be fresh soft Stages Thru Heating a Glass Tube for the Purpose of Enlarging It at a the Thumbs Placed Directly Opposite the Cut. You Then glass to be used in the flame. Given Point. Push "Outwards" With the Thumbs and a Square, Clean In no case should tubing be Break Will Invariably Result. obtained from the local hard- diameter required, the burner in its proper ware store, as it will prob- position connected to its gas and air sup- while the apparatus may look simple to ably be many years old. All this is ex- ply, thr asbestos mat and the corks where make, most all experimenters, after break- tremely important because the entire suc- they may easily be gotten at ; we will take ing enough glass to nearly pay for the fin- cess of all future operations will depend up the file and proceed to the first opera- ished article, give up the job in disgust and upon the quality of the glass. Glass tion, cutting the tubing to its proper length. worry along without the apparatus. But if tubing becomes brittle with age. and a The following operaiions should be very they had a little knowledge of simple glass- piece of tubing mach over a year old is carefully read over before being performed, blowing they would save many dollars, very apt to crack no matter how carefully even going so far as to rehearse before and enrich their laboratories with many heat is applied. hand, because there is nothing so discour- pieces of apparatus not otherwise obtain- EQUIPMENT NEEDED FOR THE MANIPULA- aging as to sneak a look at the printed di- able. 1ION OF GLASS TUBING. rections in the middle of an operation, and In the first place the manufacture of small For simple bends in tubing an ordinary then returning to work only to find that articles out of glass tubing is not hard; in Bunsen burner is needed. provided it be the glass had cooled off while you were fact, with the proper glass, the proper heat- equipt with a fish -tail tin. In fact, all reading. It should have been kept hot, and ing agents, and a little patience, nearly work which does not need fusion may be when the flame played on it again it cracked. every commercial article made from glass done with a burster of this kind. CUTTING GLASS TUBING. may be functionally duplicated. You will does For more complicated work which Glass tubing up to one -half inch in diam- notice that I have said "functionally" be- require the fusion of glass, an air blast cause often it is not possible nor at all eter may be cut with a sharp three- cornered must be added to the flame in order to file. Place the tubing in front of you and obtain the high degree of heat necessary make a single deep cut in the tube at the for the proper joining of the glass. This proper length, and then break it by grasp- may be simply a small tube held in the ing the tube in both hands, one on each .south. By blowing air thru a yellow flame a fairly good blast burner may be had, but is not very satisfactory because a steady F/ome blow cannot he maintained, nor can the size of the flame be suitably regulated. The most practical thing to do is to buy, new or second -hand, an adjustable flame blast lamp. The air supply may be obtained in several ways; from a pump, foot blower, or a water jet air pump, of the type de- scribed elsewhere in this issue. i An asbestos mat such as used on the table may be obtained at any hardware store, and is needed to lay the hot glass on while it is cooling. Hot glass must NEVER be laid on metal to cool, and as it will burn other materials this mat is indispensa- ble. The blast lamp must be placed on the experimenter's table with the flame directed away from him and with the mat on his right, so that he will be able to use both and then place hands on the glass tubing, Fig. 2. Successive Operations to Be Carried the finished product on the mat to cool. Out In Heating a Glass Tube for the Pur Fingers are better that pincers of any kind pose of Forming a Constriction. and a pair of kid gloves will save the hands from many a sharp burn. A supply of side of the cut, with the thumbs meeting 4 6 fig 4 small corks to fit all sizes of tubing may directly opposite the cut, see Fig. 1. Then If he obtained from a supply house or may push outwards with the thumbs, and a Flg. 4. Successive Operations In Making a be whittled out of drugstore corks. These square clean break will result. In case one Glass "Ampoule "; 2. One End Closed; 3, is Tube Drawn Out: 4, Filling; 5. Sealing; and are very important in nearly all operations end short, wrap your handkerchief 6, the Finished "Ampoule." and may be used over and over again. Sev- (Continued on page 340)

www.americanradiohistory.com September, 19 I8 ELECTRICAL EXPERIMENTER 325

TRICK "SHOCKING BATTERY." A NOVEL ELECTRIC ENGINE. litres from each end until you reach the A "shocking battery" represents a novel In Fig. 1 of the illustration is shown the lines A -A, as in Fig. 1. departure from the ordinary shocking coil. - side view ; in Fig 2, the end view; while After all the slots are sawed take a saw - and is nothing more or less than just such a- the cut Fig. 3, gives the working details file and file down each until the tube has coil, enclosed in a case so that it closely of armature "S." The resembles an ordinary dry cell. How to connections are shown in

make it : First turn down a wooden block Fig. 1. In reference to to 2g" diameter and %" thick. Leave a the lettering of the illus- small extension %" thick and 1" diam- tration PP' a r e two eter on one side, to resemble the car binding posts. next a bon rod of a dry cell. Drill holes icr the. brass support for M an binding posts and cut four small slots at. ordinar- electro- magnet, the edge 90° apart for the battery suppo,ts.- B' is a copper or phos- \Vhen finished paint the block black and - phrr òronze brush which place in the binding posts It should row - :Hakes contact with the closely resemble the top of a dry cell. Cut projection on S. A sheet - two blocks to 23" diameter and %" thick. - iron swing S. is made Driil a hole large enough to accommodate - after the model in Fig. 3. the coil to be used in the battery P,, not - It swings on the axle A'. drill it directly in the center but off to- B' is a brush making con- one side so as to give ample room for the. tact with A'. A' is a vibrator. - shaft which joins the The coil to be used may be an old shock- connecting rod C to the ing or "medical" coil, a telephone induction swing S. A" is a cam- coil or one may be made for this purpose. - shaft to which it fastened Another block is now turned down to- the fly -wheel F, and a 23" diameter and %" thick and properly - small pulley. Dimensions notched for the supports. On this block is can be made to suit the mounted a small single -pole, single -throw - constructor. I have used this motor Sec Dp; for some time and have found it satisfactory in i===-Iii__ - every respect. by Contributed One of the Simplest Designs of a Miniature Electric Engine ---frien PAUL NACHEMSON. Possible. The Curved Iron Armature Is Successively Drawn Forward By the Electro.Magnet and Released. By a Crank á'- Motion the Wheel is Set Spinning Rapidly. ' : . .: ' : GuNalioy PARTS. the appearance of Fig. 2. Next turn up a. command HOW TO "STEEL- PLATE" --A.:__ "How automobile parts and all sorts of hardwood or fiber plug that will fit snugly machinery are steel- plated" should be an in- inside of the metal tube. Shellac it and in- Cd// Nr/// _ i!_ teresting topic to the readers of the "E.E." sert into tube, being careful that the plug ctre.prim. ¡.. Purchase some Potassium Ferricyanid in is not longer than the distance of the tube and sac. ¡ Li ` a drug store or other chemical house. from the bottom of the "V" notches. =-=t Great care must be taken in handling this Bend the ends over as shown in Fig. 3 chemical compound as it is one of the most and drill or punch a small hole in the end deadly poisons. To show its fatal effects, of each segment on each end of the com- one can perform the following experiment. mutator. Use small escutcheon pins to nail' the ends 'down tight against the wood. t-._. 1-^`aF"ti..` Drop a small piece of this compound into an old forlorn cat's mouth. Immediately its Now hold in the vise and saw the segments head begins to droop and then the cat apart as indicated by dotted lines Figs. I and 2. It is optional, but if you wish, you T'sF T `r' .l iNrauprer stretches itself out and dies. L, Dissolve some of this Potassium Fer- may saw down into the wood '4" beyond A the brass tubing and insert firmly a strip of ,ei ,.w2...... ricyanid in water. Then put in the iron to _- - ... be steel -plated. This should be left in the mica held in place by the shellac. The solution for about 48 hours. After the commutator can be filed and sandpapered Y, ?rim áp iron is taken out it is heated in a furnace up smooth afterward. The leads from the arvrrop ...,...... ,,, sw a while. armature coils are fastened to their respec- t, or even stove for a short Then a steel coating is permeated into the iron. tive segments with solder, using rosin as a Place This "Special"- Dry Cell With Several From the chemical standpoint the action flux. Others and Ask Your Friends to Connect Up- is a very easy matter to explain: After the The writer has used this commutator with All the Cells in Series, etc. At the Pyscho- logical Moment Let 'Em Have the Full iron is taken out of the Ferricyanid it has Shocking Coll Current By Closing the Switch. a practically pure coating of iron. Then They'll Swear It Was "Static!" when it is placed in a furnace, the carbon escaping from the coal, unites with the pure side- action switch and two binding posts iron coating to form steel. for the primary. The complete battery is- This is used a great deal in auto parts now assembled, connections being made and manufacturing. parts fastened together by the battery sup- Contributed by A. MENCHER. ports which are wooden strips 6" long and fit into the notches provided for them. The battery is now rapt up in some card- HOW TO MAKE A SMALL board or heavy paper. It would be well to COMMUTATOR. fill in the space around the coil with some Procure a piece of brass tubing the di- insulating compound to increase the insula- ameter and length you wish your commu- tion. The whole is now placed in a sheet tator. Flush pipe used by plumbers is very metal container fastened to the same with good for this purpose. It comes in sizes screws which is in turn placed in an old from 3" inside diameter up to 2" and is battery carton that has the bottom knocked seamless and uniform. Square up the ends out. A concealed flexible lead is now con- in a lathe if one is handy, or, if not, a fine For Small Dynamos and Motors Thls Quickly nected to the primary binding posts and the file and try square will serve. Then, set the Constructed Commutator Will Prove Adapt- "battery" is ready for action. It may be dividers and scratch lines around tIte tube able. The Brass Sheet Is First Marked Off, Then Fastened Around the Drum. After- operated by a flashlight battery concealed from 3/16" to '4" wide, depending upon ward the Segments Are Formed By Cutting in the case with the coil. Initiate your elec- the diameter. Space off the tube into as Saw Slots in the Manner Indicated. trical friends by having this "battery" on many segments as there are slots in the the table beside several other regular cells. armature. and, with a scriber mark the sec- and without the mica, but advises the use Then tell them you will bet they cannot tions where they are to be divided. Use a of mica for any current above 50 volts. connect up the cells properly, in series, fine hack saw, or a piece of clock spring Curly maple is the best wood to use for parallel. etc. Let 'em have it, when they held on edge in the vise and hacked with a the hub, but fiber is the best of all. wet to making the connections. sharp edge file. This makes an ideal saw Contributed by Contributed by L. SVOBODA. for the purpose. Saw along the dividing HARRY L. ALLEN, JR.

www.americanradiohistory.com 326 ELECTRICAL EXPERIMENTER September, 1918 Experimental Mechanics By SAMUEL D. COHEN LESSON VI.

Thread Cutting and Metal Turning thread and space. The exact width of the cutting "V" threads, with the exception that CONSIDERING that the novice has cutting tool should be equal to the space R, a different shape of cutting tool is used. It become thorolv familiar with the or exactly equal to one -half of I'. For is impossible to cut very fine pitch square rudiments of plain " thread cutting" cutting a double or triple thread, the case threads as the pitch of this form of thread as given in the last lesson, and tak- becomes different as will be seen from the is dependent upon the width of each tooth, ing also into consideration that the third illustration, which in this case repre- amateur has become a junior master of sents a double thread. Here the pitch P, is equal to the thickness of two threads and two spaces, so that the width of the cutting tool mast be exactly equal to one -quarter of the pitch P. In the fourth drawing is shown a double thread screw with only the first thread cut. When the second groove is cut in the center of the intervening por- tions of the work, it results in a double thread. A very treat way of finishing off a square thread is to drill a small hole into the work at the end of the thread for the tool to run into, as is indicated in Fig. I. The diam- eter of the hole should be slightly larger than the thickness of the tool, and the depth a little greater than the depth of the thread. The lathe must be stopt just before I"! the tool reaches the hole, and pulled around by hand for the last turn or so. As soon as the tool finishes its cut, it is withdrawn fig B and run back again in readiness for taking a fresh cut. 't In Fig. 5, the student will note the various types of threads that can be cut with the Fig. 8. This Shows How a Palr of "Out side Calipers" Are Set Accurately on a Steel aid of a lathe. It gives a splendid idea as Scale. One Leg of the Caliper Rests Against to the kind of work the amateur can carry One End of the Rule. Fine Adjustments Are out with this machine if he once becomes Fig. 7. Appearance of Universal Thread - Made by Gently Tapping Either Caliper Leg Cutting Tool Which Carries a Cutting Head on the Lathe or Vise. Provided With Various Sized Teeth for Cut- ting Small, Medium and Large Threads. problem, the author Any Individual Tooth May Be Reground handling the shift gear Until Entirely Used Up, Without Changing will now further discuss the subject. Its Shape. The Lever Locks the Cutter In As the student will remember from the Any Desired Position. preceding lesson the subject of cutting "1V" threads was under discussion and now which is naturally wide. Square threads a second type of thread will be taken up are extensively used in machinery where and this is the square thread. A very good there is a great stress, and where a large illustration showing how a square thread motion is desired with a minimum angular looks is given in the first illustration. For movement of the shaft containing the cutting such a thread a different type of square thread. cutting tool will be required, and in Fig. 2, The experimental machinist will find of we see the type of tool necessary for this great help a newly devised rotating thread kind of work. This tool is very similar to cutting tool, applicable only for cutting "V a parting tool, only that the rake must be threads, and this tool is shown in Fig. 6. provided for in the portion that enters the Its application to the work is shown in work to prevent side rubbing, thus destroy- Fig. 7. The tool consists, as will be seen, ing the value of an accurate thread. The of a disk of steel having ten distinct teeth tool holder as shown simplifies to a great on its rim. These teeth are graded for extent the cutting of a square thread. The cutting the thread in distinct operations of tool itself is filed up out of a small round the tool. The cutter is mounted on a hand piece of tool steel, which is then fixt slide rest, which is bolted to the ordinary to the tool post holder by means of a set lathe carriage, and the tool is adjusted to screw. The tool steel being circular in each cut by the hand lever as shown in in the holder 7. taps, section, can be turned around Fig. 9. "Facing Up" the End of a piece of Fig. When fine work such as for before the set screw is tightened, so as to Steel Shaft Held In a Universal Three-Jaw ttc., is required, the pawl is thrown back give any desired degree of rake. Chuck on the Lathe. out of action, the micrometer adjustment The width of cutting edge of the tool ised, and another trip taken across the must be equal to half the pitch of the skilled in operating it, and experience is the thread. Advancing the lever one hole in thread. This is evident from the first illus- best teacher. tration where "P" shows the pitch of he The procedure in cutting square threads thread, which is equal to the thickness of a is identically the same as for those for

aa r a it Z 3 4 .5. Fig. 6. Cutting Member of Universal Thread Fig. 5. An Interesting Thread Model Showing the Various Kinds of Threads Which Can Cutting Tool as Shown in Fig. 7, Above Be Cut on an Ordinary Machine Lathe. Including Square Threads, "V" Threads. In- Each Size of Tooth is Numbered as Indi ternal Square Threads. Et Cetera. cated in the Drawing.

www.americanradiohistory.com September, 1918 ELECTRICAL EXPERIMENTER 327

Flg. 10. Illustrating How the End of a Shaft is Exactly and Fig. I1. Illustrating the Use of "Precision" Outside Calipers. The Quickly Centered By Means of a "Centering Drill" Held in a Calipers Are First Set on a Steel Scale to the Size Desired on the Hand -Chuck Mounted In the TallStock Spindle of the Lathe. Finished Work. Never Try to Caliper Stock While Revolving, and If no Centering Drill is Available, an Ordinary Twist Drill, Ground Leave a Little Overstock to Be Finished Off With a Fine File, as to the Proper Angle, Is Used In Many Shops. You Cannot "Turn" the Surface Off Smooth Enough.

the micrometer adjustment, brings the cut- which he will read on the subject. It was Care should be taken to see that the drill ting point a fraction of a thousandth of an the intended purpose of the last tlw'n articles is not fed too quickly or else the drill point inch forward. Successive trips with ad- to lead the student of mechanics to obtain may break. vance of lever will give the finest finish pos- a fundamental notion of the subject and The third step is to place the work be- sible to a thread. allow himself to grasp it thoroly by actual tween the centers of the lathe, and to secure The heel of the tooth in action rests upon practise. We will now turn our attention it to the face plate by means of a dog. Fig. 7 a stop, so that it can be ground until but to the next important subject, namely, of lesson 3, shows how this is accomplished. an eighth of an inch in thickness, and still "Metal Turning." Before starting to turn the rod, carefully retain the full strength and power to do In discussing this topic, let us take a oil the dead center as it will heat consider- the work. When once set, neither tool nor sample at random of round stock of any ably when the end of the work revolves cross -slide adjustment needs to be changed predetermined diameter, and let the problem upon it, and thus destroy the hardness of of the job be to turn down one -half of the stock to a certain diameter, also having its both ends turned to a certain prescribed length, and one end to have a hole threaded with a certain thread. The first thing to be done with the job is to cut the rod of stock one- quarter to three -eighths of an inch longer than the finished length required by the job. so as to provide sufficient material with which to "face off" the ends. Blue- prints used for machining operations are cc marked with a lower case "f" or the word Fig. 3. In Cutting a "Double Thread," the "finish" on all surfaces which are to be Thread Cutting Tool Must Be Ground to Fig. 1. A Neat Way of Finishing Off a machined or accurately finished to size. Have a Thickness of One -half That Used for Square Thread As Cut in the Lathe, and Cutting a Single Thread As Becomes Evi- Which Method of Ending the Thread Is Car- Having done this, the next step is to turn dent. The Pitch of the Single Thread Is In- ried Out By Drilling a Small Hole Radially down the ends, and care should be exercised dicated By P In the Drawing, and is Equal to Into the Work, at the End of the Thread. to see that the metal taken from each end the Thickness of Two Threads and Two This Hole is Preferably Drilled After Mak- Spaces. This Makes the Width of the ing the First Trial Cut, and It Should Be should not exceed the amount necessary to Threading Tool Equal to Onequarter of the Slightly Larger Than the Width of the Tool: make the rod of the exact required length. Pitch P. Also Its Depth Should Be a Little Greater rod is placed and firmly secured in a Than the Depth of the Thread. The scroll or independent jaw chuck on the live the center. To reduce one -half of the stock left right in cutting the screw or any number of spindle. and by means of a or to the predetermined diameter, it will be screws in exact duplication. This type of hand side -cutting knife, depending upon the necessary to utilize a diamond -point tool in requires very little grinding, as the point position of the chuck. the end is turned the slide rest of the lathe, and with the aid tool down. will find it worth of the tool is reserved and only used in the The amateur of this tool proceed to take the initial cut 7, and 9, to finishing or last cut. while to turn to lesson 3, Figs. 8 and run the tool approximately to the center give him proper information relative to line of the work. Then bring back the METAL TURNING these cutting tools. When one side is tool to the original position, and repeat tak- The author strongly advises the novice finished, the work is removed from the ing off a certain amount of metal until the to become a thoro master in the making of chuck and the other side is turned down. (Continued on page 339) threads on his lathe as after all, experience In the lathe cut proper precaution should will teach him more than a thousand articles he taken not to take off too much material, as it will reduce the predetermined length. The photograph Fig. 9, clearly illustrates how the piece of work is held in the chuck, and how its end is being "squared up.'' The next step is to provide centers on each end, so as to secure the work between the live and dead centers of the lathe. This is to be used only when an accurate job is 3 required, and especially when the work is 4 fig tE fig 2 very long. In order to do this, a center q drill will be necessary, and the work should Fig. 4. A View of a "Double Square Thread' Fig. 2. Universal Tool Holder Which Is he secured to the chuck of the live spindle. Being Cut on Round Stock With Only the Seen in This Case Supporting a Tool for se- First Thread Cut. When the Second Thread The center drill is held in a drill chuck Is Turned on the Stock, It Will Come in Be- Cutting "Square Threads." The Tool Point tail stock spindle. Illustration Somewhat Resembles the Familiar "Part cured to the tween the Convolutions Here Shown, Thus Ling Tool." Fig. 10, shows clearly just how this is done. Completing the Double- threaded Screw.

www.americanradiohistory.com 328 ELECTRICAL EXPERIMENTER September, 19 I S Experimental Chemistry By ALBERT W. WILSDON Twenty -Eighth Lesson

for the Distillation of Water, Which Fig. 130. Electrolytic Generator for Decomposing Water Into Its Fig. 129. Apparatus Employed Form, Is One of the Purest Forms and Should Be Used In All Laboratory Constituents, Hydrogen and Oxygen. With This Carbon Experiments. The Larger the Liebig Condenser, the More Water Electrodes Are Utilized, and May Be Replaced By Copper, Plati- Distilled, and the Greater the Cooling Surface. num, Silver, Etc., Sealed In Mercury in a Glass Tube. This Type is Very Efficient.

WATER, HYDROGEN PEROXIDE mixturejust changes from yellow to orange chlorid in one gallon of water. Repeat this AND OZONE. or orange red. Then stop, read the burette, test with well -water. and the number of cc. of standard solution CHLORIDES. used (for this quantity, 50 cc. of water) WATER FOR MANUFACTURING PURPOSES. and especially the THE ,chlorides, will equal the number of grains of sodium Experiment No. 143 chloride of sodium, is universally present in natural waters, being de- QUALITATIVE TESTS. rived both from the dried salt spray Half fill three test -tubes with well -water, in the atmosphere and from the soil. and test them as follows: The amount present in perfectly pure water 1. For Chlorides. -Add one or two drops varies enormously, depending largely upon of dilute nitric acid and one or two drops the distance of the locality from the ocean. of silver nitrat. Result-precipitat of silver from saline springs, from beds of rock -salt. chlorid. and also, in general, upon the nature of the ? For Sulfates.-Add one or two drops soil. Besides this. common salt is always of dilute hydrochloric acid and one or two present in considerable quantities, not only drops of barium chlorid. Result- precipi- in animal excreta of all sorts, but also in tate of barium sulfate. kitchen refuse, etc., which forms a large 3. For Linie. -Add one or two drops of part of ordinary sewage. ammonium hydroxid and ammonium It is easy to determine, with great ac- chlorid then add a little ammonium oxalat. curacy. the quantity of salt present in water Result -precipitat of calcium oxalat. or in other neutral solutions, by using a Repeat these tests with Croton water, and standard solution of silver nitrat, with a notice that in this the precipitates are almost few drops of potassium chromat to act as imperceptible, altho quite distinct in the an indicator. The red cromat of silver pro- ell- water. duced by the latter is decomposed into silver Quantitative Determination of Hardness. chlorid as long as any chlorides remain in Place in a stoppered bottle 100 cc. of Croton solution. But directly the latter have been water and add, from a burette, some precipitated, the silver chromat gives a red "Standard Soap Solution," shaking well or orange color to the solution. Thus as after each addition. Stop when a perman- long as there are soluable chlorides present, ent lather is formed, and when, on shaking, AgNO, + NaC1 = AgC1 -I NaNO, it sounds and feels soft. but when they have all precipitated. Each cc. of soap solution used is equal 2AgNO, h5CrO, = Ag,CrO, + 2KNO3 to a quarter of a grain of calcium car - The standard solution, of the strength bonat in one gallon of water. used and described, contains I gram of Repeat this test with 50 cc. of the well- silver nitrat in 401 cc. of water. water. Notice the formation of a "false Experiment No. 142. lather" of lime or magnesium soap before Determination). the true soft lather. With this quantity of CHLORIDES (Quantitative water, each cc. of soap solution corresponds a Measure 50 cc. of Croton water into to half a grain of calcium carbonat per beaker, and add one drop of potassium gallon. chromat. Now run very carefully, from a burette, (See Fig. 128) the standard Silver MINERAL WATERS. stirring constantly with a Nitrat solution, No. 144 rod. Notice how the red precipitat of silver Experiment chromat which is formed by each drop of " of mineral water as the silver nitrat solution. dissolves when it l'est the sample follows : is mixed in with the yellow liquid, and is or yellowish cloud of 1. Bicarbonates of Sodium, Calcium and converted into a white Magnesium. silver chlorid. dissolves slowly (a) Notice that the water is alkaline to When the red precipitat boiled a difficulty, add the silver nitrat Fig. 128. Method and Apparatus of test papers, after it has been for and with Quantitative Determination of Chlorides or two to expel the carbon dioxid- a at a time, stirring well A So- minute solution only drop in Water. Standard Silver Nitrat on page 3411 after each addition. until the color of the lution is Added to the Water. (Continued

www.americanradiohistory.com September, 1918 ELECTRICAL EXPERIMENTER 329

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This department will award the following monthly prizes: First Prize, $3.00; Second Prize, $2.00: Third Prize, $1.00. The purpose of this department is to stimulate experimenters towards accomplishing new things with old apparatus or old material, and for the most useful, practical and original idea submitted to the Editors of this department, a monthly series of prizes will be awarded. For the best idea submitted a prize of $3.00 is awarded; for the second best idea a $2.00 prize, and for the third best prize of $1.00. The article need not be very elaborate, and rough sketches are sufficient. We will make the mechanical drawings. Use only one side of Make sketches on separate sheets. sheet.

FIRST PRIZE, $3.00 SECOND PRIZE, $2.00 THIRD PRIZE. $1.00

HOW I MADE A "RADIUMGRAF." THE COLLAR BUTTON AN ELEC- FOR PLUVIUS' SAKE -RAIN TRIC I am sending you a picture, or rather NOTION. ALARMS AGAIN. I give herewith a diagram of a rain "radiumgraf," in the hope that it may prove Fig. 1 shows a spark gap made of a base alarm of some interest to fellow experimenters. and two binding posts of the type shown. which I think original. Its principle lies in the fact The picture was made with a spinthari- Simply pass the wires from the secondary that, when a board is wet scope. It was made thru two thick- of a spark coil thru the posts. Next slip nesses of black paper. The word "Radium" on the buttons, as illustrated, and adjust the distance. In Figs. 2 and 3 the buttons are used as contact points (as for example, on a loose coupler). In Fig. 2 the board must be of a thickness equal to the length of the button less its head. Drill a hole large enough to pass the head of a button, which head is then flattened. Now place the wire in the hollow bottom of the button and solder it An Interesting Radium Photo Which Can Be In Fig. 3 the board may be of a smaller Made By Anyone Possessing a "Spintharl- thickness, as here the button is shortened by scope." cutting off the bottom part (Fig. C). Drill a hole large enough to pass the neck of the was cut out of heavy lead foil and pasted but not the Flatten on the paper so button, head. the head as to read backwards. An wanted) and ordinary photographic plate was placed. (if the bottom. Then insert the wire and emulsion side up, under the paper. Then solder. Contributed by B. DOPPKE. For the Love of Mike! Another Rain Alarm. the lens of the spinthariscope was re- A Thin Wood Strip Bends When Wet and moved and the part containing the radium Closes an Electric Bell Circuit. salt was placed over the first letter. It on one side. it warps. Referring to dia- should be left on each letter for at least gram, rain falls on -eight hours board A, causing it to forty to get good results. warp. closing contacts and ringing bell in As will be seen the lead foil stops the circuit. Board A has one end to rays, free per- while the black paper does not. In mit its warping. The thumbscrew is this respect turned they are similar to X- rays.- until correct distance is obtained. Contributed by Contributed by JACOB E. VOLLMER. VERNON G. CLEMENTS. A "BLOWN" FUSE ALARM. Sometime ago while doing some experi- A MINIATURE "BOOK" LIGHT. menting which involved the blowing of Here is a miniature light for use on fuses, I could not readily tell without test- books when traveling, etc. A simple book ing for current, whether my fuse was blown light can be made by bending a strip of or not, so I hit upon this scheme. brass g -inch thick and 1 inch wide, as I first procured a base of wood of the shown in diagram. Bore a hole thru it large size measuring two incises larger than the enough to receive the lamp, which should fit fig. 2 fig 3 rod R, which can be of brass or copper and snugly. Attach two strips of thin spring should have three small holes bored in it. brass % -inch wide to the other end of The one at the top holds the fuse wire F. the first piece of brass to act as spring, The other end of the fuse wire is twisted which can be slipt over the cover of the around the post connected to the feeder. book. The wire connections are shown in The center hole has a spring fastened so the illustration. that its tension draws the rod up against Contributed by e posts C, closing the hell circuit and ringing MERREL the same. The rod is pivoted at the bottom HALLOWELL. Spark Gaps, Switch Points. ad lib.-All Are Possible to Mr. Doppke If He Only Has a Few hole. Tile feeder should be connected to Spare Collar Buttons on Hand. Look Under Pa's Chiffonier Where You Will Find Dozens of 'Em, Fellow " Muckers." Ye gods, what next? After this we pre- sume one of our ardent contributors will Teed wire A', insulated from lamp.' send in a design of a 10 H.P. dynamo made socket of 27 assorted buttonholes, a thimble and a package of hairpins. And, alas, the worst of it is that Mr. Doppke's suggestions are not half bad- Bross spas, Editor. feed w,re 8 brass GLASS -BLOWING LESSONS. EE In the October number there will ap- F/sBAW!coer When the Fuse "F" Blows the Arm "R' pear the second paper of a series by Prof. Springs to the Right, Closing the Alarm Cir Herbert Metcalf on the art of glass -blow- cult. ing. These lessons explain every step with the fuse wire so that when blown the rod For the "Book- Worm " -A Handy Electric Book Light That Clamps on Cover. A Flash clear illustrations, so that you can learn will he disconnected from the feeder. light Battery and Lamp Complete lt. the subject easily. Contributed by BERNARD COHAN.

www.americanradiohistory.com 330 ELECTRICAL EXPERIMENTER September, 1918

EDITED BY S. CERNSBACK

ELECTRO ZINC PLATING. THE MYSTERIOUS FIGURE NINE. A rivet is fixt to hold the guide arm and To zinc plate steel and other metallic Has it ever occurred to you what strange band together. Make a dent with a center objects mix together about 4 drams of zinc feats may be performed with figures? punch above the rivet both in the arm and sulfate with 4 ounces of water. Place Take the figure 9, for instance. Multiply band to hold the former in place, as in the case it by 2, and you get 18; and 1 and 8 make of the extension or commonly called 9. Five 9s are 45 and 4 and 5 make nine zigzag rule. No dimensions are given, again. Three 9s are 27, and 2 and 7 make altho for an ordinary pen -holder (A) could 9. Four 9s are 36, and 3 and 6 make 9. equal i% ", B -% ", C -1' ", D=,/2", and Take any row of figures you fancy, say a Y -1 %" 8642, and if you reverse themand subtract A desirable feature of the device is that 8642-2468 -you have left 6174, which the guide arm may be folded so that the added together makes 18, or twice 9. Take pen may be dipt in the ink bottle as shown in Fig. 1, in it be the 18 and 1 and 8 make 9 again. If you and that position can used take five figures, say 76543, reverse them, 34567, and subtract you get 41976, which, added together, makes 27 -that is, 2 and 7 make 9, or three 9s are 27. Thirty -seven is another number specially adapted for figure juggling. Multiply by three, 37 becomes 111 ; and no matter what multiple of three you use the figures in the results will all be alike. Twelve times 37 is 444, 37x21 becomes 777, and so on.

It's Easy Enough to Zinc Plate an Article, as You Will Find in Following the Instructions Herewith. HOW TO DRAW LINES WITH this solution in an ordinary glass jar; next WRITING PEN. fasten a wire to the positive pole of a bat- Those who have tried to draw straight tery. Let this wire lay submerged in the lines with a writing pen and rule, nine times To Draw Straight Lines Is Not So Simple a solution. The wire which you have fast- out of ten have obtained an unsightly blot Matter as You Think, but with a Little Help ened to the negative pole of the battery for their labors. You Will Soon Attain Perfection. should be arranged so that it will hold some Neat and clean -cut lines may be drawn metal object which is to be zinc plated. with the use of the following device. The as a clip to hold it in the pocket also. The Drop the wire with object to be plated in thickness of the lines will depend on the band may be constructed in any design suit- the solution. Care must be taken not to let kind of pen points used. The guide arm able to the maker. the two wires touch, for this will cause a (A) may be constructed of brass, altho Contributed by D. HUGHES. short circuit of the battery. Using a 4 -volt steel is preferable in this case. The band 60- ampere hour storage battery the action (B D) should be made of spring steel, a WAX FOR BOTTLE SEALING. of the solution will be much quicker and piece of spring of an old clock would be Mix rosin or cheap sealing wax with art the quicker will the zinc deposit itself on the sufficient. All that is required of the ma- equal amount of beeswax in a water -bath. object connected to the cathode. terial would be that it should hold its form Dip bottles in hot solution and lay on side Contributed by ED. H. RANSON. and not be easily bent. . until dry. MISCELLANEOUS RECIPES AND To this add 5% drams kermes. Filter and Water 50 " FORMULAS. mix this solution with 5% drams tartar, 11 Solution No. 2: drams sodium hyposulfite and 1'/z pints of Aniline 6 TO SOLIDIFY ALCOHOL-Heat 500 parts parts of denatured alcohol over a water water. Polished sheet brass placed in the Hydrochloric acid. 9 " warm mixture will assume a steel -blue Water 50 " bath to about 140 deg. F. and add 1 part color. Two coats of solution No. I are applied of gumlac and 15 of dry Venetian parts TO with a applied soap (powdered). GIVE APPEARANCE OF CASE- brush -the second coat being HARDENING-To 20 parts water add I after the first has dried. The surplus of BLUING (COLORING STEEL) - part nitric acid. Immerse the piece in the the second coat is removed by rubbing, Small articles made of steel are very often solution for about 30 seconds, remove and after which solution No. 2 is applied in blued. A very convenient method for the wash in clean warm water and oil. two coats. When thoroly dry, a coat of experimenter is to place the articles in an TO REMOVE PAINT -To remove raw linseed oil is to be rubbed well into iron pan containing a quantity of clean dry paint without leaving any traces use ether the wood with a cloth impregnated with it. sand over a fire. Move the pieces around on a piece of cheesecloth. WALNUT STAIN- Dissolve in 30 oz. constantly until the color is desired NO -GLARE HEADLIGHTS -Paste a of water 1 oz. permanganate of potash. achieved, then remove and plunge into piece of ordinary paraffin paper on the Apply this solution twice. Wait a few clean oil. It is very necessary that the inside of the glass. A light so fixt is minutes and wash with clean water. When metal to be colored is clean. lawful and gives a good driving light. dry oil and polish. TO GIVE STEEL A BLUE -BLACK LITMUS PAPER -This paper is pre- TO STAIN PINE A WALNUT COLOR -At times a blue -black color is pared by boiling litmus, and steeping the COLOR -Mix thoroly I pound burnt sien- preferable to a blue. Melt together in an paper in the liquid; this paper turns red na, I pound dry burnt umber, and 4 oz. iron dish 10 parts of saltpeter and 1 part when touched by acids. lamp black ; add to 1 gallon of very thin black oxid of manganese, and heat until ROSEWOOD COLOR -Boil in % gal- shellac. Apply with brush. When thoroly a pine shaving thrown on the surface will lon of water. 1 pound logwood chips and dry rub down with fine sandpaper and then catch fire. DO NOT ALLO \V IT TO pound red sandalwood. Apply to the give one coat of shellac or varnish. BOIL. \\'ire each piece of work and sus- wood, then go over it with a mixture of WALNUT STAIN FOR HARD WOOD pend in the mixture. Be sure that each asphaltum and turpentine. -To 1 gallon of strong vinegar add 1 article is completely covered. Do not let ACID PROOF TABLE TOPS -The pound dry burnt umber, % oz. rose pink, them touch the container. at any point. following solutions render a table top im- and % pound dry burnt Vandyke brown. When the desired color is obtained, wash pervious to the action of acids and alkalies. Mix thoroly and apply with a brush. in hot water. dry in clean sawdust and oil. Solution No. 1: The above recipes and formulas have all TO COLOR BRASS A STEEL -BLUE Iron Sulfate 2 parts been tried by me and have proven satisfac- -Dissolve 3 drams antimony sulfid and 4 Copper Sulfate 2 " tory in all respects. oz. calcined soda in 1% pints of water. Pot. Permanganate. 4 " Contributed by H. W. H. (Chemist.)

www.americanradiohistory.com September. 19 18 ELECTRICAL EXPERIMENTER S)I

Automatic Aircraft Steering rent. In the design shown. s:x car- ting and receiving scheme for in- Revolving Electric Sign for Water Mechanism bon chambers are used. stallation on ships, etc., the prin- Tanks cipal object of which is a motor- (No. 1 64,966, issued to Gustave (No. 1,268,375, issued to Frederick Nordstrom.) Electric -Driven Refrigerator William Meyer.) (No. 1,263,633, issued to Heinrich This novel patent covers speci- Zoelly.) fic means for mounting the re- This refrigerator embodies an volving electric sign which is of the electric motor at the top as indi. circular type and so arranged as to Gated, and there is also incorporated be suspended on tracks running P\ in the make -up of the machine a around the tank. An electric motor works in a toothed rack mounted - - special form of compressor which is used in compressing the refrigerat- around the interior surface of the ing medium, which may be methyl sign in such a way as to propel it chlorid, and which in the course of continuously as long as the motor the refrigerating process is used is operated. Electric current for / over again. The refrigerating me- operating the lights on the revolv-

operated switch which alternately cuts in the radio transmitting and Among other things, the inventor receiving set on the antenna. The claims to have solved the follow- speed ut the switch can be regulated ing: by gyroscopic and other elec- so that radio signals can be sent out trical means, the stability of the air- and received in alternation during craft is maintained in all directions, brief or sufficiently p r o l o n g e d and also the vessel can be held, by periods to be effective. The switch means specified, upon a predeter- may be operated by electric motor. mined direct course if so desired. Again means are arranged whereby A. C. Telegraph Sounder the wings the of craft will be banked W. automatically upon taking a curve, (No. 1,265,589, issued to Arthur and the vessel may be set to follow Beauprie.) various courses other than direct. He provides a duplex core so arranged that there will be a mutual Electric Typewriter attraction between the two parts (No. 1,268,491, issued to Paul C. thereof, irrespective of the character Rawls.) of the current passing thru the solenoid or magnet. In this way, the When any key is deprest for inventor claims, the results are such either a short or a long period of that the residual magnetism in the time, then the various operations members will at all times necessary to complete the printing two core ing sign is carried to the lamps thru be great enough to hold the same insulated rings and brushes. of a character and to return the type in ocntact during the passage from bar to normal position will be auto - a positive to a negative wave. matically and progressively carried out. The movement of the type A Lamp Socket Meter (No. 1,264,982, issued to Edmund O. Schweitzer.) This meter involves a small ilium is comprest to a pressure cor- electrolytic cell which is appropri- responding to the cooling water tem- ately connected into the lamp socket perature and passes hereupon into so that after a certain length of a lower pressure chamber, and it time the elements making up this eventually finds its way thru a water cell will be decomposed by the pas- jacketed chamber, and thence into a condensing chamber.

Current Amplifier (No. 1,264,813, issued to August J. Kloneck.) An amplifying telephone relay is bars as the various keys are deprest means, interposed between the signal sta- is caused by electro- magnetic embracing two Point and to reduce sparking at the con- tions, dynamo -electric Electrical Contact current generators designed with 1,264,685, issued Giuseppe tacts whenever the electro- magnetic suitable differential regulating coils (No. circuits are opened, the inventor pro- Alberto to absorb as the diagram shows. Also the in- of vides a suitable condenser ven or provides rotary members in This contact point is formed the extra energy created in the cir- tungsten or molybdenum, having an cuit by the self- induction of the exceedingly high melting point, and magnet windings. A set of selec- which is united with the support by tive electro- magnets and an electro- electro- thermical welding at a very magnetic power armature are utilized high temperature so as to render the in operating this electric typewriter. whole contact member electrically homogeneous. In this way it will resist- Multi -Unit Telephone Transmitter have a minimum electrical ance, and this resistance is further (No. 1,264,507, issued to William reduced by means of a coating of Wallace Hanscom.) some such conducting metal as rop- A novel scheme for mounting the these relays which do not bave any per or silver around the contact carbon cells is employed, and also in collecting rings or commutators. face of the support, with the excep- conjunction therewith a common The amplifying coils of the relay cooling chamber is devised so that generators are arranged so as to be a continuous stream of cold water cut by lines of residual magnetic or other liquid can pass into the force of a rotating armature bobbin, microphone chamber and circulate which is induced in the latter thru by the thin walls of the carbon the field coils of a generator. A cur- rent from a transmitter surges in the same direction thru the differ- ential coil as thru the main field sage of the current feeding the lamp, coil and thus energizes the genera- and which will cause the circuit of tor; but an amplified current from that lamp or apparatus to open. Be- this generator surges thru a differ- fore this lamp or apparatus can be ential coil in the opposite direction again used, and more electric power to that in the main coil, thus nulli- consumed, the owner has to screw fying its action. another meter unit in the socket, a supply of which he could have on hand of course. Novel means are Automatic Wireless Signal provided whereby the consumer is (No. 1,265,633, issued to Gustaf notified by a flickering of the light Engelbrekt.) lion of the two faces between which a short time before the current is An automatic wireless transmit- the break takes place. shut off by the electro- chemical de- cells, and thus carry off the heat composition of the meter elements, produced in these cells when the COPIES OF ANY OF TIIE ABOVE PATENTS SUPPLIED AT 10e so that he will not be left in the microphone is carrying a heavy cur- EACH. dark.

www.americanradiohistory.com 332 ELECTRICAL EXPERIMENTER September, 1918

Our Amateur Laboratory Contest is open to all readers, whetber subscribers or not. efficiency of the The photos are judged for hest arrangement and apparatus. To increase the interest of this department we make it a rule not to publish of Dark photos photos of apparatus unaccompanied by that the owner. preferred to light toned ones. We pay $3.00 prize each month for the best photo. Address the Editor, "With the Amateurs" Dept.

"Amateur Electrical Laboratory" Contest In this Issue we publish some Interesting facts with excellent photos, describing one Amateur Electrician's experimental labora tory. Now "Bugs " -we want to publish a snappy one like it each month. Here's our proposition: Why not write up your "Eiectrlca. Lab.," In not more than 500 words. Dress it up with several good, clear photographs. article in display style If we think it good enough we will publish the and pay you well for It. The prize awarded to such articles will range from $3.00 to $10.00. And "Bugs" - don't forget to make your article Interesting. Typewritten articles preferred. Address the Editor of this Department. THIS MONTH'S $3.00 PRIZE WINNER- EUGENE McGOWAN HEREWITH are five photographs of my experimental laboratory. The lower right -hand photograph shows my chemical The table which laboratory. upon the apparatus stands was 'constructed from an old counter that was once used in a grocery store. In the center of the table there is a small basin that serves for washing test tubes etc. There are also spigots for hot and cold water. Shelves were placed on the tcp to bold the chemical bottles as the picture shows. It may be of interest to the readers of the ELECTRICAL EXPERIMENTER to know that this table cost less than $4.00 to make, including the shelves, sink and the pipe fittings. There are about one hundred chemical reagents, including a few of the rarer elements like Radium Bromid 40X and Uranium Metal. I also have balance scales, Kipp's apparatus for generating sulfuretted hydrogen, condensers, burettes, and other common laboratory glass ware. The center and upper left.hand views show the Electrical "Lab." and most of this apparatus was constructed from data given in articles that have appeared in the "E. E." In the right-hand corner of one photo may be sects the vacuum pump, which was constructed according to the directions given in the "E. E." by Raymond F. Yates November, 1917, issue. There are also spark coils, Tesla coils, a Hughes induction balance, galvanometer. storage batteries, static machine, Leyden jars, a small dynamo, several motors, Geissler tubes, a synchronous motor made according to the one described in the "E. E." April 1918. Storage batteries are kept in a box under the table. The top right-hand photo illustrates my Tesla cocoil in actual operation. It stands two feet high and throws a discharge about one foot long and several inches thick. Eugene McGowan, Philadelphia, Pa.

www.americanradiohistory.com September, 19 I8 ELECTRICAL EXPERIMENTER 333 Phoney Patents Under ibis beading are publlebt electrical or mechanical Ides. which you haven't smell of Patent yet. After they have allowed the Pat- sur clever inventor, f best known to themselves, have as yet ent, you must pay another $20.00 a a final fee. That'. $40.001 WE not patented. We furthermore call attention to our celebrated Phoney PAY YOU $3.00 and grant you Phoney Patent in the bargain, so you Patent Ofza for the relief of all suffering daffy inventors in this country save $43.0011 When sending in your Phoney Patent application, a. well as for the entire uni be sure that It Is as daffy as a lovesick hat. The daffier the better. We are revolutionizing the Patent business and OFFER YOU THREE Simple sketches and short descriptions will help our staff of Phoney DOLLARSARS ($3.00) FOR THE BEST PATENT, if you take your Phoney Patent Examiner to issue Phoney Patent on your Invention in a Patent to Washington, they charge you $20.00 fer the initial fee and then jiffy.

Prize Winner: BALDHEADFLYSWATTER. Be It known that I, Dickson Reck, have invented a startling and withal hair -raising Invention for the purpose of refreshing baldpated old ladles' and ginks' who are troubled In the summertime with the usual nuisance -flies. My apparatus, which is simplicity itself, operates as follows: A small but powerful mutt "A" preferably of the genius "homo gazabo" Is caused to run perpetually after the bone "B," on a tread power, said tread power being connected by means of a suitable belt to a serles of cups mounted on an endless belt. This belt carries the cups around thru a tank of water, and the cups as they reach the maximum of their upward movement, discharge the water into a basin "D," which allows the water in It to ooze thru a nozzle onto a water turbine, "E." The water discharged from the turbine passes thru a shoot and back into the original water tank. The turbine "E" Is belted to a flexible rubber fly -swatter "F," which when not busy killing flies and other Insects, causing them to fall Into the combination fly -container and cuspidor, Is caused to massage the owner's baldpate with his choice brand of hair tonic. The belt from the top of the water bucket hoist, connects with the han. bone "B," to make it wabble thus irritate the mutt "A" more efficiently. Inventor, Dickson Reck,. Gary. Indiana.

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COLLARBUTTONFINDER. Behold! my latest and greatest invention! An automatic electric collar- button -finder or retriever which should be a boon Indeed to all bachelors; not to mention the married gents, whose wives regale them periodically and regularly, especially on bright Sunday morns, with longwlnded exhortations and admonitions to "geti drest at once for church." Zipl goes that Infernal collar button under the bed, of course. I provide herewith a guaranteed retriever for all unruly collar buttons, Involving an automatic electric vacuum cleaner which Is connected with a serles of openings one foot apart all over the boudoir floor. Storage battery connects with the light- ning rod on the house and Is charged free. The storage battery runs the motor, and the motor runs the vacuum pump. Zipl goes his button- Whaml goes the electric switch, and Presto! comes the button from the trenches right Into your Jewelry tray.- Inventor, Franklin Kral, Washington, D. C.

www.americanradiohistory.com 334 ELECTRICAL EXPERIMENTER September, 19I8

The "Oracle" Is for the sole benefit of all electrical experimenters. Questions will be answered here for the benefit of all, but only matter of sufficient interest will be publisht. Rules under which questions will be answered: 1. Only three questions can be submitted to be answered. pencOnly one side of sheet to be written on; matter must be typewritten or else written in Ink, no iled matter considered. 3. Sketches, diagrams. etc., must be on separate sheets. Questions addrest to this department cannot be answered by mail free of charge. 4. If a quick answer is desired by mall, a nominal charge of 25 cents is made for each question. If the questions entail considerable research work or intricate calculations a special rate will be charged. Correspondents will be informed as to the fee before such questions are answered.

ARC WELDING OF RAILS. ELECTROLYTIC GAS PRODUCERS. etc., was given in the June, 1917, issue (947) Lewis F. Bailey, Spartanburg, S. (949) John L. Shaw, Hickman, Ky., of the ELECTRICAL EXPERIM ENTER. C. writes the Oracle: asks several questions concerning the elec- The rate of production of these gases Q. 1. He asks several questions relative trolytic gas producer. depends upon the area of the electrodes, the to arc welding. A. 1. If an electric spark is past thru amount of current flowing, the resistance A. 1. Your information is at hand; such the medium wherein oxygen and hydrogen of the electrolyte, etc., and it must be borne a welding scheme is quite possible, but you gases are mixt, combustion takes place al- in mind that by properly adjusting any of have forgotten to mention the voltage, etc. most instantaneously thruout the entire the above values, we can maintain a con- stant production of gases. b /ro //ey gire PHOTOS WANTED AT RADIO TROUBLES. Steel Mec/rode ODD $1.00 EACH! ! ! (950) C. Vetter, Wessington Springs, about several radio .Vow S. D., writes the Oracle J/C oe/weeo rod is the time to make your problems which are puzzling him. We ad- crd steel a rc'r de, Kodak pay for itself in a real practi- vise him as follows: cal way. 1Ve are after interesting A. 1. Tigerman vacuum tube to our .^.evsi/ed sled photographs of ordinary The out -of -the- mind is as good as the rest of the tubes electrical, radio and scientific sub- from our experience. This tube can be jects and are willing to pay $1.00 cash with good results as an amplifier. every one we can usc. Please used for A. 2. The appended diagram shows the bear in mind that for half -tone re- connection for two -step amplification. For production in a magazine, a photo- one step amplification, leave out the third graph should be particularly sharp Audion circuit and place the telephone re- and clear. Of course, if a subject Utilizing the Intense Heat of the Electric Arc ceivers where the transformer T, now is. Steel Rails and Plates are Now Welded by happens to interest us particularly A. 3. We herewith give dimensions for This Method. well, we can have the photo retouched. several types of loose couplers. (3,000 For the general run of subjects, how - meters.) ever, it not pay to go to However, does such Primary 5" long x 4" dia. with No. 24 or the general method is to ground expense. Therefore, please take pains one terminal of the apparatus as shown in 26 S. S. C. the accompanying to properly focus and expose your Secondary 4/" long x 3/ dia. with No. diagram, and the other pictures. It often happens that a terminal is usually of steel or carbon, de- 28 S. S. C. really mediocre subject well photo- The secondary should be wound with No. pending upon the particular case for which an graphed wins approval over ex- 34 (Audion circuits.) you desire to use it. cellent subject poorly photographed. If you refer to the article on the Elec- And don't send us plate or film "nega- trical Furnace in the April, 1918, issue of 6,000 Meters tives"; send unmounted or mounted Primary 8/" long x 5" W with No. 24 this journal, you will obtain some idea of "prints," preferably a light and dark the size of electrodes to be used. S. C. C. one. 8" long x with No. We Secondary 4/" W make note of a particular case where- As to what to photograph: Well, 30 S. C. C. in the electrical railway companies use an that's lard for us to say. We leave The secondary should be wound with No. electrode of steel and the rail as the other that up to you, and every reader now 34 (Audion circuits.) electrode, and whereby the arc causes the has the opportunity to become a re- 12,000 Meters metal to be welded to the rail, which is the porter of the latest things in the realm other electrode. of Electricity, Radio and Science. Primary n" x 7/" with No. 24 S. C. C. Rut, please remember -it's the "odd, Secondary 10" x 7" with No. 30 S. C. C. novel or practical stunts" that we are The secondary should be wound with No. interested in. Every photo submitted 34 (Audion circuits.) COMPUTING CAPACITY OF should be accompanied by a brief de- CONDENSER. scription of 100 to 150 words. Give (948) R. Howell, Los Angeles, Calif., the "facts" -don't worry about the asks: style. We'll attend to that. Enclose stamps if photos are to be returned Q. 1. About the size of secondary capac- ity and place a piece of cardboard in the for one -inch spark coil and how to envelope with them to prevent muti- compute the area of dielectric required. lation. Look around your town and A. 1. The value of the capacity for use sec what you can find that's inter- across the one -inch spark coil secondary, esting. should be adjustable to .02 m.f., and should Address photos to- Editor "Odd consist of about 2,200 square inches of tin- Photos," ELECTRICAL EX PER NI ENTER, foil placed between glass plates at least 1/5 233 Fulton Street, New York City. of an inch thick. Below is given the form- ula for calculating the area of active di- i electric: mass, which will cause a sudden increase Two -Step Amplification with the Tlgerman tXCX10n in volume, or in other words ail explosion Vacuum Valve and an Audion Bulb. area = will take place. K X 2,248 An extensive article covering a new in- We use finer wire on the secondary be- Where: t = thickness of dielectric in inches. vention which utilizes the electric current cause by doing so and with a given num- K = dielectric factor. to decompose the water so that the hydro- ber of turns, an increase in voltage is ob- C = capacity in micro - farads. gen gas can be used for an explosive mix- tanned, the induced E. M. F. being propor- Area in square inches. ture in connection with engines for autos, (Continued on page 336)

www.americanradiohistory.com September. 1918 ELECTRICAL EXPERIMENTER 333

IN TES1, LE " E oF`qON .Más,ti«,,,n. 1VSitIA ..w", tc ^,. M... `' ^a°b `.?`.`::''dsa,ncw:` r wO,w+M,, ti . Special offer now. Pay nothing for this Test Lesson in :`. ..:^.::` ; Drafting prepared by the experts of the Chicago Technical ; ; ^ .° College. Learn from a study of this lesson how well equipped ti.` : :: ;` - ..` `: ' .: +,.,^ .ti .`:,. .,, you are to take up drafting as a profession. Also see from `'`. it how clearly the Chicago "Tech" Course in ``:":::`.;,,, N".." Draftsmanship .:..,- , :.; explains every point -and how it will give you a practical ,. = :-:. ., .=,w in ;` '' .=';,`.. ^.^; ..` .,` `; training Architectural, Electrical, Structural Steel, Machine 11.00 : .ti.,.,, Drafting or any other branch of Drafting in which you may be c ``-`` ` . ti interested. No charge whatever for this lesson. We invite ``qsa ^L "':``... every ambitious man to send for it. To ask for it places you no COLLFCP under obligation. Get it while the offer holds good and let it show you whether or not you are a man who can study this technical calling to advantage. Just sign and mail coupon. Send no money. $2500 to $10000 a Week Positions are always open to competent draftsmen and the war conditions are sure to create an extra demand. These positions pay good salaries and the well trained man always has the best opportunity for advancement. Our course gives this training in the shortest time consistent with thoroughness. Its practical value is proved by the success of our grad- uates. If you are in a position where the future looks doubtful, if you want to be a technical expert, if you want to be master of a calling which will make you independent, at least get the Free Lesson and the information we send upon request. Come to the College or FREE Instruments Every student of the Chicago Study in at Home "Tech" Course Drafts- You need not leave your present occupation to get this manship receives this set of expert training in Draftsmanship. We will teach you by mail instruments. or a cash credit and you can study at home in your spare time. The work is in case he already has a set. the same as given in our Day and Evening Classes at the Col- We start our students at lege here in Chicago. Your instruction will be given directly once in practical work with _ by men who are engaged in the very work they teach. They necessary equipment. will teach you how to do just what is being done in the drafting rooms of big organizations where Chicago "Tech" graduates are always in demand at good salaries. Builders' Course Easy Payments Men in the Building Trades whether working now Pay for the course as you go along. The fee is so small as mechanics or contractors should get information the terms so easy that no matter how moderate your income about our Courses in Hlan Reading and Estimating. may be, you can afford to get this training in Draftsmanship We teach men how to make money through knowing which will prepare you for an important paying position. more about their business. We want to tell carpen- Catalog and all particulars sent free with the Test Lesson. ters, bricklayers, stone masons, and other men en. gaged in building work about these courses. Write for free Lesson in Plan Reading, Builders' Catalog See For Yourself and other instructive information. This Free Lesson is an absolute test, pure and simple. Send for it today. In the privacy of your home study it, then you Chicago Technical College, will know for yourself whether you are proper material for a 945 Chicago ''Tech" Building, Chicago successful Draftsman. Other institutions will ask for your Without obligation to me, please send me your FREE Test money first. You find out later at your own expense, whether Lesson in Draftsmanship and other interesting literature cov- you can adapt yourself to ering the subject indicated below, theworkand succeed in the profession. X in which you are interested, We do not charge you one cent for the Test Lesson. either Mark opposite work specially now °Architectural Drafting - Builders' Course or later. It is absolutely FREE. Nor do we obligate you Machine Drafting Plan Reading in any way whatever by writing for the Free Test Lesson. so O Electrical Drafting O Estimating. send coupon or write postal request today. If you do nothing °Structural Drafting Surveying else but secure the Free Test Lesson you will gain such valu- °Sheet Metal Drafting °Map Drafting able knowledge as will be beneficial to you through life, for the Free Lesson rives the very fundamentals of draftsman- Name ship which are helpful to every man. Mail the coupon. Address CHICAGO TECHNICAL COLLEGE 945 Chicago "Tech" Building Chicago, Ill. City State College or Home Study? State which

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www.americanradiohistory.com ELECTRICAL EXPERIMENTER September, 1918

THE ORACLE. (Continued from page 334) tional to the number of turns used on the BOOK R Mesco Telegraph primary and secondary. For example- EVI EW-40, When ten turns of the primary are being i i used, suppose we happen to get. best re- Practice Set sults with 50 turns in the secondary. Now this means that the E. M. F. is being i11- TELEPHONE APPARATUS; AN INTRODUCTION For Learning Telegraph Codes creased in the ratio from 1 to 5 times its value in the primary circuit. TO TILE DEVELOPMENT AND THEORY. By G. D. Shepardson, Sc.D. Size 6/ x 9l/t incises, Cloth Bound, 115 illustrations, MULTI -AUDI -PHONE HOOK -UP. 337 pages. Publishers, D. Appleton and Co., New York and London, 1917. Price. (951) D. Horace Parrell, Philadelphia, $3.00. Pa., asks: A most complete and authentic work on modern Q. 1. For a design of regenerative Au- telephone apparatus, covering all the important dion receiving set. points in daily practise from the lineman to the A. 1. A design for a short -wave regen- planning and research engineer. The principles are fully discust so that even the layman may erative Audios) set is fully described its the glean a good deal of valuable information, while December, 1916, issue of this journal. A to the more advanced worker, especially those hay- tickler coil is nothing more than an induc- ing a knowledge of algebra, trigonometry and the The Practice Set comprises a regular tele- laws of physics and currents, the book will prove graph key, without circuit breaker, a special tive coupler with sufficient inductance nec- a great benefit. high pitch buzzer, one cell Red Seal Dry essary to transfer the oscillations from the Many circuits as used in American relepbony Battery, and four feet of green silk covered grid to the plate circuit of the Audion. It practice are included in the work with a complete flexible cord. description and working detail of each part. should a tube wound The key and buzzer are mounted on a consist of primary A subject admirably treated, so that all may a highly finished wood base, and three nickel with No. 24, and secondary wound with understand and yet gain specific knowledge there - plated binding posts are so connected that No. 28 magnet wire; the dimensions are of-a work which should be possest by everyoneone the set may be used for five different purposes. interested in telephony, especially students of List No. Price 6 inches long, 4 inches wide. It is advis- art. 3422 Telegraph Practice Set, with Bat- able to take about % dozen taps from each tery and Cord 82.70 coil. THE CALCULATION AND ÌA'IEASUREMENT Weigh, lbs. packed. Q. 2. How is the Multi- Audi -Phone OF Price does not Include postage. hooked up? INDUCTANCE AND CAPACITY. By W. H. Nottage, MESCOGmbuIin hedee Se lw learrnstne Morse A. 2. The underlying principle embodied B.Sc., 145 Pages, 5% x 834 sod CeeheeaW road sod Aadibie Cedes inches. in the construction of the Multi -Audi- Cloth Bound, Price, 60 cents. Phone is shown in the diagram. con- The Wireless Press, Ltd., London, En- It gland. sists of a high resistance 'phone magnet actuating an iron diafram has This book is a very helpful aid to those who which some have occasion to design, calculate or measure the fine carbon balls on its top and is then values of inductance or capacity. as encountered in radio work, telephone work, etc. The treatise consists of numerous examples worked out, such as Corson p/a /e the inductance of a straight wire carrying ether Ccrocn bous a.c. or d.c., the inductance of different types of iron Ciofrom coils, the capacitance of different forms of con- densers, and antennae, etc. There are also de- scribed a number of methods for the direct meas. This outfit is the only reliable lnetrument which will urement of inductance and capacity, e.g., by the enable tudenta to become proficient operator, in the U. S. Naval Service. because It la equipped with a Fleming -Anderson bridge, Butterworths' bridge, buzzer and miniature lamp enabling the user to Owens' bridge Hays' bridge, Wiens' series bridge. master both the Isu and audible segnale quickly. Fleming and Dyke bridge, etc., etc. Towards the List No. 52- Praetleo Set with Red Seal Bt end of the book there is given a set of tables tery and Cord 33.60 which aid considerably in the quick solution of Weighs 4 lbs. packed, Price does not include postage. problems. a few of the tables of which are: Nagaoka's factors for the Inductance of a single layer coil; Capacity of parallel wire antennae; Send for the New Edition of Wave -length of an aerial with series inductance; Wave-length of antennae with series capacity, et Our Catalog W28 cetera. it is pocket elze. contain, 248 pages, with over 1.000 As a whole the book fills an important breach Illustratlone, and describe, In plain, clear language The Hook -up of the MuItI -Audi -Phone Am in radio literature and will prove of use to all all about Bella, Push Buttons. Batteries. Telephone in engaged in radio and other branches of electrical end Telegraph Material. Eleetrlo Toys, Burglar and glitter a Radio Receiving Circuit. Fire Alarm Contrivances Electric Call Bells, Electric science. Alarm Clocks. Medical Batteries, Motor Boat Horns. Electrically Heated Apparatus, Battery Connectors. a is con- Switches. Battery Gauges. Wireless Telegraph In- covered with carbon plate which struments. Ignition Supplies. etc. nected as shown, the signals being increased LEARNING TO FLY IN THE U. S. for by virtue of the fact that the resistance be- ARMY, by E. M. Fates. First Edition, Send the Catalog Now tween the balls is altered when a radio 180 pages; fully illustrated; size 7% x 5 Manhattan signal is received. By properly connecting inches; flexible covers; cloth bound. Electrical an apparatus of this kind, messages can be McGraw -Hill Book Co., New York, pub- Supply Co., Inc. automatically recorded. In fact, one of the lishers, 1917. Price, $1.50. NEW YORK: CHICAGO: ST. LOUIS: leading companies are at present selling A complete pocket manual of aviation giving all 17 Park Moo 114 S. Wells St, 1106 Pine Si. such a machine for recording purposes. the points of the game from A to Z. It has evi- San Francisco Omce: 604 Mission St. dently been compiled with extreme care and atten- tion to details and should find a ready welcome from all interested in flying, either for army prat LAMINATED IRON V. S. EDDY tise or sport. Early efforts in the air are described with a full CURRENTS IN A. C. history of the first attempts of flying and the WIRELESS MOTORS. various causes which led to failure, until the individual instruction continues under the Minidoka, Wright brothers made their first successful flights. general supervision of E. E. Bucher, In- (952) Ivan Redeker, Idaho. Front the failures and successes of various ex- structing Engineer, l ;,rconi Wireless Tele- states that he has had considerable trouble periments the present army aeroplane has been graph Co. in an A. which he has developed, and this is made the subject of very operating C. motor interesting reading. built. Then follow numerous chapters giving the prin- LAND -WIRE A. 1. After carefully considering the va- ciples of flight, constructional details, motors, pro- Air. C. E. Palmer, Chief of the we pellers, wings, controls etc. Operator rious details as outlined by you, offer -country Western Un :on Telegraph Co., is now in The Of special note is the chapter on Cross supervision of the Land -line Department. the following suggestions. laminations Flying, which gives the pilot numerous hints on Touch Typewriting and 'Morse' in Com- which went to snake up the field and arma- the care of bis aeroplane during such a flight, the bination is taught according to the most ture should have been shellacked, for as is picking out of suitable landing places and all data modern methods to which is necessary in making a successful flight. the case in all A. C. machines, Eddy cur- The erection of aeroplanes which have been Boys, Girls, Men and Women rents arc generated, and are one of the shipt from the factory forms the topic of another biggest factors to handle. These Eddy cur- interesting chapter, giving the correct methods to follow in setting up an aeroplane, with pointers Y.M.C.A. Telegraph School rents tend to stop the motion of the arma- on what and what not to do. This should prove Marcy Av., near Broadway, Brooklyn, N. Y. ture. This effect can be seen very easily of especial value to all as much of the success we rotate a copper disc between the depends on the proper afigninQ of the planes. if The proper inspection routine is carefully ex- poles of a powerful electro- magnet. It will plained, and iff rigidly followed will do much to BOOK ON AIIATION be noticed that when the current is off, the prevent needless wrecks and accidents. copper disc can be rotated very freely, but All in all, it is a work well worth reading by ,.earn of the great opportunities in this new anyone, and right now it should be of inestimable 11,WO,000,0001ndoetry. Tboneend. of men needed. as soon as the current is switched on pro - Learn by moil -free book tall. bow. W rile at once. value. pampa, sue nolin,, grad rag ranaaawa..gNpa. (Continued on page 338) (Continued on page 338) You benefit by anenfioning the "Electrical Enccrintntter" when writing to advertisers.

www.americanradiohistory.com September, 1918 ELECTRICAL EXPERIMENTER 337

In the Great Shops of

PRACTICAL COYNE FINISH IN Schools INSTRUCTION Dept. 399-5E E.gIllinoIllinois 3 MONTHS Thousands of skilled Electricians are needed. The demand is becoming more urgent every day. The Government is employing every one they can get which is causing a great scarcity throughout the country and big salaries are being paid everywhere. Right now is your big opportunity. Make up your mind now to prepare for one of these big jobs and then get here as quick as you can for your training. Earn $100.00 To $300.00 A Month In the Electrical business. Come here where you will be trained in these great $93,000 shops. Experts show you everything and you learn right on the actual apparatus. You work on everything from the simple bell to the mighty mo- tors, generators, electric locomotives, dyna- mos, switchboards, power plants, every- thing to make you a master electri- War Demands Have :ian. We have thousands of suc- cessful graduates. Just as Taken Thousands of Men soon as you have finished from this Profession. Men we assist you to a good position. We Must be Trained to Fill their Places. now have more Prepare Now for a Big Paying Position. positions than thorough, short and praetical. All instruction given on we fill. These courses are can the actual equipment. No books or useless theory. Each man trained indi- Think vidually and stays as long as he likes. Start any time -day or evening. of it. Our graduates are in great demand. We are continually receiving letters, telegrams, ;ittd telephone calls from contractors, manufacturing firms, etc., seeking our graduates to fill responsible positions. We have now more positions than we can fill and the demand is steadily growing. Every comfort is given our students while here. They live in comfortable homes in the most beautiful section of Chicago -on the lake.

DRAFTED MEN READ THIS LEARN DRAFTING Skilled Draftsmen are always in demand. Our courses a short time until you are It will only be are thorough- short-practical, preparing a man fully This is a war of skill, called into service. to hold a position of responsibility. we have more must win brains, and machinery. Uncle Sam positions than we can f.11. We also have thorough this war and must have tens of thousands of practical courses in Plumbing and Heating and Motion men skilled in modern trades and professions such Picture Operating. as Electricity, Drafting, Plumbing, and Sanitation. Such men will be quickly recognized and given an EARN YOUR WAY opportunity to rise. It is not too late for you if you Niany students earn a large part NM MN of their living expenses by do- r- - act at once. ing a little work in their CGYNE TRADE AND spare time. Our employ- ENGINEERING SCHOOLS In most cases those of our students in the draft, who ment dept. furnishes Dept. 1596, 39 -51 E. Illinois St. these positions with- have been called before completing their course, have been .Chicago, III. given an extension of time by their board sufficient to finish Please send at one your big Free P.00k -1 am interested in their course, owing to in the great need of trained men these Electricity [ I Drafting [ ] Plumbing lines in the Government Ser\ [ ] Motion Picture Operating (Chrtk trade interrrtrd in)

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www.americanradiohistory.com 338 ELECTRICAL EXPERIMENTER September, I 9 I 8 THE ORACLE. (Continued from page 336) Morse or Wireless Code ducing the magnetic field, the motion of the copper disc is retarded at once; in fact, the effect is sometimes so great as to stop Adjustable Buzzer Practice Set it entirely. Quickly Gives You Speed -No Tools Needed Touch You will therefore see that since your -A of Your Finger Adjusts It motor runs, This practice set with its adjustable it must be due to this effect, BUZZER enables you to learn telegraphy, and we advise you to shellac each plate of Morse or Wireless Code, In shorter time than ever before thought possible. A the armature and touch of your finger to a thumb screw gives the field, and we are sure any pitch desired to the BUZZER. that when this is done the motor will run Especially designed to give very clear sound of exceptionally high all right at the pitch even on ONE DRY desired speed. CELL. AS SHOWN The running effect of the The adjustment of the BUZZER to WITHOUT motor is not any pitch is made without the aid hampered much in your particular case in of any tools -simply by the thumb screw. The greatest improvement BATTERY reference in practice to the construction of the field sets ever made -superior to any on the market. Beauti- poles. You state that fully made; mounted on substantial base. $ 2.90 the armature was turned down, the slots were cut in, etc. Price $3.50 This is very bad for as you see the idea in WITH the shellacking of the laminations is to in- BATTERY AND WIRE sulate the stampings from one another,. Complete Ready for Use. Immediate Delivery and Money Refunded if not satisfactory therefore it is necessary to file off the Send for lilu d Folder slight remaining sharp edges which result from such operations. THE TEWNO CO. 41 Park Row N. Y. C. :. UuU :::::: BOOK REVIEW. : :.: :::: ::: ï. ::::::ï .:a:ï ï:V Siii:e (Continued from page 336) IIOVOLT HOW TO FLY, by A. A.C. Frederick Collins. CHARGE Cloth bound; fully illustrated; 182 pages; YOUR size, 5 x 7% OWN:: inches. D. Appleton & Co., New York, publishers, 1917. Price, $1.10. F -F A timely BATTERY:: and useful book which should find a ready demand from all interested in aero matters, especially those belonging to or intending to join BOOSTER the Aviation Section of the Army or Navy. Much attention is given to details and the author FULL WAVE A. C. RECTIFIER : has certainly covered his subject well. With a U!s\\\ \ >" `\ brief history of flying the reader . ? ' Be Your Own Service Station progresses, step : by step, thru the important phases of the art For Public or Prioete U e The reason why an aeroplane flies is clearly set Thee little menders to selling . forth, as well as the mechanical conditions, the e slastfil SMUT. like hot cakes and maker every various conditions of the air, gravity, stability, purchaser smile at his own Dust -e pressures, etc. n aspelty, sod wonder why A comprehensive r \ be hadnt bought one before. chapter is devoted to the build. \ ing of aeroplanes, covering practically everything from the general design, wings, etc., to rudders and running gear. ijk The engine is discust from every point of view, giving its theory construction C erginr Rheostat pwith ammeter and application, with 'and current feNLtor for terries - data on sue') refinements as self -starters. on D. C. circuits. ie The closing chapter deals with the qualifications MAGNETIC RECTIFIER. PAT'D APR. 101e necessary to become a successful pilot, It, $24 Comp leSte , where to ti learn to fly, etc. The aeroplanes uses in the Caln laenp present war and interesting notes and data giving The France Manufacturing ek vane .saler pr far{ rules Co., Cleveland, 0. Bulletle No. and regulations for obtaining a Pilot's Cer- 1! tificate are included. A large appendix contains the following in- formation: The Barometer, Table of Altitudes, The Sperry Synchronized Drift Set, How to Make Aeroplane Calculations, and a chart showing the Organization of the Air Service of Use "RED DEVIL" Blades the U. S. Army. MANUAL OF PHYSICAL TRAINING For Hardest Cutting AND THE ORGANIZATION OF "RED DEVIL" Flexible Hub Saw Blades are made from BAYONET FIGHTING. Size 6% x 4g Tungeteo steel only. This steel gives maximwa hardness inches, profusely illustrated, without brinlene,s. By a special process the teeth are made guarantee dark blue extremely hard and strong. but the back is left flexible. DEVIL' to last cloth, stiff covers. This book was origin- at least 30% longer than ally prepared Every blade Individually tempered. This costa extra money omen. by a Board of Officers of and takes extra time, but gltes a blade that cuts practically the United States Army. It contains 208 anything without breaking. or the teeth stripping. pages. Price 75c, publisht by National The teeth are milled "RED DEVIL" Hard Blades and Power Blades from the blank, out punched. This painstakingly Military Publishing Co., New York. Is also a slower and costlier process -but ensures sharp. arAsk your RRmadeD dDEVIL" It is a treatise on the subject of physical souare teeth this cut metal as easily as a ripsaw wood, Bladed and train- cuts other tools. ing, and gives in a very complete way the subject of marching, attention, and especially on setting. SMITH & HEMENWAY CO., INC. 107 Coit Street, IRVINGTON, N. J. up exercises. It treats at the beginning on the rudiments of military requirements which are very essential. The different physical exercises are il- lustrated in various motions. The chapter on rifle exercises is well presented. "THERE'STHERE'S MONEY /N/T" The illustrations therein show how the soldier of arms performs the various exercises with the aid of the rifle. The subject of gymnastic exercises is -HOME -LEARN TELEGRAPHY= treated at length. It includes wrestling, boxing, gymnastic contests, one -legged tug of war, and the - MORSE AND WIRELESS- siege." The subject of swimming is explained in - a _- very clear manner, and the illustrations show the various motions and strokes. The authors give an TEACH YOURSELF excellent description of bayonet fighting. In half the usual time, at trifling cost, with the wooderful Automatic Transmitter. THE OMNIGAAPH. OUR ARMY AND NAVY AND HOW Sends unlimited Morse or Continental meesagea, at TO KNOW IT. Edited by A. A. Hop- any speed, just as an expert operator would. kins, publisht by Munn & Co., New York., Adapted ay U. S. Gov't. 4 style'. Catalogue !rm. 4 x 5% inches, profusely illustrated, 144 nages, lithographed stiff paper covers. OMNICRAPH MFC. CO. Price, 50 cents. 391 Cortlandt St. New York The book is divided into two parts. In the Erst half of the book the author discusses the Army, Í and gives in the opening chapters the names of the You benefit by mentioning the "Electrical Experimenter" when writing to advertisers.

www.americanradiohistory.com September, I 9 1 8 ELECTRICAL EXPERIMENTER 339

various organizations and the salaries of the men in the U. S. Army. Many illustrations are given of various insignias of the different branches of the U. S. Army to familiarize the civilian, or the man in the service with the different branches. A complete table is given of the forts, arsenals and cantonments of the U. S. Army, also special army schools. officers' training camps, National Guard tent camps, and a detailed Army map of the United States. A colored chart of Army insignia hat bands is also given, designating the character of service. An excellent double -page illustration showing the leading types of American aeroplanes is given. Several pages are devoted to the differ- ent types of war medals. The publishers of the book print it in a reverse manner, so that half the book is consigned to the Army and other half to the Navy. In the second half the subject of our Navy is taken up, and the same order is followed in this portion as the first. Various colored plates are given, showing the rank of the Navy officers. An excellent color plate on shoulder marks for line officers, and insignia of rank of naval officers which are worn on the sleeves is also shown, including the various hat band in- signias as worn by enlisted men. There can be very little chance for a civilian to be mistaken in determining the rank of the officers both in the Army and Navy, if he becomes familiar with the various insignias as given in this book.

EXPERIMENTAL MECHANICS. (Continued from page 327) "I'm as Good a Man as predetermined diameter is reached. In order Jim!" to guide one's self to cut to the proper "They made him manager today, at a fine increase in salary. He's the diameter of the work, it will be necessary fourth man in the office to be promoted since January. And all were to use a measuring tool set to this diameter. picked for the same reason had studied in spare time The name of this tool is the caliper. There -they with the are two types, one called an inside caliper International Correspondence Schools and learned to do some one thing used in measuring the inside diameters, and better than the rest of us. second an outside caliper for determining outside diameters. The latter is the one "I've thought it all out, Grace. I'm as good a man as any of them. which we are interested in since we desire All I need is special training -and I'm going to get it. If the I. C. S. can to cut an outside diameter to a certain raise other men's salaries it can raise mine. If it can bring a better home value. It will thus be advisable at first to with more comforts to Jim and his family it can do it us. set the legs of the calipers to the value of for See this the predetermined value. Fig. 8 shows how coupon? It means my start toward a better job and I'm going to mail a pair of calipers are set on a scale and it to Scranton tonight!" adjusted until the second leg touches the Thousands of men now know the joy value which is required in the turned down Some Facts About the of happy, prosperous homes because rod. The cutting tool is caused to travel World's Greatest School! they let the International Correspondence back and forth and take a cut at each jour- Schools prepare them in spare hours for ney, is The first student was enrolled in the International which continued until the work is Correspondence Schools on October 15, 1811. bigger work and better pay. You will find reduced in size so that it will allow the Today the records of the Schools show an enrolment them in offices, shops, stores, mills, mines, calipers to just pass over. At this point the of over two million. This Is over six times greater than the total enrol. factories, on railroads, in the army and diameter of this portion of the work is the meni of Harvard in the 278 years since lis organization. navy -everywhere. correct diameter of the predetermined size. It Is more than ten limes greater than the total en- Don't jam the calipers over the work; feel rolment of Yale since its doors swung open in 1701. Why don't you study some one thing and get It Is over five limes the total enrolment of all the ready for a real job, at a salary that will give your the size carefully. This is one of the tricks colleges, universities, and technical schools in the wife and children the things you would like them of the trade. United States combined. to have. You can do it! Pick the position you I. C. S. text - books are used in class -room work want in the work you like best and the T. C. S. will On very accurate jobs, the cutting tool is and for reference purposes by 304 universities, colleges, prepare you for it right in yourown home, in your government schools. institutes of technology and voca- spare time -you need not lose a day or a dollar prevented from taking off any metal at a tional schools, by the U. S. Navy Department in its from your present occupation. point where the diameter of the work is a Shipboard Training Schools and by many of the largest industrial Corporations. Yes. you can do it! More than two million have trifle larger than the opening of the calipers. About 500 students each month report advancement done it in the last twenty -seven years More than The remaining metal is removed by either or salary Increases as a result of the I. C. S. training. 100,000 are doing it right now. Join them without Reports of 1.500 typical students show that at time of another day's Mark and a flat fine file or else with emery paper or enrolment their average monthly wage was $53.00. At delay. mail this coupon! cloth. This is done because the time theymost recently reported advancement their the knife is average wage was $182.48 per month. an increase in earn- unable to take a very fine cut, so it is prac- ing power of $125.58 per month through 1. C. S. training. ticable to use a file to bring the work to the Reports on 27.000 typical students show 14.099 now INTERNATIONAL CORRESPONDENCE SCHOOLS receiving $1,500 a year or more; 2,451 receiving $2.500 or proper finished diameter. Never use the more; 413 receiving $5,000 or more; 20 receiving $10,001 Box 5392, SCRANTON. PA. calipers to gage the diameter of the work or more; and 8 with annual Incomes of $25,050 or more. Explain, without obligating me. how i can quell!y for ha position, or In the subiec , belore which 1 mark I. when it is revolving, as it will spoil the ELECTRICAL ENOINEER CHEMICAL ENGINEER calipers or it may catch on the work, and Electrician SALESMANSHIP Note the number of I. C. S. Electric Wiring ADVERTISING MAN may cause damage or an accident. Fig. 11. Electric Lighting Window Trimmer shows a Students in your State Electric C. Running Show Cud Writer piece of metal turned down to a Heavy ElectricTralon Outdoor Sign Painter certain diameter and the manner of apply- State Number State Number Electr ".el Draftsmen EMIR OADER Alabama 13,920 Montana . . 11,700 Eleetele Peebles Designer ILLUSTRATOR ing the calipers in measuring it. Alaska 1,560 Nebraska. 18,240 Telegraph Expert DESIGNER Arizona 8,440 Nevada 4,600 Practical Telephony BOOKKEEPER This is the first job that the amateur Arkansas 8,600 New Hampshire 12,780 MECHANICAL ENGINEER se 6e6Trpht California. 80,840 New Jersey 63.566 Mechanical Draltsmo Cert. Pub. Accountant should thoroly master, and he will be sur- Colorado 35,060 New NOxico ...... 6.700 Ship Draftsmen Teal lie Management prised to see how much patience and time Connecticut 31,140 New York 217,040 Machine Shop Practice Commercial Lew Delaware .. 4,800 North Carolina 134,760 Gm Engineer GOOD ENGLINH is necessary to be given in producing a Dist. of Columbia.. 8,280 North Dakota 6,600 CIVIL ENGINEER Connue Scheel Sebieet. perfect piece of work. This is a funda- Florida 5,780 Ohio 116.200 Surveying end Mitering CIVIL SERVICE Georgia 5,480 Oklahoma 8,32u MINE I OKEM'N OR F.5n'It Reilw.y Moll Clerk mental job and it should not be overlooked, Idaho 10,720 Oregon. 15,800 STATIONARY ENGINEER Terme n er beeL Illinois 288,840 Pennsylvania 170,720 AOKItt'LTERE as a ...... ARCHITECT number of the most important basic Indiana 55,520 Rhode Island ...... 19,280 Arealteeteral Drafts... Nevlgalor q Spauhk operations are inherent in this first job. Iowa ...... 40,100 South Carolina... . 6,720 PLUMBING A N 11 HEATING PeoltryNeldeg hp Preeeb Kansas 86,000 South Dakota 6,760 Sheet Metal Worker Apter.Mier Renee

Each and everyone of the progressive stu- Kentucky...... x,780 Tennessee . 15.020 dents of "Experimental Mechanics" 11,860 Taxas ...... 30,520 should Maine .. . 22.480 Utah 16,420 Name try his hand on this work and in the Maryland 21,680 Vermont 7,850 Massachusetts. _. 83,040 Virginia 31.500 Present Seventh Lesson further interesting details Michigan ...... 68,040 Washington 37,160 Occopatlon_ as to "Metal Turning" will be given. Minnesota...... 32,480 West Virginia 24,680 Street Mississippi 6.100 Wisconsin 62,320 and No (The next installment will appear Missouri.. 53,010 Wyoming ...... 6.080 15,000 Total. 2,007,080 in an early issue) Navy City state

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www.americanradiohistory.com ELECTRICAL EXPERIMENTER September, 1918 The Manipulation of Glass Tubing in the Experimental Laboratory (Continued front page 324) around the short end before trying to break it has been cooled, it must be annealed. it, to prevent the glass from flying and This is done by holding the tube in the cutting you in case you have a bad break. yellow flame and keeping it there until it is Immediately after breaking, smooth off all thoroly tooted up. It may then be allowed sharp edges of the broken ends with short to cool on the ntat. Every bend of any de- quick strokes of the file. This is much scription must be treated in this way in quicker than rounding off the ends in the order that its brittleness may be removed. flame' and serves the same purpose. Never A bend which has not been annealed has leave glass tubing around the laboratory no strength. with sharp edges -file them all as soon To make wider bends a greater length as they are broken, and save yourself and of tubing must be heated. For this we use your friends from being cut. the entire length of the fish -tail bunter and Tubing larger than one -half inch in diam- proceed as eve did with the sharp bend. eter is somewhat harder to cut successfully. The greater the length heated the greater If one has a special cutter which will cut the curve to the bend. A sharp bend is not a groove around the inside of the tube it possible with large tubing. As a rule, the may easily be done. The best way, if no larger the tubing the the curve Have larger will Every Experimenter Should cutter is available, is to cut a deep groove have to be. Its bending large tubing care half way around the outside of the tube should be taken that the tube is very evenly CHEMCRAFT and then try and break it as with the heated thruout its circumference, otherwise THE BOY'S CHEMISTRY OUTFIT smaller sizes. It may or may not be suc- the inner part of the tube will buckle when cessful, depending on the quality of the it is bent. A bend of the buckled sort Chemcraft will be an endless source of infor- mation and amusement. With these outfits you glass. will not be strong, and will usually break can make inks, test your water supply and foods, Trying to cut very large glass tubing while cooling. make soap and fire works, prepare dyes and pig- without a special cutter is very unsatisfac- In making all bends these things must be ments and countless other interesting things. You can entertain your friends for hours with tory, yet may sometimes be accomplisht kept in mind and carefully observed. First, wonderful experiments In Chemical Magic and with a file and a hot iron. File a deep notch the tube must be evenly heated and heated it is possible to work out many new experiments at the proper length on the tube and then up gradually. Second, it must not be the instruction books. which are not listed in touch the red hot point of a spike directly heated too hot. Third, the bend must be CHEMCRAFT IS MADE IN THREE SIZES over it. Repeat until there is a tiny crack annealed by cooling it down gradually in No. I sells for 51.25 started. Then by repeatedly touching the a yellow flume until it acquires a coaling of West of the Mississippi and Canada, $1.50 tube just ahead of the crack with the hot soot. Fourth, the bent tube must be laid No. 2 sells for $2.50 iron, the crack may be led around the tube. down on the seat to cool. West of the Mississippi and Canada, 53.00 The tube is then broken and the edges Bends made in the above manner may No. 3 sells for $5.00 West of the Mississippi and Canada, $6.00 smoothed off. take a little longer to make than the ordin- If your dealer hasn't Chemeraft write for full The old method of breaking tops off ary rough and ready bends, but the ex- Information and the name of the nearest store bottles may be used to obtain large tubes perimenter will be amply repaid by the that sells it. from tall olive jars. Wrap several layers stability of the bent tubes, for the bend will of string around the jar and then soak the be fully as strong as any other part of the THE PORTER CHEMICAL CO. string in gasoline, alcohol or kerosene. tube. Dept. B, Hagerstown, Md. Light the string and just before the flame It can easily be seen that by varying the goes out plunge the jar into water. It length of the heated portion of the tube, ought to crack in a fairly circular line. If and by repeating bends any desired figure it does not, try until it does. Keep the jar may be made. In small tubing bends may turning all the time so that the heat from be made 360 degrees if necessary. In large the burning string may be evenly dis- tubing this is not practical and four right tributed. Tubes made from bottles of this angle bends will do the work as well. kind cannot be worked in the flame as they CLOSING THE ENDS OF GLASS TUBING. are made from too brittle glass, but are To close the end of a very useful in making certain kinds of glass tube properly the end should be slowly heated for a very apparatus, as for instance battery jars, etc. short distance only. While the end is melt- MAKING SIMPLE BENDS. ing down the tube should be continually Bends in glass tubing are progressively rotated so that the closure will be even. It harder as the tubing enlarges. The entire is quite a common mistake of many ex- success of the bend depends oit the handling perimenters to melt down the end until the of the glass in the flame. It is not enough glass meets-but the end is not fused. The to stick the tube in the flame and then bend glass must be firmly fused over the end or it when it gets red hot. A bend made in there will be leakage thru the minute hole this manner is not a good one, and will in the supposedly closed tube. You will break under the slightest strain. find that the closed end will be mach thicker To obtain a sharp bend, the narrow edge than the rest of the tube and will break of the fish -tail burner should be used, twirl- easily. These faults may be remedied by ing the tube rapidly until there is an even first blowing in the open end just as the reddish white glow around the tube at the glass fuses, and then by careful annealing place where the bend is to be made. The of the end by sooting. Ends are most tube must then be taken out of the flame, easily closed with a blast lamp as it allows .J Stop!! and immediately bent to its proper shape. the end to close quickly enough to prevent A bend of over 90 degrees cannot be made the glass from thickening. To obtain a If you are aiming for New York, in this manner. Also the tubing must not square end on a glass tube after it has fused, why not strike the center? This is be too hot or a poor bend will result. Re- it may be prest on a red hot plate and theft where the HERMITAGE is located. member in all operations with glass tubing annealed and allowed to cool. The sealing In the middle of the Times Square that it should be heated slowly, otherwise it of tubes containing liquids will be de- district. The HERMITAGE touches will crack. scribed later. elbows at once with the great amuse- After a bend has been made and before (See Part 11 in next issue) ment and business centers of the metropolis. POPULAR ASTRONOMY. Some astronomers have made attempts to modify the nebular hypothesis that has held Thoroughly modern and fireproof. ( Continued from page 311) Rates: $2.00 to $3.50 sway for so many years in order to make it ent members. Paths of comets pass around fit in with more recent discoveries but The Management of the HERMIT- angles others feel that a new theory is now re- super- the sun at all and some comets move AGE is now under the personal in their orbits from west to east while quired to explain the origin of the solar vision of its proprietor - others move in the opposite direction or system. Several theories have been ad- FRANK C. HURLEY, retrograde. The behavior of the asteroids vanced but no new theory has yet definitely and comets is not at all in accord with the replaced the famous nebular hypothesis of Formerly «ith .duditoriam and Chicago the noted French astronomer La Place. .lthletir Club. Chicago. the Denison theory that was, until recently, universally Hotel and Columbia Club, Indianapolis. advanced to explain the origin of the vari- (Next installment will appear in ous members of the solar system. October issue.) You benefit by mentioning the "Electrical Experimenter" when writing to advertisers.

www.americanradiohistory.com September, 1918 ELECTRICAL EXPERIMENTER 341 ALGERIA HAS IMMENSE WATER POWER SITES. A French engineer has found 35 localities can be constructed From Wining Bells to Chief in Tunis where dams that can be made to provide from 30 to 600 - horsepower of continuous energy. Electrician at 52OOaYear EXPERIMENTAL CHEMISTRY. (Continued front page 328) Wh a t Me n C an D o (b) Add some acid to the water. Notice the effervescence of carbon dioxid gas. (c) Boil some of the water in a beaker if They Mast er Electricity for 5 or 10 minutes. Notice the white deposit of calcium carbonat and magnesium Thousands of men fact this remarkable carbonat, which dissolved with effervesc- have the natural born Cyclopedia of Applied ence in acids. i "knack" of understand- Electricity explains 2. Chlorides, principally Sodium Chlorid. ing things mechanical. everything from wiring Determine the amount of sodium chlorid in Without the slightest bells to the newest dis- the water, as described above, using how- instruction, many of coveries in the electri- ever, only 5cc. of water for the test. dilut- them have learned how cal industry. ing it with a little Croton water (distilled to wire bells, and other These seven volumes water will give more accurate results). In simple principles of electricity. alone will enable anyone who has a liking this case the number of grains of salt per If these men only knew, they could for the work to master electricity and gallon is found by multiplying by 10 the quickly acquire a thorough knowledge qualify for the big positions open, or en- number of cc. of solution used. of every branch of electricity, rising to ter into business for himself. But with 3. Sulfates. -Test for these with barium the position of Electrician or Electrical the seven massive volumes, the American chlorid and hydrochloric acid. In most of Engineer. This is best illustrated by the Technical Society offers a full year's con- the common mineral waters this test will story of a young man in the Middle West sulting membership without extra charge. be very faint. who jumped from the job of wiring bells This entitles you to the advice and help to that of Chief Electrician at $5,200 a of a corps of electrical experts. Many 4. Iron. -In siphon waters and in most of the table mineral waters this element will year. men say this personal help has been not be present. \\'hen testing Saratoga This young man knew nothing what- worth hundreds of dollars to them, yet waters, however, or any others where even ever about the real principles of elec- it is yours free, if you act quickly. small traces of iron are present it is gen- tricity. He only knew that by putting The seven volumes are so valuable that erally possible to notice the brownish flakes wires and batteries together in a certain the publishers are anxious to send you of Fe,(OH)e floating in the water. way, he could make a door bell ring. He the entire set for free examination. You went from house to house getting odd need send no money in advance. Then, To prove its presence, add enough nitric jobs, repairing and installing door bells, if, after examination you decide to own make the slightly acid, warm acid to water and he earned anywhere between $12 this set send only $2 within a week after for a minute or two, and test for (Ferric) $18 a week. receiving NH.CNS. and the books, and only $2 a month Iron with This young man realized that the op- -an average of only 7c a day -until the 5. Calcium and Magnesium.-Add am- portunities in the field of electricity were special half price is paid. monium hydroxid, ammonium chlorid and as unlimited as the possibilities of elec- It is not necessary to send a penny in ammonium oxalat to some of the water. tricity itself. He figured that the electri- advance, Just mail the coupon below Result -precipitat of calcium oxalat. Heat, cal profession was in its infancy in spite and the books will be sent to you at once. filter carefully, and test the filtrat for mag- of the tremendous advancement that had The regular price of the seven volumes nesium with Na_HPO.. been made in the past few years. He is $35, but on the present special offer the found that there were unlimited possi- price is only $19.80 the PEROXID. for complete set, HYDROGEN bilities for positions which would fit any so you are getting a rare bargain. Re- Hydrogen Peroxid, H.O. was first pre- degree of ability he attained. He studied member it is not necessary to send any pared by Thenard in 1818, who named it the problems of electricity in his spare money now. Just mail the coupon. If "oxygenated water." Its occurrence in time and soon became switchboard man you like things electrical, there is no nature is not abundant, but it is sometimes for a telephone company. In a few brighter future in store for you than found as traces in the atmosphere, rain and months, he became Exchange Manager, through the development of your latent snow. and later Wire Chief. Leaving the tele- ability along these lines. To attempt to Preparation :- phone field, he engaged in central station master electricity without help is like try- dioxid work as an electrician, and was appointed ing to operate an automobile without in- Almost any acid acting on barium A short after (BaO.) will yield hydrogen peroxid, thus: operating engineer. time struction. With the help of these seven that, he was appointed Chief Electrician volumes mastering electricity becomes a BaO. H.SO. = BaSO, + H.O at a salary of $5,200 a year, fascinating and easy subject, Just mail Other reactions being: The man who has a knack for the the coupon below or copy it in a letter, Na2O. + 2HC1 = 2NaC1 + H.O simplest electrical operations has tremen- and the seven massive volumes will be BaO. + H,PO. = BaH PO. + H.O_ dous opportunities before him, if he will shipped for free examination. The year's BaO. + CO. + H.O =BaCOx + H.O. only develop this knack to its fullest pos- consulting privilege is free if you decide Hydrogen peroxid solution when used .for sibilities. And this is now made easy, to keep the Cyclopedia of Applied Elec- medicinal purposes must be as free as pos- for 27 authorities have placed their tricity. knowledge in seven massive volumes sible from soluble salts, especially barium, American Technical Society, and for this reason, only such acids as issued by the American Technical Society sulfuric and phosforic (usually both), of Chicago. Dept. E -3386, These seven splendid volumes contain which form insoluble barium compounds, CHICAGO, U. S. A. are used. over 3,500 pages and over 3,000 illustra- tions. Each book measures 7" x 10 ", and For bleaching, oxidizing, and as a pre- is 2" thick. Everything electrical is ex- servative agent, the Magnesium or Calcium plained in such easy -to- understand lan- AMERICAN TECHNICAL SOCIETY peroxid may be used in conjunction with guage, that it makes studying more like Dept. E -3386 such organic acids as give rise to harmless a game than like work. These volumes soluble salts, thus: tell all about Elements of Electricity, Chicago, U. S. A. 2C.H2O,H. + 3MgO. = Electrical Measurements- Underwriter's Please send Cyclopedia of Applied Electricity for Citric Acid Requirements- Theory- Calculation, De- seven days' examination. I to pay shipping charges. I will send 82 o within seven days and $..00 a sign and Construction of Generators - month until I have paid $19.8o or notify you and Mg.(C.HeOr). + 3H2O2 Dynamo- Electric Machinery- Lighting hold the books subject to your order. Title not to Magnesium Citrat Machinery-Power Transmission -Elec- pass until fully paid. Sodium perborat (NaBO.), when dis- tric Railways -Power Stations- Switch Name solved in water, forms the unstable meta - boards and Switching- Electric Ele- borat (NaBO.), which with the carbon vators - Storage Batteries - Electric Address dioxid of the water is converted into borax Welding and Heating-Electro -Chemis- and sodium carbonat. try- \Wire and Wireless Telegraphy. In Reference You benefit by mentioning the "Electrical Experimenter" when writing to advertisers.

www.americanradiohistory.com 342 ELECTRICAL EXPERIMENTER September, I 9 I 8

NaBO, = NaBO, -I- H,0, due to liberation of free oxygen, perhaps NEW OLIVERS 4 NaBO+ + CO, = Na,B.O7 -}- Na,CO,. as ozone. By using 14 grants of perborat for each Strong solutions bleach the skin white, as Free Trial -No Mooey Dowo 100 cc. of water, a 10 volume hydrogen well as bleaching organic pigments, hair, Latest Oliver sine- standard peroxid solution is obtained. feathers, bone, etc. visible, brand new. Direct from lactory to you, saving For preparing the medicinal yon., 551. Easy terms. The exact machine solution of hydrogen peroxid uoed by big busiuess. Over 600.000 sold. barium dioxid is first hydrated: Our startling_ "The nigh Cost of Type. -{- waters -The Bonex,m sad the Remedy" tells the Bat), H:O = BaO(OH)2 ,tor? Get your copy tarte). It is free. A 11W by slowly adding to it about machine for 549. This book leilc how pimple it Is to pet a new double its weight of distilled tinter for free Iris) -our low water, ice cold, and, after terms-a year to pay. Send for your copy today. standing about 30 minutes, either phosforic or sulfuric THE OLIVER acid with water is gradually TYPEWRITER CO. added with constant stirring, 67 -C Oliver Typrwriter Mt. keeping cold by employing ice, Chicago, IlL (60?) until the mixture remains slightly acid. It is then made neutral by adding more of the "I Would Not Part dioxid. Air or@aygen Properties: entrance with it for $10,000" Physical:- It is a nearly So writes an enthusiastic, grateful customer. In like manner testify over c o l o r l e s s (slightly blue in 100,000 people who have worn it. Con- quantity), syrupy liquid. [eoc ';sea' serve your body and life first. It possesses a metallic, cor- I;4g /3/ rosive taste, and pungent odor. The "Siemens" Ozone Tube. With a Little Ingenuity the The Natural It is miscible in water. Experimenter Can Make One. of These from Two Glass Test Tubes Cemented Together. Body Brace Its specific gravity is about 1.5. Overcomes WEAKNESS and ORGANIC AILMENTS of It volatilizes at about 84 degrees F. It also reduces, as well as oxidizes and is WOMEN AND MEN. Chemical :-It readily decomposes into a powerful disinfectant and germicide. Develops erect, graceful figure. oxygen and water, even when in dilute USES. Brings restful relief, corn. For fort, ability to do things. solution, especially if exposed to heat or . The chief use of hydrogen peroxid is as health and strength. M- sunlight. Concentrated solutions are' un= an antiseptic and germicide. While this is Wear It 30 Days Free etre!' stable, and slowly decompose, increasing in by far the most important use, the solution at Our Expense Also rapidity with rise of temperatures, and near' is employed sometimes by artists to renovate Does away with the strain and pain of standing and 100 deg. decomposition usually takes place; old paintings. Its oxidizing action adapts walking: replaces and supports misplaced internal organs; reduces enlarged abdomen; straightens and with explosive violence. it as a bleaching agent for cotton, wool, strengthens the back: corrects stooping shoulders: 2H,0, = 211,0 -I- O silk, ivory, hair, oils, etc. It is also used develops lungs, chest and bust; relieves backache, Explosion of concentrated solutions may for sterilization and preservation of foods. curvatures, nervousness, ruptures, constipation. Comfortable and easy to wear. also be caused by the introduction of solid It is employed in photography to remove Keep Yourself Fit matter or finely divided platinum, iron, the last traces of "hypo" from prints. Write today for illustrated booklet, measurement magnanese oxid, or carbon. Tests:- blank, etc., and read our very liberal proposition. It is one of the strongest oxidizing agents Upon the addition of hydrogen peroxid HOWARD C. RASH, Pres. Natural Body Brace Co. and antiseptics, and will even oxidize silver, to a dilute solution of potassium iodid con- 286 mash Bulldlne SALINA, KANSAS

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www.americanradiohistory.com September, 1918 ELECTRICAL EXPERIMENTER 343 taining starch, and a few drops of ferrous sulfate, a blue color will appear. The fer- rous salt is oxidized to the ferric state, which in turn liberates iodine from the Stlo o2tism potasium salt, to form starch iodid. If a few drops of chromic anhydrid Judged by solution, or potassium bichromat Results (CrO,) acid, added to hydrogen with sulfuric are BROUGHT to Its final analysis, every system of healing must peroxid, a blue color (of perchromic acid, be judged by the results It produces. I have been acclaimed H,CrO.) is obtained, which dissolves upon the most perfectly developed man by competent authorities. shaking with ether. with a blue color. I am the product of the system I teach. Thousands who bare fol- lowed my teachings have overcome weaknesses, eliminated dis- ease and attained health after all other means had failed. t Ozone have learned from Nature the secret of reaching. strengthening and developing the Internal muscles which control the function HISTORY. and nutrition of the vital organs. This enables the system to throw off impurities and disease. Thousands of my pupils have When a static electric machine is in voluntarily written me of the wonderful benefits they have re- are a few of their letters: operation, a peculiar and characteristic odor ceived. here The depressing metal symptoms 1 was down and out when I is present. It is also observed, to a slight of auto- intoxication disappeared started your Course 6 weeks ego. from the beginning of your Course. My Interest in life le returning. I extent, in the air after a lightning stroke. My color is now as It should he. My have clearly demonstrated my In- Van Marano, in 1785, described his observa- surplus adipose hen all dlsappaafed. creamed efficiency by vastly improv- 1 set sod feel like an entirely new ing the production records where 1 tions, and that he had obtained the same person, and my rupture is aotlrely am employed, and am accomplish- odor in the gas given off from the anode cured. My truss has been discarded ing twice sa much work sa I used since the third week of your Course. to. 1 have confidence In myself flow. when acidulated water was subjected to Considering the handicaps of ab Willis A. Casey. dentinal adhesions which I had and 12% Tafta St., Cambridge, Mass. electrolysis. Schönbein applied the name the fear of attacks which hung over ozone, signifying a smell. me and the limited exertions which I have gained in development. I was able to make io the begin- muscles are Orin and skin U cleared ning. I consider the results truly of all pimples. I feel a different PREPARATION. remarkable. men resolute, able to meet the Drifts, Pa. Cornelius B. Kunkle. world. 1 will do any hest to imbue in other weaklings with the greet bless- Ozone is evolved at the positive pole I have gained eleven pounds. My huts to be obtained through Strong- the electrohsis of water acidulated with nervousness has entirely dlsappeantl, iortlam. my strength has Increased five fold. George Fair. either sulfuric or chronic acid. grown threequarters of an Inch Centertos. lid. taller and my shoulders have broad- It is also formed by the silent discharge' ened nut. Ms mental energy has I hava improved wonderfully in 131,. increased wonderfully; I never feel every corner of my body and have of electricity thru air or oxygen. Fig. tired; am full of "pep" all of the shown a big Increase In chest ex- shows a tubç known as Siemens Ozone limo, and last I em much happier Dangle*. I em perfectly satisfied. 1 than I used to be. 1 might add have palmed Mean pounds and feel Tube" consisting of a glass tube covered that I eat about half the food that one hundred per omit. alive. with tinfoil, which is' placed inside of a 1 used to. stick to Strong - Rudolph Oros,, Jr. fortism as long as I live. 15 William St., New York City. larger one covered on the out -side with Harold McCullough. 262 Main St., Petaluma. Cal. I don't know what to say to jus- tinfoil. The outer and.infier coatings are tify the condition I feel I am lo. coil Never even as a boy have I possessed connected to an induction while a cur- Oh what a change. My face is no wonderful longer greasy and has Mat Its sal- such feeling of vigor and rent of air or oxygen passes thru. strength as 1 do now. lowness. pimples. bolls and black- Henry is when is per- heads. Am rapidly takiog on the B. Freeman. It also obtained phosforus healthy look and color. My ayes Ill Clinton St.. N. Y. City. mitted to slowly oxidize in the air, or when Sr. petting strainer. Another thing I want to say that your I have noticed Is ally disposition: Course oxygen is past over pieces of moist phos- to has dome me a world of geed. I before starting with you I went wish I had known about It years f orous. work with a grouch, now it la quite ago. I am a happy man today. the reverse. 1 go to work whistling Henry Plater. and humming. and could shout for 1121% Jackson SL, Seattle, Wash. PROPERTIES. the pure joy of living. All this Is due to your efforts, for which I Y. M. C. A. With the Colors. Ozone is a colorless gas with a peculiar thank you. F. A. Hall. Rome time ago I bought a Course 65 lilt. Royal Ave.. W.. Mootrea l, you had made up for me on in- odor, such as is noticed about moist phos- Can. creased height. It certainly has forous. It reverts very gradually into done the work. So far 1 have pained ordi- is It so, or am I dreaming? Here 2'/a lychee. Tours truly. nary oxygen, which change is hastened upon are soma of the results that are un- Chas. H. Runkel. deniable. I have the Most bowel Camp Meade, Maryland, Md. heating. Ozone dissolves readily in the action that I remember la years. volatile and fixt oils, and at 12 degrees every day sure 'fine and easy sa Your Course has done for me you say, 2 each day." I don't hava what you claimed It w cold water dissolves one -half volume of the gas, to arise at night any more to urinate strengthened me both physically and which is since starting with you. Before it mentally. It has put me on the solution gradually converted into was a nightly occurrence, and moms- right road to MANHOOD, and good oxygen and hydrogen peroxid, thus: times two or three times. I alee, living. I sbell never indulge n that well now, and the beauty of It Is HABIT again. Thanking you a H2O 4 0, = O,+HrO, that I am waking up more refreshed thousand times. Yours, In the morning than for years. (Name Withheld on Request.) It bleaches organic colors, such as indigo, Every time 1 get through with Me Watertown, N. Y. lessons I feel like a young home litmus, etc., phosforus, sulfur, arsenic, and turned loose and then I have more I bare not a bit of trouble from all metals, excepting gold and platinum, are Pen -Nerve, it seems like, since Indigestion or constipation now, and Fb'e-1 was a boy. I am actually getting am 2 pounds heavier than I was converted into their respective highest LIONEL STRONGFORT young again. I am amend, delight- three weeks ago. oxides, ammonia being oxidized to am- The world'. strongest and meet perfect ed, at the improvement. Alliance, Nehr. Boyce Hamilton. athlete. whose unaccepted challenge O. M. Mitchell. I feel 100-%better now. The monium nitrat. Silver is blackened thru et competition to the greatest living Y. 51. C. A.. South Bend, lid. quality of the muscles has Improved "strong men" still studs. very much. A. J. Loyka. the formation of black silver peroxid, and Cedar Since I joined the army, where you have to look out for yourself, 1 have Rapids, Iowa. lead sulfid is converted to lead sulfate. found that the training I bad from you bee put me in a place where I can Before taking your Course I was Detection :- TAKE CARE OF MYSELF. When they ask me where I got my strength a physical wreck. You have done from I say. from the finest man 1 have ever seen, and that le Lionel Strong. wonders for me. I have passed the (1) Paper moistened with potassium fart, mid I believe you are for 1 was under two physical culture directora examining board for Military Duty befor,, I took your Course. as physically fit. Leave for camp In iodid solution and starch paste turns blue Pte. Joseph Atherton. a few days. when exposed to an atmosphere of ozone, On Active Service. American E,ped. Force, Feb. 24, 1518. \Willis E. Bacheller. thus:- Jennings, La. 2KI H_O + O, = 02 + 2KOH - I, Seek Help Where It Abounds 1 ------It fa an axiom to law and science that the testimony Other oxidizing agents, as chlorin, bromin, of several reliable witnesses establishes a fact. The FREE CONSULTATION COUPON nitrogen dioxid, also produce this reaction. FAITS in regard to Stmngfor(i,m have been proven Mr. Lionel Sroogfort Newark. N. 7-Please beyond ell question by thousands of send me your book- "PROMOTION AND CON- (2) Paper impregnated with a tincture of is a burden s because e of SERVATION OF HEALTH. STRENGTH AND weakness. or you are ham- MENTAL of which I en- guaiac, and moistened with water, turns pered as the result of dis- ecents nR stamps. I haveemarkede (x) be- ease. let the above letters, fore the subject in which f em Interested. blue. the sincere expressions of graeful hearts. taint you . Colds ..Stomach ..Despondency (3) The bright surface of silver is black- to Strongfortlsm -your Sal- ..0 Disorders ..Round Shaul- ened by ozone; no other oxidizing agent vation. Take heart. Nature . Asthma ..Constlpallen den cannot fall. . Obesity .. Biliousness ..Lung Trouble. producing this effect. Send for My Free Booklet .. Headache .. Terold Liver ..Increased Paper "Promotion and Conserva- ..Thinness .. Indigestion Height (4) moistened with a solution of tion et Health, Strength ..Rupture ..Nervousness ..Stoop Shoulder, t e t r a- methyl -diamido -diphenyl -methan in and Mental Energy" will ..Lumbago ..Poor Memory ..Muscular tell you all about the ..Neuritis ..Rheumatism Development acetic acid, gives a violet color with ozone, ..Neuralgia ..Impotency ..Great Siren th quick. easy. simple Strong- ..Flat Chest ..Vital Lewes ..Weight Lifting yellow with nitrogen deep blue fort way to get hack the dioxid; with buoyancy of youth. whether ..Deformity ..Youthful Errors ..Advanced Course bromin or chlorin; and no color with hydro- you have loin It Iw burning the cantle at both ends or .. Intemale) ..Heartweakness Barbellelght gen peroxid. are simply weighted down ..Short Wad ..Poor Circulation . Professional with years. I will send ..Flat Feet .. Skin Disorders Training Uses:- you a copy FREE. on re- t665) ceipt of three 2e clamps to Ozone is employed in industrial bleaching rover packing and rows:.. processes; for the destruction of fusel oil Name in alcohol; for the cleansing of wine and LIONEL STRONGFORT beer flasks; and, for the sterilization of Physical and Health Specialist I Address water. 665 Park Building Newark, N. J. I (To be continued)

You benefit by mentioning the "Electrical Experimenter" when - 'lug to ad:erasers.

www.americanradiohistory.com 344 ELECTRICAL EXPERIMENTER September, 1918

EXPERIMENTERS! ATTENTION1° "ELECTRO" LOUD -TALKER We present herewith two little instruments for which enamel wire for five ohms, standard with our Detectiphone. we have had a long and persistent demand. This instrument works best on four dry cells, and par- This outfit has been gotten up solely for the Experi- ticular attention is called to the fact that in order to work, ....menter and for this reason we are selling it "'Knocked the loud -talker requires a fairly heavy current and for that Down." In other words, the instruments come all ready reason thick wires must he used for connecting the trans- for you to assemble, all the parts, screws, nuts, washers, mitter with the loud -talker. If this is not done, the voice etc., being furnished. Complete directions bow to assemble will be weakened considerably. If no heavy wire is at accompany each set. With a pair of hand, more batteries must be used pliers and a screw- driver, the outfit to compensate. can he readily put together in less USES: This instrument can be used to than twenty minutes. transmit phonograph music from one room to another; used as a Detectiphone; as a Radio is that Amplifier; as a telephone extension (by plac- The most important point ing the regular telephone receiver against the the telephone receiver spool comes sensitive transmitter with the loud -talker); already wound complete, and the for salesmen to talk "through" window Experimenter will, therefore, not (Loud -Talker outside In street, microphone transmitter for salesmen, talking Into same) ; need to wind his own spool. for restaurants for talking to the chef, and a hundred other uses. Many young experi- The outfit when assembled com- menters are developing a lucrative business prises a highly sensitive CARBON selling this appliance to various merchants GRAIN MICROPHONE with carbon at a good profit. same type Outside of the two instrument parts, one diaphragm of exactly the three -foot cord is furnished with sensitive as is used with our $15.00 Detecti- microphone as shown; instructions, etc., are phone. (See our Cat. No. 19.) furnished. No. AEK204 " Electro" Loud- f The receiver is a special low re- Talker Outfit Parts "Knocked $ sistance double pole type with the Down," complete No. CEK205 "Electro" Loud - difference that no magnet is used Talker Outfit, same as above in the same for the reason that the except that it is already as-rp of this instrument is elec- and tested at factory 41 function Set complete tro- magnetic, the same as all loud - 3.5U talking phones. Shipping weight 2 lbs. The spool is wound with special Immediate Shipments

S. O. S. ! ! A REAL ELECTRIC Learner's Telegraph Outfit for 25c Prepaid 15 of its ex- If the telegraph does not : In the years STRONG come up to expectation istence our company has O MTMAGNET will cheerfully r e f u n d never offered such a bar- J one. money. Boys order 6 to 25 gain as the present of instruments. Sell Just think of it, a real these learner's telegraph I like hot cakes to friends electric for 30 to 40 cts. each. So outfit with which to learn I or to telegraph to I small can be slipped into the code I=00 aSE1 pocket. THE your friend six blocks INICKEL BINDING ROSTS= =0 LEARN .ear- as - CODE DURING SPARE away, for 25 cts.!! Impos- sible -you say. Quite so. TIME. TELEGRAPH OP- cost, ERATORS ARE SCARCE. We do sell them at THOUSANDS. but we do it solely to get you acquainted with us and UNCLE SAM NEEDS in your bands. And if Important. As this telegraph is sold at cost, we place our wonderful catalog order (hy refund- this telegraph pleases, you will order other things reserve the right to decline your has a red -lacquered wooden ing the money) unless you order one of our free from us. This telegraph at the same time. Should you base, strong electromagnet, nickel binding posts, Cyclopedia Catalogs generous telegraph knob and nickel clicker. Tele- already have our Cat. No. 19, it is necessary to cut out the coupon, writing across it: I have Cat. No. 19. graph measures 31/ x 11/2 x 11/2" over all. Full direc- learning the code, and a fine CODE CHART This is done for the guidance of our catalog checking tions for Of course, if you have Cat. No. I9, you go with the telegraph, all packed in neat box. Tele- department. graph works easily on a single dry cell. Two instru- need NOT send for it again. We are prepared to 1111 orders for 10,000 of these tele- ments may be ordered for 50 cts. if wanted, to graphs this month. They are in stock NOW. Your order or two bouses. 12 hours. 25c telegraph between two rooms will be filled within 25c ta MEN MM MI= t ta "THE LIVEST CATALOG IN AMERICA" ELECTRO IMPORTING COMPANY 231 Fulton St., New York City Our big. new electrical eTelopedia No. 19 Is waiting for you. Positively the most corn- 111 plde Wire/tas and electrical catalog In print t «lay. 200 Mg Paaes. GOO dlástrstlnne. 500 Instreata and apparat. etc. Big 'Treatise on Wireless Tetearaphy." 20 FREE cols- 1 enclose herewith 6 cents for postage In stamps or coin pons for cor 160 -cage FREE wireless L'ourse In 20 lessons. FREE Cyclopedia No. 19 1 for which please send me your latest Cyclopedia Catalog 19 described. III measure, íaY.S", %height t.4 lb. Beautiful stiff covers. No. u "THE LIVEST CATALOG IN AMERICA" sr IIII Now before you tom this page write Your name and address on coupon at right, eut NAME var out. enclose 0 eta. stamps to cover man charges. and the Cyclopedia U yours by return mall. ADDRESS THE ELECTRO IMPORTING CO.. 231 Fulton Street, New York City "Everything for the Experimenter" STATE I E. E. 9.1Fß ....You benefit...... by mentioning the "Electrical Experimenter" when writing to advertiser,.

www.americanradiohistory.com September, 1918 ELECTRICAL EXPERIMENTER 343 The Einthoven Galvanometer, Its Theory, Operation, Construction. (Continued from page 319) No. 30 drill, and are used to take out the as a means of supporting the viewing tele- leads from the winding. The core between scope. Their details are given in Fig. 9. the bobbin ends is carefully shellacked and The telescope hole is drilled to receive a covered with two layers of paper for in- three- eighths inch tap. This should be of sulation. The bobbin is then wound evenly, No. 40 pitch thread. full with No. 24 double cotton -covered mag- The movable wire- supporting stand 7, is net wire. The leads are carefully removed made as shown in Fig. 10. It is composed from both ends and properly secured so as of a solid brass rod three -quarters of an to prevent them from breaking off at the inch in diameter and cut to size with two ends. The magnet yoke 3, is made from 8 -32 tap holes at each end as indicated. wrought iron bar and its lay -out is given This is secured to the wood base, and a pro- in Fig. 7. It is very essential that the drill- jecting arm 8, Fig. 11, is used to support ing should be very accurate and dimensions the wire containing tube 10. It is made carefully followed, as the accuracy of the from stock brass measuring 3-5/8x7/8x3/8", whole instrument assembly depends upon and two holes are made at each end, one the drilling of these few holes. After the %" and the other with a No. 18 drill, as coils are wound they are then set in the shown in the figure. A tension controlling respective holes in the yoke and firmly tube 10, is inserted in the 4" hole, and this secured therein by set screws or by a close is made as indicated in Fig. 12. The 4 -32 fit. tap hole is used to secure a notch piece, The $95 an Hour! active magnetic pole pieces 5, 5, are Fig. 13, to prevent the tension rod Fig. 14, used for concentrating the magnetic field in from turning when it is tightened or re- "Every hour I spent on my I. C. S. the string region, and Fig. 8 shows their leased. This rod is made from a No. 10 Course has been worth $95 to me! My construction. They are also made from soft brass rod. One and one -half inches from income, my wrought position, my $5,000 a year iron. Altho their shape may seem the end, cut a. three-sixty-fourth inch slot, home, my family's happiness owe it all peculiar, yet it was found thru actual test three- sixty- fourths an inch -I of deep. This to my time training with the Inter- that the magnetic field was strongest with can he done easily without either a shaper spare this type of construction than with any of or milling machine, by taking two hacksaw national Correspondence Schools!" the others that were tried. These pole pieces blades, and securing both of them in the Every mail brings letters from some of' are fastened to the electro- magnet pole hacksaw frame. Care should be taken that the two million I. C. S. students telling of pieces by means of 8-32 set screws as noted. the teeth of both be in the same direction. or increases in salary as the Two auxiliary promotions pole pieces 6, 6, are used to The rod should be firmly secured in a vise. rewards of spare time study. increase the magnetic path service and also (To be continued) What are you doing with the hours after to let them slip Deflection is mm. I mm. dcfl produced by supper? Can you afford by unimproved when you can easily matt^ Material of Diameter of Reaieunce Period io Magnifica- Factor of Fibre Fibre io ohms eccooda lion Per Per Merit. them nican so much? One hour a day micro. Icro. micro-ampe. microvane amp rvolt spent with the I. C. S. will prepare you for the position you want in the work you like best. Yes, it will! Put it up to us to silver wire 0'020 mm. 47 - 500 4.4 0.94 2.3 . 10 -' l -07 - Silvered quartz flora 0002 nom. 20,000 - 500 62,500 3.13 1.6 . l0 -r 3.2 . 10-' - prove it. Mark and mail this coupon now! 0'003 mm. 6600 -t 650 333,000 50.5 3 s 10-' 1.98 . 10 -' ------vapour - - - ., 0002 mm. 5860 0.008 750 30 0 -005 3'3 . 10-r 2 . 10' 117,000 INTERNATIONAL r SCHOOLS- .. ,, 0002 mm. 3890 0005 750 H 0003 1'03. 10-' 4 .. I(F 117,000 :' BOX 5393, SCRANTON. PA. Explain, without obligating me. hop' I can qualify for the position, or In the subject, before which 1 mark X. POPULAR DEMONSTRATION OF esting experiment at a distance of 41 miles. ELECTRICAL FNMA ta.R CHEMICAL ENGINEER Electrician SALESMANSHIP THOUGHT TRANSFERENCE EXPERIMENT 11. -Showing the effects of Electric wiring ADVERTISING MAN AND OTHER PHENOMENA. concentra ed thought. When sudden con- Electric Lighting Window Trimmer Electric Car Running Show Card Writer (Continued front page 304) centrated thought (arithmetical problem) is nn Outdoor Sign Painter To note the action on the pulse over a executed, some agents may influence the ElectricaleDralDraftsman RAILROADER Electric Machine Designer ILLUSTRATOR Treat distance, suspend a coil of wire from pulse but all may do SO if RED MATERIAL is Telegraph Expert DESIGNER a PraeucN Telephony ROOKN.EF PER room fixture (aerial) and to the latter placed on the agent's head. Mechanical t.aftsEFIl Stenographer and Trol,t connect a wire (see experiment III and Fig. Note the influence of different colors Mechanical Draftsman Cert. l'ut' Accountant Ship Draftsman Traffic Manngt ment 3) with the pit of the stomach of percipient on intense thought or willing by the agent. Machine Shop Practice Comme retal I. aw (over the clothing). If the agent executes RED and YELLOW increase and PURPLE de- Gas Engineer IGOOD ENGLISH CIVIL Common School Sableet. willing at a distance (in the percipient's creases the effects on the pulse. Surveying and Mapping CIVIL. SERVICE Clerk the may EXPERIMENT I I I.-Showing that cotFCen- MINE Olt I Wit Railway Mail direction) latter be informed over STATION eltlARE l.\OI \l F.It Textile O. er,eer or Sapt. the telephone the moment he wills by an- tration of the mind is literally true. To ARCHITECT A g utlt'l' lit' Ill: Architect or al Draftsman Navigator anl.h other who announces the fact the moment prove this brain focusing, let the agent con- PLEMPI MI A511 Ill l'oon'y Robing French the pulse of the percipient is retarded. centrate the mind on one of several wooden SheotMetal Worker otemohtle. Itallao I have successfully conducted this inter- or paper objects in the room. One end of a Name - Present Occupation YOU HAVE A BEAUTIFUL FACE Street BUT YOUR NOSE ? and No

WANTED - Railway Mail Clerks $1100 to $2000 year Franklin I "stitute BEFORE AFTER Dept- T 102 Common t:t:uca- N. Y. IN THIS DAY AND AGE attention to your appearance Permit no one to ee you looking otherwise: It 1111 Iolure fion Sufficient Rochester. is an absolute neeemlty If you expect to make the moat your welfare! [Trott the Impression you constantly make Simi out of life. Not only *Mould you wish to appear u rests the failure or success Of your life. wtdch is to be Sure pay. O' (1) DledanllwaythMali Clerk attractive as posalble, for your awn self- satisfaction, your ultimate des My My new Nose-Shaper. "'Mews" Life job. Examination questions: 121 ached - which Is afore well worth your efforts, but you will find 24) corrects nowow ill- shaped noses without opera- Ja the world in general Judging you greatly, If not wholly, tion. quickly, ear 1y and permanently. Is pleasant and Pull unnee- CO Govern entt comingceexxuÑeátionss: (31 by your `look*, therefore tt pays to 'look your beat" does not Interfere with one's daily occupation. being wom essart'. lint of other government lobs now open, at all times. at night. : ' and (4) free book deecnbtog them. Write toddy for free borkld, w5ich (ells you how to correct ill shaped nom wt(hou( cost if ne( satisfactory. NAME TRI LETY, Face 1038 Ackerman Bldg., Binghamton, N. Y. M. Specialist AI)DRF,';Q You benefit by mentioning the "Electrical Experimenter" when nvitit g to advertisers.

www.americanradiohistory.com 346 ELECTRICAL EXPERIMENTER September, 1 9 I 8

wire* (A) is connected with the percip- "Supremacy ient and aerial and another wire (B) is connected to the aerial (Fig. 3). Learn Aviation Mechanics in the air Fig. 3.- Showing connections of wires Train yourself for the Aviation Service by availing yourself of the Preparatory A and B. A, is connected to aerial and Ground Course in Aviation Mechanics, affording preparation prior lo entering the Key to Government Ground School. covering aero- dynamics, nero- engines, rigging and stomach of percipient and B, to aerial with Lewis gunnery. Previous experience unnecessary. Victory!" one end for touching objects or for use in

1 °eluding a e r o- studying gravitational energy. Wires may COMPLETE COURSE engine course, WE ARE THE PIONEER AVIATION SCHOOL be hooked directly to a fixture. taken 1n six weeks (three hours daily) or An independent person now touches three weeks (six hours daily) $60 with the other end of wire B, the several objects in succession. The moment the object on Special Aero- Engine Course $35 (;«ks) which the agent has concentrated is touched, the effect on the pulse may be noted. Per- Wireless Course (we $25 mit the wire to remain in contact with each ks) object for several seconds. Write for our Illustrated Booklet "II " -"A Message Telephone Bryant 9078 to You on Aviation" 110 -114 WEST 42d STREET, NEW YORK EXPERIMENT IV. Proving that good thinkers use two sides of the brain and that ordinary drinkers use only one side. Genius is a matter of bicerebration. Use two wires as in experiment III. While the agent is engaged in some mental arithmetical prob- For lem (addition or multiplication), an inde- Home pendent person places one end of the (B) wire in contact with one side of his head Use (5 inches) directly above the extreme upper Violet Rays end of the ear). If there is no pulse re- sponse try the other side. Note that, in Wonderful HEALTH and BEAUTY GIVER the good thinker, there is a pulse response from both sides of the head whereas in the ordinary thinker, the response is from Electricity from your light socket transformed into the one side only. Reliera greatest health -giving agency to Science VIOLET known - EXPERIMENT V. II is said that the secret porc(; . RAY -powerfully effective, yet soothing and gentle in rn OOtafista of gravitation is the greatest problem still ec action. Benefits of tremendous voltage of electricity ab- unsolved. Prove the correctness of the erre.i.e. ed, sorbed by the human body without the slightest shock, author's theory, viz., that, A gravitation muscular contraction or pain of any kind; pleasant and 1o°edr 4./ is an electrical attraction and that the perfectly safe. ether is in itself an electrical charge of positive and negative electricity; that B stars. the ether's composition is derived from the radioactivity of all substances in the RenuLife Violet Ray universe. Wonderful Use two wires as in experiment Ill. Beautifier Place wire B on the floor and note each Brings the glow High Frequency Generator time a heavy body is raised, the effect may of health- be noted on the pulse. The shearing of the ful beauty to Used endorsed by physicians beauty ether's electricity into positive and nega- the complexion, and and specialists; removes blem- saturates the body with soothing, invigorating, curative tive may be demonstrated by bringing the ishes, pimples, violet rays, producing New Life, Power and Beauty; end of wire A in contact with the VAGUs warts, etc. purifies the blood stream and brings the circulation to NERVE (instead of pit of stomach) as in parts treated, renews and builds up. experiment VII. Note that, by the latter maneuver, at the Every home should have this mar- symptoms while steadily removing center of gravity of the raised object, the 'ciao; invention; benefits every per - the cause: bringing back normal son in sickness or health: smallest conditions. electricity is negative and positive, on either infant. aged or feeble. It is not side of the gravitational center. cure all-but treats success- fully a wide range of ailments EXPERIMENT VI.- Showing that personal because it is systematic magnetism has a literal significance. That in effect-relieves the radiations arc constantly emanating from our bodies and that temperamental indi- viduals discharge radiations of great inten- LOWEST PRICE sity. That the "laying on of hands" in the This is the lowest priced. most cure of disease is not mythical. That tele- effective instrument of its kind in kinesis (movements of objects without con- the world, guaranteed. Price so low tact with the mover) is a reality. That the that no family can afford to be Use without it. effects of human energy may be exerted at reai a greater distance in a dark than in a light Get Book "Health" explains why in ma- : At Home FREE room. The latter fact Successfedly You Send for our booklet "Health" tell- terialization, a dark séance room is de- the benefits in th- r ing in detail the. ssonderfut story of manded for better propitiation of the spirits. own home here, , wcur- the Violet Rai -- Prove that telekinetic and kindred pheno- Rheumatism able through cost- ly treatments. mena are dependent on a compound of the Neuritis RENULIFE ELECTRIC CO., elementary consciousness of the "sitters "; Lumbago each sitter enters as a dynamogenic ele- 538 Chest Pains ment (production of nerve force) in the Marquette Catarrh production of energy. Bldg. Approach the percipient with the ex- u Headache one hand directed toward Detroit, tended fingers of Ear Diseases the pit of the stomach. Note the retard- Mich. Hardening of Arteries ation of the pulse. Note that temperamental Wrinkles persons can exert this action at a great dis- WANTED tance whereas others can only do so when Skin Diseases the are almost in contact with Alen and women finger tips Falling Hair representatives to the pit of the stomach of the percipient. demonstrate to Etc. Etc. doctors and In- Note that when the finger tips of both dividuals. Earn 850.00 a. week up. ti'ith all experiments with wires A and B the Treatment Chart We give full tn- latter should be insulated. excepting at the ends in atructloas. o e t . furnished our proposition. contact with aerial and pit of the stomach of per- showing to the latter with a cord g. cipient. it can he fixed use for over 100 SOLO ON (over clothes), fastened to the skin with plaster or 1 ailments. LIBERAL held by an assistant in such a way (also wire B) TRIAL PLAN that the insulated portion of the wire is grasped with the finger ends directed away from the pit of the stomach (Fig. 3).

You benefit by mentioning the "Electrical ExPerinienter" when writing to adveriiters.

www.americanradiohistory.com September, I918 ELECTRICAL EXPERIMENTER 347 hands are extended at the latter site, no THE GYRO -ELECTRIC DESTROYER effect on the pulse can be noted until one -ONCE MORE. hand is removed. The human is essentially (Continued front page 313) a battery, from the finger tips of one hand I urge you to make the attempt. You positive electricity is discharged and from have the and it won't cost a the other hand, negative electricity. One journal, lot to make the attempt. The electricity neutralizes the other and there whole result might astound you, and if our is no energy evolved until one hand is re- struggle moved. joint efforts could shorten this one month even, the money would be The radiations the hand cause a from well spent. contraction of the heart (reflex) which is \Vhy not go to it? practically telekinesis on a small scale. Note \VOLFE, that, with subdued light the energy from CHARLES S. 1200 Stambridge St., the finger tips, has a more accentuated Norristown, Pa. action on the pulse at a further distance than in the light. All of the letters received read prac- Man is a transformer of energy which tically alike, but the strangest part about he receives from his environment. Note the whole matter is, that altho in cor- that the pulse effects are greater after ex- respondence with certain U. S. Senators, posure of your body to an intense light or a to whose attention I had brought the Gyro - current of electricity than before. Electric Cruiser, I had never thought about Note that when several persons grasp building a machine and subsequently turning hands and one of the persons presents the it over to Uncle Sam. Be a Doctor of fingers of his disengaged hand at the pit But, ExPERU MEN TER readers evidently of the stomach of the percipient a greater know and sense more than I, yvitll my nose affect is noted. to the everlasting grindstone, so if my Chiropractic EXPERIMENT VII. -Showing that polarity reader -friends desire to wish a new job on Build a socceasful career in tbia great rofes- sion- Chiropractic, the advanced ecieneeof treat- is not the exclusive'prerogative of magnetic me -well I can only say that they will find ing disease through spinal adjustment. The de- materials. On either side of the wind -pipe me ready. mand for Chiropractors is conatantly increasing. In larger numbers than ever before intelligent. in the neck, (Fig. 4) are the right and left It is quite an idea at that, and I am glad thinking People are becoming convinced that it is pneumogastric nerves. \Vhen these nerves me. I'd much the common sense and really scientific way to re- it did not originate with lieve pain and tseaee. are stimulated, the needle movements show rather have the "other fellow" endorse the We teach you by mail or in clam less amplitude and when they are deprest scheme. earn Instruction under the personal of a faculty of compe- the movements show greater amplitude. Besides, Readers, wouldn't it sound good Aa Horne tent, practical Chiropractors. You can master this good paying profession and Fig. 4. -Lines indicating the site of the if, after the War, we could say, casually: graduate with the degreeof Doctor of Chiroprac- right and left pneumogastric nerves. "The Gyro- Destroyer? Oh, yes! My tic while holding your present position. No special Preliminary study and no more than a common Take a bar -magnet (held at end with dollar went into the first one -and that school education are required. The coat is small fingers at right angles and directed at a dollar proved SOME fighter!" -terms easy. right angle) and note the following effects Here's my plan: A small model about on the amplitude of the needle: IO feet high will cost about $8,000, figuring $3000 to $5000 aYear labor, engineers, shop equipment The success of many Chiropractors bas come so materials, quickly as to be almost startling. Incomes of MALE. to build it, etc. A half "life" size model, f ni Á3000 to 58000 are not rare -nome upwards (20 feet high) might cost as much as $20,- of 510.000 a year. Dr. M. D. Moore. of Kentucky Nerve reports $9000 a year; Dr. L. If. Roche, New Jersey Right Pneumogastric - 000. But what is that for 100,000 readers? $5000; Dr. Hanna of Florida, over $51X5. You will receive the saem kind of instruction which these Positive pole (N) Increases amplitude Let every reader send in his contribution of Chiropractors received. Your provecte will be as Negative pole ( Decreases amplitude he can afford and we bright as theirs. There Is no reason why you -) any amount should not do as well or better. will build whatever size model the and printed Left Pneumogastric Nerve- amount received enables us to. FREELitbogrephed¡ lore. Actual value. total 131.50. o thisoferyou get Positive Decreases amplitude If every reader contributes $1.00 we 22 Charts tbem ell free. (fend coupon for facts about this free offer- s1sa72- Negative Increases amplitude can build a complete and full size page Free Book which telle all about la ursctie Destroyer to turn over to Uncle Sam. and de wonderful This ie youry big opportunity to enterter a dignified profession. be FEMALE It is self- understood that 1 must account your own bosom be occupied in pleasant, profitable work and become independent. Mail coupon today. Right Pneumogastric Nerve - for every cent taken in as well as spent. Positive. pole Decreases amplitude Each contributor's name will be printed AMERICAN UNIVERSITY n Negative pole Increases amplitude in the magazine, as well as a final state- Manierre Bldg., Dept. 299 Chicago, Ill. ment showing how the motley was spent. Without cost or obligation send me by mail. $5,000 is taken in the money your new il: strated 72.page book and your Free Left Pneumogastric Nerve - If less than Charts Offer. Positive Increases amplitude will be returned to its owners. If a suffi- amount is collected a real working Negative Decreases amplitude cient Name model will be built as fast as it is possible, Note that the foregoing refers only to while EXPERIMENTER readers will be kept De- Addreae the normal male and female. If, in a male informed as to the progress of the stroyer. or female, the polarity is reversed, the male te as it is completed it will be SL- would react like a female and vice versa. As soon n neonJ Sexual inclination is a matter of polarity formally turned over to the War Depart- and its determination may thus be demon- ment in the name of the readers of the strated. A mistake in your deduction is a ELECTRICAL EXPERIMENTER, while a printed 7 serious matter. Note that the extended list giving the names of the contributors SIGNAL CORPS -NAVY- AVIATION same finger tips of the right hand of a normal will be furnished the officials at the still need great numbers of male directed to the pneumogastric nerves time. case. act like the positive pole of a bar -magnet Now you know the arguments of the RADIO OPERATORS whereas the fingers of the left hand act like Judge for yourself. But before I close re- Importent and pleasant :work the negative pole of a like magnet. The member that in the February issue, for Special Courses for Men Subject :to;Draft opposite holds good in a normal female. military reasons, 1 did not divulge certain great Hundreds have been trained HERE Note that YELLOW MATERIAL on the head or important features which tend for Modern Equipment -Low Rates body of a normal male or female will re- efficiency of the destroyer. I furthermore Gymnasium- Dormitory verse the polarity of their finger tips. That did not divulge a very important protective START TRAINING TODAY is, the male will show female and the fe- feature, to prevent the Destroyer from be- ing bombed from aeroplanes above. All of Write or call for male, male polarity. illustrated booklet COLOR may thus influence sex tendencies. these features would of course be incor- Show effects with the positive or negative porated into the model, and as we would Y. M. C. A. Radio School end of any dry cell like with the magnet. no doubt be able to obtain Government 145 E. 86th St., N.Y. 'Phone Lenox 6051 Many other interesting experiments will sentries to protect the shop while the model suggest themselves to the interested experi- was being built, there would be little chance BEST RADIO SCHOOL IN NEW YORK -f/ menter. Remember, however, that the most of important information leaking out. mystifying phenomena rest upon the least Now, the Gyro -Electric- Destroyer is in "EXPERIMENTS" $1.50 P. your hands. 1 am not going to annoy you By Edelman complex causes; and the simpler a thing is, Wanda out amongst books like this mu- the harder it is to understand. Observe with a stereotyped patriotic appeal urging mane does to the periodicals. The one As a mat- book you want on Bolanee Wonders-Moo- all the details as suggested. To demon- you to sign the appended blank. tetchy. Wlreteae, Chemistry. Mechanics. strate phenomena which have heretofore ter of fact, I do not wish to urge you. It is Laboratory 8 IUD P. 258 DP. Illustrated and Gold camped cloth. Ouaranteed. 81.60. baffled the scientific world is at least worthy entirely a matter of your judgment P. ECELMAN. Pub. of patience. whether you believe in the Destroyer. 1802 Hague Ass.. SI. Paul. Mims. You benefit by mentioning the "Electrical Experimenter" when writir g to odi ertisers.

www.americanradiohistory.com 348 ELECTRICAL EXPERIMENTER September, 1918 fi TRW;.

Submarines, torpedoes, Hying machines, machine guns, immense howitzers, the British "tanks," and an untold number of other of American brains, are dominant factors in the Great productsVar. We are just starting, our -YOUR- iogenuity must lead to Victory. Uncle Sam -the whole civilized World -is seeking ideas that will aid in the fight. Can't you help with even ONE of thousands of simple things that will win recognition -perhaps fortune for you? The need is for inventions of peace, too. Never before was there such a demand for new ideas of all kinds-never before have so many manufac- turers, and other patent buyers, written me for good things protected by OWEN PATENTS. There is, to-day, a market for thousands of ideas including YOURS. Write for my free booklet and see -read for yourself- the hundreds of requests recently received. You incur no obligation by writing mc. My advice costs nothing and I make no charge for an opinion as to patentability of your idea. If my opinion is favorable I will back it up by a Guarantee Contract which protects you fully. If you want to sell your invention, I will help you, nd will advertise it, free of charge, in 'INVENTION AND MANUFACTURING." A simple request will bring to you at once, my four free books: -"SUC- Edited by CESSFUL PATENTS" a 72 page guide telling how to proceed, gives refer- In this Department we puhlleb ences, etc.; "STEPPING STONES" tells the truth about prizes for uch matter as inventions, gives hundreds of hints of inventions wanted, etc.; PATENT Is of interest to Inventora and particularly to BUYERS" publishes over 400 requests of manufacturers and others who those who ara In doubt to certain Patent want OWEN PATENTS, together with ideas they wabt; "PATENT PRO- Phase. Regular Inquiries ddreet to "Patent MOTION,' tells you bow to sell, why some inventors fail, discusses the Advice" cannot he answered by mall free of value of your idea, etc. charge. Such Inquiries are publlaht here for tie Write for these books to-day. I will send you a signed agreement that benefit of all reader. If the idea le thought to will protect you before you disclose your inventon. be of Importance, we make It rule Dot to divulge detail., In order to protect the Inventor as far as It is poIble to do so. RICHA.RD B OWENPaieni LanlgEr Should advice he desired by mall nominal charge of $1.00 1 made for each guatloa. 164 Omen B1do VashiNtonDC2276-ß Wool}uorth BldpNenl York- Sketches and descriptions must he clear and Jd explicit. Only one aide of sheet should im written on

Readera' attention is called to the fact that due Invent Something to the great amount of letters to this department it is quite impossible to answer them all thru YOUR IDEAS MAY BRING WEALTH IF PATENTED these columns. The inquiries answered in this L Now is the time to patent a meritorious invention. We are con- issue date as far heck as April, and it readers wish speedy service they should carefully note stantly receiving letters from manufacturers and investors in- the announcement appearing in the preceding terested in new inventions protected by patente secured through US paragraph. L H. TALBERT and which can be turned into money through proper handling. Labor shortage has Increased the demand for Inventions In U Unes. Talking Moving Pictures. Uncle Sam Wants New Inventions to Help Win the War. (253) Douglas C. McCall, Opelika, Ala., submits Write m today for free and our Evidence of Con- an ingenious scheme for talking moving pictures, or 104 g Disclosure and the idea isi apparent from our illustration. book, PATENTS Certificatet nw h i e As it will be seen, Mr. McCall wishes to uti- Patent and What to Invent." At the prove of value and assistance to you. same time /lend us sketch, model or Our Credit System will enable you to photograph with written description ale your application and proceed of your Invention for our Free Opin- without delay. Patents secured by us lea and Evidence of Conception Cer- are advertised at our expense In Popu- Utleets. If your invention fs proper lar Mechanics Managing'. To protect aublect matter for a patent we wlUyourself write for our free book and send you our Certificate to that effect submit your Invention to us today. TALBERT & TALBERT, 4287 Talbert Building, Wash., D. C. Patent Lawyers- Successors to Talbert & Parker High Frequency Bargains In taking our inventory we found over 200 Violet -Ray machines of all makes. We selected 100 of the best machines, which we thor- New Talking "Movle" Scheme Having oughly overhauled in our factory making them better than new. Many Voice Record on Same Film with of these machines cost over $40.00. Pictures. We have placed all these instruments in two groups and are dis- line the celluloid film for two purposes, namely, posing of them for the ridiculously low price of $9.75 and $12.50. for the registering for the film itself as well as the registering of the voice. In a former issue of the ELECTRICAL ExPERiM ENTER there was de- How to secure one of these scribed a scheme of a New York inventor, showing bow a plurality of phonograph records could be registered simultaneously on a celluloid film. Mr. machines McCall makes use of the same idea, except that Send only 50 cents to pay express charges he incorporates it in connection with talking mov- ing pictures. From our illustration it will be and we shall send you one of these instruments seen that X and K are Mm reels. A is the roller by express for your examination. This amount over which the film passes. C is a sounding box, will be deducted from total cost of machine. and B reproducing born; D point where film passes before lens, throwing picture on screen. You need not accept if not satisfactory. A. To our mind this is a very good idea, altbo Send at once for we shall send the best ma- it probably will be found that a special phono- graph is required as well as a steadying device. chines out first and the quicker you send in We also would think that a microphonte repro- your order, the better machine you will get. ducer instead of a mechanical one shown at C would be preferable. We believe the idea is We shall also send our beautiful booklet patentable. "Violetta" describing the many uses for the high- frequency current. Write us before pur- " chasing any kind of Violet -Ray Machine. War Tank. (254) Kenneth Harlan, Albany, N. Y., wishes to know if a patent has been issued on a small war tank which operates the same way as the big BLEADON-DUN CO', Dept 2AD P CH CAGO tanks, power to be furnished by a small motor or clock work. }'ou benefit by mentioning the "Electrical Experimenter" when writing to advertisers. www.americanradiohistory.com September, 1918 ELECTRICAL EXPERIMENTER 349 GOVERNMENT TO CONTROL ALL WIRE SYSTEMS. A bill to authorize the government during U.S PAT NTB the war to take over control of all telegraph cables and and telephone communication, I , wireless stations, was recently signed by President Wilson. The Nation's communication lines went tinder Government control on July 31. It is reliably reported that the control will in- Ili" and cables. The FREE-* clude telegraph, telephones JUk-HULLETINS a --lt`dILE radio systems of the country already are under Government supervision. REGISTERED ATTORNEYS LANCASTER &ALLWINE ELECTRIC FURNACE TO MAKE WAR ALLOYS. 255 OURAY BLDG, WASHINGTON, D. C. Plans for the erection of an electric fur- nace in Spokane, Wash., for the production Don't Lose Your Rights for war uses, on a site to be fur- We publish forms called "Evidence of Con- of alloys ception" by which you can establish your rights H. GERNSBACK nished by the Washington \Vater Power before sending the invention to anyone. It is your Company, which is also to furnish the power best protection. We issue up- to-date bulletins of A. Nothing of this kind is patentable. We for the experimental purposes, were discust improvements wanted; aid inventors to promote presume our correspondent refers to small trench auspices their rights; render reliable opinions free of charge tanks which are sent out over "No Man's Land," at a recent meeting held under the and secure valuable patents and trade-marks on the notion being controlled by a cable or wire. of the industrial committee of the chamber reasonable terms. Personal service assured by our Quite a good many schemes of this kind have been of commerce. Those present pledged $1,000 Service Guarantee Contract. References: proposed, but unless there are unusually new 2nd National Bank. Washington, The John P features connected with it, we doubt if a patent toward the $2,000 needed. Washington Roth Packing Co.. Cincinoati. could be obtained. State college has pledged $500. SIMPLY MAIL COUPON LANCASTER a ALLWISE, 255 ()any Dldn.,Ws. l.staa, D.C. Send me free book "Inventions -Patenting and Linotype Gas Lighter. Promoting." Bulletins of Improvements Wanted (255) Walter Lichtenberg, Tacoma, Wash., sub- As a symptom of the recent rapid develop- and blank form "Evidence of Conception." mits a diagram and sketch of an electric auto- ment of Japan's commercial interests in matic linotype gas lighter, the idea being to have Shanghai, Japanese lighting interests are Name it controlled by a clock so that the gas could of the be turned on at a certain pre -arranged time in now supplying a large proportion Address order that the linotype operator would not have electric lamps for the city which were for- a to wait until the metal is melted. merly imported chiefly from the General A. This scheme is very clever, hut we are quite IN Electric Company in America. The fact is for Auto Thee Double pliley prevent blow- certain that no patent can be obtained because b eud 4aly aoll there are no new functions contained in this idea. pointed out in the report of the Japanese pumlpee.. u It is merely an adaption of well known as well consul -general at that point. Aiwa r.Aoc *** * Co.. Dent.s3.Clnel ent14 as old principles towards something that may not have been done before. Phonograph. (256) 3. Brewton Berry, Orangeburg, S. C., thinks he has an idea whereby the volume of a Victrola can be greatly increased and the music be made more distinct. He thinks that by attaching TE1sITS WANTED a small piece of isinglass or some such material to the arm to which normally the phonograph TRADE-MARKSand COPYRIGHT needle is attached, the sound will be greatly In- creased. A. From the sketch and description which ac- LArdest Patent Firm companied this article, we fail to see why a greater volume of sound should be obtained by in the World this means. All phonograph sound boxes use a reproduction. Before &ending your Invention to any attorney or mica disc for manufacturer or dlsdoeing your invention. write for our tree blank form PROOF OF CONCEPTION In order to protect your Invention and secure your Street Car Indicator. rights. This should be signed and witnessed and re- turned to us, together with model or sketch sod de- (257) Gerald Lyons, Cleveland, Ohio, submits sedpttos of your Invention. and we will give a FREE diagram and description of a street car indicator. OPINION as to the patentability of the Invention. If we The idea is to have a ratchet wheel strike at a report the taveotloo patentable we will fumleb a Certificate protruding notch placed on the rail. Every time of Patentability. the ratchet wheel bits this notch, a drum will This Certificate of Patentability, together with our blank form SPECIAL Proof of Conception will protect the Inventor sad serve as proof be advanced which shows the street indicated. Is the U. S. Patent A. There is nothing intrinsically new about this OFFER of the Invention until the can can be flied Victor J. Evans. idea, and the worst feature about this is that as- schemes of this kind bave always been looked OBTAINING ASSISTANCE FOR INVENTORS -Our certificate is of great upon with great disfavor by the traction com- to inventors who require financial aid to obtain patents panies, for the reason that anything that tends sistance to interfere with the regular operation of their LED FREE standardized equipment is not popular. It would OUR FIVE BOOKS MAI (See Coupon Below) also be more or less dangerous for vehicular traf- ever issued for free distribution. fic, to have an abundancy of notches of this kind to any address. Send for these books-the finest publications on rails going thru streets, etc. WHAT TO INVENT HOW TO OBTAIN A PATENT wanted and Guide Book la n Book Contains a valuable list of Inventions Our illustrated eighty-page concerning profitable Information prizes offered [tore Innen- Air Compressor. leal movements. Illustrated andd dewsribed.ppTells how al o DOLLARS to Invent for profit [ions amounting to ONE (MILLION (258) G. Clarke, Toronto, Can., submits an idea OF PATENT BUYERS of a comprest air tank system whereby a gage LIST promoters for Contains requests from manufacturers. mall order houses Loa by us and eusgestlone as to New Ideas they with to purchue. patents secured witt ice of charge. We have recently om m ufectu41B [received ve 300 request, t -MARKS MILLIONS IN TRADE regard- t Shows the value of Trade -Mark, and information ing unfair competition \ Curers luentlsa Free In WA Tess. noos- advertiseiOur World's Progress. Samtlr !r copers. in manufacturera' Journals and in After We save and LuIMIa the patent we assist to sell sour patent. WANTED NEW IDEAS FREE COUPON! VICTOR J. EVANS & CO. PATENT ATTORNEYS New Vara Offices: Plnabur, Must Phlledelohla Offices: 1001 to 1007 Woolworth Bldg. 51. Empire Bldg. 1429 Chestnut St. Automatic Ale Compressor Gage D. Switch Which Cuts ON Pump Motor Main Offices: 779 Ninth Street, N.W., Washington, C. as Soon as Pressure Exceeds Certain Value. Name Address You benefit by mentioning the "Electrical Experimenter" when writing to adrertis,rs.

www.americanradiohistory.com 350 ELECTRICAL EXPERIMENTER September, 1918

automatically cuts off the electric current from the motor as soon as the pressure becomes too high. This scheme is readily understood rr` by E T 5 h ^ NEW studying ¢ÑT Ñ TRADE MAMAS the attached diagram. Our advice is t COPYRIGHTS¡.`. i DttSIa/,S asked as to patentability, etc., and if the scheme s' _ is feasible. SERVICE A. While the specific means to cut off the cur- rent as shown in the diagram is new, the general U. S. PATENTS underlying principle is quite old, as nearly all compressors work on a principle of this kind, for particularly those used on elevated and subway MAKE IDEAS PAY trains. Usually a gage is made use of which has a diafram, the latter, when expanding, makes or Hundreds of inventions are sold INVENTORS breaks the contacts. It appears to us that the yearly. We will help you sell yours scheme as outlined by our correspondent seems without cost. I personally report somewhat more complicated than the existing means of this kind. Before sending your inventions to upon, prepare and Form prosecute every case anyone send for our "Blank submitted Bicycle Brakes. of Disclosure" that will Protect to me. I filed give every case my (259) G. L. Kochis, Braddock, Pa., writes as you until your application is follows: in the Patent Office. - closest personal at- I have an idea for an emergency brake to be tention. 1 do not entrust Our book "Making Ideas Pay" gives full lour interest to assistants. My used on a personal service on your bicycle. By pressing a lever the rim information relative to securing Patent Pro- invention is of vital advantage of the front wheel is tightly clasped. Such brakes o you. This is new efficiency. tection. Manufacturers are writing us con- new promptness in patent could be made and sold for 25 cents. service. 1 report on your case in two days. No longer that, is tinuously for new inventions. o days to prepare A. There nothing new about an idea of this your taw for filing. Send sketch or kind, quite a number of bicycle brakes of this Send for Book and Blank Form of Disclos- model for prompt search and report. sort being in existence now. ure today. Prompt service. Best results. A. M. BUCK & CO. Propeller. Patent Attorneys Secaed National Bask Bldg.Washinpan; D.0 PATENT My FREE Book (260) P. C. Sauther, Brooklyn, N. Y., writes as LOS follows: Enclosed you will find description and. KNOWLEDGE Free, my new go-page booklet, sketch of a new propeller on which I greatly de- for "Patent Knowledge for Inventors." sire your advice. As you will notice the improve- ment is merely in the arrangement of the blades. A volume of real information on The INVENTORS patents. propeller now universally used. if revolved Different from the usual too quickly, would "churn"-that is, one blade "Circus Stuff." Contains startling merely opening up the water for the next blade to PATENTS information usually not told. Write almost entirely thru empty space, besides the THAT PROTECT AND'PAY for this free book today. It will osslpass of slippage, which varies from 15% to 30% in open your eyes. all propellers now used. Books and Advice Free You will note that besides each blade individ- It you want to sell your {Intent. take It out through my office. GEORGE KIMMEL Patent Lawyer, ually screwing itself thru the water the ar- MODEST REFERENCES. BEST RESULTS. P. rangement of the blades also forms a screw. The 88-1 Oriental Bldg., Washington, D. C. distance between blades would, of course, vary WATSON E. COLEMAN, Patent Lawyer with the pitch of the blades. 624 F. Street N. W. Washington, D. C. Not only, in my opinion, will this increase the speed of a ship but will save that energy which now goes to waste n slippage due to the ineffi- EVERY INVENTOR ciency of the present propeller. should here ails book. "PATENTS AND PATENT check A. This is a good idea but we doubt if anything POSSIBILITIES." It is in the propeller full of ideas and practical advice. telling Can You line of this sort is patentable. The what 10 Invent and where to .sell. write most you can get is the so-called "Design Patent," for your copy today. IT 18 FREE. think of a simple, practical which would not afford you much protection. I have requests for patente upon sound idea that will fill one of the many Ship ropellers have been brought to the highest Intentions of all kinds. Can YOU help SIM- PLY 'the demand? requests we have on file for new pitcb of" efficiency in the past forty years and we We I. dividpal, prompt tad .et.I.et are almost certain that an idea of this kind must It r .ap.d.eas. mon . dt.et I. .e. inventions? It may mean a fortune have been tried before. aer.Ó to ..cots oases. Si most o.uibi test. for you. Thousands of things are need- H. S. HILL, 801 Mctacklee Bldg., Wastage., D. C ed right now. Your brains can help. THE MIDGET SLIDE RULE Send today for our great new book- EXPERIMENTAL PHYSICS. tilt add. subtract, multiply. dl- tide: solve problems Involving even "Inventions and Trade -Marks (Continued front page 315) and uneven roots and powers. Also gives the logarithms of numbed Their Protection and Exploitation" Bend a piece of No. 14 copper wire (b) in and the Sines and Cables. Tan- the approximate shape of a circle (see Fig. gents and Cotangents of all angles. and learn more about mak- Its operation Is very simple :0ulek - 82 -I). Suspend it by a fine thread (a) so ing money from that the ends dip into lelym n ablymathematicalsid cf metal. ideas than mercury troughs in Adapted for shop and once use. block of wood (d). The mercury troughs Fits the pocket. 3i5 Inches diam- you ever eter. Price with Instructions.S1.00 are connected ; knew before. It tells to the binding posts P and P' Your mecer back It tee sr. set .sU.nee on Gilman Slide Rule Ca.. Niles. Mich. many things are passing a strong electric current thru the that Read wire we find wanted, too. Invention end that it slowly but surely (the Manufacturing speed depending upon A postal will the strength of cur- DUCK'S do- The best thing rent). turns so as to lt la free printed for the men assume an East -West BIG 300 pp. ELECTRI CAL - position. who likes to "dab This is identically what would and WIRELESS CATALOG We Help ble" wlth'mechan- happen if we were Our Im, electricity. to suspend freely a mag- iMailed upon receipt of 8c In stamps ckemfetry. aero- netized circular disc. It would assume an or coin which may be deducted on a Clients nautics. 10e cola East- \Vest I first dollar purchase. Catalog con- from your news position in order that its mag- ; lain, 160 pages of wireless Instru- without charge to dealer. Send w 25o netized faces might point in North -South I mente and 140 pages of electrical get the for 8 numbers. supplies. No bigger or better values dollars out Retter still. is SI direction. Hence we conclude that A CIR- ara obtainable elsewhere. We have bill for a a of their ideas -hav- years CULAR WIRE CARRYING A - complete stock of everything listed eubeerlptln - 12 CUR In this catalog. %Viceless orders ing facilities none issues. RENT ACTS AS A MAGNETIZED , Promptly filled. others possess. Advice free. Don't delay - DISC. THE WILLIAM B. DUCK GO. 230.232 Superior St. Toledo. Ohio get the book at once. Let us apply the righi -/land rule. If the AMERICAN INDUSTRIES, Inc. current is traveling in a counter -clockwise MECHANICALLY RIGHT -A REAL LATHE direction, (as in A Repulse lathe. not a fey 215 Patent Dept., WASHINGTON, D. C. figure) upward at the left 'tnd downward at the right ; the rule applied to either the left or right gives the same re- sult, i. e., the face of the "disc" (Fig. 82 -I) towards us is "S" and the face away from "The Book sis is "N" and the lines of force go from PATENT-SASE us into the plane of the paper. In Fig. 82 -II, Swing 4 Inches, 11 inches between ren- the Inventor ters. 17 inches total length. Net weight ....mrnm-x-atvnens the rule gives us N at the right and S at B Ilse. Slipping weight 13 lbs. the left, i. e., The bed of tits lathe la machined. S.. the lines of force are from Workmanship Is first class throughout. KEEPS" left to right. We found that the loop turns Leib, comp eoulpped with wood turn- ing chuck. Lathe can be fitted with 3 Worth more than to an East -West position. It is important Inch face plate and drill chuck as special egulpmeoL Order to note that the loop in turning to this posi- one today. l'rlee $4.50 cash with order. all other patent SYPHER MFG. CO., DEPT. C, TOLEDO. books combined. tion TURNED SO AS TO INCLUDE AS OHIO FREE. MANY AS POSSIBLE OF THE LINES OF FORCE OF THE EARTH'S MAG- Feldman's " Geyser" 1" Write NETIC FIELD. EXPERIMENT 92 an Electric Water Heater LACEY & LACEY -Bend insulated wire in the form of a helix. Pass a current thru Instantaneous Hot Water LACEYa IACCY 131 Springer Bldg. it W.ahIeetee, D. G and bring the helix near a compass (sec ESLblllahed 1888 Fig. 83-I). We find that the compass needle FELDMAN MFG. CO. behaves just as if the helix were a bar 1500 Times Bldg. New York City }a14 benefit by mentioning the "Electrical Experimenter" when writing to advertisers.

www.americanradiohistory.com 35 I September. 1918 ELECTRICAL EXPERIMENTER magnet (see Fig. 83 -I). (See Lesson 12.). We could easily have predicted this result for can we not consider the helix to be many of the discs of the preceding experiment When this series of discs Send For This placed together? are placed side by side all the poles are neu- tralized except those at the two ends; since in the other cases a N pole is in contact Free Book about with S pole. This is obviously analogous to a bar magnet. The right -hand rule slightly modified as follows is convenient the Latest in determining the direction of the field of a helix, knowing the direction of the cur- rent and vice versa. GRASP THE HELIX IN THE RIGHT HAND SO THAT THE FINGERS ENCIRCLE IT IN THE DI- RECTION IN WHICH THE CURRENT IS FLOWING IN THE WIRE. THE THUMB THEN POINTS IN THE DI- Learn all about the wonderful Skinderviken Transmitter. Nothing RECTION OF THE NORTH POLE OF like it on the market. Will make an old transmitter better than new. THE HELIX. IF THE HAND IS Adjusted in a jiffy. Supersensitive. Talks at all angles. Patent just PLACED SO THAT THE THUMB allowed. Price $1.00 each. Discount in quantities. POINTS IN THE DIRECTION OF THE Another Skinderviken patent -a battery saver, is worth investi- NORTH POLE OF THE HELIX: THE gating. See how it prevents waste of current and prolongs the life FINGERS WILL SHOW THE DIREC- of batteries. A wonder that sells for 25c. TION IN WHICH THE CURRENT IS FLOWING. (see Fig. 83 -II), The writer Read the full details of the Skinderviken Private Service Sys- suggests that the reader test himself on the tem. Even though you may have a party line this neat little attach- knowledge of these important 'rules by con - ment makes it possible to have all the secrecy of an individual ceatin9 the battery so as not to know the wire. Then there is the Victory 'phone -the smallest, handiest, direction of the current and determining and most compact wall telephone ever built. Absolutely the last the direction of current flow, and also by re- word in 'phones! All these latest inventions are fully described moving the compass and determining the in our book-free for the asking. Get ...a.. BIN a..aae. polarity. your copy at once. (To he continued) Mail Coupon Now STECO, 2136 N. Clark St., Chicago We will also send you our price list Please send me free book and price list showing how we can save you money without any obligation. GENIUS AND ULTRA VIOLET on all kinds of telephone accessories RAYS. and supplies. Write TODAY. Name (Continued frons page 296) STECO Address his imaginative power together with his 2136 N. Clark Street Dept. A Chicago cheerfulness. As the day declined his i City mental activity diminished until he fell into a lethargy which lasted to the following day." "Giordani could only compose in the sun, or in the presence of abundant light and great heat." There have been also many geniuses who could compose only in :Wireless Taught By Mail the presence of great heat. Sylvester. a great mathematician, tells how when on DRAFT MEN -THIS IS YOUR OPPORTUNITY board the "Invicta" beneath the vivifying ]ten and women. urgently 1,1 for Army. Navy and Aviation Service. e 40,000 wireless Operators, -commissioned grades with Advanced Excellent opportunities to win promotion to commissioned and non the rays of a powerful sun, the method of Pay. wireless work trains you for position as Commercial Operator, after solving a multiple equation occurred to wit. with pay up to $200 a month. ¡I him, and he succeeded without pen or , Ten Weeks pencil. Many other examples could also Complete Course by Mail in be cited but the reader can refer to them \ Start studying NOW In spare time at borne. Complete Practice apparatus sent with first lessons. we help You enter any branch of Radio Service you himself in many biographies. select. write TODAY for full particulars. A Postal will do. We then see that not only is the sun the "all life giver" but that he has aided NATIONAL RADIO INSTITUTE geniuses in their creative works by means Dept. 63 Washington, D. C. of its ultra violet rays acting on the cerebral substance as stimulants.

THE N. Y. ELECTRICAL SCHOOL Is the pioneer and premier school of the "Learn by Doing" method. When you have completed this t'ourse you shall be fully qualified to handle ALL branches of Electrical Indu+try. The equipment of this School is unequalled and up -to- the- minute. No preparation needed to become a "learn- er" In this school. You can start to learn on any day of any week throughout the whole year. Send for cata- logue. OPEN ALL SUMMER NEW YORK ELECTRICAL SCHOOL 29 West 17th St. New York City advertisers. You benefit by mentioning the "Electrical Experimenter" when writing to

www.americanradiohistory.com ELECTRICAL EXPERIMENTER September, I 9 I 8

, .r r_ra.iOri11510Mare! irlor ..,, N. _ . . r.riiiiir' EXPERIMENTERS!

Student's Chromic Plunge Battery This is an ideal battery for electrical experi- mental work where a. very powerful current Is not required. This battery trill light a 2 voit _ lamp for several hours on one charge: it will run a small toy motor surprisingly well: it will do small electroplating work; it. Is Ideal for testing work: It gives a fairly steady current. and as the zinc electrode can be pulled clear of the electrolyte. no materials are used when bat- tery stands Idle. Best Amalgam Zinc only is used, as well as a highly porous carbon to ensure a steadier current. we furnish enough chromic salts for 4 charges. Full directions for operation and caro of battery are Included. Each battery tests 2 volts and 6 amperes when set Up fresh. Not over 2 amperes should he drawn from battery contlunousiy. Ity using nix or eight of these batteries. a great many experiments can be performed. No solution can run out of this battery if upset by accident This makes It an Ideal pm-table battery. Size over all is 5 "x2". Shipping weight, 1 lb. No, 999. Student's Chromic nge Battery dtOeSo SHIPMENTS YJ91''1r The "Electro" Radiotone HIGH FREQUENCY SILENT TEST BUZZER This Instrument gives a wonderful high pitched MUSICAL NOTE lit the receivers. impossible to obtain with the ordinaryordinary test homer. The RADIOTONE built along entirely now lines: it Is NOT an ordinary burner. reconstructed In soma manner. The RADIOTON}; has a Angle fine steel reed vibrating at a remarkably high speed, adjusted to Its most efficient frequency at the factory. hard sliver con- tacts aro used to make the instrument last practically forever. Yes, the R.ü)IOTO\T3 is SILENT. In fact. it Is so silent that you must place your ear on top of It to hear its beautitui musical note. You will be astounded at the wonderfully clear 500 cycle note, sounding sharply In your receivers. To learn the cedes, there Is absolutely notelet) like It. with (be radiotono, a key and one dry cell and ANY telephone, a fine learner's aet is had. Two or morn such seta in series will afford no cad of pleasure for intercommunication work. Shipping Weight I lb..... Radiotone as described each EDIATE SHIPMENTS J The "Electro" Telegraph is not a tor, but a practical, honestly built telegraph outfit, which not only sounds hut works like the big commercial Inslru- mente. Sty studying the code for 30 days you can become a first-class telegraph Operator. Such operators are in big de- mand now. Outfit consista of TWO complete telegraph Instru- ments each measuring 31h x 2.5 x 2tá. All metal parta are high- ly nickel plated. Including key lever. Noto hard rubber knob. Tolegratb Code Chart. telegraph blanks and connecting wire comes with set, but no batteries. Outfit works n 2 dry cells (one cell for each Instrument). The Electro" Is the ONLY Outfit that works both ways. each canon can call: no switches, no extras. Nothing to get out of order. Guaranteed to please you or money back, Price Complete u Illustrated (TWO INSTRUMENTS)., Shipping Weight. 2 Iba. .25 IMMEDIATE SHIPMENTS The "Electro" Codophone (Patents l'ending) Whatth la r e m arkahle $1.50 Instrument Is and does. lVo. EX2002 /- The "Elee- tro" Cod c- THE BOY'S ELECTRIC TOYS" contains enough mate- ohere is TO MAKE AND COMPLETE OVER TWENTY - positively the rial only instru- FIVE DIFFERENT ELECTRICAL APPARATUS with- ment mad e out ony other tools. except a screw driver furni,hcd with the outfit. The box that will complete instruments and apparatus which are already Imitate a 500 contains tho following cycle note assembled: Exactly as Student's chromic plunge battery, compass galvanometer, solenoid, telephono heard in a receiver, electric lamp. Enough various parts, wire, etc., are furnished to w'iretees re- make the following apparatus: ceiver. The Electromagnet, electric cannon.' magnetic pictures, dancing spiral, electrio loud-talking receiver equipped with a horn, talks so loud that you can hest the sound all over the room, men if there in a lot of other noise. hammer, galvanometer. voltmeter, hook for telephone receiver, condenser, THAT'S NOT ALL. By lessening or tightening the recelver cap. a tone sensitive microphone, short distance wireless telephone. test storage battery. from the lowest, softest quality, up to the loudest and highest screaming shocking coil. complete telegraph set, electric riveting machine, electric buz- sound can be had in a few seconds. zer, dancing fishes, singing telephone, mysterious dancing man. electric Jump- FOR INTERCOMMUNICATION. tieing two dry cells for each Instru- figures, rheostat, erratic pendulum, electric but- ment, two Codophones when connected with one wire and return ground. ing Jack, magnetic geometric can be used for Intercomrnunlration between two houses onr -half nine apart. terfly. thermo electric motor. visual telegraph, etc., etc. One outfit alone replaces the old -fashioned learners telegraph set, con - This does not by any means exhaust tho ilst, but a great many more ap- doting of key and sounder. paratus can be built actually and effectually. The "Electro" Cedephone in a handsome. well made Instrument, fool which we furnish, hundred experiments that proof, and built for hard work. Coolacts are of bard silver rÁ Inch in With the Instruction book one diameter, that will outlast the instrument can be made with this outfit are listed, nearly all of these belog illustrated There Is also a neat ode chart and full directions enabling any lehlll- with superb Illustrations. No other materials, goods or supplies are neces- lent young man or girl to learn the codes within 30 days, practising ono- sary to perform any of the one hundred experiments or to make any of the half hour a day. As can be constructed and accomplished by means of Slxos: 6sá x 3 x 2hon Shipping weight. " lbs. `lYa 25 apparatus. Everything The "Electro" Codophone 1e5o this outfit, two bands, and a screw -driver. as described, conplete material and 24 pieces finished The outfit contains 114 separate pieces of of "The Llvest Catalog In America" articles ready to use at once. Our big. new electrical cyclopedia No. 19 1s waiting for you. Positively Among the finished material the following parts aro included : Chromic salts the most complete Wireless and electrical catalog In print. today. 228 Blg bottle mercury, cure wire (two different lengths), Pages. 600 Illugtratlons, 500 Instruments and apparatus etc. Ills "Treatise for batter', lamp socket, of }R}.71 a Iron filings, three spools of wire, carbons, a quantity of machine on Wireless Telegraphy." 20 coupons for our 1C0 -page FREE Wire- bottle of less Course In 20 lessons. F1tEI. Cyeintedla No. 10 measures îx5,á..- screws, flexible cord, two wood bases, glass plate, parafine paper, binding Weight h lb. Beautiful stiff covers. posts, screwdriver, etc., etc. The Instruction book is so clear that anyone can make the apparatus without trouble, and besides a section of the instr::ction ra taw ta rases is of electricity to acquaint the layman - hook taken up with the fundamentals - - - - with all Important facts In electricity in a simple manner. ELECTRO IMPORTING COMPANY We guarantee satisfaction, 231 Fulton St., New York City The size over all of the outfit is 14 x 9 x e-?¡. Shipping weight, 8 lbs.$500 I enclose herewith C cents In stamps or coin for No. EX2002 "The Boy's Electric Toys." outfit as described 99 which memo, trend me Tour latest cyclopedia Cata- IMMEDIATE SHIPMENTS log No. 19 as described. NAME ELECTRO IMPORTING CO., NEWuIYORK ADDRESS ":': q"1177Ml7 ,!:'° ". ':";' ;F6 ,'IT,,IC'.l'C;. STATE E. E. ^-IS You benefit by mentioning the "E:rcarfcot Experimenter" when tariting to adtcrtirerr.

www.americanradiohistory.com September, 1918 ELECTRICAL EXPERIMENTER > > 3

"OVER THERE " -A MINIATURE row higher than the one before. In be- WAR PANORAMA. tween are the various continuous chains which have attached to them soldiers, tanks, PAGES (Continued front page 303) and army wagons and by an ingenious ar- Ï4 LUSTRATIONS of Robert Barker. He was a painter rangement of the scenery it always ap- and teacher of drawing in Edinborough. pears as if a perpetual stream of them I.C.S. One day it occurred to him as he stood on were coming and going. ELECTRICAL 1-11GIIIEER$ a height overlooking that city that he could Most marvelous of all is the clever elec- HANDBOOK make such an immense bird's eye view of trical arrangement that regulates every per- $ 1 MaaD600t it as to give a person standing at a point formance to the same length of time and of vantage in the middle of a building a causing each succeeding incident in the liv- ELECTRICITY! full idea of its inllnensity and all the de- ing panorama to take place at the same HERE'S just the book on tails of its appearance. He first developed instant in each showing. This is taken care Electricity that you need the idea by painting on slips of paper and of by a large drum having numerous elec- to answer your many ques- mounting these on pieces of linen. trical contacts arranged oit its surface; see tions-to solve your knotty Then he went to London to submit his insert figure in the illustration. This drum problems, to teach you new kinks, ideas to Sir Joshua Reynolds, tltett the is about five feet in diameter and is started to be your memory for tables. rules, formulas and other Electrical and centre of the artistic world. The latter by touching a switch, which is so arranged Mechanical facts that some people pronounced it original, interesting but not that it cannot be left shut and has to be try to carry in their heads -and fail. practical, adding: '1f you ever succeed in held in position until a contact is reached With this "Little Giant" I. C. S. finishing it as you plan, I'll get out of bed on the drum which closes the circuit to the Electrical Engineer's Handbook in any time to see it." Several years later, motor which keeps it running for the length your pocket. toolchest. on your work bench, drawing table ordesk, Sir Joshua did hurry from his breakfast of the performance, which lasts about an hour or a day need not be lost table at the invitation of Barker to rush to twelve minutes. The drum makes just one "digging up" some forgotten rule. some un- see his original panorama of "The Rattle ot complete revolution in the twelve minutes familiar fact ; you'll just turn to the very com- plete index and gel it'"in a jiffy." Just a few Waterloo." This was the first ot a series and about a minute and a half before the of the subjects treated are of itnmense designs which the elder Barker close of the show, the lecturer in the audi- Electricity and Magnetism; Electrical Sym- created in the building especially constructed ence receives a warning signal which en- bols; Batteries; Circuits; Magnets; Direct and for him by Lord Elco on Castle Street, ables him to make his final speech. Just as Alternate's Curreots; Dynamos and Motors; Leicester Square, London. Others were: he gets to the last word, the contact is Belts; Shafting; Electroplating; Electrical Measurements; Meters; Arc and Incandescent "The Siege of Paris." "The Battle of closed for the raising of the curtain and Lamps; Mercury Arc Rectifiers; Transformers: Copenhagen," "The City of London" and the "show is over." Insulation; Electric Cars; Single and Multiple - the "Fleet at Spithead." Another novel arrangement consists of a Unit Control; Transmission; Rail Welding: Tables of Wires - Sizes, Capacities. etc., - Robert Barker's work was continued by special battery of guns to give the effect Mathematical Rules; Formulas. Symbols; Tables his son, equally distinguished in the field of bombardments, explosions, etc. It con- of Constants, Equivalents, Roots, Powers, Re- of the panorama. He was Henry Aston sists of a series of large pipes about eight ciprocals, Areas. Weights and Measures: Chemistry; Properties of Metals; Principles of Barker, and the work of these geniuses was inches in diameter and about ten feet in Mechanics; First Aid, etc. again continued by Robert Burford. height. The lower ends are sealed and at The Electrical Engineer's Handbook is one of 22 Hugh Thomas at Luna is imbued thoroly the top, in a horizontal plane facing for- I. C. S. Handbooks covering 22 Technical. Scientific and Commercial subjects. (See titles In coupon below.) with the art of the creative panorama. His ward, are inserted large funnels. By an- They have the contents of a full -size book condensed first big opportunity came to him at Luna. other automatic electric contact drum ar- Into pocket size ready to go with you anywhere and be at your instant command. Substantially bound in It was the creation of the "Submarine At- rangement, as seen in the small insert, the cloth. red edges, goldleaf stamping, printed from new, tack," said to be the most effective indoor firing of the miniature artillery is con- clear, readable type on good quality book paper and Illustrated wherever a will help. spectacle ever accomplished. trolled. The plan on which they work is picture "Over There" is the actual depiction of like this :-Illuminating gas is admitted thru No Risk Money -Back Offer! the scenes back of the lines in Picardy. In a stop -cock in the base of the pipe to the The price of the famous I. C. S. Handbooks, of which more than 2,000.000 have been sold and are in practical it are a mass of details connected with the inside; also thru another stop -cock com- everyday use, is it per copy. So confident are u e mechanism of as now prest air is admitted. When it is near the that you will find them exactly what you need for war proceeded with. ready reference in your work, that we stand ready to The gigantic task accomplished by our men time for the gun to "fire," these stop -cocks for over in is are automatically shut and the circuit closed reason t1Yyou are not fullysatisfied with tttheir aluany France carefully, almost rever- Simply send a letter or the coupon below. enclosing fi ently, set before the spectator. The bird's - to an ordinary auto spark coil which causes for each book wanted. If at any time within 10days you eye view is scientifically followed and a a spark-plug in the head of the pipe to wish to return the books, yonr money will be refunded. zone of fire covering 1,000 square miles is ignite the mixture -giving "some roar" that INTERNATIONAL CORRESPONDENCE SCHOOLS laid before you. Your French villages are would do justice to one of those 100 mile Box 5396 Scranton. Pa. shown in the process of abandonment by guns ! ! ! This process follows in regular the Germans. There is a river and the order, viz : while one gun is being fired, INTERNATIONAL CORRESPONDENCE SCHOOLS mountainous, forest -grown country of ac- another is filling with the mixture, while Box 5396, SCRANTON, PA. tion is carefully depicted by this master of still another in being set ready to fire, etc. I enclose t - _ for which send me postpaid the Handbooks marked X, al tl.m each. I may return any or "war in the miniature." Add on top of this the fact that a dozen or all and get my money back within ten days from receipt, Most interesting of all to the uninitiated so of big "forty -five" automatics are con- Electrical Engineer's Advertiser's would popping 'l Iepb.aod Teleg,Eselaeer's Business nlon's be the "spectacle" that goes on be- tinuously off for the small arms Mechanic's bookkeeper's hind the scenes. Out front with the blare effects, and you have as near to what Sher- Steam Engineer's Sien.u,d rorr..noaaear. Westinghouse Air Brake Salesmen s of trumpets and the 'bally-ho' the crowds man said war was, as even the most zealous Civil Engineer's Window Trimmer's assemble, then pass thru a true representa- and fearless arm -chair patriot could desire. Coni a Cotton Textile Worker's Concrete Engineer'sE Farmer's tion of the trenches "Over There "; and nuu,lle Trades Ponhermens Plumber's and Fivers Marmara thence to their seats in the auditorium. The NEW NATURAL COLOR Chemist'sChemises Automobiles curtain falls (in this case it is more feasible PICTURES. to have the curtain fall) as therefore it By GEORGE HOLMES. Name gives one a chance to see things in a natural The seemingly impossible has been ac- Street perspective. I The distant scenery comes complisht Not in theory but in fact, so and No.- - first to view and gradually draws nearer, that now one may see all the beauties of showing the large shell holes and uptorn nature and life to their true and actual Cray rtatc terrain. We see the ammunition trains at colors! work and the Red Cross and the trucks, From years past men have been trying to WAR CONDITIONS DEMAND while men with training. close to hand are the Army Staff take and produce photographs in actual col- (laving trained ever Headquarters with the sentries doing duty, ors without any complicated process. In ELECTRICAL 2000 young men, The et cetera. Then there is the various degrees succeeded but it all, Electrical School, with Its well.equipped shop, and great "battle" they have laboratories. Is peculiarly qualified to give a condensed with the evacuation of the occupied area remained for Mr. Leon Forrest Douglas, oou.e. In Electrical with by the German Troops and its subsequent the inventor and perfector of the Victrola, Mathe- recapture by the French. Most ENGINEERING matics, beautiful, to not only discover a simple method of Steam and Has Engines, Mechanical Draw- and Prac- might be said to be the battle effects which taking and producing color pictures but to 1 ng. Shop Work, and TheoroUcal tical Electricity. Students construct dyna- are most realistic and inspiring; and taken actually apply the principle to motion pic- mos, Install wiring and test electrical ma. all in all we who are "Over Here" may tures. chinery. Course, with diploma. complete gain a tolerably good idea of what is doing Mr. Douglas, of San Rafael, Cal., for on IN ONE YEAR the other side of the Big Pond. many years, devoted his time to inventing For practical young men with limited time. 26th year opens "Back of the Scenes" everything appears processes which would bring superior tone Sept. 2511, Catalovue on request. topsy tervy, especially to the layman, but qualities to the talking machine and it was 260 TAEOMA AVENGE, WASHINGTON D O. to the initiated everything seems simple - due to his inventive genius that the Victrola everyone knows his place and all that is has been brought to the high standard of BOOK ON AVIATION expected of him. There are rows upon excellence as a sound -reproducer which it Learn of the great opportunities in this new "$1,000,000,000 industry. Thoosande of men needed. rows of trees, houses and trenches arranged enjoys to -day. Having mastered the laws Learn bymail- free hook telle how.Write in the form of an amphitheatre and each of sound, he took up the problems of re- asn0an aseo INSTITUTE. Ont nits at ort You benefit by mentioning the "Electrical Experimenter" when writing to advertisers.

www.americanradiohistory.com 354 ELECTRICAL EXPERIMENTER September, 1918

producing pictures in their natural colors, and for many years made most exhaustive experiments to develop a theory which he had formulated when he first began this WIRE the CORE work. Success has been attained, and We have been fortunate in securing thru auction several Ions of guaranteed pure, double annealed faithfully invention this wire to "Experimenter" readers pictures show how the Norway Iron Core Wire and are selling is able to reproduce every hue, shade and PRE -WAR PRICES 2Octs LB. tint of the colors of nature. AT The process is not only practicable, but is This wire Is just the thing for spark coils. transformers, etc., and It is, of course, a very much more superior product than the usual Iron wire. We absolutely guarantee the quality. comparatively inexpensive and simple. By If you ever thought of building a spark coil, transformer, or similar apparatus, now Is the chance means of a small and inexpensive color to get the right material for It. As far as we know this is the only lot of iron Norway Core Wire In the screen attached to any motion picture hands of any dealer at the present time, and none can be gotten until after the war. camera, several color values of the image We only have these three sizes: photographed, are given to the negative, 24 INCHES 26 INCHES 36 INCHES from which positive films are printed by a Thickness about No. 21 B and S secret chemical process. A film is thus pro- If either of these sizes should be too long we advise cutting the wire down yourself by means of duced which contains a series of images so shears. It will pay you to do so as real Norway Iron Wire, sold by a few dealers last year, brought front 40e to 50c a pouud. American core wire now sells for from 30e upwards per pound. colored as to give, when projected, a mov- As long as the supply lasts we offer this wire as described above to our customers at the very low ing picture in natural colors, without the price of 20e a pound. Order at once. use at all of the rotary colored shutter which is usually required. By this con- ELECTRO IMPORTING CO., 231 Fulton St., NewYork City trivance, the brilliancy and intensity of the projected colored picture is increased and a stereoscopic effect is obtained, impossible in black and white. There is no more light required than is used in projecting black RADIUM and white, and a speed of only 24 to the and second is required; thru certain experi- RADIUM CARNOTITE ments being made, this speed will be re- Salts, containing one dao- Radioactive (Radium Mineral.) The American Radioactive RrD- duced. The cost of producing pictures by ggrram pure Radium. Very powerfull Pitchblende found in Colorado. from which llar.r white luminescence m the dark! Substances Realities la ertraeted. this process is slightly more than that for 10 Milligram of this most carefully pre- for pared Radioactive Salts. sealed In glue A generous piece. enough to conduct making black and white ones, while the tube (protected by a metal container). experiments. such as affecting photo- Radium experiment can graphic pietas tbre opaeue material (dm- advantage in the art of producing motion with which every Experimenters Iler to x -Ray pictures), first made by be conducted. are furnished. Sir W. Crooke and llime. Curie, is fur- pictures is considerable. Price et one rube of Radium Salts as nished described, lent prepaid 51.00. In neat. wooden box. The effects obtained are marvelously true The contents of thla tube can be mixed Pried of ens specimen of Carnotite as to nature. The range of tint and hues un- with special eulphlder to form reel Radium deecrlhed above, lent prepaid 90.25. paint. limited. The presence of grays and neutral Small bottle of Special Sulphide with SeneIUee. prepared Pbotographio film Ileuld adhesive. prepaid 10.50. work for above tints which are always present in nature, Send for one of these preparation. to- e a erlmeote furnished a ftior 1 0.10 each down the extra. and which soften and tone harsh day. CARNOTITE colors, are plentiful in these pictures. Thus, in addition to showing the vivid col- SIDNEY SPECIALTY CO., 233 Fulton St., New York City ors, all the delicate shades and hues of flesh tints, of clothings and draperies, of the gradually changing sky tints of sunrise and ACTIVE SERVICE sunset, are reproduced with magical sub- tlety. The author had the pleasure of seeing these new wonder pictures and they cer- tainly merited the frequent applause, as 125 Dependable lur a lite time. Made right to write right. Long or ehort -Red or Black. each new possibility was unfolded on the beeluu ,comity to any busine.s man or woman. UneeOWed for general writing. billing. ruling $25 d menlfoldmg. Made of pure rurcaniged rubber with son- corrosive, durable writing point. screen. In order to bring out all the beau- Lock-Cap prevent. leaking. Extra else, 8 In., bleak only, $1.50. Your name in gold lulu 95o. ties of colors three scantily clad- young rafO: Liberal supply of Ink with retell order.. Agents wanted. Good profits. J. R ULLRICH & CO., 27 Thames St.. New York women in Greek garb danced On a lawn; and the pictures showed wonderful color- ing, the trees, lawn, bushes, and soft nat- ural hues of the girls' complexions being TYPEWRITER SENSATION beyond compare. Then followed the scenic 00 A Month Buys wonders of Yosemite Valley, Yellowstone Park, Bridal Veil Falls and the recent .e., a Visible Writing Smith bathing girl pageant at a southern Cali - Ma Yerfect mechlnee only of standard elle with keyboard of standard militarist arrangement- bas Beeksp.cer-Trbullmr -two Dolor rlbboo -Rau Bearing mostmdUon -oeery operating fomia resort, all in natural colors. convenience. Five Days' Free Trial. Fully guaranteed. Catalog and special price amt Ire.. H. A. SMITH, 738 -231 North Welle Street. CHICAGO, ILLINOIS MAKING SYNTHETIC GEMS IN THE ELECTRIC FURNACE. Your Vacation Begins the Moment (Continued front page 297) so far they have been the most successful You in this class of work. Step Aboard The first amongst these is the resistance furnace with electrodes of grafite with the The Ideal crucible placed between the electrodes and directly into the flame. Another way of Tourist Route making the synthetic gems is to have the Picture to yourself the luxury of a electrodes set in a flaming arc of about 111 magnificent, mammoth floating hotel, 3,000 degrees Fahrenheit, and the ingredi- perfect in its comforts and con- ents are dropt thru the flame in one batch ' veniences, with staterooms de luxe. and caught in a crucible set underneath, _ ^,7,,, t private baths and private balconies, ap- the crucible setting in water so that the 1 petizing meals, beautiful ballrooms, en- molten mass is suddenly cooled, thus ob- trancing music. Enjoy the grandeur of taining the necessary application of ex- ,e- "`-,=ßr the scenery on the historic Hudson re- treme heat and rapid cooling with the at- vealed by the giant searchlight. tendant and much desired pressure. Lately Dr. Aisen's son has been the dis- The Largest River Steamships in the World coverer and has actually made synthetic NEW YORK ALBANY TROY diamonds that bid fair to rival the genuine. Leave Pier 32. N. R. -6.00 P. M. The results have been the crowning effort HUDSON Sundays and Holidays -9.00 P. M. of many years of painstaking research and West 132d Street, half hour later. investigation. The method of procedure is NAVIGATION "THE SEARCHLIGHT ROUTE" somewhat along the following order: COMPANY Telephone Canal 9000 In a crucible set in the electric furnace is placed iron of the best grade which is

low benefit by mentioning Ike "Electrical Experbnenter" when meriti, g to advertisers.

www.americanradiohistory.com September, I 9 1 8 ELECTRICAL EXPERIMENTER 355 27 Years the Enemy of Pain super- heated until in a molten state. Then a pure grade of carbon is added and allowed to combine with the iron; when brought up "I Can to the desired degree the crucible contain- ing the highly heated mass is plunged into cold water. As carbon is absorbed less in Succeed! cold iron than in super- heated iron the men action of the cooling of the mass serves to "What other throw out the excess of carbon from the have accom- mixture. This carries, ofcourse, some of plished through the iron with it which forms around the I. C. S. help, I can. edges of the crucible in the shape of dia- If the I. C. S. have mond crystals. This is perhaps one of the raised the salaries greatest of all accomplishments in this field. of other men, they A very interesting procedure is the actual can raise mine. HEADACHE making of a synthetic jewel and the author To me, I. C. S. had the good fortune to see the operation. means 'I CAN One of the accompanying photos shows Dr. SUCCEED. "" Aisen watching the slow process of the makini; of a precious stone as it grows Get the "I Can Succeed" spirit, for TABLETS gradually before the eyes. It is necessary to wear heavy goggles -dark ones of course the International Correspondence -as the glare from the arc is very blind- Schools can raise your salary - ing. The component elements are contained whether you're a dollar -a -day man 10F 25 in the cup at the top of the arc and every or a dollar -an -hour man, a long -hour three or four seconds it receives automatic- manor short -hour old. )yc s1nl ally a slight tap which allows a very minute man,young or quantity to drop thru the hollow electrode No matter where you live, what you and onto the stone that is in the process of now do, or how little time or money RrIleadachés, making. The stone itself is perched on top of the lower electrode and the tapping proc- you may have, the I. C. S. have a Neuralgias, ess is controlled by a motor- driven arm. Course of Training to fit your needs. La Grippe an? Colds In another view we see the bank of elec- Hundreds of thousands of ambi- tric furnaces wherein the elements are tious men have achieved success Women's Aches 8.r3 IUs, placed in a crucible and then heated to the desired degree after which they are left through I. C. S. help in the past 25 RÍleumaticand SciatiicPains to cool in the furnaces gradually. When years -over 100,000 are now study- cool the mass is removed and the solid ing, getting ready for the big jobs PaiILMylktrer Wfere chunk of glass, for that is what it resem- ahead. Join them and make your bles, is broken and then comes the final life lrk Yo 11r ug g is t fb r A -ll TJ6/e is processes of cutting, grinding and polish- something to be proud of -you can do it. Se e /lcv r o g mA (Aas ing. In all of the methods used, it is neces- ra ( a q the uiDe sary Mark and mail the coupon TODAY and The Antikamni:, Chcmwal to go thru the usual routine of cut- Co., St. Louts ting, grinding and polishing, the same as find out how; it won't obligate you in the with natural stones as found in the rough. least. -- TrAC OUT car Numerous methods have been employed ------in the artificial manufacture of precious INTERNATIONAL CORRESPONOENCE SCHOOLS gems, which apparently sound very simple BOX 5395, SCRANTON. PA. as explained here, but one must not forget Explain. without obligating Mr, how 1 can quallfy for the position, in the subject, that many years of patient laboratory re- or Injure which 1 mark X. ELECTRICAL ENGINEER CREMICII, ENGINEER search were first necessary, not to mention Electrician SALESMANSHIP TELEGRAPHY the study numerous Electric YVlring ADVERTISING MAN of scientists who have Electric Lighting Window Trimmer devoted their lives in the search for Dame Electric Car Running Show Card Writer Nature's secrets. Heavy ElectrlcTreciion Outdoor Sign Painter AND FOR So that it is indeed won- Electrical Draftsman RAILROADER RADIO derful as one stops to consider these beauti- Moon+. )larhlne Designer ILLUSTRATOR Telegraph Expert DESIGNER ful man -made jewels, the product of the Practical Telephony BOOKKEEPER electrical furnace, the great NECMCNICAL ENGINEER Stenorrepber sod Typist stride made in Mechanical Draftsman Cert. Pub. Accountant MEN IN DRAFT the advance of the chemist's art. Ship Draftsman Traffic Management Practice Commercial Law Om Engineerp IGOOD ENGLISH Send for our latest folder on CIVIL ENGINEER Comeau School SnhJeels Surveying and Mapping CIVIL SERVICE Land Wire Telegraphy. Day MINE EIIRERN Olt ENGlI Railway Mail Clerk and Evening STATIONARY ENGINEER Testlle I eereeer or Sept. classes prepare for THE PHENOMENA OF ELECTRI- ARCHITECT AGILICILTI itE all branches. Particularly attrac- Arehile.loral Malloeaa Navigator Spo ilsh CAL CONDUCTION IN GASES. PI.UMRINO AND HEATING Penh', Robley E tive work. Sheet Metal Worker Aatemoblie. Italia (Continued from page 314) Day and Evening Name classes in Present RADIO for Naval Reserve, from the surface of the water W, and cool- Occupation Aviation, Signal ing due to the expansion causes this to Street Corps and Mer- condense. If neither ions nor dust are pres- and No chant Marine. Beginners every ent no cloud will form, but if the chamber Monday. Send for prospectus. A is subjected to X -rays or an electric City stttr spark, a cloud will form, each little droplet condensing EASTERN RADIO INSTITUTE about an ion. Prof. 899B Millikan's experiment which is so Boylston St. Boston, Mass. often referred to, and which is probably the most accurate determination of "e" yet accomplisht, is really a modification of these earlier experiments, and instead of dimin- ishing the credit due him, the cleverness of these modifications demands even more praise. Instead of calculating the charge of one ion from the charge of a large num- T SMALL ENGINES ber, Prof. Millikan actually isolated and Perfected l;ax.Lne km,p ore-- or choice of 11 styles, colors and sizes in the famous Ranger p.-for measured a single ion, and he used the line of bicycles for you to keep am: use a month as yew-own, aandl Shop 1 uuae Il 11 smallest possible ion, a negative electron. agree to show or bicy cle to and up. Also Would You tenthen or snore cf your friends and tell WASHINC MACHINES De did this by letting a single drop them the ridiculously low factory once, easy terms,unusual We chip on tria. Seed fer conditions an d except; Booklet and Special Offer. from a cloud fall into another cham- onal offers f would make,a Il of which SIEVERKROPP ENGINE CO. 1 will explain to you if within ten days of seeing this you It01 -I1)th St.. Realm. WI. ber, and he used oil drops instead of water will say to a letter or on a postal, Send lay, in.lars of so as to reduce evaporation, and enable Bicycle Offer" and address your postal card or letter: STARTER for FORD CARS Pr.n+untfor G. L. LEWIS, Manager him to examine the drop for a long time. MEAD CYCLE CO.. 107 Dleud Block, Chicago Yon benefit by mentioning the "Electrical Experimenter" when writing to advertiser:.

www.americanradiohistory.com ELECTRICAL EXPERIMENTER September, 1918 356 NEW BOOK ON The amount of electricity, or "e," he calcu- was ROPE SPLICING lated by measuring how strongly it Useful Knots, Hitches, Splices, etc.( or repelled in an electric field of attracted How Ditterent Knots Are Made end WhlThey Are Used For BOYS known strength. INDISPENSABLE TO. EVERY MECHANIC AND RIGGER it the handbook giv- Millikan's calculations of "e,' give PRICE A most practical Build and Fly value 4.77 x 10'° electro- static units of quan- comete and tity. The mass can now be calculated and 70C -t!° Ilion foil making all\thedmost it conies out the mass useful knots, hitches, rig- Your Own for positive carriers ging. splices, etc. Over of the appropriate atom present. For nega- 100 illustrations. All is 10' it about wire rope Training Plane tive carriers whose value of e/m attarhments.lash- is different, however, and the mass "m" ins.. blocks. tackles, 37 Heraldic Knots Train yourself In Atlatl<.n. comes out about 1 /1,500 that of the lightest etc. Be an AMliteUt n with an Illustrated. Of great value to own. Learn is the electron. echanlea riggers, romper., Aeroplane of your r hydrogen atom. This then 20 oo,ieald. bow Aeroplanes area bunt: learn besttn.,' Price rents the principles of construction. In making such measurements as these Johnsen Smith A Co... Dept. 931, 51 W. Lake St.. Chicago and control. With operation frequent variations were found in the mass. DeummaAebleActlen IDEAL Accurate Seale Draw- Ha Revolver end Flying by "The Baby" u a Inge, and Building \ow the mass of any object is defined Men and Moat an 22 Weapon. M a., 0 instructions. you can build Manes Limp. .c..aidle« $ 4s perfect Model Aeroplane. 3 ft. its inertia or property of resisting motion. size, that will rise from the been known that an electric ground by Its own power and It has long fly like a big one. Send now charge possesses inertia and the question for the Pico. tor the one you of an want to build. now arises as to whether the inertia OtawMaa end Instn,cuena for ion is due to its electrical charge or to Curtiss Willa, Tractor on which the Monoplane something else more material that ram Planet .< W rt Monoplane or to both. Some experi- o C charge exists, w te.°.a... Taub* Monootene 5f: ïM i e TM. by Kaufmann on this subject show s ^eatue....erbe Curti. Flsdn a... EACH ments rÌOi unkwraetr2itr n n I.al..i Wright Biplane very conclusively that the mass varies with ,r NS 0,1., wets. Cecil Peen Racr (T leg 51.50) eau,.a:á.1 ä aS .ra ,.W h,,t...a as"?Sail, Na ".Gi'aaa. the speed, and he was first tempted to think dar Send lee Our Aeroplone Catotog ay u'u. &MrTN ca..Ó.... I es W. Lake \M.. CÑICÁÓO Tells about Model Aeroplanes. Racing Aeroplanes, that perhaps a third or a fourth of the mass Flying Toss, and parts and supplies to build them due to electricity alone. He observed with. I3 pages. Send 5 cents for It today. was IDEAL AEROPLANE L SUPPLY COMPANY the charged particles given off by Radium, 76.92 Weal Broadway Now York CID some of which approach the speed of light Make Your Watches, Clocks:Ete.r of which are much slower. By Visible by Night c:r<: q+",=.t ,z' and some r be.;CYet mathematical interpretation of these and a..u, aaabÑ ,,.m. et

WITH this new Electrical Wonder you let the NEW SCIENTIFIC WONDER and a shave at RADIO AS pleasant effect of massage ELECTRICITY AND a RArCURla the some time. This razor is on the market "MOVIE" SPIES. and we ere shipping all poiou in the United States USED BY sod South America. g be need without electricity like the front page 299) CR1Ó V This device can (Continued PRICE As a - ordinary safety recors, but is supposed to be used with altanatiog current. The blade moves ¡zoo time. Embassy, aroused the sus- of the German a minute and actually cuts the hair without putties. in IOC. . -BIG FUN per picions of the Secret Service. The change "on Ppnr.nt'y Price $10.00. \ s. F a' discovered before many shells ROESo stVine. ,Inv obJtOt. thr,noneeh Omaha. Neb. plans was Haven. Coon. Vibrating Electric Razor Co., had been manufactured under the false MARVEL MFG. CO., Dept. 52, New specifications. WITH HB BATTERY CHARGER The loading room of a munition factory YOU CAN MAKE BIG PROFITS LE Owners of HB 500 watt equipment re' VA EVI E by Imperial to EGO a month extra I STA G was the place of attack chosen clearing 560 profit. d, l tell roo howl Fascinating profession for another plan in re- So can you. Write for full particulars either nez. Big salaries. Experience un- German spies in case or send 215 with this ad for trial this money- bF,ii necessary Splendid engagements always gard to the factory miscarried. An electric order which will put for travel. Theo, maker in your garage. Balance waiting. Opportunity wire was installed by the head electrician In 0 monthly payments of $20 trice' agents and authorities endorse my was in German pay, which each. Absolute money -back guar- , methods. Thirty years' experience as in the plant, who antee. You run no risk. and performer., Ulnetrated a spark by the throwing in of manager would throw HOBART BROS. CO., Box 9 -1, hay, Ohio e- book "All About VaudovIllo" sent FREE, the power house a safe distance Ls Delle. Sta. 266Jackaoo. LJ. a switch in Predarlr away. but Ztun Watchwork, Jewelrywork and big powerful. permanent: lift Slakberg, the ring -leader, is caught A fine trade commandinga Rood sal- ne e tus Magne,..,Ma Shout 3 cos. Elucatlonal, his cigar. The cigar is picked :ngraving cry, and your services are always In fui. Sent parcel post 21.00 each. throws away "t and in it he finds a lemand. Add ree, HOROLOGICAL Department, up by the electrician .Bradley institute, Peoria, III., for our latest catalog GENERATORS up the works. He immedi- We also bare a number or bleb grade Meltzer - note to blow Cabot Hand Generators which we will dispose ately jumps a freight bound for the factory. of at bargain prices. Glee up m 110 volte. A. C. he is followed by Miss Dixie WHY "FLUNK"? You an ake direct and run by pulley if de- Unobserved inLatin,eudesla CAESAR'-FIRST Er BOO KS - sired. Fine. wets -made machines. built for operative, who tries word tee wad each. Order to- Mason, a Secret Service "CICERO", OR "VIRGIL' 4.1 ethers, bsadeled, service. Special pria $5.00 in mob. postpaid. day direct from this ed. G y Free. to stop him from throwing the switch Imo ENGLISH. Cemplele, ddhheend, 11.00 WATSON ELECTRIC CO., house. Running t11ru the works MONONGAHELA NOVELTY CO.. BOX 299, MONONGAHELA, PA. Cool 19 122 S. Michigan Ave.. Chicago. the power- writing to advertisers. You benefit by mentioning the "Electrical Experimenter" when

www.americanradiohistory.com September, 1918 ELECTRICAL EXPERIMENTER 3íi

she shouts a warning to the employes but Build Your Own PHONOGRAPH, arrives too late to save the switch from be- It's Easy With Orr Hero SAVE ing thrown. A brief struggle ensues at the A (env hours interesting work her arm and power -plant switchboard in which saves many dollars give, \ \a you a machine exactly to awl OVER Is jammed in the switch by the electrician your ideals. We motors,-furnish HALF commences (see Fig 2). tone arms. case material. blue and the dirty work Prints and full instructiuls She faints and is found thus by the Presi- Plays any record. You can make Our profit building phonograph, dent of the Criminology Club who, altho for your friends. he has begun to love the girl, imagines that Write Today for Our Free Blue Print Otter. Silents she is also a spy, in that she is always with wanted for our ready built them. Little does he realize that she is also ChetaIrons. a Secret Service operative working "in- CHORALEON CO. special orders that he knows Elkhart, cognito" on 709 Monger Bldg., Ind. nothing about. Therefore, hearing some more explosions, he handcuffs her to the railing while he goes in pursuit. But al- 35 MILES PER HOUR resourceful she manages to short - Built by a boy from Junior parts fur- ways nished by us. Any boy can build this a and a rub- Is circuit the handcuffs with tool car. Carts very cheap. Send 26 nearby, by so doing melts Record oits for blur prints and price list ber glove and f arts showing I how lo build this the connecting link and gets free. Of This npredy little car. in Electricity Cr Next we have the daring "Raid of the Big Money U -53," which came to our shores and started The electrical industries offer wonderful a rumpus on which a quietus was soon put opport.Lnitiee to boys with a liking for Elec- by our vigilant Navy. Dixie Mason, the tricity. á'The salaries paid to trained men are young and pretty Secret Service operative, large, promotion comes rapidly and, best of is trailing Captain Karl Boy -Ed, the former SYPHER MFG. CO. all, the work is fascinating. naval attaché of the Imperial German Em- The discovery and development of new TOLEDO. OHIO.[ He has returned to bassy at Washington. lines (such as wireless telegraphy and tele- the United States in disguise after his dis- phony), from time to time, promise attractive is in a nearby missal as an envoy. Dixie and paying fields to those who wish to Boy - place and witnesses a meeting between specialize. The quill to do and Spinal Train- Rose of the "U -53." h.d and Commander ing will bring success to you. e to the dock where the She follows them The International Correspondence Schools submarine is lying. As a means of get- in electrical attracting can help you to become an expert Cash with order buys thin ting Boy -Ed on board without no matter what branch you like best. 3 boat is suddenly opened to work, BENCH LATHE attention the Thousands of young men have already won a C. Shipping Wt, to lbs. and in the crowd which flocks on Swing l in. In. to,.. visitors through I. C. S. help. You can do Peter Austin 910 W. First C.E. Muncle.lnd. biiard Dixie easily follows Boy -Ed. She success as well as anybody, if you try Everything is former envoy secreted in a com- sees the made so clear that you can learn in your partment, and she hides in a locker in the on Approval spare time, regardless of where you live or Shipped torpedo room. Unaware that Dixie is on books to buy. Note at once or wn+ ars e siPmeeta net my 46. page what your work No driva and dee sooetrais the ash board, the "U -53" puts to sea. catalog. Atenta wanted Cu. oyp?rtanitr There's big money in Electricity. Get aStroPass.,34.7 H. P. ' 172x334 Wee toMrfo tootpr Dixie remains in her hiding place until yo.reommlaetppa. by marking and mailing the Coupon Agents mWepe the first torpedo fired in the raid on ship- after it er.sbiemwts today. Finding oui root you nothing. Bosh ping has been trained on the Strathdene, a are r®pt.guaranteed or British freighter. She bursts from the iilamoÁel.rtaa . 11-Inwheelbase locker and commands Rose to stop in the teen eat Me -- Doke l Ele et. 5tg.aLtg. PR..['IiepLB, 6 name humanity. Sailors hold her while RCM ROTOR eOIIPA]Y, Saab Teeple, Chicago, umala of INTERNATIONAL CORRESPONDENCE SCHOOLS the torpedo is discharged and the Strath- in the BOX 5394 SCRANTON. PA. Learn _ Simplified dene sent to destruction. Two more of 6 Lvning SHORTHAND Explain, without obligating me, how I eau quellfy for mho Learn Easily at Home deadly weapons are fired from the subma- posltlon, or m the subject, before which I mark X, Practical K. I. Shorthand; quickly rine each finding a mark in the vitals of un- ENGINEER Grimmest. ENGINEEn learned. You attain speed easily. ELECTRICAL a vessels. Then she is Electriden SALESMANSHIP Great saving in time cad pense. protected merchant Electric Wiring Guarantee and 30 days' trio! give.. released. The sailor who has had her in Electric Lighting WADVERTISINWindow Trimmer Home study. Many eodorsemeuta. Electric Car Running Show Card water Usedin Government service. in nor - his grasp believes that a feigned weakness Heavy ElearicTraction Outdoor Sign Palmer pporations, hoofs. professional nod Draftsman RAILROADER offices. has been caused by her struggles. In- Electrical losses FREE. Elettele Machias Uotreer ILLUSTRATOR Brochure .webers stantly Dixie seizes a wrench and before Telegraph Expert DESIGNER rookie. KING INSTITUTE. ED -300. BOOKKEEPER tee utti she can be stopt has wrecked the remaining Practical Telephony E.al i. sheab.ad.' - Station F. New York, N. Y. 9ECHANICAL ENGlSEEIt Stenographer sod Typist three torpedoes on the submarine by Mechanical Dal omen Cert. Pub. Accountant knocking the propellers off. Ship Dniteman Trauic Management %a Machine Shop Practice Comm: rein] Law SAVE 25 to 60% Orders are given to raise the U -boat to Gee Engineer GOOD ENGLISH en Ilabtlr geed CIVIL ENGINEER Common School Sohleets GRAFLEX- KODAKS the surface, to continue the destruction of Surveying and Mapping CIVIL SERVICE der 1ptloa. the deck guns. For a mo- RINE FOREN'S Ott I.NG'H Railway Mail Clerk Cameras and Leases et Beery shipping with STATIONARY ENGINEER Testae 0eeaere or Sapt. Equal to sew. Sava moony. Write now foe ment Dixie is left to her own devices and ARCHITECT AGRICCLTCRE Free Bargain Book and Catalog Areblteeeeeel Draftsmen Navigator Fathead? lietins bandeade of maner- sortsa hoorahs. she sees a memoranda as to the location of Pooltr,ebiarR French new cameras Needsóedsssold on Ì0 Trial. hase beet a supply base for the submarine on the Sheet Metal WorkerlNO atoaphuea hells. dealing se, We bars been In éheppbéwe;:pbl . coast of Maine (see Fig 3). She rushes stole le rest, Write New to the deck of the submarine and dives Name CENTRAL CAMERA CO., Deal. 124 Wabash Ave.. Chkaga 179. So. to a Present overboard with the object of swimming Occupatlo- United States destroyer which is some dis- Street Convert Your Bicycle loto a Motor -Cycle tance away watching for any violation of and No neutrality on the part of the "U -53." We sell you the motor complete Cit. State or furnish you with the finished The episode ends with destroyers and parts Iron) which you can build aeroplanes searching for the supply base, the motor yourself with few tools. Grant, and Dixie, We send you the printed instruc- under the direction of tions with blue prints of the drawings for $.2225 or with information as to its location, swim- dal fuit pa Mentors for 3 -cent stamp. ming for the destroyer in the Atlantic Don't Shout" hear STEFFEY MFG. CO.. S025 Brown St.. Phila.. Pa. Ocean. "I hear you. I can now as well as any- Last. but not least, we have the superb body. 'Howe With MOTORCYCLES T H E M O R L E Y $40 photo -play production "Over the Top" with ill sod BICYCLES atout price.. Empey. PHONE. Pre a pair Singles and twine 32510 3100. our great war hero Sergeant Guy my ears now, but they New Motorcycle Tires $3. Figure 4 shows an exciting moment from are Invisible. I would Automobile Tires $3. Best the Top" in which a German Count not know I bad them in. 1407 ty'-tom Motorcycle Carboy- "Over only that I hear l$ ié a -board of myself, band Marcia. H. Tandems 115. New Bkrdea .Veston Prie.. and his accomplice at the switch all right. MORLEY Dialager, The Price Cutter. Roebeeter. New York a tall office building somewhere in down- PH a town New York, are about to throw the D E A F switch at midnight which will light a signal to to the ears what glossa TYPEWRITERS Invisible. ALL MAKES. SAVE $25 TO SSO on top of the tower, notifying the other are to the eves. on rebuilt by the well -known "Young Protract." comfortable. weightless Sold for low cash - installment or rented. spies on the Jersey shore that it is time to and harmless. Anyone can adjust It." Over one hundred Rental Unpile. on purchase price. Write or begin blowing up monition factories and thousand sold. write for booklet and testimonials. full details end guarantee. Free trial. Young Typewriter Co., Oept. 655. Chicago ships. THE MORLEY CO.. Oept. 74B, Perry Bldg.. Phila. You benefit by mentioning the "Electrical Experimenter" when avitlg to advertisers.

www.americanradiohistory.com ELECTRICAL EXPERIMENTER September. 1918

Laboratory"Chem>Istry By Richard B. Moore, Instructor in Chemistry, Ì>LI(1). University of Missouri. Contains 195 pages, innumerable illustrations and experiments. Printed on highly finished book paper. Handsome stiff cloth cover. Size 5"x71/2". FREE with a year's subscription. Add postage for 1 lb. ,. Experimental Obs' H Electricity Course S. GERNSBAC This masterpiece contains I60 Size .LESCiUZ pages, 400 illustrations. of book 5 "x9 ". Printed on 11V/. extra thin paper, so book can be slipped into pocket. Hand- some flexible cloth cover. FREE with a year's subscription. Add So for postage

Wireless Course The most compre- hensive Wireless Course ever printed. Contains I60 pages, 350 illustra- tions. Size of book 63% "xl0 ". Very fine flexible cloth cover. FREE with a year's subscription. Add 6e for postage Read This Remarkable Offer It may be withdrawn at any time, due to the tremendous cost of paper, which IS JUST DOUBLE WHAT IT WAS ONE YEAR AGO. We only have a limited supply of these fine books on hand; after they are gone we cannot reprint the books until conditions become normal again. THIS MAY BE TWO YEARS OR MORE. Now is your chance. The publishers of this journal have earned an enviable reputation of giving more than 100 cents' worth for each dollar spent with them. Profit by this liberal opportunity NOW; it may never be made again.

.t. s : HERE'S THE OFFER Subscribe to the ELECTRICAL EXPERIMENTER for one year, at the Gentlemen: regular subscription price of $1.50 per year (Canada, foreign -Ind Please enter s and we will send you FREE any one of the above books. my subscription N. Y. C. $2.00) to the ELEC. T If you subscribe for two years, TWO BOOKS WILL BE GIVEN FREE. EXPERI- TRICAL All THREE BOOKS will be sent FREE with a three -year subscription. MFNTER for the fL, If you are a subscriber at present, take advantage of this wonderful term of year _(- extend your subscrip- for which I enclose here - opportunity anyway. If you do, we will present th s G tion from its expiration date. You will also send me at once ), FREE your book This Offer Limited. Act Now. \ 223 EXPERIMENTER PUBLISHING CO.,

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www.americanradiohistory.com September, 1918 ELECTRICAL EXPERIMENTER

Opportunity Ad -lets OU will find many remarkable opportunities and real bargains in these clumns. It will pay you to read and investigate the offerings made v every month by realiable firms and dealers from all over the country. No matter what you may be seeking, whether supplies, automobile accessories, the opportunity to make money, or anything else? you will find listed here, the best and most attractive specials of the month. Advertisements in this section six cents a word for each insertion. No advertisement for less than 60c accepted. Name and address must be included at the above rate. Cash should accompany all classified advertisements unless placed by an accredited advertising agency. Ten per cent discount for 6 issues, 20 per cent discount for 12 issues from above rate. Objectionable or misleading advertisements not accepted. Advertisements for the October issue should reach us not later than August 22, OVER 100.000 CIRCULATION GUARANTEED, A. B. C. AUDIT EXPERIMENTER PUBLISHING CO.. INC., 233 Fulton Street. New York, N. Y.

91NABNtlAtnAWUI111WIINIIIIIIIIIIWIIINIINWIWIWWW1AWIII11WNIIIIlI1NnW11WAWIWWIIW6 aWlllmun;mlNWlmm0110117,11 lNNamnNlmINammoinutie 11VIW1zzartuWW niumimnum mum umlllu!e.. mru!nl Automobile Accessories Aeronautics A'ews Correspondents Attention! Carbonale equal to twenty gallons Aerial Age, America's leading illustrated week- Earn $7S Weekly, spare time, writing for Gasoline prepaid anywhere, $t. Absolutely Guar- ly, presents the latest developments in aero- newspapers, magazines. Experience, unneces- anteed. Products Co., Elgin, Ill. nautics throughout the world. Up to the minute sary; details free. Press Syndicate, 566 Louis, St. amenummaammunauressupitimmuumalsonissis technical information concerning aero- engines, Mo. aeroplanes, accessories and patents. Complete 151111aa ®W$aammlIMEMMWOIWWWf®annommaIO Agents Wanted model, news and instruction. Trial subscription ounnommuumma six months, twenty -six issues, one dollar. Sample Business Opportunities lnsyde Tyres, inner armor for automobile tires. copy toe. Aerial Age, aso Madison Ave., New double mileage and prevent punctures and blow- York City, N. Y. Make DieCastings. Sketch, Sample, Booklet and Proposition sac. R. Byrd, zzy, outs. Quickly applied. Cost little. Demand + aummmmlllm! mmmllmmmmnormnounllrnmmlmanlnnullummtlmmammmn Box Erie, Pa. tremendous. Profits unlimited. Details free. How to become a successful inventor. American Automobile Accessories Co., Dept. 54. Motorcycle Free particulars, Engineers, 2348 Armitage, Chicago. Cincinnati, O. Motorcycles From ew an second- $10 Daily refinishing chandeliers, brass beds, hand. Easy terms, large list to choose from, all Stop -Read -Dollars made at . home; all or automobiles by new method, without capital or makes. Send 4c stamps for Bulletin "A." Peer- spare time. send 25c silver, quick. M. A. Carr, experience. Free particulars and proofs. Write less Motorcycle Co., Watertown, Mass. Columbia, Tennessee. today. Gunmetal Co., Ave D, Decatur, Ill. Indian Used Parts 1912 -13 model. Cylinders "Quick- Action Advertising -How it is Build - RINIaa$tIIWUWIEImmWialllllln Imm ®mlgnfllmlml®® $4, pistons $t? carburetors $4. Presto Tanks $5. ing Business for the Progressive Advertisers of Mechanical oilers $3. Free list. Victor Help Motor- America ": A little story of RESULTS, told by Wonted cycle Co., Desk "A," Victor. Colo. the advertisers themselves -not the publisher. You will be interested in reading this little Men, Women, IS or over, wanted immediately JJIIIIIIiIIIIGIIIIIIII !'! ":Cil!IIII( VIII! Illlllllllllllllllllllllllllllmlllllllllllll 'llìl',Jf'iH il!IIIIIIIIIIIIIIIIIII' for U. S. Government War positions. Thou- booklet which we have prepared for prospective sands Clerical positions open, sino month. Easy Van Wert, Ohio, advertisers, a copy of which will be gladly work. Write immediately for list positions. July 20, 1918. mailed to you upon request. It tells you how Franklin Institute, Dept. T26, Rochester, N. Y. EXPERIMENTER PUBLISHING CO., INC., to talk business with t,000,000 intelligent, inter. 233 Fulton St., ested 'and responsive Americans every month - owls uIl w!IIWIIMIIIIIIIIIII EtUNaalIUIIWIIamllllll !IIUmll1111W11111111WWIMI Ith New York City. men who know what they want and who have Gentlemen: the money to buy it. Write for particulars and Auctions Enclosed please find remittance amount- rates today. Douglas Wakefield Coutlee, 225 mg to $1.38, for which please enter our ad M. \Vest 39th Street, New York. Auctioneers make from $to to $15 a day. Free atalog. Missouri Auction School, Kansas City. M the Classified Section of the September Mr. Business- Man -Your advertisement Itere issue. will be read by over wo,000 live prospects. The mummetormaosnemmammummommuommauttumusimum E. t \re have the VERY best confidence in "Opportunity Ad-lets" of the Electrical Ex the "E. E." advertising medium. From our perimenter bring quick and positive results. Books July ad we are receiving on an average of For proof of what they have done for others ad 50 ORDERS PER DAY. The week of 8th dress Classified Department, 233 Fulton Street, BOOKS - Novelties - Postcards - Catalogue, to 13th we shipped 383 Hotpoint Irons. New York. 3e. Vim Company, East St. Louis, Illinois. Like Rastus Jackson says, "Ah gives my Our New Directory, sources of supply and first appetite all my attention," likewise we are nmlllm1IWllmommnmmmuunmuuuunauumummu mlmlluuu!uumllmllmWlWlumlaft hands over t,000 lines, $t. Products Co., Elgin, Ill. now giving the Hotpoint orders all our at- tention and we are growing bigger and M. Patent Attorneys To Get Better Pictures: Read the Amateur stronger. Your Idea Wanted, Patent Your Invention. Photographer's Weekly; illustrated; weekly Yours vcry truly, I'll help you market it. Send for 4 free books, prize competitions; print criticisms; many unique BAER ELECTRIC COMPANY. list of patent buyers, hundreds of ideas wanted, teatures; $1.5o per year: three months' trial sub- etc. Advice free. Patent advertised free. scription z5c. Abel Company, 401 IIIIHIIIIIIIIIIIIIIIIIII! 1111111811111iINElllnlmlllnlnllllllllllII IIII Illlllllllllllllllllnlnlnlnllllllllllllil Richard B. Owen, Patent Lawyer, tao Owen Caxton Bldg., Cleveland, Ohio. Bldg., Washington, D. C., or 2278T Woolworth Read "A Man's Secret," 25c. Paul Duff, 2713 Electrical Supplies & Appliances Bldg., New York. Mozart. Chicago. I,ON "Hotpoint" Electric Irons, $4.25 each, pre- Patents on Easy Payments. Send model or A Binder for The Electrical Experimenter will paid: Satisfaction or money.refvuded. Read our sketch for Free Search and Certified Registra- preserve your copies for all time. Price, Soc. July and August advertisements. Baer Elec. tion of Your Invention for Your Protection. Postage on 3 lbs. is extra. Send for one today. cric Company. Van \Vert, Ohio. Free Book Tells What to Invent and How to Experimenter Publishing Co., 233 Fulton Street, For Sale 3" D.C. Voltmeters Scale 3y to 8% Obtain a Patent on Easy Payments. C. C. New York City. Volts. Automobile and Switchboard Service, Hines & Co., 593 Loan & Trust Bldg., Wash $3.25 each prepaid. S. A. Meier, 2445 Logan ington, D. C. Fire Sale of Slightly Damaged Books. Due to Blvd., Chicago, Ill. fire in our stock rooms, a great many of our Millions Spent Annually for Ideas! Hundreds books were water stained, but not otherwise Exchange or Sell: Electrical and Wireless now wanted! Patent yours and profit! Write damaged. Rather than dispose of them to deal- goods; Tesla Coils; Wireless transformers; today for free books -tell how to protect your- ers we prefer to give our readers the benefit. Cameras; Sporting goods; Motor and Ice Boats: self, how to invent, ideas wanted, how we help Look at this list! Our celebrated Wireless Printing presses; typewriters; etc. WANT you sell, etc. ziz Patent Dept.. American In- Course, Mo pages, goo illustrations; Experimental Electrical Apparatus; Wireless Goods; Labora- dustries, Inc.. Washington, D. C. Electricity Course, Mo pages, 350 illustrations; tory Supplies; Books; Machinery and Tools, How Make or most anything. List for purple stamp. Give Inventions Wanted! Manufacturers constantly to Wireless Sending Instruments. writing us for patents. List of inventions ac- These three books for $t.00 prepaid. Regular details of what von have and want. LaRoy Zehrbach, Dept. E -E -n, Monroe, Mich. tually requested and book "How to Obtain a selling price of these three books is $2.$o. We Patent" sent free. Send rough sketch for free guarantee you will be satisfied. Experimenter Bargain -.00 strap Keys, 15c each. postage Publishing report regarding patentability. Special assist- Co., Inc., 233 Fulton St., New York extra. J. Wiseman, 2io9 Second Street, San ance given our clients in selling patents. Write City. Diego, California. for details of interest to every inventor. Chand- Old E. E. Back Numbers: We have some valu- Electrical Tattooing Machines and supplies. lee & Chandlee, Patent Attorneys, Est. 2i years. able old E. E. back numbers on hand as follows: Catalogue FREE. Prof. Temke, Exp., 6:7 Cen- 551 7th St., Washington, D. C. 1915-Jan., March, June, tral, Cincinnati, Ohio. April, July, Aug., Sept., Patents -Without advance attorney's fees. Not Oct., Nov., Dec., price each 35e. :916 -Jan., Feb., a111NnmliImINIIWIINntiuiImiNII uiliniNIUWalIJItWmnIUIINIIIIII March, May, !1rncilnallmltlB due until patent allowed. Send sketch for free June, August, Sept., Oct., Nov., Books Dec., price each 35c. ¡917 report. free. Frat.k Fuller, Washington, -Jan., Feb., March, For Adt'ertiscrs D. C. Apr., ,`lay, June, July, Aug. each 35c; Sept., Oct., Nov., Dec., each woe. "Quick- Action Advertising -How it is Build- WI'mlllmmmP imllmm!13'l :r:Imllll...' -,. ¡918 -fan., Feb., Mar., Apr., ing Business for the Progressive Advertisers of May. each zoc; June, July, Aug., each Ise. We For Inventors can fill orders at once upon receipt of your remit- America "; A little story of RESULTS, told by tance, and iJ you have not these numbers the advertisers themselves -not the publisher. already You will be interested in reading this little Expert Engineering Service for Inventors. now is your chance to get them, as they probably Reasonable rates. \lagnacal, 162A, Orange, New will be snapped up very quickly. Experimenter booklet which we have prepared for prospective a of which will be Jersey. Publishing Co., 233 Fulton St., New York City. advertisers, copy gladly mailed to you upon request. It tells you how mlml .l::al':IJ mm11011 ^.III11011 l 111711nll "!t1r:.alli lnlnamlNnimuulmnNmlWtimmni mllmm to talk business with i,000,000 intelligent, inter- ested and responsive Americans every month - (lotion Pictures ll'atches men who know what they want and who have the money to buy it. Write for particulars and Motion Picture Machines bought and sold; Expert Watch Repairing Reduced Prices. rates -today. Douglas Wakefield Coutlee, 225 bargain lists free. National Equipment Corn. References. Leo Hirsh, Elkhart, Ind. \Vest 39th St., New York. pang. Duluth. Minnesota.

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www.americanradiohistory.com 360 ELECTRICAL EXPERIMENTER September, 1918

i'L....,. w,....,..,.. u,. "1 . C.'i.`".'"n'- ° °11.111^:nl®I'R2,11I7w1WllL Song Poems Wonted .Models and Model Supplies a We write music Collapsible Scenery for all Plays. Amelia Write the Words for Song. Grain, Philadelphia, Pennsylvania. Producers of Results: Inventions developed and guarantee publisher's acceptance. Submit Models, Experimental Work, anything special c Z,2.72.7.71uAUw1LI00011111 411 :1111111111111,11441 . wS C :: ulnlwwunI:::I s1C71L01 poems on war, love or any subject. Chester in metal to order, novelties spinning castings Music Co., 538 S. Dearborn St., Suite 265, Chi For Sale in any material, electrical devices, patterns of cago. Mountings for window shades. Patented to all kinds, plating, general manufacturing, de- C. S. and Canada. No nails, tacks or screws. signing, special tools, punches and dies, stamp- Phonographs Does not mar window casings. Eugene M. Starn, ings. Send drawing or sample. Expert infor- 225 N. Main St., Butte, Mont. mation free. John's Engineering Company, Dept. E. Cleveland, Ohio. Build Your Own Ph pin and manufacture l9lwr.- x84.110 it;0ult. ul, IrW.!u, ".,,7:,111711:1I11111111;111 them for profit. Drawing instructions, Parts, Chemicals n "Tf 11T-1.111111'dIBWINIC111 ;u1111111I1I1011111111,il11I11111111110 31111L1III111311111nlb Price List, Blue Print, etc., complete, sent free Miscellaneous upon request. Write today. Associated Phono- Chemical Apparatus for use in the experi- graph to.. Dept. Et, Cincinnati. Ohio. ments of this month's Experimental Chemistry. Tobacco or Snuff Habit Cured or no pay. Build Your Pbonograph. "Perfection" high Electrolytic Generator, with carbon electrodes, $t.00 if cured. Remedy sent on trial. Superba quality spring and electric Motors, Tone Arms, each $6. Leibig Condenser, 20 inch, each $t.55o. Co.. SA, Baltimore, Md. Reproducers. Wonderful results, big saving. Burrette with glass stopcock, each $2.50. With- out stopcock, $1.40. Vacuum Pump, for obtain- Closing Out Sale! New $20o Stock Remnant at Handsome new catalog free. Indiana Phono- one ing high vacuum with mercury, unmounted $3. -half. Electrical, Chemical, Manual, Wireless. graph Supply. Indianapolis, Ind. Take in trade E. E's, tgto to t9í6. List for stamp. Mounted on wooden frame $5. Our glassblow- fitia11=1111Ci=I1::i.,ulNw Lüü41124, I.ärs41YrliiI ing department can furnish any piece of ape Address Amateurs Central Association. Diet. Stamps and Coins paratus of special design, including \Ray and Wilbur C. Bickel. Claypool, Indiana. Geissler tubes. as well as experimental glass- Ginseng planting Instructions free, too seeds all different, free. Postage 3c. ware. \ \'e can supply any piece of chemical 23e, 1,000 $1.00. Specialty Farm, Rockford, Minn. Stamps -st apparatus you Mention paper. Quaker Stamp Co. Toledo, Ohio. need, including electrical acces- Pyorrhea-II. E. Kelty, D. D. S., M. D., pyor- sories for electro- chemical work. Write your rhea specialist for 15 years, has developed a Sea Finely Mixed United States or Foreign requirements. or send stamps for List B." N. successful home treatment for pyorrhea. Puri Stamps, lx. Philatelic Star, Madison, Y. Experimental Chemical & Research Laboratories, fying, healing, preventive. Full month's treat- 2M all different, really fine Postage Stamps, 183 West Loth St., New York City. ment and booklet $1. Circular free. Dr. H. E. 23c. Dayton, East Foxboro, Mass. Experimental Chemists. Extra help and per- Kelly, Glenwood & Woodland Aves., Leonia, N.J. I011111Nalae1l1110a11211Ma®I®t sonal coaching by mail of my chemistry lessons We Have a limited number of beautiful art Engines, Molars, Dynamos in titis journal. One dollar per lesson. Twelve pictures on hand of Nikola Tesla and Dr. Lee lessons Ten Dollars. Albert W. \\'ilsdon, 183 De Forest. These make a handsome decoration West loth St., New York. for any Small Motors di Generators: Large quantity laboratory or workshop and should be 7liftE TZ1111IIM6MIlAfIIIIINI IIIITIlmnnIl"w 1111 ;;" " " +,IC:II ":I!OfWI011111 prominently displayed. Price for both, prepaid, A. C. Motors, H.P. $15 each 44 H.P. $35 each. Sá loc. Experimenter Pub. Co., 233 Fulton St., New Battery Charging Sets: too Robbins & Meyers Tcicgrophy York new Motor Generator Charging Outfits, all sizes, City. 53o each and up. Charging, Lighting and Mov- Telegraphy -Both MORSE AND WIRELESS; Bargains in Tennis Rackets. We have ust se- ing Picture Arc Generators, Slo and up. A. C. STATION AGENCY, taught quickly. TRE- cured an immense shipment of Tentais Rackets, MENDOUS DEMAND-greater than supply. Motors 1 & 3 phase up to 5 H.Y. for immediate made by one of the largest firms in the country, delivery. Bankruptcy stock -Less than half PERMANENT POSITIONS SECURED -BIG which we will close out at slashing reductions. price. Special Bulletin 89. Johnston, West End,, SALARIES. IDEAL WORKING CONDITIONS. No 2375 -Extra best Tennis Racket, $5 grade, air Pittsburgh, Pa. GREAT OPPORTUNITIES FOR ADVANCE- dried ash, popular long oval form, concave walnut MENT. WOMEN OPERATORS also needed. I®111118u1in0t wedge- superior quality of gut; each $2.75. All expenses low -can earn living while attend- No. 2377-First grade Tennis Racket, second Tricks, Puzzles and Gaues ing. Oldest and largest school -established 44 growth ash, walnut and maple throat, very good y ears. Endorsed by Railway, Western Union grade of gut; handle of cedar with leather cap; Itching` Powder, Sneezing Powder and Flashy and Marconi officials. Now offering special three doz. a $3.25 grade; each $1.85. Stage Money. toc each. 3 for 25c, Soc per months' Radio course for young men subject to No. 2376 -Medium _grade Tennis Racket made of and Magic Fece. Syl. Lesson in Ventriloquism draft, enabling them to enter Signal Corps the saine stock as No. 2377 except the gut. A per- Magic Shop. 192 Providence, R. I. - vian's Clifford, "PREFERRED SERVICE," Large illustrated fect $2,25 grade. Ideal for beginners. Each $1. 5. Tricks, Puzzles, Jokes. Toys, Games, Novelties, catalogue free. Correspondence courses also. Shipping weight of each size two pounds. Order Doll and Cane Racks, Plays, Wigs, Stage Sup- Write today. ENROLL IMMEDIATELY. today. "First Come, First Served.' Don't forget plies, Escapes and Illusions. Large 1917 catalog DODGE'S INSTITUTE, Lone St. Valparaiso, to include money for postage. The Electro Im- free. Oakes Magical Co., Dept. 443, )shkosit, Wis. Indiana. porting Co., 233 Fulton St., New York City.

Scientific Exchange Columns undoubtedly have something you'd like to buy, sell or exchange. In your attic, or workshop, or some far corner of your closet, you IOUprobably have dozens of long-forgotten articles, useless to you now, hut very tseful to someone else. Live readers with something to "swap" or sell have found that the surest and quickest nay to make the desired trade is thru an ad in these columns. Remember. the U. S. Postal Laws protect you. No one can "do" or cheat you. Of 3,495 "ads" published in these columns during the past five years, only twelve complaints were reported to us, and each one was adjusted to the full satisfaction of the complainant. The rates are: Fire cents per word (name and address to be counted.) Remittance must accompany all orders. No advertisement for less ac- than SOe accepted. We reserve the right to refuse any advertisement which we consider misleading or objectionable. Dealers' advertising cepted in Opportunity Ad-let columns only. Advertisements for the Oct. issue should reach us not later than Aug. 22. OVER 100,000 CIRCULATION GUARANTEED, A. B. C. AUDIT

Exchange for good rifle and dynamo: Plate I will give you goods worth $305.75 for $too or Sell -Shaw Motor Attachment in excellent con- camera and outnt, excellent condition. John new twin motorcycle. List free. B. F. Swanson, dition. Battery ignition, run about three hundred Burke, 17 Eli St.. Valley Falls. R. I. Pierson, Fla. miles. Make offer. Eugene Brown, Winchester, For Sale -A necessity for electrical labors Indiana. photogra- tortes, efficiency experts, astronomers, 1mdIIIIp11111111l -- or 3'flH.P. 220 Volt D. C. Motor, surgeons, nurses, JI1m1 - 'I'm IIII III on 1111111mei11111EiuuumISE Trade Sell- phers, chemists, physicians, nao volt D. C. Motor for H.P. aio and for all sports. H.P. y Inspectors of target practice 329 Volt A. C. no cycle motor. Adolph Gedeon, 16 size, open Elm St., Penn Yan, N. Y. New York Standard Chronograph, t= 3296 W. 5oth St., Cleveland, Ohio. face, i5 jewel movement, m year gold case. Gentlemen: Make is accepted same will be I wish to tell you of the successful re- offer. If offer sults I obtained from my ad in the "E. E." Exchange for good Spark Coil or Transformer shipped c.o.d. Cost me $25; good as new. a good High Frequency Outfit. Write for list. W. Bilodeau, Lyndonville, Vt. != They have been "pouring' in at the rate St., Ohio. J. = of several each day. B. J. Fisher, 317 \Water Akron, For Sale or Exchange -Bausch & Lomb Model To date, I have received sixty -three in- telescope, Ambio Electric Trouble Shooter for Automo- FF8 Physician's Microscope, small = quiries and have disposed of most of articles biles. Will sell cheap. chemist scale and weights, chemical rectifier, In first-class condition. advertised. \ \'rite J. Schmidt, 518 Oneida, Joliet, Ill. variable condenser, universal shunt box, 1.5.3-30 Inquiries have come from as far South volt \Veston D.C. B volt Weston D.C. Voltmeter, 5o as Florida, West from Colorado and several -0 Wanted -t K.W. Type R, Thordarson Trans- Voltmeter, 30o wont Weston U.C. Voltmeter, from Canada. former, n K.\V. Tesla Coil, t K.W. Key, Polar Wheatstone bridge. wireless tuning coil, Leeds Thanking you for your promptness in ized Relay, Selenium Cell, Microphone, X -Ray & Northrop Galvanometer, 1on,000 ohm laboratory inserting my ad, I remain, Tube, Stand and Fluoroscope. Must be new. resistance, etc. F. Jos. Lamb, 264 Jefferson LESTER CHISHOLM. Give description and make. Burrows Rogers, Ave. East. Detroit. Mich. Cainsvillc, Mo.

Edison Moving Picture Machine and five thou- I III III 11111 11111i1111 ll lin 1111111111 II takes bargain. Fred. For Sale -Professional Microscope, two objec- sand feet of film. $5o all- and erick Martin, 33 Willis Street, Dorchester, Mass. tives, in good condition. Also Police Camera For Sale- Magneto, $4; Dynamo, 52.50; Genera Enlarger. Write Stephen R. Hardwick, Belmond, Wanted-Goad Audion detector bulb. Price tor, $i; Battery motor, Soc; Spark Coil Second- Iowa. reasonable. Glen Coleman. Wheeling Avenue, ary. soc. Ruben Hilborn, Brown City, Mich. Muncie, Indiana. Wanted -Motorcycle engine and chemical out- Wanted -D.C.Generator not larger than 2 K.W. Will pay S20 for a medium or large size Milo fit. Horace Risteen, rio Coleman St., Chippewa Harry Ostness, River Falls, \Vis. Bar -bell. Martin Knox, Granite Falls, Minn. Falls, Wis. You benefit by mentioning the "Electrical Experimenter" when writing to advertisers.

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Motor information you need to help you in your every day work is in NO. 2 principles- armature reaction -motor starting - calculations -brake horsepower -selection and installation of dynamo and motors -galvanometers- standard cells- current I a nut- resistance measurement - voltmeters - watt- meters watt hour meters -operatmn of dynamos-operation of motors, etc. 3 Contains 300 pages, 423 Illustrations. Dlstrlbution No. Systems -wires and wire calculations- Inside, out- HAWKINS side and underground wiring -sign flashers -lightning lime tection- rectifiers -storage battery systems, etc. 4 Contains 270 pages. 379 illustrations. Altemeting ELECTRICAL GUIDES No. Current principles-alternating current diagram. -the power factor-alternator principles -alternator con - These books place electricity at your finger ends. They cover every Imaginable etrucUon- windings, etc. subject, principle, theory, problem, trouble, and way of doing things electrically. 5 Contains 320 pages. 614 illuetretioos. A. C. Moor. Every subject Is Indexed so that you can turn right to it. They are a study course No. -synchronous and Induction motor principles -A. C. commutator motors -Induction motors. transformers: and a reference guide in one. written in plain every day language -no wasted words construction. laten. -only what you need to know-chock full of upto- the -minute electrical knowledge. cooaedione. tests- converters -rectifiers, etc. Contains 298 pages. 472 Illustrations. Alternating The guides are a complete course in electrical engineering. They will help you in No. 6 current eyatems-switching devices- clrruit break. every detall of the day's electrical work. 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Elm- see these hooka and No. 9 trie railways- "It is only right for me to recom- rut them Into actual use; ou will never scam want to be ing-trolley electric locomotives-car light- , mend highly the Hawkins Guides. for without them. Try It at our expense. car operation- miscellaneous applications they bare bun of the greatest assist- motion pictures -gas engine ignition-automobile selt- ance to me in placing nee in my pres- tarters and lighting systems. electric vehicles. etc. ent position as Superintendent of Con- Contains 513 pages. 599 Illustrations. struction Department of one of Om 's NO. 10 Elevators- cranes -pumps --air corn- SEND NO MONEY eleetrie heating electric largest Electrical Companin. I would Pressors- - welding- TH EO. like to sae every man have s set of soldering and brazing -Industrial electro- Hawkins Guides." It rill cost you nothing to receive these books-to look lysi, -e ectrn plating- electro- therapeutic AUDEL & CO. Geo. Knecht. Columbus. 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If sat 10 electrical guides. Superintendent When you decide to keep them you only have to pay I- factor, I scree to send you gl 51.00 down and remit the balance of $9.00 on the easy There are over 13, within seven days end to further "I am now superintendent of the layment of $1.00 e. month till recd far. 500 cross refer- mail you fÌ each month until paid. Dunnville Hydro - Electric Systems. Use this coupon to get the books. It will pay you ences. You find and Hawkins Gulden were great hell. many times over. to me to holding down responsible what you want Slanatura to know in- Position-. stantly. W. E. Swarta, Dunnville, Ontario. THEO. AUDEL & CO. Occupation Wireless Operators 'T have worked wirelesa for ten 72 Fifth Ave. New York, N.Y. Business Address year. --but I wish I had these Wink. sears ago, is they have aaved me gnat deal of trouble... It. Manball a # Rastaanee Steamer M d R No. S. W alkervN e. Or _ Nalereeee E. E. Nept.

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