'.•"'',"« «••'• pUce l this 'V.''»«"ne « «nt •tampon notice, band »me to any postal employee and it will be IIV/NOTICFIV^Li TOIV/ 1\L./\L7L.I\.RFADFR* plirnd^^'"J"".^"'^*',n the hands of our 1 soldiers or sailors at the front. /Vo lOroppinK—no orfrfre^..— A. S. BURLESON, Postmaster-General. Tl OVER
CENTS 175 L ILLUST.
ELErCTRIO-tt^L^ JNliiVVCi AJLrl-#U« TREATED
i^ LARGEST CIRCULATION OF ANY ELECTRICAL PUBLICATION !
ELECTRICITY MADE SIMPLE ^ The demand for trained Electricians is immense. Fine positions are everywhere. E.xperts must be MADE— to fill them. This situation offers you the best chance you'll ever get to forge ahead Ql'ICKLY in this greatest of all professions. Earn $2SOO to $8000 a Year! QUALIFY for a splendid career through my course. It is snn- plified to the point of perfection. You'll enjoy it. I and my assistant engineers have worked to make it the most exact, simple, compre- hensive and interesting course in America. To show you how PRACTICAL it is—and PROVE vou can learn Electricity with SPEED and EASE, I will send vou proof lessons—FREE OF CHARGE. Let a Practical Engineer Personally Train You at Home L. L. COOKE The well-known consulting and advisory engineer, for- merly member ot Engineer- CAN DO THIS ing StaBs ot American YOU Bridge Co.. Pressed Steel Car Co., and Millikan Bros., great international engineers, in New York. London and So- Africa.
I will give you tlie practical training vou need — AT HOME. 'l will PERSOX- .\LLV train vou in a WORKING knowledge of Electricity in your SP.\RE TIME. .\nd I am so sure ou will make a splendid jccess in the study of tliis •\iscinating profession — liat I will give vou a i;f.\R.\XTEE BOND to AFTER HOME STUDY : fund the full tuition cost o you, if you arc not en- tirely satisfied when you receive your DIPLOM.\ and Electrician's Certifi- 3622 TO $10022 A WEEK cate. Proof Lessons—FREE!—Free Electrical Outfit! tuition. If I hear from you at once I will send you the Proof Act (luick()U1C and secure a big„ reduction in cost of ^-^ tools, y.(\«()/ij FREE, and I will also she you a big outfit of Standard size electrical materials, etc.. abso- lutely FREE, ^lany other vakiable benefits too numer- -| ous to mention. Send Coupon NOW— for full details. MAIL THIS COUPON Don't fail—only a practical engineer can teach you the things vou MUST know to succeed big—and as Chief Engineer of the Chicago Engineering \\'orks, I am in a
Dcpi. 25, position to help you iinmensely. Send coupon or write CHIEF ENGINEER. Chicago Engineering Works, today sure 441 Cm St., Chicago, Illinois. Without obligaiion on my part kindly send at once, fully prepaid, particulars CHIEF ENGINEER COOKE of your complete Practical Home Study Cour>c in- Electricity. Chicago Engineering Works DEPT. 23
Street Chicago, III. Addn 441 Cass
T0W1 ; ^ !
March. 1918 ELECTRICAL EXPERIMENTER 737 i IIIBIIIIBUIlHIIIIIHIBIIIIIBIIIll EXPERIMENTERS
Student's Chromic Plunge Battery
Thl> Is an Ulcal haittry tf>r tlcclrii.*! t-Mitri- iiRtital work nhtrc a VL-ry i*owcfful curreiil i.-> nol rt;nuire«l. Tliia biiltcry will lltlht u 'i volt
lamp f«)r Hcvera] liourn on one chartft- ; It will niii a small u>y motor hurprlHltijdy well: It will
t'. small .-li-itrMiihitinK wi.rk ; it i-* i ji!\ i t. siitiK' "'irK : It «'i^rs ;i I dirlv sU ur rnp . ;in(l as the zinc electrode can be pulled clear of the electrolyte, no materials are uied when liat* tery stands Idle. ({t-st AnialKam ZItic onb' i» used, ait wi'll us a hlRlil.v |i(jr The *'Electro" Radiotone HIGH FREQUENCY SILENT TEST BUZZER This itiHtninieiit kIvi-s a wondi-riul lu^h riLi.'iH'.i Ml'SnWL NOTK in the receivers. ini|j(js^ilili- 111 ohtiiln wilh the ordhiar>- l.',st buzzer. The RADIOTONK Is built alonijt entirely new lines; it Is NOT an (irdinary hu/.zer. reconstructed In some manner. The RAniOTONE bas a single fliii- Kteel reed vihrulinR at a remarkably liiKh spee The "Electro" Telegraph is not a toy. hut a practical, honestly built li-k'sraiih outfit, which not only sounds hut works like tJic big conitucniiil instru- ments, IJy studying the cwie lor :iO days you can brrDine a first -class teleuraph operator. Such o|ieralor,s aie in hig de- mand now. Outfit consists of TWO civniplete telegraph instru- iin'iits rai'li itiiasurlng .3^^ x 2\fe X l^U. All iiu-lal parts are high- ly nickel iilaled. lucluiliiig key li'ver. Note hard rubber knob. Telegraph Code Chan, tcleuraph liiaiiks and contncinig wire comes with set. but no batteries Outfit work^ nn li dry ci-iiH (one cell for each instrumentl. The "Kleciro" the ONLY Oiudt iliat works both ways, each station can call: no switches, no t'Xtra.s .\"iliinn III get out i>r order, (Juaranteed to please you or money :. Price Compkte as li'ustrat-d (TWO INSTRUMENTS).. Shipping Weight. 2 lbs. $1.25 IMMEDIATE SHIPMENTS The **Electro" Codophone ( PaU-nts Pendin-;^) What this 5i1 rk\\ remarkable n^ ^ M, •KJ\J ^SIh^F^^""^ instrument Is — and does. No. FX20n2 Tlic "Mi-c iro" Codo- ««rT^HE BOY'S ELECTRIC TOYS" contains enough mate- phone IS rial TO MAKE AND COMPLPJTE OVER TWENTY- positively the --I only Inslni FIVE DIFFERENT ELECTRICAL APPARATUS witli- nient made nuf any other tnnls, exi-ept a sfrew-ririv.T *'iirni^IuMl with the outfit. The biix that Willi apparatus which are already imitate a 5IH' contains tlie following complete Instruments and cycle note assenililtMl exactly as Student's clirnmic iduuKe battery. enmpass-Kalvannnieter, solenoid, telephone heard in a receiver, electric lamp. Enou;:li \ariims jiarts, wire, etc., are fiirnislled to Wireless re- ceiver. The tnalie tlie toiiowin;: apparatus: r . loud-talking receivi ; ru. talks so l»md that you can hear Electromagnet, electric cantion. magnetic pictures, dancing spiral, electric the sound all over the room. i\iii ii tii.Te is a lot of oilier noise. tiammer. galvanometer, voltmeter, hook for telephone receiver, condenser, THAT'S NOT ALL. Ky lisscning or tightening the receiver cap. a tone sensitive microphore, short distance wireless telephone, test storage battery, troni (be lowest, softest qUiilitv. up to the bnuiest and highest screaming snuiid can he shocking coil, complete telegraph set, electric riveting machine, electric buz- Imd in a im s.-c.nds. FOR INTERCOMMUNICATION. T'sing two dry '»"« for each instru fishes, telephone, mysterious dancing man, electric jump- zer, dancing singing nicnt. two Codophones when connected with One wire aud return ground. ing jack, magnetic geometric figures, rheostat, erratic pendulum, electric but- can he tised fnr inicuoiiiinunicatlt)n between iwo houses one-haU mile apart terfly, thermo electric motor, visual telegraph, etc. etc- One ou Ht abme replaces the old-fashioned learner's telesraph set. con- This does not liy iiiiy niciins cxiiaust llie Ust. but a great many more ap- sistiiig of key and sininder. The "Electro" Codophono is a handsome, well made Instrument, fool paratus can tic built actually and ctVcctn.iIIy. |)roor, and built for hard work. Con(aci.s are of hard silver Mi Inch In Witli the Instruction liool< wiildi wc furnish, one hundred experiments that diameter, that will outlast the instrument. can lie made wllli tliis outitt are listed, nearly all of these being illustrated There is also a neat <'n4ic cbart and full dinvtions enabling any IntellU with suTierli lllu.strations. No otiier materials, foods or supplies are neces- g' uritinij to advertiser. You benefit bv mcutiouittfj the 'Electrical nxpenmcntcT zvhen 738 ELECTRICAL EXPERIMENTER March, 1918 YOUR COUNTRY NEEDS Airplane Mechanics and Aviators '^'oung men contemplating entering the United States air ser- vice will now be able to obtain sound preparation under ex- pert instructors of AIRPLANE MECHANICS and AVIATION ENORMOUS DEMAND FOR TRAINED MEN ''^'^ heard of Uie proposal of 100,000 planes to be provided ^ (<1 \ 7^ ^^^° ^"^ much VV by the United States within the next year. In a countr>- where one great • ^ industry produces a million and a half motor cars per year, the fabrication of *'ne hundred thousand planes might seem easy, but actual figures, based on three years of actual experience in the war, show that there are now between forty and fifty men of the auxiliary services required for each active machine at the front. If the saTOe ratio should be adhered to in our service, it would mean that some 4.lt(.Kl.ouil men would be required in our aeronautical department on foreign soil between our ports of debarka- tion and the fighting front."—Statement of Howard E. Coffin. Chairman of the Air- craft Production Board, in The New York Times. .Taiuiary 11. 191s SCHOOL'S METHODS THOR- COMPLETE EQUIPMENT IS OUGHLY ENDORSED PROVIDED School was founded to meet an urgent E'S'ERY appurtenance needed for iostruction THEneed by former Army and Navy men oi is provided in the school. A complete air- highest standing, who appreciated the re- plane is in the class room. sponsibility. Recognized as experts in the avia- Several airplane motors are provided and tion world, they planned the details of all equip- pupils are instructed concerning each pan and ment and instruction- The school has been investi- how to assemble them. Lewis gun instruction i^^ gated by llie technical journals and newspapers given with an actual Lewis gim. This enable* and thoroughly endorsed. Every applicant for tui- the instnictor to combine theory and practice, linn is pres;ented with proofs of the school's which gives the pupil knowledge that readily ^>- reliability before his enrollment is solicited. r Instruction given in airplane mechanics and aerody- Lewis Gun Instruction namics under three aviation officers who have had active included in service in France. Daily lessons (three hours), morning, CADETS' afternoon or evening. COURSE FLYING TAUGHT for men prior to going to ground school. Course also covers Engines, Planes, pArTT.FAvTATTnNjgHfln' Aerodynamics, Construc- tion, Riggings, etc. i^ew YorK, k ll^Wey'l 42^/'lreel y Oft' benefit hy inctitioning the "Electrical Experimenter" whe$t writing to advertisers. ! — ! Electrical Experimeimter 233 FULTON STREET, NEW YORK P.ihlisht liy Kxpermuritrr Piil.li-hing C.mpany. I,k. ill. ( .,rn>l,.i, 1.. PreM.liiu; S. (k-rnsl.ack. Treasurer;) 233 Fulton Sireet, Xew York Vol. Whole No. 59 V MARCH, 1918 No. 11 UBUATS USE BALLOONS I'OK WIRELESS 1-roni Cover VISITING ARLINGTON VIA THE TALO CLUB I-'roni a painting by (icorgc Wall "°""" '" PRESIDENT'S SPEECH TO WORLD VIA CABLE AND RADIO 741 DESIGN AND USE OK .°' ^ THE WAVE-METER. . CAN ELECTRICITY .^^Z DESTROY GRAVITATION?.... 743 ^^^ ^'"°' '*" ELECTRICITY AND WAR IN THE -ITLMS" 744 THE HOW AND WHY OF RADIO APPARATUS^"" ELECRIC WINTERTIME COMl'ORTS 74S ^."''^' ^^^=- '« SOME NEW STATIC EXPErLmENT^"':^"'. ' ^ ^ HOW U-BOATS SEND RADIO 1,000 MILES By H. Winfield jecor 746 '** A SPEEDOMETER FOR SMALL BATTERY "ioTORS^!"^.''.'"''" ELECTRIC BOILER MOST EFITCIENT 748 ELIMINATNc; THE .*'°°" "" SMOKE NUISANCE BY EI.ECTRIciW. . MY ELECTRICAL LABORATORY. (Special pL^el^To"?^. By William H. Easton 749 THE FIRST TROLLEY By George Holmes 750 HOW TO MAKE A •BLINKER LIGHT" FOR MO'fo^^BOA^l'' 772 ELECTRIC POWER FROM THE WIND 751 SIPHONS—HOW THEY WORK ...... ' WOMEN LEARN RADIO y-,o By I- . ,.„„, W. Russei and j. L. Clifford 773 SEAPLANE CRASHES INTO RADIO TOWER 753 A SPECIAL GOLD LEAF ELECTROSCOPE FOR RADIO-ACTIVE JUMBO GETS HIS HIDE VACUUMED 754 EXPERIMENTS By J L Clifford 774 AN ELECTRIC SHELL FOR FKJHTING U-BOATS 75S AN AUTOMATIC ELECTRIC RAILWAY By Arthur "''"ePriebe 775//j HOWTOMAKE-IT ""^ PRIZE CONTEST . ANNUAL ELECTRIC LOAD RELIEF MAP RESEMBLES WRINKLES, ••ROCKIES' 756 RECIPES AND lOR.MULAS. .Edited by S. '^""=°^''GernsbKk ""779 EXPERIMENTAL 22nd . AT WAR WITH THE INVISIBLE By K. and G. Winthrop 7^8 CHEMISTRY— Lesson '''""'°" EXPERIMENTAL PHYSICS — LESSON 11 — PHOTOGRAPHI'. .'".'".".'. '''; -ELECTRICAL LABORATORY"-Prize Conti't ^f? CONCLUDED By John J. Furia, A. B.. M. A. 76n LATEST PATENTS DIGEST j%\ RADIO DEPARTMENT 761 PHONEY PATENTS—CONTEST ^Sf WIRELESS STATION IN FRENCH • TRENCH 762 QUESTION BOX ^34 Dormant Forces URlNf j the nasi few months we have read them. .\11 about us— in every stone, in all metals, in a good deal in the daily press about a every piece of wood, every material in fact—billions of wonderful new force purported as having horsepowers are laying, locked up, dead and inert. The been discovered b\' an Armenian gentle- atomic energy locked up in a one-cent piece is sufficient man by the name of Garabed Giragossian. to lift up the W'ooKvorth building several thousand feet "Garabed," as the new "force" is now into the air. The only trouble is we do not as yet know popularly known, is supposed to drive ships across the how to unlock this tremendous energy. We are still oceans at a fraction of the cost it is possible of doing blind towards atomic forces, just as blind as the savage the same thing now. Aeroplanes with a "handful" of is towards a cubic foot of Trinitrotoluol. It means Garabed will cross the Atlantic in a few hours, so we nothing to him, for he can kick it around to his heart's •ire told ; in short, all our known notions of present-day content, without danger, and nothing will happen. Even energy-producers will be thrown on the ash-heap, if we did supply him with the necessary percussion cap always providing that Mr. Giragossian will be able to it would not help him to unlock the iO.OOO cubic feet make good his promise of gas lying dormant in that one cubic foot of explosive. That the scientific press has kept itself aloof—never He would not know how to apply the cap, which per- even mentioning the supposed invention—matters little. haps is a good thing— for he would never have to try Scientific men quite properly like to deal with facts, not it again —at least not after his relatives had discovered suppositious inventions. But Mr. Giragossian has been his remains, miles away from the scene! able to interest our Government, and at the present time Some of the newspaper editors ha\ e ridiculed Mr. five scientists of repute are looking into the merits of Giragossian, as the.\- thought he meant perpetual motion the "discovery." Whether Mr. Giragossian has actually by his perhaps rash term of "free energy." These made a great invention or not is beside the scope of worthy gentlemen evidently forget that their fathers this article. The point we wish to make is that the some forty years ago talked in like terms when the world, as far as cheap energy is concerned, still sleeps Niagara Falls were first spoken of to run the street cars the sleep of the ages. We cannot even claim that the in Rochester and Syracuse—over 100 miles distant world in that respect is still in its infancy. It is much All this of course is ancient history now, but it is further back than that—it has not even been born. simply a conversion of a natural power, and "free" What are we to think of ourselves and our much- energy in a sense. For it costs man actually nothing; \aunted science when we contemplate the fact that, for the power is there, all we need to do is tap it, and we instance, when burning coal to produce electric light do not have to expend additional energy- in so tapping we get 6/10 of 19r of useful light from the energ>- it either, as for instance we must do in mining and stored in our coal when we burn it, the other 99 4/10% hauling and handling coal. being totally lost in useless heat which we don't want. Of course, this tapping of our waterpower to-day is Just think of the tremendous energy we expend in first a barbarous procedure, one our grandchildren will laugh mining coal, then hauling it over a thousand miles of at; but for us it is as wonderful as t was for our rail, then transshipping it a dozen times, re-loading forest ancestors when they tried labciously to make and unloading it before we finally drive an engine with a fire by rubbing dry wood sticks together. the little heat we can actually extract from the coal. But the new energy- is coming as surely as the sun Is it not tantalizing to realize that the latent energ\- will rise to-morrow, and just as sureh- this force will stored up in ^ ounce of coal— theoreticallx —can haul make man free from most of his present physical a long train over one thousand miles I .\tomic forces drudgery. are so gigantic that we cannot begin to even coni!)rehend H. Gernsback. Tlie ELECTRICAL EXPERIMENTER is imhllshl on the l.nih of each iiiniilh at IIMH Kultoii lioiis cannot he returned unless full liosiage has lieen included. ALL atx-epted contribu- Slrei't. New ^ i>rk. There »re Ili tnunhers per year, Suliseniitinn [irice is $l.oU a year in tions are liaid tor on publication. \ sitecial rate Is l>aid for novel esiicrluients ; itood U. S. ajid pos9e,s.slons. Oanuila and fureltin enuntrtes. $i; no a veiir. li. S. eohi as well photographs accompaiiybic llieni are highly desirable. as IT. S. stamps neeei>ted 1."! Om foreimi eohis or stamps I .simile enpies. rents eaeh. A EI.EfTniCAI. EXPERIMENTER. Monthly. Entered as second-class matter >t the sample copy will he sent uratis on reciueat. t^'hecks aiul money orders should Iv drawn to New York Post ttmee luider Ael of t'onnress of March -t, lS7fl. Title registered I' S order of KXl'KUI.MKNTKIt ITHl.lSIIINt; l\).. INC. If .vou ehanite vnur address nutltv I'aleiil (Ifflee foliyrlnlit. lulS. Iiy E. P. Co. Inc.. Xeiv York. The Contents of this us iironiptly. In order thai eornes iire iiol miscarried or lost. areeii wrapper Indicates A niaga2lne are copyrlghtei] and must not be reproduced without giving full credit to ttie expiration. No copies sent after expiration. publication. AH communications and contributions to tills journal should be adilrest to: Edllor. The El.EtTRUAI. EXPERIMENTER is for sale at all neivsstauds in the United States F3I,»-TRICAL BXrEBIJlENTER. 233 Fulton Street. Now York. Unaccepted contrlhu- and Canada: also at Brenlano's. 37 Avenue dc TOlHra. Paris. 739 740 ELECTRICAL EXPERIMENTER March. 1918 LEARN BY DOING' The Only Way to Learn to be the only men that are fully quali- you will want to join the New York fied to satisfy EVERY demand of the Electrical Schixil. It will be an advantage Electricity Electrical Profession. to you to start at once. Hurrj- and send The only way you can become an ex- At this "Learn by Doing" School a man for our 64-page book which tells you all pert is by doing tlie very work under com- acquires the art of Electrical Drafting; about the school, with pictures of our petent instructors, which you will be called tlie best business method and experience equipment and students at work, and a upon to do later on. In otlier words, in Electrical Contracting, together with full description of the course. You need learn by doing. That is the method of the the skill to install, operate and maintain not hesitate to send for this book. It is New York Electrical School. all systems for producing, transmitting FREE to everyone interested in elec- Five minutes of actual practice properly and using electricity. A school for Old tricit}'. It will not obligate you to send directed is worth more to a man than and Young. Individual instruction. for it Send the coupon or write us a years and years of book study. Indeed, letter. But write us noiif while you are .\ctual Practice is the only training of And Now thinking about the subject of electricitj'. value, and graduates of New York Elec- If you have an ambition to make a trical School have proved themselves name for yourself in the electrical field School open to cisitors 9 A. M, to 9 P. M. New York Electrical Schoo 29 W. 17th St., New York, N. Y. 'p/i/!7vec WIND wc If r^TKI*' Please send FREE and without obligatioti to me your 64-page book. I NEW YORK E^^ 29w.i7i«st Name I 1 NEW YORK, N.Y. A ddrcss You benefit by mentioning the "Electrical Experimenter" uhen u^riting to advertisers. : ELECTRICRL EXPERIMEMTER H. GERNSBP^^K editc7R H. W. 5E.ZDR /555PClftTE EDITt7R Vol. V. Whole No. 59 March, 1918 Number 11 President's Speech to World Via Cable and Radio LITERALLY to the ends of the earth used for the transmission, and the oper- kept under lock and key or under naval President Wilson's recent "Peace- ators at both ends were locked in their guard. Advance information would have . terms" address was sped by cable, rooms lest by any chance there might be been almost priceless to Wall Street specu- -^ telegraph and radio as soon as he a leak as to the nature of the speech before lators. began it, and thru the newspapers Mr. Wilson delivered it. At thirty minutes past noon the word of every civilized country the whole world's Then, in order to insure absolute ac- came "Release President's speech," and the reading population has become acquainted curacy, the address was "read back" to cable and telegraph operators started click- with America's war aims in detail. Washington over a private long-distance ing it off to the four quarters of the globe. Map of the World, Showing Principal Cables (Full Lines) and Land Lines (Dotted Lines) By Which President Wilson's Recent "Peace- terms" Address Was Broadcasted to Every Civilized Country as Soon as He Started Speaking at Washington. The Powerful U. S. Govern- ment Radio Stations at Darlen and San Diego Flashed the Message to Ships at Sea and the Smaller Islands in the Caribbean. Union This was one of the l)iggest and swiftest telephone. When it had been verified, it was To London it went by Western the Reuter. bits of news distribution on record, and it cut into "cable takes" of approximately 100 cable. There it was given to was done in this way words each, and the operators who were to Exchange Telegraph and Central News it to all the The speech was telegraphed in advance handle it opened their keys and got ready agencies, which flushed at once the day before the President spoke, to the for the "flash" which would tell them to newspapers they serve. Via Western Division of Foreign Press of the Commit- start sending. The speech contained about Union cable the message flashed to London tee of Public Information at New York 2,700 words. Every one wlio had anything and was actualLv delivered in that city in 2 City. The Government's private wire was to do with the handling of the speech was hours and 35 minutes. Renter's airency in 741 — 742 ELECTRICAL EXPERIMENTER March, 1918 AUSTRIANS USE RADIO IN ALPS. oil as indicated by the thermometers on of a square metal tube 4 ft. 8 in. (1.4 The Radio operator in active military transformers, the Pacific Power & Light metre) long and 2 in. (5 cm.) square. At service does not always have a hut or dug- Co. in one of its sub-stations has attached the ends are placed two mirrors facing out in which to set up his instruments. The periscopes to each transformer to enable each other at an angle of 45 deg. with the photo herewith illus- sides of the tube. trates a temporary The lower mirror is Austrian radio sta- V/s in. (4.8 cm.) tion near the top of w'ide and 3 in. (7.6 a mountain peak in cm.) long, while the the Alps. The small upper one is i^ in. antenna mast is (4.8 cm.) by 3l4 in. guyed in position a- (8.6 cm.) loiig. The shown and the op- upper mirror is erator at the foot made longer to give of the pole is bus> a longer view of the receiving a message thermometer scale. At the e.xtreme right an officer is makiny ELECTRIC SHIP observations which HAS FUTURE. he reports to the The electric ship wireless man for is no longer a dream but a reality, it t r a n s m i s sion to and headquarters. Note is quite possible that the two industrious within a few years radio squad men of the close of the kneeling down in the war every new ves- center of the photo. sel of any size will They are the "dyna- be driven, steered, mo men" and their stopt, reversed or duty is to turn the turned, merely by crank and spin the the pressing of a dynamo until the series of buttons on voltmeter registers the bridge. The ap- 110 volts. The op- plication of this erator can then press principle will enable his key and send out ships to be run with efficiency h i s message. No the highest current is necessary at an even speed, for receiving the permit marine engi- neers more liberty messages, photo © ijy Dnderwood and Underwoo'l Far Up in the Cold M ountaln-tops, Thousands of Feet Above Sea Level, the Wireless Proves of design and yield Is Being LIsed an Austrian Signal Corps Itself Invaluable. Thi s Portable Radio Set by Squad proportion ately In the Alps Region. greater cargo space PERISCOPE FOR READING the operator to observe the temperature than the present cumbrous form of ma- TRANSFORMER TEMPERATURES. from the floor. This makes it unnecessary chinery allows. The newer American mer- In order to read the temperature of the to use step-ladders. The periscope consists chant ships are electrically controlled. London also recabled it immediately to the It was sent to Australia by the British first place the modern atlas and geography American Ministers in The Hague, Stock- cable which runs from Vancouver, B. C, to "map of the world" does not show any- holm, Copenhagen and Christiania, thus cov- Sydney. It was telegraphed to San Fran- where near all of the cables now laid and ering Holland, Sweden, Denmark and Nor- cisco in the short time of 1 hour and 38 in successful operation in various parts of way. The Ministers gave out the speech minutes, and then cabled to Hawaii, to the world. as soon as they received it to all the news Shanghai (there distributed by Renter's) Several interesting long-distance cable agencies in their respective countries. and to Tokio. where the Japanese agencies routes used in broad-casting the President's From London the speech was sent also —Kokusai and Nippon Dempo— sent it out. speech of 2,700 words to the world are to Petrograd and distributed to the news By cable the speech went by direct cable the following, and which were not men- agencies by a branch of the American Com- to Havana, Port au Prince, Hayti and Car- tioned in the newspaper accounts. In the mittee on Public Information in the Rus- raccas, Venezuela. It also went via direct preparation of this article the editors have sian capital. From Petrograd it was tele- cable to Colon, across the isthmus to Pan- had the assistance of Mr. Donald McNicol, graphed over land lines to Moscow and ama, and from there down the west coast Assistant Electrical Engineer of the Postal thence to Brest Litovsk, the scene of the of South America to Santiago, Chili, whence Telegraph Co., and Mr. Walter S. Rog- recent Russian-German peace parley. it was telegraphed across the Andes (over ers, Director of Foreign Press Division at To Paris the President's address was sent the longest under-ground cable in the New York. by way of the Commercial Cable in the world) to all the lower capitals of South The speech reached the "Far East" space of 1 hour and 38 minutes. There it American republics, reaching Buenos Ayres India. Sumatra. Java, Ceylon (of Lipton was given out to the Havas News Agency, first. tea fame) and the Malay Peninsula by the Agencie Radio and the Maison de la From the naval radio station at Darien, cable. The message sped over the ocean Presse, the French official institution for on the Isthmus of Panama, the address was cables from Lisbon, Portugal, down along distributing news. These organizations for- flashed out. to all the little islands and ships the west coast of Africa, via Cape Verde warded it to Berne, to Rome, to Athens and in the Caribbean. The naval radio station Island, to Cape Town, South Africa. From to Madrid and Lisbon; thus covering at San Diego, Calif., also flashed the mes- here it was telegraphed across country to Switzerland, Italy, Greece, Spain and sage to ships in the Pacific. Durban, on the east coast, and flashed on Portugal. The United States and Canada, of course, via Mozambique north to Aden, at the south News wires are working between Berlin received it thru the ordinary news agencies end of the Red Sea, thence by cable to and the Holland border, as well as to the which supply both. Bombay, India. It continued from here by Swiss border, so the speech got into Ger- An idea of the speed with which the overland telegraph to Madras, on the east many certainly from one or another of speech was sent out may be had from the coast and, once more speeding under water. these border stations, (the message re- fact that Buenos Ayres reported back that reached Penang on the Malay Peninsula. ceived in Holland and Switzerland being it had been received in full one hour and From Penang the message spread to the transmitted to the German border by forty-five minutes after the operators here several islands in the East Indies. An alter- courier, from which point it was telegraphed had stopt sending. Meanwhile it had been native cable route, but liable to interruption to Berlin) and doubtless was sent down retelegraphed across the mountains down in due to present naval activities in the Med- thru the Central Empires from Berlin. South America. iterranean Sea, lies along the coast of Por- South Africa and India receive their Many extremely interesting points were tugal from Lisbon, via Gibraltar, thru the news thru the Renter Agency in England, revealed by this gigantic news propaganda Mediterranean, thence along the Suez Canal and the speech was cabled to them by that which the average person, who never uses route, thru the Red Sea cables, to Aden organization. the cables, knows but little about. In the (Continued on page 802) BACK NUMBERS!—Many readers desire to obtain back numbers of this Journal. We have a limited quantity of these back Issues on hand and can supply them at the followlnp rates:— Back numbers of The Electrical Experimenter not over three months old, 15 cents each; over three months old, 20 cents each tver one year old, 35 cents each. March. 1918 EXECTRICAL EXPERIMENTER 743 Can Electricity Destroy Gravitation? it possible to nullity, and further to Nipher supplies experimental evidence that of this bar two small lead spheres of even reverse, the effect of gravity by gravitational attraction can not Is only be known mass. Two equal large balls of electricity? This scientific conundrum suspended or nullified by the electrical cur- solid lead are placed seems about to solved, close to the small be at least to a rent, but it actually can be transformed into !" suspended spheres in the manner shown. certain extent. To begin with, every- "gravitational repulsion Now, remembering our law of physics body is familiar with that law of physics AH during the summer of 1917, Profes- stated above that every body in which states "that all — space at- particles of matter at- sor Nipher had his apparatus in almost tracts every other body proportionally to tract each other with a force which is their respective masses and inverselv greater tlie nearer the as particles are to- the distance between them then it is evi- gether," and to be still more definite, New- — dent that when this apparatus is set up, that ton's law says that bodies behave as if every the small suspended spheres will be slightly particle of matter attracted every other par- attracted by the larger, stationary balls. ticle with a force that is proportional to the This condition is represented in Fig. product of their masses and inversely pro- 1. Before connecting any form of electric portional to the square of the distance be- current to the modified Cavendish ap- tween them. It is the gravitational attrac- paratus. Prof. Nipher took special tion between the earth and the bodies upon precau- tion to carefully screen the moving elemen; it which causes the latter to have weight. from any electro-static or electro-magnetic This fact is often lost sight of and should effects. His apparatus briefly consists be well understood by eveo' student. To of two large lead spheres ten inches in diam- make the matter more clear let us imagine eter, resting upon heavy sheets of hard that a man's body is .(as by flying, jumping, rubber. Two small lead balls, each one diving from a high point, etc.T) for the inch in diameter were now suspended from moment separated from the surface of the two silk threads, stationed at the sides of earth. As soon as the mass of the body is the two large lead spheres, from which thev separated from the earth, gravitational at- were separated a little distance. Moreover, traction is set up between the two masses. the suspended balls were insulated elabor- The earth pulls the man's body, and also ately from the large spheres by enclosing his body pulls the earth, but as the mass them first airtight in a long wooden box. of the earth is infinitely greater, its move- which was also covered ment cannot be detected. with tinned iron sheets as well as cardboard sheets. There The scientists of to-day believe that in was, furtheremore, a metal shield between some mysterious way the minute electrical the box and the large metal spheres. The charges existing on the particles making up large metal lead spheres now exerted a molecules and atoms are definitely linked Prof. Francis E. Nipher, of the St. Louis Academy certain gravitational pull upon the up and concerned with such basic of Science, Who Has Proved By sus- phenom- Laboratory Experiments pended small lead ena as gravitation. That Gravitation balls as indicated in Fie. Since all bodies are Can Be Nullified and Even Converted Into 1, and the small lead balls were slightlv made up of atoms it would seem to logically Repulsion, By Electric Currents Properly pulled over towards the large spheres. follow that the forces of gravity must de- Applied. In his first pend in some way upon experiments Prof. Nipher attractions which applied a high atoms exert tension current from a upon each other, and due to continuous operation and the experiments static machine to the large lead balls, see the fact that the atoms are separated, at have been repeated time and again, always Fig. 2. No difference least in solids was noted whether and liquids, by extremely with the same result. the positive or negative terminals were ap- small distances, we might expect these inter- Prof. Nipher's mechanical apparatus re- plied. In one of these experiments atomic forces to be relatively more powerful the sembled that used in the "Cavendish masses were "repelled" thaii are those of ordinary (normal gravita- gravitation experiment," by which it was first experi- tional attraction had been nullified and Until recently, however, the mystery link- mentally proved that Newton's law of uni- changed to repulsion) by a force nearlv ing this inter-atomic activity with the force versal gravitational attraction applied to tzvice as great as the of gravitation initial gravitational baffled all attempts at solu- small bodies in their action upon each other repulsion. This effect is shown at Fig. 2 BIFIL/IR FIBRE. NORM/IL - I NORM/IL -H SUSPENSION GRAVITY Lme I GRflVirrLINE REPULSION SUSPENSION"^. IOLE/)DBALLS FIBRE rLE/>DB/m$ MOVING BflUS MOVING BALLS iNEUTR/IC ENCLOSED IN (MASS RESTORED, ENCLOSED IN L POSITION' NIETALSCREEN MET/lL SCREEN GRAVIT/mOML i CRflVIT/ITION/)L »TTR/KTiai.^ I REPULSION ^ MET/IL BOXES BfiLL iNOM/fSSj .repeued\ ^,.:,MEr/)L .. MET/IL 1^ SHIELD ^SHIELD 1 ATTRACTIVE" - EFFECT OF GR/) VI T/i TIONAL REPUL PROF NIPHERS EXPERIMENT WITH TWO WHEN ZO AMPERES /}.C. WAS P/IST THRl- Oft/lyirY BETWEEN L/llfC'E SION~ CAIUSED BETWEEN METHL BOXES FILLED WITH COTTONIN THE LAKOE BAELS, THE GRAVITAT/OHAL 1NP sn/tLL n/isSES. L/tRGE/f/VOSM/TLL M/)SSES PLACE OF L/IRCE LEfID SPHERES. I NO ATTRACTION WAS REOUCEP TO ZEKO J'ND NO CURRENT. CURRENT ON. MASS) HO GRAVITATIONAL CHANCE MADE NEGATIVE. THE REPULSION WAS WAS CAUSED WITH CURRENT ON OROFF SO'I.OFTHE NORriAL ATTRACTION. Several Simple Diagrams Which Show, In a Manner Understandable to All, the Essence of the Epoch-maklnn Exp eriments on the Effe^ of Electricity on Gravitation, as Conducted by Prof. Nipher at Washington University. St. Louis, Mo. tion, altho many scientists had tackled it. at short distances, just as well as it did to In further experiments Prof. Nipher de- But at last experimental proof has been small terrestrial bodies under the influence cided to check his results. To do this he forthcoming thru the untiring labors of of the earth. This apparatus consists of a replaced the large solid lead spheres with Professor Francis E. Nipher, of the St. delicate torsion suspension fiber (see Figs. two metal boxes, each filled with loose Louis Academy of Science. In a pamphlet 3 and 4) a light, rigid arm at the lower end cotton batting. These hollow boxes issued November 8th, 1917, Professor of the fiber suspension, and at either end (Continued on page 803) — 744 ELECTRICAL EXPERIMENTER March. 1918 Electricity and War in the Films THRILLS, thrills and still more servation post by telephone. Another scene THE TELEPHONE MOUTHPIECE- thrills I seems to be the slogan be- shows the up-to-date radio equipment on HOW TO USE IT. hind the majority of motion pic- board the Zeppelin. Science and experience have combined tures on the screens in tliese tem- The mammoth Marconi wireless station to determine the shape and size and ma- pestuous times. Surprising it is located just outside Los Angeles, Cal., re- terial to be used in the proper construction indeed the extent to which producers will cently taken over by the U. S. Govern- of the most efficient mouthpiece. go to secure the '"reel" hair raisers, and in ment, was made use of in filming some of This part of the telephone is designed to nearly every instance Science plays the all the important scenes. gather the sound waves of the voice, and important role. The third photo shown is taken from a will do so more efficiently when the lips of In the wonderful advance made by the later episode of the gripping film drama the per.son speaking are about half an inch photoplay in the last few years, from, and directly in front of it. the small and intricate details It is designed exactly for the have come to receive more and purpose of most efficiency by ac- more attention. The critical commodating the sounds from public has learned much in re- close pioximitj- and excluding cent years : therefore it would the distant sounds which would not do to make use of scientific interfere with the transmission. apparatus nowadays without Did 30U ever stop to consider some regard for its cor- liow you hear only the speaker rect appearance and application. and not the other sounds of the Foremost amongst the new films room in which the speaker is? may be mentioned Thos. H. Ince's When speech is directed to the latest production "The Zeppe- mouthpiece at an angle, or from lin's Last Raid." Mr. Ince has a distance of from six inches to had a phenomenal rise in the a foot away, the person at the motion picture field and must be other end of the line cannot complimented on this splendid hear your voice distinctly. Above—Two Teuton Plot- ters Operating a Spy Radio Set in the Woods in "A Daughter of Uncle Sam." Left—Preparing Zeppelin Bombs for Action by Means of Magnet in "The Zeppelin's Last Raid." Sight— Another Scene on the "Zep," Showing the Radio Instruments and the Operator. and timely picture. A word would not be "A Daughter of Uncle Sam." showing the The best results will be obtained by speak- amiss regarding the work he has done to inner workings of the German spy system ing directly into, and close up to. the mouth- advance the motion picture along the path in this country. The action abounds in piece in a clear, not-too-loud tone of voice of big things. Five years ago he was next many stirring scenes and the one illustrated to being down and out. but he had an idea shows two German plotters secretly operat- WIRELESS FOR ST. PETER'S IN and struggled along till the chance came to ing a concealed Radio station in the woods. ROME. produce on a big scale, his foremost and The establishment of a wireless station on initial photoplay sensation being "Civiliza- NIGHT DARES tion," which cost thousands of dollars and HUN RADIO AT the dome of St. Peter's in Rome has been employed hundreds of people to produce. U. S. TO STRIKE. suggested to the Vatican so that it may se- transmission foreign "The Zeppelin's Last Raid " shows vividly Commanders and crews of the American cure independent 'of the danger that the United States is exposed destroyers operating in European waters messages of diplomatic character in code to, and to save us if possible from the are talking about a grim piece of Hun hu- and also receive confidential and reliable re- lesson that was so bitterly learned by Bel- mor. Nearly every night the commander of ports from the Vatican's representatives gium, France and England. one of the destroyers receives by wireless a abroad. The question of speed is involved The story is woven around Mr. Hick- message reading: since at present wire transmission from man, the commander of a Zeppelin, and "My position is (so many) degrees north France and England consumes 24 hours Miss Markey, a young and pretty' girl who. and (so many) degrees west. Come and while much longer is required to receive with hundreds of others, is secretly work- get me. I'm waiting for you." The mes- messages and news from the United States. ing in an effort to rouse the populace sage is always signed, "Hans Rose." It is pointed out that the wireless would against Kaiserism. The commander, like Rose is the German who took a submar- have the advantage of dealing with Switzer- many other officers in the army and navy, ine into Newport two years ago. Accord- land, .\ustria. Germany and Russia. The is also a member of the same organization. ing to the story past around by the men Vatican never has been able to rely upon The attack of the Zeppelin upon the de- engaged in the thrilling and hazardous task newspaper reports for quick news. fenseless British hamlets is one of the most of seeking submarines, the captain to whom The Italian Government is not likely to strikingly realistic scene? ever converted is directed the nightly messages of the Ger- raise decided objections because the Vatican to the screen. The biggest thrill comes man sub-sea craft, sank two. The com- never has paid tolls on its messages. when the commander of the "Zep" dyna- manders of both were intimate friends of mites it, at the moment the crew attacks Rose. He has sworn vengeance. him for refusing to hurl bombs upon the It is disquieting for the American com- ELECTRIC LIGHT TO MARK defenseless citv- below. And the nerve- mander, but he has no fears. Twice, it is AERIAL ROUTES. stirring scene of the flaming dirigible rush- stated, he has swiftly guided his craft to Electrical companies and town councils in ing downward to destruction is one not the location described by his enemy, but has the United States are offering to provide the easily forgotten. The "Zep" is complete found nothing. Still the mysterious wire- "lighthouses" necessary- to mark the aerial in every detail and in one of the photos less dispatch comes every night, no matter routes between Daj-ton, Ohio, and Indian- herewith may be seen the releasing of the where the destroyer may be. Others catch apolis. Ind.. and other cities to be used by powerful death-dealing bombs. The orders it, and thus the weird story is told where- the aviation corps of the United States are given to the men from the main ob- ever the hornets of the sea are seen. Army in training students for this service. ' "ELECTRIC WINTER-TIME COMFORTS Oh! Clarice! We Didn't Know You Had T 5 New Electric Heater lor Use on Auto Englnei. It Plugs Into Ne» In Hot Water Devlces-the a Faceache But Rpst Assured. ThU something and Makes Starting the Engine a Sure — Spigot." Heals the Water l«- Any Lamp Socket Electric Warming P.id Will Alleviate •Electrlo Thing In the Winter. Attaches to Any Water PIK. I Your Suffering In a Short Time. Con. stanlly and nects With Any Lamp Socket. ' I IWIIIll ll ll I. IWlll 1II ' [ J JI jlLJM ,l.j^ ii'iM^yi^ M !!«tsa6s«s^9&%iiasas^8iSs«w«'B5*!.5s^iiS 745 746 ELECTRICAL EXPERIMENTER March. 1918 How U-Boats Send Radio 1,000 Miles By H. WINFIELD SECOR Germans have developed sub- in the balloon antenna and the balloons are would be to connect up the high capacity THEmarine radio-communication to a taken inside, hatches closed, and the craft djTiamo to these engines, and this' in turn fine art—they had to. This is so for submerged—all in almost less time than it to the special high power radio transmitter. obvious reasons—chief among which takes to tell about it. It is difficult for an Such a set, including the dynamo, would is that the success of the U-boat enemy ship to see the balloons as they are not occupy such a large space as might be campaign depends to a large extent on cleverly camouflaged, being painted partly imagined off-hand. Also the newer U-boats keeping in wireless communication with white and partly blue, so that against the are veritable submarine-cruisers, several the individual sub-sea boats and the pos- sky they are practically invisible. The hundred feet in length, which, of course, sibilit}' of certain of their number trans- antenna wire is, of course, quite fine and gives a much greater space for the radio mitting intelligence to the nearest land base. invisible at even a short distance away. equipment. At first the submarines made use of fold- It has been a mooted question for some Many ingenious folding and other types ing or telescopic masts which did not ele- time as to just how far such a radio-equipt of masts have been perfected for medium vate the radio antenna very far above the sub-sea fighter could send a message. The and short range radio work on the sub- deck—not more than 20 to 30 feet in most receiving range with such a balloon sus- marine. Several of these masts are illus- C 5—^Ttr^&«w» ^'"'^ 'ro. i—r^ .-/y^..^» ;• -~- TogPeffoes Sectional View of Modern Submarine Showing the New Telescopic Collapsible IVIasts Supporting the Radio Antenna, as Well as Motor Actuated Cable Windlass for Rapidly Reeling in Balloon Aerial Wire. The U-boats Are Said to Be Using the Balloon Aerial for Communi- cating by Radio Over Distances of Several Thousand Miles. cases. For ordinary inter-communication pended aerial is easily several thousand trated in the drawing herewith. An inter- between submarines this collapsible an- miles, using modern amplifiers and other esting practical telescopic mast was patented tenna served its purpose admirably. Where refinements in the radio art. The writer by a Yankee inventor several years ago long ranges were to be negotiated, either asked several well-known radio experts (U. S. patent No. 1.099,861) and is shown in in receiving or transmitting, however, it their opinion on the possible sending and detail at Figs. 1 and 2. The inventor, Mr. became a real problem. receiving activity of a balloon-aerial equipt Joseph Raes, covered several modifications One of the latest Teutonic improvements U-boat and they practically all agreed with of the basic idea in his patent. In one type in this arm of the naval service is the the ideas exprest by Mr. F. H. Kroger, a continuous flexible metal cable is used. utilization of balloons for elevating the chief engineer of one of the leading Ameri- Figs. C and D. By following the path of the U-boats' antenna wire to a height of 1,000 can radio companies, that ; with fair cable in the drav.ing it is seen how, when a feet and more. In this way vast distances weather conditions, and with the proper pull, as produced by a motor, is applied to can be covered and valuable intelligence radio transmitting apparatus tuned to a the lower end of the cable, it causes all of sent by radio to a second relay submarine high wave length, it would be possible for the sliding telescopic members to be ele- if necessary, so that it is not improbable the submarine to send a wireless message vated. The upper end of the cable is se- that the news of ships' sailings from Ameri- 2.000 miles, and possibly 3,000 to 4,000 miles cured to the bottom of the top telescopic can ports could have been radioed to Ger- under extremely favorable conditions. The member. When pressure is removed on the many by the aid of three or four U-boats. transmitting set used might, of course, be cable the mast descends by gravity. Our front cover illustration, as well as a special one rated at 15 to 25 kilowatts. A similar type telescopic mast is shown the ones herewith, show clearly just how If the sub-sea boat wanted to transmit an at Fig. B, only in this case the individual the balloons, two in number and fastened important message, she would in all likeli- sections are raised and lowered by a clever to a rigid equilibrium member, carry up the hood choose the night-time. She could then arrangement of gears and shafts. This antenna wire to a height of several thou- emerge and fly her balloon aerial with rea- elevating scheme would be considerably sand feet if necessary. The antenna, at its sonable safety. And for a long range mes- slower than the previous cable-operated type. base, is wound on a special electric-motor sage requiring as much energ>' as men- The author su.ggests herewith a pneu- driven drum. This drum is instantly con- tioned above, it should be remembered that matic telescopic radio mast of the type illus- trolled by the throw of a switch, so that if there is available all the engine power re- trated at Fig. A. This is similar in principle a ship comes into view, it can rapidly reel quired. All that would have to be done to the pneumatic (comprest air) lifting ; — : March. 1918 ELECTRICAL EXPERIMENTER 747 cranes used in iiiaiuilacturiiij^ plants, A WAR-TIME SUGGESTION TO tho, we amateurs have built up our present foundries, etc. With the proper pressure RADIO AMATEURS. organization upon our own lines. As our of comprest air, it is only necessary to close problems were presented and By 1 lowARD S. Pyle, we worked the suction blower pipe valve, open the high Electrician-Radio, U. S. N. finally overcame thefn. They were our pressure air valve attached to the pipe line problems—we fought them as such. Mean- from comprest air tank or Hasks, and the FELLOWS, in writing this, I want to while the commercial companies met their mast rises up by expansion of the air within address it to the Amateurs— the real, barriers also and overcame them. Now it. When it is desired to lower the mast dyed-in-the-wool "hams," who have doesn't it seem reasonable that the com- quickly, the comprest air valve is closed and started in the right way—a spark coil of mercial companies, having to build their the suction blower line valve slowly opened ; uncertain antecedent, a few discarded drv organization to the highest stage of devel- the air is thus re- opment, as theirs is moved and the mast a cold, commercial collapsed. Ordinar- proposition, many ily, no suction people being de- would be required pendent for their to lower the mast hving upon the suc- merely a valve cess of wireless as a openinp to the at- commercial enter- mosphere thru prise — doesn't it which the comprest W^ seem reasonable to air could rush to you fellows to the outer air. grant that these An ingenious col- companies have a lapsible radio mast higher, more effi- was invented in cient service than Germany some Airtight rpachng the amateurs? Of years ago and sev- 7e/escop/c^'" course they have, as eral of them have Secttons they must have to , been used in this remain in business. country. It was Supposing a com- perhaps the lightest mercial telegraph ever designed thus company accepted a far — possibly t o o message from Port- light for submarine land, Oregon, to requirements — but Los .\ngeles, Calif., it possest the ele- Gears would they deliver ment of speed. It it at its destination, employed four flex- a week or so after ible strips of. metal the filing? Would rolled on drums at a company send a the base. These message from Seat- strips were notched tle to Portland, on both edges and and effect To yoci/um Oregon, when the handle pump the transmission in was turned, the a few minutes but four notched strips liang the message of thin steel inter- up at its destination meshed with each Comprss/a/r/oravse /nasf and deliver it four o t h e r. making a days later ? How lock - cornered Some Examples of Collapsible Radio Masts Adaptable For Use on Submarines. The Types long w'ould they re- Shown Include the Comprest Air, Steel Cable and Gear Actuated Telescopic Forms, square tubular mast A main in business if Motor Operates the Gear and Cable Types Directly. about 8 inches they did? Yet these square. It w'as are both actual found possible to raise a platform contain- cells from the family Ford, a lump of amateur examples of occurences on this ing two men on it to a height of 80 feet for silicon you the type. Fellows that — know coast in one week ! In the former case observation purposes when necessary. Two started with gigantic problems to fa'ce, no no excuse as a line of communication is men could raise the mast in a short time by one to help and who have "stuck to it." available (or was at that time) between turning a geared crank handle. We have today, altho at present closed those tW'O points at all times, with numer- by our Government, such an efficient chain if necessary. In the latter case: The accompanying illustration of a mod- ous relays of amateur stations in this great country connec- ern submarine shows how the various com- also inexcusable as direct 'phone of ours, that, were it forecasted ten years tion between the receiving operator and partments are arranged. It was prepared ago, would have brought derision down the addressee to be had. The latter from ofHcial plans of such a craft. The was upon one who would be so bold as to sug- finally heard of the message in a round- location of the collapsible radio masts is gest it. And if you will look up the "star" about after trouble and in- gi\en, as well as the position of the motor- way and some stations, you will find that they are prac- convenience, finally got it. driven winch for hauling in the antenna tically all in the hands of fellows that ten balloons. .'\n interesting feature not gen- .Mtho I'm in the commercial game now, —yes, even five years ago—were strug- erally known is that submarines are now yet I'm a "ham" at heart always, and want gling thru many failures, working out their fitted with submarine telegraph apparatus to see them make a name. I keep in own problems, 'nary a beacon to guide them which operates by means of soinid waves close toudi with the fellows, altho I'm in the right way. Look where they stand sent thru the water from powerful electric "all over the ocean" at times, so to speak. today — foremost among the country's vibrators mounted on the hull of the sul)- It's only since breaking into the commer- youthful scientists and possest of an en- marine. Sensitive microphones suitably cial game that I saw the faults of our or- viable knowledge of that most fascinating mounted on either side of the hull enable and I would suggest that our of mysteries— WIRELESS! ganization the commander to tell when a ship is ap- best "hams" spend a little time in com- I have watched and grown up with them proaching, even at a considerable distance, mercial service even only a few trips on for the past ei.ght years myself so am — by the sound of her propellers which is vessel. Operators are scarce and jobs basing this on facts. While my stations some transmitted thru the water. never hung up any extraordinary records plentiful and I'll warrant you'll have your it will result in better Then there is the latest safety feature lor transmission, due to several handicaps eyes opened and in the future our sta- the telephone buoy. If the submarine should from outside sources which it was impos- service among own sink and become unmanageable, the crew sible for me to overcome, yet my interest tions. Think it over, fellows. If you can pull a lever which releases the tele- has been just as keen thru all the years don't feel like joining the U. S. Navy, why phone buoy, which rises to the surface ot and I hailed each new record with as much not try the U. S. Naval Reserve Force. the water. .-Xny craft passing in the vi- delight as if it were my own. I did have They are looking for good radio operators cinity of the sunken sub-sea boat can open sensitive rccei\ ing apparatus, however, every day. Come on. fellow "Radio-bugs" this buoy and, by means of the telephone which I kept strictly up-to-date and have —put on your hat and take a walk to the inside it, speak to the imprisoned crew. spent many, many pleasant evenings (and nearest recruiting office—and don't forget Submarines send out sound signals of dis- wee hours) with the 'cans" on and am the great chances looming up now fur a tress tliru the water also, which may be proud to consider myself one of the "self- berth as radio officer on the vast merchant intercepted by another submarine or by a mades." marine fleet L'ncle Sam is building. Look warship or steamer. To come to the subject of this article. into this—it will pay you. : 748 ELECTRICAL EXPERIMENTER March, 1918 Electric Steam Boiler Most Efficient one year ago, in the March, 1917, for a short time. They may, in fact, be injector, a steam valve, a water gage, a JUSTissue of this journal, we had the considered as serviceable appliances for pressure gage, a receiver for soda solution, pleasure of describing and illustrating turning to account any superfluous hydro- a water-level regulator, which automatically a remarkable piece of engineering electric power available, and as such they governs the working of the apparatus, a work carried out successfully by Ital- were utilized in numerous installations in safety and drain valve, a handle for work ian engineers, viz., the application of vol- Italy before the war, when the price of coal ing this valve by hand and a feed-water canic heat to a steam boiler and thence did not exceed $8.00 per ton. At the pres- valve. to a dynamo, from which several thousand ent time they are also found to be practical The high-tension tj'pe has the same com- horsepower were distributed at high poten- and economical, even in cases where hydro- ponent parts as the low-tension type, and tial to a considerable area differs from the latter only in northern Italy. Now, in the shape of the elec- we are confronted by an- trodes and the dimensions other ingenious and suc- of the steam dome, which cess f u 1 steam - electric STEAM passes into in the high-tension type THESEHOLES INP/PE stunt, due to an Italian en- has the same diameter as gineer—Colonel Revel of the steam space. the Italian army, whose One of these high ten- extremely simple electric- ELECTRICFEED W/REN°Z sion installations in actual ELECTQIC FEED W//IEN°I steam generator is de- use in Italy consists of scribed in Engineering of eight apparatus, taking London. As we do not STE/IM PRESSURE G/IGE K three-phase current at know just yet how to pro- 6,000 volts, each apparatus duce electricity direct being capable of generat- INSULRToA OPPOSITELY CHARGED from coal or other com- ing 900 kg. to 1,000 kg. of STEEL ELECTRODES bustive or explosive fuel, steam per hour. we shall not find, possibly. In the Revel generator a very extensive field for ELECTRODE N93 the transformation of elec- Colonel Revel's new elec- trical energy into heat tric-Steam boiler, as it uses takes place in the body of electric current to convert WPTERG/IGE CH///1BEP the water contained in the water into steam. But steam and electrode cham- where there is superfluous STEAM V/)LVE the water acting as an BAFFLE- ber, hydro-electric power avail- ohmic resistance inserted able, there we should find Y/ATERLEVEL between the electrodes ; the the Revel electric boiler of production of steam there- great economic value. fore varies with the im- Especially when it is con- mersed surface of the elec- sidered that steam is pro- trodes, and assumes all duced by the passage of the values between zero and electric current thru water the maximum, correspond- at the almost unbelievable ing with the various levels efficiency of 98 per cent. of the water in the steam That is, 98 per cent of the chamber. energy in the electric cur- COLD WATER C/i/fA^SEP- FEED WATER INJECTOR For starting the gener- rent sent thru the water is AUTOMATIC VVATEP FEED WATER VALVE ator the circuit-breaker is actually converted into closed, the feed-water LEVEL REGULATOP /NCOTiWG FEED WATEP steam. The efficiency of valve is opened, and a the average coal-fired boil- small quantit}' of soda er is only about SO to 60 solution is introduced per cent. from the small receiver to The principal character- give a suitable conductiv- istic feature of the gen- ity to the water. When erator is that for the trans- the water has reached the formation of electric height of the lower edge energy into heat, and of the electrode segments thereafter into steam, use the current flows thru the is made of the ohmic re- water and commences to LEVER sistance of the water which TO HAND CONTROL raise steam, the steam has to be evaporated. The production increasing as Revel apparatus can be in- S/iFETYAND DRAIN VAL l/E the water-level rises, until serted in any alternating- it reaches the working current circuit of from 200 pressure required. At this volts to 3,600 volts, and moment the automatic This Illustrate s Graphically Just How the Revel "Electric Boiler" Generates these are the form of cur- Steam by the Passage of an Electric Current Thru the Water Between the regulator enters into ac- rent and pressures which Circular Metal Plates. The Resistance of the Water to the Passage of the tion, and the water-level, Current Causes Steam to Form. are usually supplied for and hence the steam pro- industrial purposes. In the duction, remain constant. Revel system, moreover, the production of electrical power has to be paid for at the In order to stop the apparatus the feed- steam is regulated automatically and con- rates now ruling. The Revel electric boiler water valve is closed, the steam vaKe is tinuously as required ; the apparatus is has been in successful use now for some closed slowly, and the bottom drain valve entirely automatic in its action and demands time in many Italian works. is opened by acting upon the hand lever no attention. Lack of feed water would The semi-sectional view of the new Revel until the ammeter has returned to zero only result in a decrease or a stoppage in the electric-steam generator here shown will When the feed water leaves a calcareous production of steam until the feed water aid in understanding just how tliis simple deposit it is advisable, ever>- five or six difficulty was overcome. A 97 per cent to 98 yet wonderful device operates. The work- hours, to free the boiler of the sediment de- per cent efficiency is claimed for this type of ing drawing shows one of these apparatus posited at the bottom of the truncated cone. machine, since the whole of the heat gener- taking current at a pressure of 500 volts, in This is obtained, without interrupting the ated by the electric energy is absorbed by the which we find the following arrangement working of the machine, by increasing the water, the only loss being that caused by At the center, as shown, there is an elec- water feed and by acting at the same time radiation from the body of the apparatus. trode and steam space ; at the bottom a on the drain valve handle, the excess water The Revel generators are constructed to cold water space. Thru the steam dome washing away the sediment; this operation, work at any pressure up to 14 atmospheres, cover run three brass rods electrically in- by a suitable action upon the feed water and can be connected up at any time with sulated from the cover. In the steam and and drain valve and by following closely the steam pipes from the ordinary steam electrode chamber there are three sets of the ammeter and maintaining the current boilers; owing to the rapidity of their ac- circular steel electrodes separated a short intensity constant, is carried out without tion they take up any excess of hydro- distance and rigidly fixt to the rods shown. changing the water-level and without im- electric (i.e., water-power electric en- Next we find a vertical steam pipe and pairing the working of the apparatus. The ergy) energj' which may be available even steam pipe support and baffle; a feed-water apparatus may find adoption in this country. Ma 1918 ELECTRICAL EXPERIMENTER 749 Eliminating the Smoke Nuisance by Electricity By WILLIAaM H. E.VSTON VVestinghouse Electric & Mfg. Co. aS every reader of The EuEcrKiCAL Ex- properly adjusted, an almost complete re- system from static surges. Powerful coils mounted in the transform /\ PERIMENTKR kiiows, if a rubber comb covery of the suspended solid or liquid choke arc -^ ^is rubbed against a woolen cloth, it matter, can be secured. It is, however, ers for this purpose. Each transformer has taps so becomes electrified and is able to attract impossible to remove gaseous particles in a number of different, high voltage particles of paper, threads, and other small this manner. that the voltage of the direct current can at the objects. This peculiar phenomenon was It is, of course, impracticable to gen- be adjusted to suit the conditions known Id man lung before the Jauu of erate directly the necessary high voltage installation. direct current. Alternating current is, All switching and control arrangements therefore, stept up to the desired voltage are placed in the low voltage side of the by means of special transformers and this high voltage alternating current IS then changed into direct current of equal voltage by means of a rectifier, which is simply a large revolving com- mutator. The alternating current can be taken from the regular power line, but it is generally best prac- tise to have the en- tire Cottrell system independent. Sepa- rate generator s, driven by motors operated from the main power line, are therefore usually employed. The sys- tem is also usually divided into a num- ber of independent imits, each with its Close-up View of 100,000-Volt Mechanical Rectifier, Direct-con- to Synchronous Driving Motor. Note the Sparks at the own e n e r at o r, nected g Edge of the Revolving Disc. transformer, recti- New Electric Smoke-eliminator Outfit, Show- fier, and set of pipes, Direct-connected to ing Motor-generator units can be shut down system, the path of the high voltage cur- In the so that one or more Rectifier. 100,000-Volt Transformer to the Background. n ithout interf erring with the operation of rent from transformer and rectifier kept as direct and the plant. It is essential that the rectifier precipitation pipes being history, for electricity gets its name from revolve in synchronism with its alternating- simple as possible. needed for precipi- the Greek word "electron," meaning am- current generator and so it is usually The power actually insignificant in amount, ber, which, of course, acts just like rubber. mounted on the shaft of its generator; but tating the dust is part generated is It is our nature to endeavor to put into sometimes synchronous motors are used for and bv far the greater Hence practical use everything we know, and it operating the rectifiers. absorbed as losses in the system. process is small. is therefore very remarkable that for at Great care must be taken to guard the the cost of operating the least 3,000 years no commercial applica- Much has been said recently about the tion, outside of a number of interesting recoverv of potash from cement dust. This laboratory experiments, was made of elec- valuable by-product is obtained by means 100.000 V. lead Irnstatic attraction. of the Cottrell process. Today, however, this principle is being most TocfiJinney extensively used to solve one of our itigh tension IRON CRUCIBLES INSTEAD OF perplexing industrial problems—the sup- 'insulator. PLATINUM. pression of smoke and dust. The smoke At from chimneys, the dust from cement Platinum is more expensive now than at mills, blast furnaces, etc.. and the acid any time in its history and yet it is regarded plants not only as an indispensible medium as a crucible for fumes from chemical are [lectrified chain intolerable nuisances, but also the visible use in analyzing certain compounds. It is. evidences of a great waste of valuable ma- however, possible to dispense with it in terial. Many attempts have been made to ani'yzir.g ferro-silicon, an important alloy check these emissions but the Cottrell elec- used' in making steel. According to Dr trostatic process, (so-called after its in- soot precipitated Herwig, in a German technical paper, iron ventor) appears to be the most successful. by electrification^' crucibles can be used for this purpose if. In this process the gases containing the on mtloftulfg instead of the usual carbonate of soda and dioxide is used in the solid particles of soot or dust, or the liquid ttotgoi frsin potash method, sodium particles of acid, are past thru vertical furnace or ignition mixture. . Great care must be taken tubes or pipes in the centers of which fine boiter to reduce the ferro-silicon to as fine a pow;- wires or chains are suspended. The cen- der as possible, to remove all coarse parti tral conductors are connected with a source cles, and to mix the powdered silicon thoroly of direct current of from 40,000 to 100,000 and very uniformly with the dioxide, as volts potential and the pipes are grounded. otherwise dangerous ebullition might take The floating particles in the gases passing place, which would nearly empty the crucible thru the tubes become electrified and are and cause spattering. attracted to the walls of the tubes to which f/pegrd. Cleon out door they adhere. At intervals the current is NEW WIRELESS STATION turned off, the tubes jarred or hammered OPENED. by a motor-driven device, and the accu- The newspapers of Willemstad, Curacao, mulated dust then falls into suitable hop- Section Thru One of the Electric Smoke Pre- recently began publishing wireless pers below. When all conditions, such as cipitation Units. Several of These Are Used S. A., the Boiler. The wireless sta- the In the Chimney-path from dispatches received by the new the length and diameter of tubes, the Electrified and Deposited Soot Particles Are tion there. Dispatches are received from speed, temperature, and consistency of the Walls of the Chamber, the Latter Upon the and American stations. pases, and the voltage of the current, are Being Cleaned Out Periodically. several European ! — — 750 ELECTRICAL EXPERIMENTER March, 1918 THE FIRST TROLLEY By GEORGE HOLMES GREAT deal of historic interest is up a little-ways, then pop went the motor. and weld the particles of brass to the com- attached to the modern trolley Mr. Sprague, who realized the car wouldn't mutator segments, short-circuiting them car. Its evolution has been gradual make the hill, told the commission that some fire works ! ! It used to cost some A and the present car is the result of some "testing'' had to be done and sent one nine to ten dollars a day to buy brushes for many years of trials, experiments of his men to "bring the instruments." The a half dozen cars. Later on the present and failures, not to mention the many amus- crowd waited and waited as the hours past style carbon brushes were brought into use. ing incidents tliat went hand in hand with and finally left for their homes. Mr. Sprague stuck to his job, however, and the early pioneers. Mr. Sprague laid down upon the seats among several hundred other inventions he is responsible fgr the multiple-unit control system now in use, whereby a train com- prising any number of motor cars can be started and stopt from any individual car in the train. In marked contrast to the first commer- cial trolley of uncertain progress, we show herewith the very latest "one-man" automa- tic trolley. The problem of providing better and more frequent service as demanded by growing communities, and at the same time reducing operating costs to meet the com- petition created by the so-called "jitney" automobile in the electric railway field has led to the evolution of various forms of light weight "Safetj-" or One-Man Cars. This type of car is now in operation in many parts of the country and enables sub- stantial economies in the direction of re- duced power consumption per passenger haul, reduced car and track maintenance and reduced platform and operating ex- pense, not to mention a relatively low first cost. For branch lines and territor>' having an intermittent traffic, tliis type of car ap- pears to be especially well adapted. While safety is fundamental in any oper- ation of railway cars or trains, this factor is, of course, particularly important in the operation of the new one-man Safety Car. \Vhere a single operator is entirely respon- sible for the control of the car and the sole dependence in the event of danger, such Yes, They're Old-timers — Heroes of the Initial Run of the "First Electric Street Car." service demands that everj- automatic safety The Now Familiar Trolley Pole Was Unknown Then. Instead, a Small Four-Wheeled feature possible be provided in the system Trolley Bogie Was Hauled Along, the Current Flowing In Thru One Set of Wheels and Out Thru the Other Two. Two Trolley Wires Being Necessary. by which the car is controlled. In addition, practical economy and convenience argue The first attempts in electrifying street and went to sleep ; about ten o'clock his strongly for the performance of all possible cars met with great opposition from the assistant arrived bringing the instruments functions automatically. then existing horse and cable car companies, two mules ! The safety control devices are air oper- and even the public was slow to grasp its Before the final car was made the engin- ated and act in such a manner that the full import. The few concerns which eers W'Cre pretty much on the go—every motorman must be at his post and attentive sprang up at that time used many and varied car was tested after a run (every half- to his duties before the car can proceed and ways to induce the transportation companies hour) the road being about ten miles long. must remain alive and alert in order to keep to adopt the new means of propulsion. The brushes had to be replaced after each the car moving. Should the motorman be It is amazing to note that the engineers trip, as they were made of brass and oc- incapacitated by sudden death or should he in those days took on contracts for in- casionally the entire car was out of running remove his hand for any reason from the stallations that even now would be con- order. Sometimes the brushes would arc (Continued on page 805) sidered "big chances." With hardlj- any factories for making such parts as were semi-standard, (for most of the installa- tions varied pretty near as much as the weather) and the difliculty of securing funds and materials, they agreed to have cars running in such short periods of times as two or three months. Tracks, pole lines. power houses, cars and all the other para- phernalia ! The Bentley-Knight Co., had its shop on Tenth Avenue, New York City, where most of the equipment was made and many patents were granted them, among others being that on the underground "shoe" con- tact system. Frank Julian Sprague's early efforts also tend to show what difficulties were experienced by his company. During a storm the overhead wires be- came covered with ice and the motorman had to get on top of the car and hack off the ice with an old broom. The first trolley cars installed in Rich- mond, Va., were rather unique, seating but a few passengers. The trial trip was to take place in the early evening with Mr. Sprague and his as- sistants ; also most of the town was out to see the grand sight. The car ran fairly In Marked Contrast to the Early Trolley Ca r Shown Above, Is this "One-man Automatic well until it struck the up-hill grade. On Trolley." It Is Built Like a Machine Gun. The Motorman Controls the Power, Brakes, it's seven odd horse-power motor it labored Track Sander, Door Openers, C ollapslble Steps, Bell and Lights. Ma 1918 ELECTRICAL EXPERIMENTER 751 Electric Power from the Wind Fuel Administrator has had a given distance from the center of the wheel nical minds of the country have been con- that the power then is delivered to the sulted on this problem and in the weeks just THEhard time of it, trying to "educate" and tlie people in all parts of the coun- power shaft, instead of acting as a barrier try to burn less coal. Coal is expen- to the wind. This is one of the features sive to-day—and hard to get^ Think which give greater efficiency to this type of how much easier would be the Fuel Di- wind power wheels. rector's problems if the land was dotted Another feature of this design of wind with thousands of electric wind-power poweu wheel is the automatic controllability. plants of the type here illustrated. It is By means of a centrifugal two-ball gov- not necessary that such plants be ket)t small ernor or by a resistance type electric gov- ernor, the vanes arc varied in their angle to the wind in case of high wind velocity so that the motion of the wheel is kept from running above a given speed. This pro- tects both the power plant and machinery from unnecessary wear and strain. The automatic means for stopping the mill when the storage batteries are charged and throwing it in the wind when an> given number of ampere-hours have been discharged, all simply means that when the plant is once properly installed you are assured of perpetual and abundant service, without further expense or attention except oil for the plant once a year, distilled or rain water for the batteries and reasonable attention to your generator. The small farm type plant here shown supplies electric power for a large group of buildings. It is automatic, starting and stopping according to the condition of the storage batteries. It charges the batteries about once a week on the average. One of the photos shows the electric control switch- board, including the volt and ammeters, automatic charging cut-out. THE THIRD LIBERTY LOAN AND YOUI This country had not been at war with Germany for many days before realizing the essential importance of the trained elec- trician in the Navy, in the trenches, behind Appearance of Automatic Electric Switch- the lines, at the various headquarters, and board Used in Wind-power Electric Plants. in Washington. To consider that city alone, American Wind-electric Generating Plant ot It Cuts in the Dynamo When the Wind-mill and none of the others where war prepara- New Design. It Charges a Storage Battery Has Attained the Proper Speed. Once a Weel<. The Plant Shown Sup- tions are going on, the About demand for electrical plies Electric Light and Power for a Large service is insistent. The War Department's Group of Buildings. like those seen here and there on farms system of communication with the outside thruout the country—they can be built in world must be of the best. Here there must there have been many adjustments ir large sizes so as to develop hundreds of past be no fraction of a second lost in the trans- and efficiency. horse-power—even thousands of horse- the interest of speed mission of messages. The best of the tech- in this war stands in tht power. Such a large wind-power The electrician of the ancient runner as a plant for town and municipal util- place transmitter of intelligence. He ity is illustrated here and was de- bear a message such as the signed by E. H. Manning of may brought oi Tomah, Wisconsin. first Marathon racer victory at Thermopylae In- The small farm size plant illus- the deed, the who flashed the first trated possesses several unique man safe arrival of Persh- features which lend themselves word of the ing's force in France peri'onned well to the driving of dynamos. such a service for the .\meri- The working parts of the mill just can people as did the mc^-enger are enclosed in weatherproof cas- who ^ave up his life. The .atior ings and these are filled with oil has been calling for the 't-rvices to insure perfect lubrication at all not only of the electrical techni- times. The steel tower extending but also of the man who above the wheel securely anchors cian, dreams in terms of volts until he the wheel at the top ; the bottom creates death-dealing and life-sav- is carried on heavy duty l)all bear- ing devices for use in this conflict ings, thus making a construction has the inventor taken sc which will stand the most severe Never a part in war. His ideas wind storm. Every bearing of prominent are being snatched up with the service is a ball bearing, giving greatest eagerness in the hope thai greatest efficiency at all times. be applied to a weak spot In operation the power vane? they may the Western front, to some are each rotated on their respec- on condition of submarine warfare, tive bearing in such a manner as or to the over-head warfare. to expose them to the wind at the It been impossible for most angle of greatest efficiency at every has the development of degree of the circle, while travel- men to follow times, ing with, across, and against the the electrician in war fas- wind, there being about 30 degrees cinating as that subject may be. A definite idea was presented only of the circle when the vane more comes against the wind edgewise at the recent exposition in New - Vork City. Industrial lighting to a degree where it is not efficient. devices, for instance, have been It thus becomes evident that all own WiiiJ-^.^-i. .- ^.J.i..: ..l...._, 11,..:. 1 ui.J . (Continued on pacic 796' wind pressure is delivered at a Light and Power to a Wiiole Community. 752 ELECTRICAL EXPERIMENTER Ma 19(8 HISTORIC LIGHTING PLANT AT Women Now Study Wireless APPLETON, WIS. A class in wireless telegraphy for women the Navy who went down with the Antilles The illustration shows all that is left or has been establisht at the East 86th Street According to the report of the officer in what is thought by many to have been the branch of the Y. A. M. C. by Mrs. Herbert charge of the armed guard on the Antilles first commercial incandescent electric light- the Sumner Owen, founder and director of the behavior of the \avy personnel thru- ing plant in the world. This picture was the Wireless Classes at Hunter College out was highly commendatory. The two taken recently by H. G. D. Xutting of the Electrical World, at Appleton, \Vis. It shows the steel shells of the old vertical waterwheels now broken to pieces and lying on the ground. The wood construction is what is left of the harness and support, and on the other .side of the little bridge are the ' 1 needles holding the water back in the flume, which is till connected with the Fox River This plant has been mentioned by many writers and referred to by Samuel Insull in speeches and in reminiscences of early t days. \\ hile it is held by some that it wa> f the first incandescent lighting station in the world, recent researches of William E. Keily of Chicago, who has given consider- able thought and time to investigating his- torical events in the industry, seem to indi- cate that this was the third Edison electric lighting station in operation. .\ccording to the best data which Mr Keily can obtain, the Holborn viaduct in London was started either on Jan. 12, 1882. or April 11. 1882, these two dates being fixt by separate authorities. The historic 1 - ^ Pearl Street station in New York was- started on Sept. 4, 1882. The record of the Western Edison Light Company of Chi- cago, which took the contract from the Appleton Edison Light Company for two K dynamos, to be operated from water power and to light 550 lamps, was dated Photo by Underwood and Underwood © Aug. 15. 1882. Edward T. Ames, still living An Interested Group of Young Studying the Mysteries of Wireless at a York Women New in St. Joseph, Mich., was sent by the West- School, So as to Be Ready to Do Their Part When the Call Comes. ern Edison Light Company of Chicago to install that machinery. He has stated that the Radio School. The Y. forward crews, in charge oi Lieut. and Marconi gun the .^.ppleton station was started on Oct. M. C. A. offered the use of their apparatus (Junior Grade) R. D. Tisdale, remained 15, 1882. Tbis makes it the first Edison the services of their instructor Mr. calmly at their stations the ship and gun while electric lighting station to be driven by to Mrs. Owen, so that women could was sinking and no to leave Bohn made move water power and the first Edison station learn wireless telegraphy and thus aid their posts until ordered to save themselves. in the West. their country by teaching men and replac- .\n instance of remarkable coolness is cited ing them in many posts relieving them for in the case of one member of the gun crew active service in branches where they are who was rescued from the top of an am- [Editor's Note:— Those interested m the more needed. The photo shows a class in munition box. When he saw a steamer liislory of the first steam-driven electric radio engineering. coming near to pick him up he advised the central station in America u.-ill find on au- Eighteen women have already past the ship by semaphore not to come too close as thentic article describing the Peorl Street U. S. Government tests, hold licenses, and the box he was sitting on contained live station in New i'ork City in the January. are thoroly capable of becoming code in- ammunition. 1918, issue of this journal, page 598.] structors, should the Government decide to use them. ANTILLES' RADIO OPERATOR DIED BRAVELY AT HIS POST. Secretary Daniels has sent a letter to Robert Ausbume, who is employed at the Union Club, Fifth Avenue and Fifty-first Street, New York, commending tlie action of his brother, C. L. Ausburne, radio elec- trician first class, who went down with the U. S. Army transport Antilles, when it was sunk on October 17. Attention was called to the bravery of this radio opera- tor in the findings of the court of inquiry, which stated that Ausburne went to his station to use the radio to give warning rather than attempt to save his own life. Ausburne and Radio Electrician Mac- Mahon were asleep in adjacent bunks, opposite the radio room, when the ship svas struck, .\usburne, realizing the seri- ousness of the situation, told MacMahon to get his life preserver on. As he left to take his emergency station at the radio key he shouted to his companion, "Good- by, Mac." This was the last MacMahon saw of him. Going to the radio room, MacMahon found it locked, and, realizing that the ship was fast sinking, attempted to get Ausburne out, but without success. .\usburne originally enlisted in the Navy at New Orleans. February 25. 1908. After eight years' service he reenlisted on March A Remarkable Photograph Showing What Is Thought to Be the Remains of the First Hydro- in 1882. October 15 of That Year. 1, 1916. He was one of the four men of Electric Plant In the World. It Was Built and Started on : . March. 1918 ELECTRICAL EXPERIMENTER 753 NOVEL ELECTRIC STRIP higher the temperature required to cause it SEAPLANE CRASHES INTO RADIO HEATERS. to bend still lurtlier and break the circuit. TOWER. For crane cabs, valve, meter and pump By the use ol this device it is claimed that The extraordinary and remarkable photo houses, watch and signal towers, turn table 40 per cent of the energy now used in the here reproduced shows a British seaplane cabs, theatre ticket booths, exposed and excess heating of irons, percolators, caught in the steel girders of a wireless remote rooms these are some of the loca- toasters, chafing dishes, etc., can be saved, tower over 300 feet high. The plane, while as the exact amount of heat required can emerging from a thick mist, hit the tower be obtained and the excess eliminated. and was caught firmly in the steel lattice work. The pilot, who was stunned, was 3,000,000 H. P. AVAILABLE AT flung from his seat and fell on one of the NIAGARA WOULD planes, where he lay unconscious over 300 SAVE COAL. feet from the ground. The seaplane's en- WINIjER, in a recent address gines were wedged into the interstices of CA.here before the Schenectady Section the girders so that the body of the machine • of the American Institute of Elec- stuck out at right angles. trical Engineers, urged the use of Niagara A small body of bluejackets were at work Falls power as one means of solving the painting the tower. One of them, a seaman coal shortage problem. Mr. Winder spoke of the Naval Reserve named Rath, climbed as follows up the inside of the mast until he reached "While the Nero of smug indifference and the machine, and then crawled out onto the ignorance is fiddling away, the great coal plane to hold the pilot until help came. fields of the earth are being burned up. Two more men. Ordinary Seaman Knoul- While millions of horse-power are passing unused over vast water falls, great indus- tries are languishing. Water power sites have virtually been roped off and 'Verbotcn' signs posted by our national legislators. New Electric Strip Heaters Are Well Which Now that the coal Adapted to Heating Small Booths and Clos- supply diminishes and ets. water power is throttled, what chance has the electrochemist, the greatest user of tions in industrial plants and factories power, to expand to meet the increasing where the new strip type, steel jacketed, demands of the present day? The electro- electric heater units have found application. chemical industry is vital to the success of the These units may be connectecd to either great world war ; that water power is D. C. or A. C. circuits— 115, 230 or 250 vital to this industry will be shown in the volts. As electric lamps are placed where following paragraphs," he said in part. light is wanted so these units are distrib- "The electrochemical industry can be well uted where heat is required. The dimen- divided into three classes. sions are 3/16 x lyi x 23^4- Such heaters "First—Those that can't be moved from take up a minimum of room and give the Country by any means and will stay re- enough heat to keep a small I)Ooth com- gardless of the cost of power. fortable. "Second—Those existing at present, and to a greater or less extent depending upon NEW AUTOMATIC CONTROLLER natural conditions for existence and growth. •FOR HEATING DEVICES. "Third—Those having no footing in the A Western concern is manufacturing an country or not as yet in existence. automatic controller that regulates the "The first includes copper, zinc and rare amount of current delivered to any heating metal refining and electric steel production appliance and maintains the heat of the ap- aiid is perhaps, as a class, the largest user pliance at an even temperature. This de- of power. Class two included, in the order vice is made in two types, one for alternat- of their importance, the following: .\lum- ing current and the other for alternating inum, ferro alloys, carbid, artificial abra- and direct current. The controller consists sives, alkali, chlorin. phosphorus, sodium, of a thermostat, composed of copper and cargon, disulfid, grafite and similar prod- iron riveted together, which is placed im- ucts. Class three would then include nitro- mediately over a heating coil and connected gen fixation and possibly products we know in series with the load. The heat from the little or nothing of at this time, there being coil causes the thermostat to break the cir- no power consumed within our boundaries cuit whenever the temperature rises above for products of this class. a certain point. The handle on the outside "Not a shell is made that is not shaped of the case can be set at any point lettered by electrically made abrasives. The electric from A to K. on the scale. ./ corresponds furnace from which the armor plate is with zero degrees, B with 10, and C with poured used electrodes made from coal b\- the aid of electric power, the re- sisting power of this same steel is given by electrically made ferro alloys. Merchant vessels are now using smoke buoys in which quantities of phosphorus A Remarl JUMBO GETS HIS HIDE toria, electricity can be utilized to promote ively coupled by a transformer witli a VACUUMED. the falling of rain over dry regions. closed oscillating circuit, comprising a Jumbo, the elephant, likes to have his hide The specification states that the atmo- spark-gap and a condenser, which, in turn, cleaned the modern way. that is, with a sphere is known to comprise several dis- is coupled tlirough a tuning coil. Deposi- vacuum cleaner. The illustration shows a tinct regions. The section of the atmo- tion of the aqueous particles occurs upon husky pachyderm receiving his morning sphere concerned with the process subse- and in proximity to the conductor. HEAVY DUTY ELECTRIC PHOTO- PRINTER. By V. G. KUi>. This photographic printing machine is in use by a coiicern making large commer- cial photographs in big quantities. It has an automatic time switch making and breaking the circuit for six 500 watt tungsten lamps about once every minute, all day long. By means of a clock-work. it is set to give a print any desired length of exposure to the light. Each lamp can be turned on and off individually as well as adjusted' in different positions so as to regulate the intensity of the light on cer- tain parts of the negatives to be printed. The switch has sliding contacts, mounted on a marble base which is inclosed in a sheet metal bo.x. The wiring is arranged as shown in the photograph of the device. The automatic switch terminals are of brass, insulated by fiber over which a flexible copper bar moves with perfect con- tact and without appreciable friction. As the bar slides over to the opposition It lights a red pilot lamp, thus furnishing illumination in the machine while the pho- tographic paper is being put in place over the negative. When the switch bar is half way across the contacts the red lamp is connected in series with the white lamps, preventing the current from being entirely Photic from Society for Electrical Development © Am. Press A35OC. broken at any time during the operation. Electricity Is Daily Finding More Ways of Lightening Our Labors— Here, Jumbo, the Elephant, Receives a Thoro Morning Scrubbing —a la Vacuum. Before this machine was perfected great difficulties were experienced on account of arcing switches and unreliable timing, but bath—a la vacuum. The electric vacuum quently described is termed the troposphere. this construction has given the users satis- cleaner is finding wide-spread application The earth's surface is always negatively factory service for several years. :n many parts of the country for thoroly charged, and in fair or clear weather the md expeditiously cleaning animals. Time troposphere is nearly always electrified ivas when the only hath the elephant en- positively; in wet weather, however, nega- joyed was that when he happened to get tive electrification of it is usual. The near a tank of water or a lake so he could troposphere contains transient masses of ill his trunk and spray himself. Now, the electrified particles which vary or alter the elephants belonging to such pretentious normal sign and potential gradient of zones shows as that at the New York Hippodrome of the troposphere. The invention is based receive a thoro cleaning every day. The on the diminution or cancellation by arti- animals look better and feel better—just ficial means of the potential gradient exist- the same as humans do. The elephants ing in fair or clear weather between the really seem to enjoy the novelty. elevated zones of the troposphere and the ground, so that clouds are formed in the "HOOVERIZING" ELECTRIC affected troposphere zone and rainfall is CURRENT. procured. The invention utilizes an elec- trical used to for a .\ wide margm exists for the reduction conductor form a path of household consumption of electricity, in flow of energy be- furtherance of fuel and freisht saving. For tween the earth and instance, despite the remarkable develop- such tropospheric ment of cheap, durable, metallic-filament in- zone or cloud, the candescent lamps the past few years, there conductor being con- has been no reduction w'hatever— in fact. nected to a good elec- an increase, rather—in the use of old- trical earth at the fashioned carbon-filament lamps, which the lower end, and at the modern lamps should have displaced, says upper end having a the weekly bulletin of the U. S. Food Ad- terminal of electrical- ministration. Carbon-filament lamps give ly conductive material less light than modern lamps and consume which will insure in- more electricity. The chief element in their trinsic electrical con- continued use is the fact that they are given nection with the cloud free to householders by many electric-light or tropospheric zone. corripanies, whereas metallic-filament lamps A potential of the are sold. It would pay every consumer of order of 320,000 volts electricity many times over to purchase is maintained between modern lamps and economize by reductions the conductors, caus- in electric-current bills. Old-fashioned and ing coalescence of the ineffective types of lamps are also used for aqueous particles and street lighting and should be replaced with deposition upon the large economical incandescents of the latest earthed conductor. In types. a modification a sin- gle earthed conductor ELECTRICAL PRODUCTION OF is supplied with high RAIN. tension alternating- -\rrording to Australian an patent ap- current by means of yvith This New Elec trie Photograph Printer the Young Lady Can plied for by Mr. J. G. Balsillie. of Vic- an alternator induct- Turn Out Ten Phot Prints Where One Was Produced Before. March. 1918 ELECTRICAL EXPERIMENTER 755 AN ELECTRIC SHELL FOR FIGHT- energization of the detonator the ING U-BOATS. explosive is exploded and, of It has rcinaiiicd lor Mr. Lee A. Collins, course, will destroy the shell and of Louisville, Kentucky, to invent a new any objects within its radius such electric explosive shell for combating sub- as submarines, torpedoes or other marines. vessels. This shell is one which explodes after In lieu of a spark coil a more being fired from a gun or other projectors powerful battery may be used and or when dropt from airplanes and the like the ignition wires would be con- into the water, for warfare against sub- nected directly to the terminals marines, torpedoes and the like. The in- of the detonator. Under some ventor provides in this connection two elec- circumstances, it may be more de- tric conductors exposed to the outer sur- sirable to form the insulating me- face- of the shell with insulating means dium of dry salt or like mineral, separating the electric conductors. This which will readily become a con- insulating means is soluble or made con- ductor of electricity upon coming ductive when in water. Another object of into contact with water and thus the invention consists in providing a nor- close the battery circuit to the mally open circuit adapted to be closed spark coil. upon contact of the two exposed terminals with water or other conductive means, A NEW SECRET TELE thus causing an explosion. By attaching ^ PHONE TRANSMITTER. time fuses to the electric detonator it is In order to permit jirivacy in possible to cause an explosion to take place telephoning, a Chicago inventor at a predetermined time after the shell has developed a device shown in comes in contact with conductive means, the accompanying illustration instead of the instant that the shell strikes which can be used with any tele- conductive means. phone mouthpiece. By its use, it The invention also covers means for is said, that telephone conversa- coating outer exposed conductors with a tions can be conducted in a very non-conductor covering, such as sealmg- low tone and in a whisper, under Something Every Housewife Wants a Positive Indi- wax, paraffin or other suitable means many conditions. It is pointed out — cator That the Electric Iron Is "On" or "Off." The which can readily be removed when shell that the device is not permanently Teli-tale Lamp Solves the Problem. is to be fired, thus preventing accidental attached to the telephone and is contact, which would prematurely explode therefore not a fixture. the shell. The device is held on the mouth-piece of PILOT LAMP WARNS WHEN These exposed conductors must have all any telephone, and is held securely by ELECTRIC IRON IS ON. insulation covering removed at outer ex- means of the horse-shoe shaped wire held .\ new heater control just brought out posed surface when ready for use. Heavily by the two springs, which snaps over the is equipt with pilot lights which serve as a insulated covered conductors lead from the mouth-piece of the telephone. safety check on the woman who uses an secondary of spark coil and thru wall sep- To use the muffler most effectively, the electric iron or other extension device and arating the chambers to the respective on the workman who operates an electric terminals of a detonator, which may be of iron in a factory, clothing shop or similar any suitable type. One form being a bulb commercial establishment. containing fulminate of mercury and a They enable the operator to play safe and platinum wire within, connecting the elec- avoid waste of current. The pilot light tric terminals leading from the spark coil. acts as a silent watchman and signals danger The detonator is in contact with or rests when the heating device is left in circuit against the explosive, which may be a unattended. charge of guncotton or other high ex- Take the case of an electric iron, for in- plosive, placed within the forward cham- stance, on an ordinary padded ironing ber. Obviously, therefore, as soon as the board : place it in circuit and leave it. platinum wire within the detonator is ener- with "heat on," for say fifteen minutes or gized from the spark coil, the explosive more. The probabilities are that quite an explodes, thus causing destruction to the impression will be made in the pad, and shell and all objects within reasonable quite possibly on the board also ; perhaps radius. A Newly Marketed "Secret" Telephone Muf. the iron will even burn its way right thru In operation, a shell is fired from a when fler. It Fits Onto Your Regular Telephone the board. .\nd then again, if the iron is gun or dropt from an airplane or other- and Is Removed in a Second. left to itself long enough Avith the current wise discharged into the water at an enemy on. the chances are that a serious fire may vessel, submarine or torpedo, one con- inventor states that the upper lip should result. These new Heater Control switches ductor and the outer portion of the shell. be prest gently against the mouth-piece, have been brought out particularly to min- which in this form is a conductor, will speaking slowly and articulating distinctly imize fire hazard of this sort. come into contact or be submerged into with the lips—almost a whisper (not down A wide variety of designs has been made the water when it strikes the point of aim in the tliroat). to suit practically any condition desired and closes the circuit of the battery thru If used correctly you will be plainly Each includes a pilot lamp and a 10-ampert heard at the other end, it is double-pole indicating switch. claimed, and no one near The flush tj'pes are mounted behind at- you need hear your conver- tractively finished face plates, and the sation, thus permitting pri- pilot lamp signals thru a ruby bull's-eye vacy and confining business They are ornamental in appearance and and personal affairs strictly are designed especially for use in the to yourself and those with home. whom you talk Surface types are for use in factories. They provide for regular base lamps as In Peoria, a hilly city in pilots but candelabra base lamps may be central Illinois, 300 automo- employed by using adapters. bilists operate automobiles without gasoline, that being USING EXHAUST STEAM. the number of electric pleas- More attention than ever before is being ure vehicles used in the city. paid this winter to careful use of exhaust steam in power plants. It may be applied ' '~' ' One ton of saffires will be to innumerable purposes, such as heating Electric Shell For Fighting Submarines. When Dropt In the used during the J'ear 1918 feed water for the steam boiler, for many Water It Becomes Active Due Insulation Jlo Being Dissolved jn one factorv v.'here the At Point, Closing Detonator Circuit washing purposes, heating buildings, pas- jewelled bearings of electric teurizing and sterilizing, and the like. A meters are made. The small investment in additional boiler-room the primary of a spark coil. As a result, jewels are purchased in the rough and are equipment, such as an exhaust-steam heater, the primary of coil will induce a current put thru finishing and drilling processes will effect savings of several hundred dol- into the secondary of the spark coil and which require a degree of skill comparable lars a year in the coal bill of even a mod- energize the detonator thru wire. Upon only to that of an experienced watchmaker. erate sized pcwver plant. March, 1918 756 ELECTRICAL EXPERIMENTER which close contacts for ELECTRIC LOAD RELIEF summer a deep valley will be seen in the solenoid magnets, ANNUAL time. An ordinary MAP RESEMBLES "ROCKIES." morning, between the "fall-ofE" of the the lamps at the same beginning of the day 4.5 volt battery, such as used in pocket diagram or night load and the The familiar daily load is sufficient to work this signal. load, while in winter the loads overlap in flashlights, "graph" is plotted by practically all electric the morning, filling up this valley. light and power companies. The accumu- Peaks. During the summer ALTERNATING-CURRENT GAL- months there are three distinct VANOMETER. peaks — one occurring about illustrated the new Nortb- :00 Herewith is 8 :00 a. m. ; one about 5 rup alternating-current galvanometer. The p. m.; and the third about 8:00 maker points out that it is especially p. m. With the approaching adapted to the following uses: (1) For fall and winter months, and as the accurate measurement of the resistivity the sun sets earlier each day. or conductivitv- of salt solutions and other the 8:00 p. m. peak moves back electrolytes; (2) for the measurements of toward the 5 :00 p. m. peak and the resistivity of molten salt; (3) for the near the end of Septernber the measurement of the resistivities of molten two peaks overlap, giving a metals for the measurement of any combined peak greatly exceed- ; (4) resistance in which small irregular emfs. ing any other peak, which rap- exist; (5) for the comparison of small in- idly increases in height until ductances using the bridge method and (6) the middle or latter part of December, when it becomes the greatest peak of the year. As the spring months approach the combined peak diminishes and finally near the end of March disintegrates, forming again the two separated peaks. While the above is a well known fact, the annual load relief map presents the changing condition in a most striking manner. NEW AUTO TAIL LIGHT SIGNAL. .A novel automobile signaling device is provided in this ne\\ attachment for motor cars. It is claimed by the concern now offering this new signal to the added No—This Is Not a Picture of the Alps! It Is a Com- public to represent an posite Load Relief Map. Showing the Rise and Fall of convenience and comfort to Philadelphia Day By the Electric Power Consumed in perfected b\ Day, For One Year. motoring. It was H. Hartman, a well-known lation of these curves soon becomes a mere New York inventor. record, usually filed away in some manner Usually the driver of his car has to ex- and always available for reference, and for tend his arm from the seat to warn other the study of load conditions. When con- cars in the rear, of what direction he is sidering the load thruout the year it is dif; going to turn or if he is going to stop. By ficult to obtain a comprehensive idea of the aid of this new electrical invention, all the whole since it is necessary to glance one has to do is to push a button on the separately at tlit greater portion of 365 steering wheel and the arm will indicate sheets. Such a record locks up a desired which way the driver intends turning vision in confusion. When the car is going to stop, both arms The .\nnual Load Relief Map here illiis- fly up. the entire trated is a device for visualizing Two buttons mounted on a small base is -described load of the vear and by Wm. are attached to the steering wheel—one for I. E. E. pro- Le Rov Robertson in the A. right and one for left; when both buttons 1917. Each daily ceedings for December. are pushed the stop signal is set. Something Every Laboratory Requires is load dliagram is marked off on card board a Good "Alternating Current" Galvanom- To inform the operator that his signal and cut out. The cards are stacked up in eter. This Is One of the Latest Types. is working O. K. a small lamp flashes up Fitted With Reflecting Mirror. proper daily sequence, mounted and pro- vided witli graduations for kilowatts, hours of the day and months of the year, for the comparison of capacities using the all properlv arranged. The annual load re- bridge method. the Phila- lief map here illustrated shows The galvanometer is mounted on a base delphia load during the year 1916. of ebonite provided with leveling screws. brought Day Load. A distinctive feature The field magnets are laminated. Mag- out by the annual load relief map is the netizing coils are wound on non-metallic contour of the day load which is con- spools, which are placed on the field poles sistently uniform throughout the year, al- as close as possible to the moving coil. ways picking up between 7:00 to 8:00 a. m., Pole-pieces are given a hollow cylindrical having a valley at noon and then falling off form about the moving coil, this special stands puncttially at about 5 :00 p. m. This shape preventing the coil, when on closed relief out clearly on the annual load map. circuit, from assuming a position of un- and especially well, if one will imagine the stable equilibrium due to currents induced over- absence of the night load where it in its circuits by the alternating magnetic day laps the day load at 5 :00 p. m. The fieM. The moving coil is long and narrow, to the regular av- load corresponds closely so that its moment of inertia is small, there- erage working day. by permitting high sensitivitv- with a quick A'i.<7/if Load. The night load which picks entire hanging system is ex- An Electric Semaphore and Tail Light For period. The rapidly at 8 :00 p. m. in raid-summer, and up Autos. Its Arms Point to the Direction posed to view through a glass front. The in winter, to Take. at about 4 :30 p. m. to 5 :00 p. m. Which the Auto Is About central housing is of non-conducting ma- load. It corresponds closely to the lighting terial to prevent the formation of eddy depends absolutely upon the hour of sunset currents. button base and a red light for its beginning and falls off rapidly, on the push sensitivity is adjustable thru a wide peak value. Af- shows on the attachment. An ingenious The shortly after reaching its being flashes a beam of light on range, the strength of magnetism ter midnight, it settles down to a low value arrangement that they may be variable by varying the current thru the and drops off almost entirely when the either or both arms so night. arms are worked by field coils. street lighting goes off near sunrise. In seen at The — March, 1918 ELECTRICAL EXPERIMENTER 757 A LUMINOUS BUTTON FOR PULL AN ELECTRIC CIGAR AND PIPE COMMERCIAL 110 VOLT MOTOR CHAIN SOCKETS AND LIGHTER FOR AUTOISTS. SIZE OF YOUR WATCH. SWITCH PLATES. Push the button and light your cigar or One of the largest electric motor manu- For attachment to the end of the pull pipe without a cuss word, ii your car is facturers has brought out a line of ex- chain of the pull-chain type socket and for fitted with this new electric lighter. It is tremely small motors in every size from made for 6 volt storage battery only, and 1/200 to J^ of a horsepower. Like a good not for regular electric lighting or power circuits. This Cigar Lighter is very neat in ap- pearance, takes up little room, will not "drain" the battery and will add greatly to the equipment of the finest and most luxu- rious of cars. The spiral coil clement is so arranged as to allow its use with cigar, cigarette or pipe. The casing is finished in polished nickel and the handle is of wood with ebony finish. It is furnished complete with protector sleeve and five foot cord directly connected to lighter and either one or two point Edi-swan standard auto- mobile attachment plug. Commercial Electric Motors No Larger Than By Attaching a Watch Are Now Built Regularly. This Luminous Bead to Socket Chains and Switch Plates, It Be- watch, they run sure and true, doing the comes An Easy Mat- work to which they are assigned, year in ter to Locate Lamp Control Points in the and year out, with little or no attention Darlcest Room. They The 1/200 horsepower electric motor here Darit. Glow in the shown in comparison with a watch shows how the electrical engineers have developed and perfected the motor so that a perfect machine, armature, field winding, bearings, and all results in a minimum of space. WAR INVENTIONS CLOSELY use with switch plates, a New York con- GUARDED. recent legislation empower- cern is now offering the trade a special Pursuant to radio bead and radio button which makes ing the Commissioner of Patents to with- hold the issuance of Letters Patent on it possible to quickly locate in the dark a light chain, push switch or gas jet. These the devices adopted by the Government for beads and buttons are made up of such a use in carrying on war. Commissioner New- sixty-five size as to radiate ample light, it is claimed, ton has refused patents on over to be plainly seen at distances from 10 to 15 inventions within the past few weeks. At of Point feet. The bead is made up so that it can the present time a corps West and be easily attached to the pull chain by cut- Annapolis graduates trained in technical of the problems of war, carefully consider the ting off the large ball at the bottom Every Autolst Will Appreciate the Comfort patents granted weekly for de- chain and slipping the last ball into the en- of the Electric Cigar Lighter. hundreds of larged portion of the top of the bead and tails of military significance and choose then pinching the wires close together. those on which patent proceedings should the Besides the uses mentioned, it is pointed A COMBINATION ELECTRIC CUR- be suspended during war. The inven- out that these devices are of practical use LER, HAIR DRIER AND WAVER. tors thus deprived of patent rights may old. u ill find this in lofts and cellars, where it is difficult to Ladies, both young and offer their devices to the Government and locate obstacles and lamps under other con- new electric curler, hair drier and waver sue after the war for compensation. ditions. all three in one—a great convenience. It dries the hair quickly after a shampoo. NEW ARMY FLASHLIGHT FOR To use the curling iron it is simply neces- U. S. SOLDIERS. NEW INSULATOR CLAMP RE- sary to remove the comb. To use the This new army llashlight is designed PLACES TIE-WIRE. waver, remove the shield and comb. The especially to meet the needs of soldiers device is claimed to produce beautiful and sailors. It is small in size, light in is to The insulator clamp shown designed lasting waves or curls. weight and can be conveniently carried in prevent line trouble caused the use of by kit or coat-pocket. It is claimed to give other copper tie-wires on telephone and more light than main very large flash- Besides preventing line trouble, it lines. lights—plus special service impossible lines and Saves time when constructing new with ordinary tj'pes of flashlights. For in- also when repairing and rebuilding old lines, stance it can be buttoned on the coat, leav- as it can be detached and attached more ing both hands free; can bo fastened on the quickly than tie-wires. This clamp can be belt; can be hung on any peg; can be car- used over and over again, whereas tie- An Electric Curler, Hair Drier and Waver ried by its handle, as a lantern ; can be For Milady. stood upright on its base, as a reading The heater and cord revolve together, so lamp ; can be hung that the cord does not kink while in use above a mirror, as and the temperature is so regulated in the a shaving light heater that it camiot burn the hair. Renewal batteries can readily be pur- CLEANING WARSHIPS' HULLS chased in any BY ELECTRICITY. town in the United The old methods of cleaning ships' hulls, States and Europe. which was a laborious and lengthy process, It is especial) is being replaced by electrical methods. adapted to tli> Formerly, it was customary to allow 170 wants of thi to 200 man-days for the work, but recent- Home Guard an>i ly several electrically-driven machines have Boy Scouts. For lieen found to be both speedy and effective. policemen, watch- their . detectives, To Save Miles and Miles of "Tie-Wire," An Brushes and scrapers are used, and by men Inventor Suggests the Use of This New In- means, at a moderate expenditure of elec- reporters, sports- sulator Clamp. tricity in driving the operating motors, an men and all other 18,000-ton battleship can be, completely classes of men wires have only "junk" value when once cleaned in twelve hours, and vessels dry- who need to have used. docked after having been cleaned by this both hands free, The cost of manufacturing is but little method have been found to have remained this lamp should higher than that of the copper tie-wire. quite free from any subsequent marine prove extremely latest Army Flash- useful, light for Soldiers. Contributed by A. J. VIKEN. growth. — " 758 ELECTRICAL EXPERIMENTER March. 1918 At War With The Invisible By R. and G. WEMTHROP you of the present generation, se- rewards fiendishness and malevolent ambi- minds of the allied planets. The president TOcure and prosperous in these happy tion. of the visiting commission, the Honorable days of universal brotherhood and It was in the year 2011 that Mars thrust Peros Venasarol, had hardly begun the peace, the world-destroying War of this new engine of frightfulness into the opening of his address, when the vibrator the Planets, that engulfed every strife. The terrific struggle was ending its on my pocket phone signalled. At the mo- shred of our vast planetarian system at the third bitter year and the contest between ment, the president's daughter, Ava, sat at opening of this century and pitted with righteousness and unholy greed seemed to my side. frightful force planet against planet, is be ending with victon.' on our side. As In these days, when a journey to another already becoming a mere tradition—a grue- the real character of the war had become planet is as common as a week-end trip to some, historical record of the unwise past. apparent, one after another the planets had Japan was in my time, the presence of As you glide Venusian wo- along the turbid men in our so- canals, on your cial life is ac- summer trip to cepted as a mat- Mars, with the ter of course; peculiar reddish but in 2011 their water lapping at ethereal glory the sides of the still held us en- blunt- shaped thralled, and gondolas, you Ava—Ava was pause for a few the quintessence moments to of them all. contemplate the I was one of enormous mag- the committee netic pillars appointed to in- from which terpret the were launched Earth to the the world- visiting c o m - crushing elec- missioners, but trites ; or you I interpreted it climb the grass- only to Ava. covered Battle Her presence Hill on Venus had called forth to gather sou- in a flash my venir fragments very soul, and I of the crum- laid it at her bling Flame feet with such Tower, whose generous inten- battered sides sity that she ac- now seem to be cepted it as gra- sinking into the ciously and as crest of the hill. sweetly as a But, strive as child takes a you may to re- flower. Ah ! vive the images that lilt in her of that bygone voice—the mys- age, your inter- terious, fasci- est is only his- nating chime of torical and you the bells on her cannot sense the wrist—the bells the feeling of that no one horror that could see—the comes over us bells that were older people to save us from when we re- the Martian visit these time- horror . . . But scarred, battle- I am forgetting seared scenes of the reception a past in which and the sum- w e struggled mons of the against com- pocket phone. plete extinc- With an im- tion. patient jerk I I do not ex- drew out the pect, therefore, phone, set the to reproduce in silencer so as '' your souls the not to disturb (^ emotions that those near me. adjusted moved me . in and that time of the receiver to strain a n d 'The Bells Are Inside,' Ava Explained. my head. Im- stress—I cannot mediately I hope to picture could hear In- in your minds my own mental conflicts of joined the forces pledged to destroy the gals, my managing editor. His voice was dread and triumph, of life and love and menace of Martianism. The huge V-planes tremulous with excitement. hope, when a fear-maddened universe of the Allies now surrounded Mars in a "For God's sake, Elvan, hurry back!" he fought desperately against a new force flashing ring, gradually crushing down her gasped. more bitter and relentless than any that stubborn resistance, and we looked forward "What's up?" I asked. warring mankind had ever before faced with eager hope to the approaching end. "I can't tell you—hell's broke loose on !" the Invisible Armada of the Air. But I Then came the stupefying shock of Phila- Earth want to bring vividly to your minds the delphia's destruction. "Won't to-morrow —do?" I suggested. knowledge of that event, one among a I was in Paris at the time, representing "The Honorable Peros !" thousand of the Great War, so that you the Neiv York Century at the reception to "Oh. damn the Honorable Peros may see how the Supreme Intelligence, the Commission from Venus. Around the shouted Ingals. "Start now, I tell you." working thru the mind and hand of man, table of honor were gathered the keenest And he shut off with a jerk. — — " Ma 1918 ELECTRICAL EXPERIMENTER 759 I glanced around at the assemblage, at "Impossible," objected one of his ceived a message calling me back to New the venerable high commissioner, now auditors. "The V-planes are hedging Mars York, but there were no details." fully launched forth on his impressive mes- so close a fly couldn't get thru." "There are all kind of rimiors. One sage and, finally, at Ava. An inexplicable "That's what they said in twenty-ten," says Philadelphia is gone. Another tells fear, vague and uneasy, wound like a cold, sneered the Mercurian. "Then the electrites us all America is wiped off the Earth. thin wisp of steel around Whatever it is, this is no my heart. With quick re- ^^^^^_Mii_ time to stand back in fear. solve I drew out my note- I'm going over." book to find the index sign We look upon the present World War with awe because we know it to I fell in with his stride of the American Air Ser- be the biggest conflict the world ever saw. But Napoleon's wars, Alex- as he turned, and we vice. In another moment ander's wars, no doubt were looked upon with exactly the same kind of walked aboard the Eagle, I was talking to the man- awe by the then existing humanity, because those wars were the biggest whose powerful blades ager. There was a night up to those respective times. were already slicing the express leaving London, What of the future? Suppose the Martians, whose civilization is in- air. he informed me. Whis- finitely older than our own, one day take it upon themselves to conquer At sunrise the next pering a hasty explanation the planetarian World, in order to keep their race from extinction, on morning, as the Eagle to Ava, I made my way their dying planet? It's only a step further from the present Hohenzol- soared across Staten from the hall up to the lern idea. For some day the gulf between the planets will surely be Island, I stood on her roof of the building. bridged. What then? Read this intensely interesting story of the future. dew-wet forward deck and About a dozen planes We guarantee you will Uke it. gazed ahead with a pecu- were lined up on the ^^^^^^^^ liar sense of vague fear as starting platform and I ^^^"^^^^^ ^^^^^^^" to what sight might greet selected the swiftest look- me. I gave a gulp of relief ing one of the lot. It was a long, grey began slamming us. I tell you, the Martians as the outlines of the great city flew rap- Bullet Racer. The aerist, a light-hearted have outguest us again. You listen to me idly into vision. Before I could dwell any boy still in his teens, assured me he could the Eagle won't get half way across. Take further on the meaning of Ingal's message, make the station on time with half his my advice and stay here." the great airship began settling toward her cylinders dead. "If it's the Martians," observed a placid dock. Watch in hand, I crept into the asbestos- voice in back of me, "they'll hit us here Without a moment's delay I hurried to covered compartment, seated myself by his just as quick as over there. I can't see the Century Building and soon was wind- side and we slid into the night. In a few the sense in getting scared off the Eagle." ing thru the long lane of writers' desks to moments we had cleared the city and were I turned with a smile of approval to face the editor's office. heading straight for London. Instead of the speaker. As I suspected from the ac- Again a feeling of undefined apprehen- following the well-marked route over sion chilled me as I opened the door and Calais we took the direct Dieppe path, Ingal's tired eyes met mine. No sleep had |iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiniifiioiiii hoping to gain a few precious seconds by closed his—the pupils were pin points in the lessened mileage and the lighter traffic. two sunken, blue-grey pools. I IN THE APRIL "E. E" !" For five minutes we breasted the darkness "Elvan ! Good A look of relief lit up with no sound but the purr of the motor m The April issue of the Electrical his drawn features and he leanod back in and an occasional click of the altitude lever M Experimenter will be replete with his chair. "For the love of glory, Elvan, as the plane rose or dropt to escape the H numerous timely and valuable articles get over there quick and give us a straight suction holes that our indicator showed us M on Electricity, Radio and Chemijtry m story of this convulsion," he implored. in advance. Then a light flashed out of J of interest to all readers, both young H "You're the only one can do it. All the the black, winking red and white. It was B and old. Don't miss it. It ivill pro- H tykes around here have gone insane, I be- the signal station at Dieppe, floating ten H vide many hours' instructive reading. ^ lieve.— Look what this putty-brained ass thousand feet above the city. Half the m All the latest— advances in Science g says " He held up one of the scribbled distance was behind us and I had ten min- H will be there as well as fresh news J sheets and read from it in a voice ragged " utes left. I turned to my companion with H and pictures from the war front, g with exhaustion : 'No such scene has a murmur of satisfaction. Among the April features scheduled ever been seen before. The scene beggars J M " there appear the following: s !' "You'll do it," I said with satisfaction. I description "It's easy," grinned the boy. "Last year "At War with the Invisible"—con- m "Is it as bad as all that?" I asked soberly. I pushed a V to Mars. There's where the elusion of this gripping story of war = "It's worse," Ingals assured me, becom- ing grave. "Philadelphia is buried mile lads move. A hundred a minute with the and science, by R. and J. Winthrop. g a deflectors off and five hundred when they're deep and Lord knows who's next" "The Phenomena of Electrical Con- H — on. I'd be there now if they hadn't "Surely, you don't expect duction in Gases.— IVhat is loniza- smashed my back." ^ "I certairdy do. Those vampires of M tion?"—by Rogers D. Rusk, M. A. m I turned with a look of inquiry toward Mars—" "Research and Its Importance to his arched spine. H g "Mars !" I started in surprise. For the Human Progress."—by Dr. IV. R. "Chunk of 'lectrite," he explained. "A M J temperamental Mercurian to be seeing Mar- Whitney of the General Electric grain of it humps you up." ^ M tians behind every catastrophe was quite Co.'s, Research Laboratory. A spe- As we sped over the Channel the cloud = ^ natural, but Ingals— "How could they?" cial article which every American that covered the sky opened towards the M ^ I protested. = should read. = west and I could see Mars glowing dull — "I don't know. That's what I expect you red, like a baleful eye on the horizon. m "Electro-Static Experiments" Part J to find out." His voice rose in grotesque "Whatever has happened in America," 1 B // by Frederick Von Lichtenow. m wrathfulness. "Don't stand there theoriz- ing, blue-headed son thought, "at least, it can't be due to the m "A new Electro-magnetic Ship's log." you of an inkbottle! Get on the job! If I don't soon have Martians. Thank Heaven, they are bottled = "A marvelous Electrical Tobacco something sensible to work on I'll go up securely." s Leaf Sorter" by H. Hartman, C. E. My ruminations were suddenly checked toppy." "How Electricity Changes Modern as the aerist snapt off his motor and pushed H Some ten minutes later I stood on a Stage Scenery Instantaneously"—by the snub nose of the Bullet at a steep angle ^ little height in what had once been Fair- George Holmes. towards the earth. We had reached I mount Park, gazing down on the starkest London. H "How Science Takes X-ray S desolation that the Earth had witnest since The immense dock of the .American Air M Movies of living bodies by the aid of g Sodom and Gomorrah. Where once five Service was thronged with excited groups s Electricity." a million human beings had lived and loved of people. Rumors of an awful cataclysm H "The Chemistry of Selenium— ^ and joyed and sorrowed, a vast body of in America were being stridently discust, = IVhat Happens in a Selenium Cell" g sluggish, oily water stretched before the and many passengers hesitated to board m —by Albert IV. IVilsdon. | eye. The entire southern part of the city the Eagle, which stood ready on the in- = "Experimental Physics"—Lesson a had either sunk or vanished into the air, and the Schuykill and Delaware Rivers, clined platform, her black, carbonoid body = 12, by John J. Furia, A. B., M. A. m lights from the rushing together, had converted the site spotted with even rows of "Waz'emeters— Their Uses and Con- B observation port holes. H into an inland sea. struction," Part II—by M. W. Sterns. M One Mercurian had made himself the J Up towards Germantown and Ogontz, spokesman for the timorous, and loudly ex- H "The New Electrical Laboratory M where the land was hilly, the water had and Price Storv Contest." prest the fears that animated them all. ^ not entirely covered the ground and a few "Don't tell me it's an earthquake," he was heights projected above the surface, barren shouting with the volubility and exag- of any habitation or other sign of life, gerated gestures that mark the speech of and showing by their tortured appearance his people. "Whoever heard of earth- cent, he was a Jupiterian, huge in bulk and the agony of destruction thru which they quakes around Philadelphia? It's the glittering with gold leaf and jewels. had past. Martians. They've broken loose again." "What has happened?" I asked. "I re- (Continued on page 803) 760 ELECTRICAL EXPERIMENTER March. 1918 Experimental Physics By JOHN J. FURIA, A. B.. M. A. iColumbia University) LESSON 11 the third as in (c). etc.. for all eight discs. now be used both for "dark room" and If now they are placed one on top of the other purposes. Two dry cells are re- Photography (Concluded) other and fastened at the left in book form quired to run it. Turning switch to F gives by paper fasteners, on running the leaves red light and turning to G gives white light. lesson 10, the important elements en- quickly with the fingers, (because of the Experiment 62:—The retaining of the tering into photography from the stand- persistence of vision) a moving picture of IK image after it is formed falls entirely in point of Physics were discust in detail, the radius is produced. The moving picture the field of Chemistry and is based on the together with the elements of color produced on the screen by production thru principle that chemical action is often theory. Our chief consideration was the complicated machine in the theatre oper- caused by light. For example, the fading the obtaining of the image, either reduced ator's booth is simply enlarged views of the of dyes is caused by the chemical action objects in successive >eries of slightly dif- induced by light. The formation of starch ferent positions. In the ordinary black and white photo- graphy most of the operations must be per- formed in a safe light, red in color (reason Primary co/ors: n^'jen mi/eif, oneen i>y f.'ie to be given later ) . The following little lamp eye of f/ie SJine f/rne can be constructed at a very low cost and "give appearance of will give satisfaction in even the most deli- trtiite //^.ht cate work. A box 6" by 6" by 4" should be made of %" wood and the ends joined Fig. 56 and glued so as to be light-tight. A grooved frame is made for the front, three parts of w'hich are rigidly fastened together and the When the Colors Indicated Are Mixed, by fiy. 54 Rapid Rotation, the of "White Light" fourth tight fitting but not fastened. A piece Effect Is Produced. of window glass can be cut to fit and Series of Simple Pictures, Which, When Pre- sented to the Eye in Rapid Succession. Give from the elements in water and from car- the Effect of a "Moving Picture." bon dioxid which is breathed out by human beings, occurs in the leaves of plants only under the influence of sunlight, so we see or enlarged as required. In this Lesson, in that the most important of all chemical order to conclude the subject, most of the actions (since life depends upon it) is space will be devoted to the retaining of the caused by light. If equal volumes of ferric image even tho this phase of the subject chlorid and oxalic acid* are mi.xed in the falls chiefly within the realm of Chemistn.-. safe red light of the "dark room" and then rather than Physics. (It should be noted an equal volume of potassium ferricyanid here that because of the close relationship added, the color changes but slightly. If, between Chemistr\- and Physics, one can however, this same process is carried out rarely treat of any topic in one of these in daylight the result is a pronounced blue subjects without bringing in the other.) color. The ferric chlorid and oxalic acid Experiment 61 : —When an ignited piece when mixed in the dark or safe red light of charcoal is rapidly rotated, we cannot do not react, but when mixed in daylight distinguish it. but, however, the appearance do react and form another compound-fer- of a circle of fire is produced. In a similar rous chlorid ; whereas ferric chlorid on be- manner, rain, tho falling in drops, appears Showing the Effect of Light on Silver Bro- ing mixed with potassium ferricyanid does in the air to be a series of liquid threads. mid (b) After Adding Deveioper. Solution (a) not react, ferrous chlorid does, and the re- This phenomenon is due to the persistence Not Exposed. Hence Not Changed by De- sult is the compound called "Turnbull's of vision. The explanation is that the im- veloper. blue." This illustrates the process of blue- pression of an object on the retina of the printing. The blue-print paper is coated eye remains for some time after the object Stained, or else piece glass with a compound similar to those mentioned has been removed or displaced, so that a of ruby can be purchased for a few cents. The fourth above (according to the manufacturer) and when the speed of the motion is sufficiently part of the frame is not rigidly fastened when light strikes it a chemical change re- great, the object is seen in its new position sults. On washing with water where light while its image in the old position is still struck the paper it changes to Turnbull's imprest on the retina. It is this principle blue, and the unchanged material is washed of the persistence of vision that makes away. motion pictures possible. Cut eight squares manila paper two inches on the of heavy Experiment 63: — (To be performed in side an3 find the exact center by faintly dark room.) Take equal amounts of silver square. With drawing the diagonals of the bromid solution in two test tubes, (see Fig. circles with these points as centers, draw a 56). Make sure that none but the safe the first, draw- radius of one-half inch. On "red light" strikes the first test tube (a) indicated in heavily its radius in position and expose test tube (b) to w-hite light. figure 54 (a), on the second as in (b). on This Illustrates the Photographic "Negative" • Solutions of these chemicals are to be used. and "Positive." Note That Either Is Nega- (Continued on page 799) tive and the Other Positive. for convenience in getting at the inside of the box when necessary. In the center of the back (inside) a miniature socket and three volt lamp are attached and a similar socket and lamp on the top (outside). A pair of binding posts are then attached on the top and a two-point switch (consisting of three thumb tacks and a piece of metal) is attached on one side. Connections are made as in figure .5.^-11 (A and B are the binding posts ; C and D, the lamps and E, P. G, the three point switch). To make a real good job of it the inside of the lamp This Highly Magnified View of Plate Used for Simple Home-Made Duplex Lamp- H.in:ly for can be enameled white and the outside Color Photography Shows Probable Arrange- Dark Room and Other Purposes. stained and varnished. Thi'i little lamp can ment of the Colored Starch Grains. March, 1918 ELECTRICAL EXPERIMENTER 761 Notice to All Radio Readers As most oj our radio readers arc undoiibli'dly a-^earc. ihr t'. S. Inn cnnnent has decided that all Amateur Wireless Sta- tions, "vhether licensed or unlicensed, or eqtiipt for receiving or transmitting, shall be closed. This is a very important consideration, especially to those who are readers of the ELECTRICAL EXPERLMEXTER. for the reason that a f 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 zvill demand and expert a continuation of the usual class of Radio subjects, which we have publisht in the past four years, and secondly, there will he hundreds and even thousands of nezv radio pupils in the various naval and civilian schools thruout the country, who iii// be benefited by up-to-date ivirelcss articles treating on both the transmitting as well as receiving equip- ment. Remember thai you must not connect up radio apparatus to any form of antenna.—The Editors.^ An Exceptional Amateur Radio Station WAR is Wai-we all know that. But thing"—enlisted where his services can be professional style. The transmitting plant look at the accompanying set of of the highest value to his country. V\ c was a beautiful and efficient piece of work. photos showing some of the glories present the accompanying photographs tliru including as it did -d I'/z K.W. transformer, of amatenr radio days before the war. the courtesy of his father — a co-partner in oil condenser, interchangeable rotary spark This represented the magnificent wireless gaps, radiation meters, et cetera. station operated by 21-year-old John H. Mr. Stenger built an extra large Tesla Stcnger. jr.. of VVilkes-Barre, Pa., in the transformer which he e.vcited from hh palmy days just prior to last .\pril. Radio radio step-up transformer, condenser and amateurs in the east will probably recall rotary spark gap. It gave sparks 34" long These Photographs Show Vividly the Home-made Equipment in One of the Finest American Amateur Radio Stations Existing Before War Was Declared. It Was Owned and Operated by 21-Year-old John H. Stenger. Jr., of Will 762 ELECTRICAL EXPERIMENTER March. 1918 WIRELESS STATION IN FRENCH between them. An illustrated slide was as aerials, but it did not answer very satis- TRENCH. here shown and the crowd of curiosity factory and this scheme was dropL The present illustration shows a radio seekers about the radio-car almost swamped Later a regular research laboratory was station and the operator standing outside the small car and its operators. This car establisht on wheels, being in the same class the dugout in a French, second line trench. was kept in the yards and experiments were as the safety and other exhibition cars. A made from the labora- puUman dining car was made over and a tory located in a small large aeriel set a few feet above the roof. shop nearby. It was pos- Also at one end a collapsible mast capable sible to sound various of extending about 80 feet was fastened kinds of warnings on the for experiments on sidings. A large gen- car and to start, stop and erator and a gasoline engine were installed reverse its motion by to furnish power. One end was partitioned Radio. An arrangement off for sleeping quarters. The rest of the was also worked out so car was devoted to the experimental labora- that a tower man could tory and judging by the lantern slide shown send a signal and an au- of it, it was some class ! With carpet on tomatic arm or light the floor, rest chairs and what not—well it would operate and warn certainly looked more like a grand salon the engineer in the cab. Nevertheless much important work was But this nearly always accomplisht. and exhaustive tests were made failed to work at a and charts calibrated of results. The ten critical moment and not years of experimenting fell thru when war the some few thousand was declared and the laboratory hung out times in succession that its shingle, "closed for the season I" The is required of a device paper was a change from some of the which is to be practically technical papers that have been read and adopted. Dr. Millener's personality did much to get At this juncture in the the "high-brows" in the audience in good game certain patent suits spirits and all of those present appreciated started, claiming in- his coming East to speak before the In- fringements, and there- stitute on so interesting a topic. fore the work was abandoned for a time, also certain needed ap- TEACHING U. S. AVIATORS portionments didn't quite RADIO-TELEGRAPHY. materialize in the budget. .\fter a time work was "Learn to do by doing" is the motto of again resumed and better Uncle Sam's new military aviation service. quarters were fitted up And let no one tell you that action is not and a number of stations suited to the instruction. One of the first erected along the main things new recruits have to do is to learn line railroad ; these of wireless telegraphy. Mark the application maintained direct con- of their motto : They learn the art by talk- nection constantly. Work ing across tables with one another by wire- was also done in Radio- aii man's telephony and a number less. Here is a class in action. An first step in learning the science of radio, rho:u '^ by Interoaclonal Film Semce of arcs of different tj'pes which he will shortly be called upon to use In a Second Line French Trench We Find This Interesting, were experimented with. Battle-Front Radio Station. The Aerial Is a Low Affair, so as Also some were tried over the German trenches in France, is to the Enemy. The Apparatus Is Not to Be Easily Seen by with gases contained in master the International Morse Code. The Placed in the Dug-out at the Right. the surrounding cham- men here showm are cadets at one of the ber; a disastrous attempt "Ground Schools" practising the sending of These men are almost continually under at using illuminating gas put the gas idea dots and dashes, which are immediately re- every ef- bombardment the enemy making out of the running. produced on the tape before them. This destroy the stations and the aerials. fort to The Radio-phone worked fairly \VeIl be- permits them to lengthen or shorten their The aerials extend but a short distance tween the establisht land stations but some motions until they are wholly accurate. The above the top of the trenches of course, as difficulty was experienced with the set in- teaching of Radio to the thousands of new becomes clear from the photo, as other- stalled on the train. The voice had a aviators now being schooled by Uncle Sam wise they would soon be destroyed by shell peculiar manner of dying away suddenly Radio instructor offi- or machine gun fire from the enemy. The and then after a time coming back again. is a man's-size job. civilian walks radio apparatus is located in the dug-out It was also tried in conjunction with the cers have been recruited from roof of this in many cases. shown ; note the heavily reinforced then existing telegraph lines, using the same of life for purpose, sand bags to withstand shell fire. Some of these dug-outs form entrances only to an elaborate underground operating room or gallerj'. This gives better protection and less interference due to noises from shell and rifle fire. DECEMBER MEETING OF THE I. R. E. A very interesting paper was presented at the December meeting of the Institute of Radio Engineers at the Engineering Socie- ties Building. New York, on December 5th. Many notable radio men were on hand and the attendance was large, mostly due to the fact that the paper had a good advance notice and the interesting topic of "Radio- telephony on the Union Pacific Railroad" was discust. Dr. Frederick H. Millener. the author, described with many amusing incidents the work of almost ten years spent in experimenting and installing wire- less telegraph and telephone sets on mov- ing trains and in main stations. The first researches were made on a specially constructed flat car, about ten feet length, weighing a couple of tons, in and Photo © by International Fll; with storage cells and other apparatus. fitted How Uncle Sam's Aerial Fighters Learn Radio. They Practise the Dots and Dashes at On each of the cars were set two short poles First, the Signals Being Reproduced Before Them on the Tape Registers. This Allow* and a crude four wire aerial was strung Them to Check Up Their "Sending Fist." March. 1918 ELECTRICAL EXPERIMENTER 763 Visiting Arlington via the Talo Club By W. J. HOWELL all happened along about the time southern "ether" and it was needed in its was waiting to make the trip to Arlington, that "Arlington" was first into • IT put thermal form because it was rather cold and we piled on. operating condition, that the members down tliere in November. Daylight at last Passing over the Potomac River and into of the Talo Club got the idea that they came in all its glory and made me think Virginia, was a short trip, but we nearly wanted to visit the place and see for that the sun-dodgers of our town miss killed "Mac" because the car went right themselves just 'lat really was down there something when they sit up until all hours past the Monument, and while there we that made so much noise in the 'phones at listening to radio signals and then turn in had asked "Mac" if it was the one we were ten P. M. every night. To think was to just as it gets light. Washington very looking for and, of course, he said no, act, and it was found that one of the East- shortly was reached and we piled off. thereby making us use some more leg power em trunk lines was running excursion trains After washing off the "real-estate" of in order to find it. Pretty soon the conduc- down to Washington -and back to New five states and one district, we started out tor yells out ''Radio," and we found our- York, thereby giving about ten hours in the and kept our eyes open for a place to selves jumping off at a little two-by-four Capitol to see the sights while the cost fill up our insidcs, and believe me. we felt wooden shack with a sign that stated that would be in the "Amateur" Hmits of money, in the need of something after walking, this particular spot was what is known in which in this case was three cold dollars. for Washington apparently got a divorce the amateur world as "Radio, Va." There were four of us who went, and a from itself, because one has to walk a long Crossing the track a path led us down slight mention of each into a small depres- one will not be amiss. sion, thru which past "Woody" was the big a stream of water guy who had the repu- which kept the tation for wearing grounding system sand-paper collars, in moist, but at the time other words, a rough- of our visit we found neck, while "Mac" that when crossing the was an expert brass little foot bridge the polisher at one of our stream tried to moist- leading hotels. Then en the footal supports there was "Dickey," of the party, besides the Secretary of the keeping the buried outfit, and myself, copper wires in work- who unfortunately ing condition. At the had to hold down the top of the slight rise job of President, be- was the radio station, cause none of the and altho we had seen bunch wanted the it before crossing the honor and they had track and had taken to have some one to pictures of it, the blame if things went bunch took some wrong. more, for it certainly Well, it was decided was worth all the to beat it to Washing- trouble of getting to ton and that we meet Washington just to at the station and look at those towers. take the mid -night Pictures that have train, arriving there been publisht do not about six A.M., Sun- show the spectator day morning. Of the real thing and " Going Outside to 'Spark,' It Didn't, the course, we all brought Watch the Antenna Which We Found make him feel that Famous Aerial Switch, Mounted on Two Short Poles With a Ship's Bell Attached. Guess something to eat, but They Ring the Bell When Signals Come Down the Lead-In.' Author Is Central his own little aerial "Mac" was the win- Figure In Photo. at home is a mere ner of the first prize, bird cage compared for he came with sandwiches made of time to even cross the street. During this to the one before his eyes. slices an inch thick, and butter enough to time we had about twenty fellows with all Climbing upward we came to the main feed one at the present "Hooverized" rate kinds of automobiles ask us to allow them building and walked boldly in all the while for an indefinite period. The ham was in to show us Washington for the mere sum of expecting some one to throw us bodily out, the same class, and upon our requests he a dollar a piece, but there being four of us but nothing happened, so we gathered cour- mentioned that the food supply was gotten and Audions about the same price, we de- age and started to inspect the plant. For- by talking to the cook and appropriating a cided not to indulge. At last 'fter much tunately "Mac" had been down before, and little at a time. What he talked about we hunting we discovered Bryant's Lunch while there, took some pictures and became couldn't find out, and it must have been Room about four blocks from the Capitol pretty well acquainted with one of the op- exceedingly interesting, but at any rate, we building and stopped there to eat, but we erators. In the mean time, he had had the helped "Mac" to eat what he had and often look back and wonder if Bryant was pictures enlarged and brought them along, saved ours. I brought some steamed in the food business at the time. Break- all of which made things somewhat easier chestnuts, but the jokes that were pulled fast being finished we got under way and for us because, as I look back. I don't off were enough without having to eat them looked over the Government buildings think that we would have been allowed to besides. thereabout, but the aerial on the Bureau wander over the place just as we did, with- 'Long about this time the train started, of Standards attracted first attention while out being told to beat it. That is, unless we but not before a meeting had been called off in the distance could be seen the Wash- could have managed to scrape up acquain- to order and more work done then in a ington Monument and the Towers of Ar- tance by trying a little of that "mental short time than we ever did formerly, but lington. telepathy" stuff. It works—sometimes. the idea that we were starting broke up Passing on down the avenue we came to The main transmitting room at that time this business stunt and we tried to get as 14J/^ street, and while we found the street contained the large 100 K.W. set and a small little sleep as possible while passing thru all right we couldn't locate the half, so we arc outfit, besides a regular 5 K.W. set for Trenton, West Philadelphia, Wilmington, curbed our interest on that pavement and ship work only. The ' receiving room" was Baltimore and other small towns along the wandered on looking for a car that "Mac" in the next building, and was built like an right of way. About five A.M. "Dickey" and said would take us to Arlington. icebox with walls two foot thick. The two I took a little trip thru the train, and as Well, we walked and walked some more buildings stood about three feet apart so we were in the second car, and the outfit and still no car, but our trip took us past that no sound of the transmitting set would consisted of ten coaches, we had a good the Monument which was not open for bus- reach the operator in the receptor room. chance to see the human animal at sleep, iness, altho it was an early riser and was Two men are always on dut>', one in the for believe me, the shapes that people can up when we got there. Looking at the top transmitting room and one in the "listen- get into when sleeping in day coaches gave us a permanent bend in the back of ing box," and when the fellow hears a sta- makes one wonder if their hair hurts when the neck and was good training, for we tion calling him, he signals to the fellow they bend it! sure needed aid in finding the top of the outside, and he in turn starts up the 5 K.W. We ended up at last on the back plat- Radio Towers later on. Walking on from set and stops it when signaled. A relay is form and watched the sun break thru the there about a mile, led us to where a car used so that no high voltage wires pass (Continued on page 800) — — : : — 764 ELECTRICAL EXPERIMENTER March, 1918 The Design and Use of the Wave-Meter Part I—By MORTON W. STERNS Wave-meter is an instrument condenser rises to a value sufficient to Fig. 3 represents a damped wave dis- THEused to measure and detect the break down the gap G. the condenser will charge of the limit allowed by law (logarith- length, frequency, and amplitude of discharge across the gap and set up oscil- mic decrement 0.2) which require 24 com- emitted oscillations. Essentially it lations in circuit 1, of a frequency de- plete oscillations before the amplitude of consists of an inductance connected pending on the values of L and C. the last oscillation is reduced to one per in series with a condenser, either or both If now another circuit L'C, consisting of cent of the first. It is discharges of diis of which may be variable. For standard an antenna having a capacitv' C with re- tj'pe that are in use the most at present. spect to the earth, and an inductance of a They are produced by quenched and rotary value L', is brought near circuit 1 (i. e., gaps, etc. Waves of this tj'pe are recei\ed coupled to it) energy will be transferred on ordinary receivers using crv'stal, plain from the first circuit to the second circuit Audion receptors, etc. by pure transformer action. If the values Undamped waves are represented by Fig. of L'C are adjusted so as to give circuit 2 4. Here we see that there is no damping the same frequency as circuit 1, then (ig- or decay between successive alternations noring gap action and coupling) the great- but that they remain of a constant ampli- est amount of energj' is transferred from tude. circuit 1 to circuit 2, and an ammeter Waves of this type are coming more and placed in the ground lead of circuit 2 will more into use, especially for long distance The Simplest Form of Oscillating Circuit. register the maximum current circuit communication. As can be seen they repre- Comprising a Capacity "C" and an Induct- or 2 ance "L," Connected in Series. The Basic is said to be in resonance with circuit 1. sent a continuous flow of energy and are Circuit of the Wave-Meter. The last paragraph demonstrates clearly produced by the arc, Oscillion, radio fre- the principle of resonance on which all quency generator and other means. In re- wave-meters of great precision the oscilla- wave-meters and decremeters work. ceiving these waves a special t>-pe of re- tion constant VLC is generally kept con- We will now proceed to show how the ceiver is required, embodying either a tikker stant in order that the decrement of the values of inductance and capacitv' affect the to break up the waves, or a separately instrument shall remain constant over its frequency of the oscillations in a circuit, variable source of oscillations (such as the entire range. This is done by making both and how. knowing any two of the three oscillating .\udion) to "heterodyne" or pro- the inductance and capacity variable, i.e., factors (wave-length, inductance, or ca- duce beats with the incoming waves. by fastening a variometer to the condenser pacity) the other can be found. Referring back to Figure 3, we shall con- shaft. The type of wave-meter generally The wave-length (X) multiplied by the sider what the Logarithmic Decrement is in use at present is the variable capacity number of waves per second (n) must and bow it is measured. Each wave train type, having numerous coils for a great equal the velocity* of propagation (V). is composed of oscillations which are sup- posed to die away so that the ratio of any range. Formerly, the wave-meter having or V = nX (1) a fixt capacity and variable inductance was oscillation to the one preceding it is con- much used. stant, as the ratio of A'to A. It is generally conceded that the Wave- This constant ratio is known as the damp- meter is the most valuable instrument in a ing of the circuit and the Naperian loga- Radio Laboratory as it can be used for : ritlim of one oscillation to the one preced- 1. Measurement of uaze-length. (Trans- ing it is called the Logarithmic Decrement mitted or receh-cd.) of the circuit. 2.—Measurement of decrement. A 3. Measurement of inductance. Exprest mathematically S =z log « 4. Measurement of capacity. A, 5. Making resonance curves. \\ here S = Logarithmic Decrement 6. Making various antenna measure- and e = base of Naperian Logarithms ments. (2.71828). 7.—An e.vcitcr emitting waves of prede- The logarithmic decrement determines to termined length. a great extent the broadness of tuning and 8. Measurement of mutual inductance. the amount of interference produced. Diagram Showing How Maximum Current 9. Measurement the coefficient Hence the S. (jovernment's limit that of of is Developed in An Inductive Circuit—C 1, 2, U. no coupling. A—When Such a Circuit is Tuned to "Reson- transmitter shall produce waves having a ance" With 10. Measurement of the distributed ca- an Exciting Circuit—C. G. L. greater logarithmic decrement than 2. pacity and natural period of coils. An instrument whose purpose is to meas- These various applications of the wave- Where V is the velocity of propagation of ure the logarithmic decrement of a circuit meter will be taken up in due course. radio waves (the speed of light) 300,(XX),- is known as a decremeter, which is nothing Having imprest upon the reader the im- 000 meters per second. more than a wave-meter with an indicating portance of the wave-meter, its great instrument in circuit to indicate current 1 adaptibility and various uses, we will now ratios. More will be said about the decre- n = : (2) undertake a general review of a few ele- meter and its uses in the following install- 2"^ mentary principles in order to make the VlC ments. paper intelligible to the great number of Suppose now we are to design a wave- expressing L in henr\s and C in farads. youiig men just taking up the subject of meter having a range of from 200 to 3,000 Equation (2) can be found in any text Radio at the various schools of the Army book on Alternating Current. and Navy, as well as radio students in Substituting in Equation (2) the con- general. stants necessarv- to change L to centimeters I -, Realizing the breadth of the field to be i and C to micro-farads we have covered in the space available and the \ r 5.033 10' necessity of keeping the paper very ele- X N = —-— ^— 1 mentary, it is to be expected that certain — •.epics may be neglected. Lcm Cmf \ 1 Figure 1 represents a simple circuit con- _ Putting the value of sisting of an inductance and a capacity con- n back in equation (1) we have \ \ AAA7\a'\'^- nected in series. It the condenser is 10' charged to a given potential and then 5.033 X al- u 300,000,000 - X -' lowed to discharge thru the inductance, os- = cillations will be produced whose frequency \ i-Cm Cmf will depend upon the value of the induc- /' tance L, and the capacity C. or X meters = 59.6 \'Lc„ Let us now consider this simple propo- Cmr. (3) rig.3 sition with respect to a Radio Transmitter Equation (3) is known as the ftinda- as shown in Fig. 2. mental equation of radio and much use will © Suppose the condenser C is connected be made of it in further papers. Principle of the "Logarithmic Decrement" to some source of high voltage alternating Oscillations taking place in a circuit (or Each Wave Train Decays In the Manner Shown, so That the Ratio of Any Oscillation current, such as the secondary of a step-up emitted waves) can be of two kinds, to the One Preceding It Is Constant, as the transformer. When the potential of the damped or undamped. Ratio of Ai to A. March. 1918 ELECTRICAL EXPERIMENTER 765 meters, with 20% overlap between coils, and son we have the high upper range is be- In operation the tuner is held in the coat so designed as to give small distributed ca- cause the four coils are necessary to reach pocket. By pressing the buttons of the pacity, low internal decrement, etc. 3,000 meters and the upper range of the tuner, messages are received in the dots The first thing to decide upon is the con- fourth coil is 3,740 meters. This is gen- and dashes corresponding to the radio- denser ; this is generally designed so as to erally not objectionable, but in case it is, it telegraphic code. give a variation of six times its minimum simply necessitates the selection of a dif- Contributed by HARRY E. FUCHS. capacity. By this I mean that the capacit>- ferent capacity variable condenser. at 175° on the condenser should be six times HY-TONE TESTER FOR MINERALS the capacity at 10° on the condenser. AND CODE PRACTISE. We use this value because, as shown by — 1 Being a steady reader of your paper for curve in Fig. 5, the variation of more -^ the ^ nearly two years, 1 thought I would send six times the minimum capacity of the than ^ you in a little stunt which I have been condenser does not vary the wave-length using and found very reliable and satis- as rapidly as the addition of a new coil. ^ factory. It is a high frequency tone device The condensers used in commercial wave- y for testing sensitive spots on crystal de- meters vary from .OOlSmf. to .008mf., but / tectors and wired up as shown in attached .003m f. is generally used. i sketch. By building up the felt pad, any The wave-meter is seldom calibrated be- / range froin about 300 to 1.000 cycles per low 10° or above 175° because the per cent i 2 5 * S 6 7 a second can be obtained, and it produces a capacity change per degree is so small that pure F/ff 5 Capacity (ee) musical tone of constant amplitude and the tuning becomes too sharp for accurate strength, with no scratching or frying work. Graph Illustrating the Reason For Using a noises whatever. There are no adjust- Which Gives a Varia- In designing our wave-meter let us as- Wave-Meter Condenser ments to make or anything to get out of tion of Six Times Its IVIinimum Capacity. sume a capacity of .OOOSmf. at 10° and order. .003 mf. at 175° and make our inductance .\ five ohm telephone receiver is used as next step will be to determine the coils conform to these limits. The it takes less battery, operating on from two litzendraht to be used and this is We will now consider the coils which will size to three dry cells. .\ regular 75 ohm re- and keeping be made of the pancake type, wound with largely a matter of experience litzen- litzendraht (insulated stranded cable, each the meter decrement low (3x16x38 standard wire being insulated) and banked by layers. draht is much used). Next a that the bob- These exploring coils will be connected to mean diameter is selected so bins of all the coils are the same size; the meter by a flexible 3^ ft. leather cov- of ered cord. and using Perry's Formula the number sooc^c/e easily calculated. The lower limit of the meter is 200 meters turns are (Tn coutituicH i and this is at .OOOSmf. he X = 59.6 equation (3) "SECRET SERVICE" POCKET "VlC RADIO RECEPTpR. Where L is the inductance in cm. and C This is a "real" pocket receiving set, one that actually receives while you are out on the street or any other place. The set consists of a special tuner, condenser, de- tector, 'phone and an "invisible" aerial. The tuner is 4 inches long, ZYi inches deep and IH inches wide. As shown in the -1- illustration, A is the wire of the tuner, B Clever of is a strip of spring brass, C is a knob of Form "Microphone Howler" For Radio Tests or Code Practise Work. It Gives brass soldered to the spring strip, D is a a Pure Note of From 300 to 1.000 Cycles. De- tieedle point (not steel) soldered to the pending Upon the Distance Between Micro- Receiver. spring strip, E is the condenser (fixt), F phone and is a detector made of a blown-out cartridg* fuse as described in the April, 1917, num- Illustrating the Principle of the "Undamped Wave" as Used In Radio-Telegraphy and ber of the Electrical Experimenter. All Telephony. There Is no Damping or Decay the spring strips B are connected to bind- Between Successive Alternations. ing-post G by means of a wire. One end of the wire on the coil is connected to is the capacity in microfarads to give a binding-post H. Selectivity is obtained on wave-length X. X- = 3550 LC. this tuner by pressing the buttons C. The aerial is composed of a long flexible - L = wire sewed in a zig-zag way in the back 3550 C of a coat and insulated by empire cloth. 40,000 L = : 22,500 cm. 3550 X .0005 Hook-up of Microphone Howler to Primary .At the upper limit where C = .003mf. and of Loose Coupler "LC," So That Tuning May L = 22,500 cm. Be Practised In Natural Manner. X - 59.6 V 22500 X 003 = 490 ceiver can be used, but this will require more battery, from 6 to 8 cells. This also Now to allow an overlap of 20%. the makes an excellent wireless practise set. 1 minimum wave-length of coil No. 2 must wired it into my set with a small three- equal 80% of the maximum of coil No. 1. pole knife switch as shown, but alinost any X = .80 X 490 — 392 meters at .OOOMiif. hook-up will do. In connecting up the capacity. Therefore: however, it will only operate with (392)^ battery, the current in one direction, or the cur- L = = 86,400 cm. rent must flow to build up the permanent 3550 X .0005 magnetism of the receiver and not neu- X max. = 59.6 \ 86,400 X .003 = 960 meters. tralize, .^ni sending you this idea for I know it works perfectly, with no trouble Following this method we find we need or bother whatever. four coils which are tabulated below, show- Contributed by CURTIS KISSELL. ing the individual inductances ;uk1 range of wave lengths. RADIO CLUB OF AMERICA NEWS. Clttb Inductance \\'.ive Length The Radio of .\merica held a meet- Radio Set For Secret Ser- Coil No. in cms. Range A de Luxe Pocket ing at Columbia University on October 27, vice and Like Work. Rapid Tuning Is Accom- 22,500 200—490 meters pllsht by Pushing on the Various Contact 1917. Two important papers were read, 2 86,400 392—060 Buttons—One at a Time. namely. "Thermo Couples in Electrical .1 338,000 774—1900 4 1,310,000 1520—3740 Measuring Instruments" and "Radio Fre- A ground is obtained by running a flexible quency Instruments" by Dr. H. O. Taylor It is, of course, understood that the rea- wire thru the trousers to a brass heel plate. and Mr. Charles G. Kahant, respectively. — 766 ELECTRICAL EXPERIMENTER March, 1918 The How and Why of Radio Apparatus By H. WESTIELD SECOR, Assoc. I. R. E. No. 7 Radio Receiving Condensers. showing a fixt condenser and B, a second terminal to the insulating medium, called From time to time we uilt describe one way of representing a fixt condenser, while the dielectric, and this dielectric is the mem- particular instrument used in either the ra- C shows how a variable or adjustable ca- ber that retains the charge, and not the dio transmitting or receiving set, explain- pacity is indicated, viz., by drawing an ar- metal electrodes. This being the case, and as becomes evident, the capacity ing just how it works, and why. We have row thru the two plates diagonally. Fig. 2 of any received so many requests from new read- illustrates the construction of simple fixt condenser depends upon the coefficient of ers asking for such explanations, that we and variable condensers. Fig. 2-A illus- electrostatic induction of the dielectric have decided to publish this matter in serial trates the construction of the simplest form This factor is generally called the "specific form. In the course of several issues all of fixt condenser, having a dielectric C, inductivity" of the material used as the of the principal transmitting and receiving charged by means of two tin-foil or other dielectric, and as a basis to work on, air is apparatus will have been covered. The conductive plates A and B. The metal taken to have a specific inductivity of 1 at subject for the seventh paper is RADIO charging leaves placed on alternate sides standard atmospheric pressure ; the in- RECEIVING CONDENSERS. and in contact with the dielectric are always ductivity of any other substance is meas- cut somewhat smaller than the insulating ured by the ratio of the capacity of a con- denser, when its plates are separated by PRACTICALLY all modern radio re- medium, to prevent leakage, and the pos- ceiving sets employ some form of .sible chance of short-circuits. The small that substance, to the capacity of the same condenser or capacity, either in the fixt condensers found in a great many radio condenser when its plates are separated by form of a definite fixt capacity or else receiving sets are made up of from ten to the same thickness of dry air. in the form of a variable or ad- fifteen paraffined paper sheets, about two This specific inductivity factor is also of this install- by three inches, interleaved with alternately justable capacity. The aim known as the "K" value of the dielectric Radio charged tin-foil leaves. Every other tin- ment of the "How and Why of Ap- Any electrical or radio text-book contains a foil leaf is cotmected to a common terminal, paratus" series is to describe. in detail the table of the various insulating mediums used as dielectric in building condensers and the corresponding "K" values. A verj- com- plete table of these values and of particular service to radio men, appeared in paper No. 3 of this series (see Feb. 1917 issue) and also contains the necessary formulae for computing the capacity in micro-farads of any condenser. Resuming, Figs. 2-B and C illustrate in a simple manner how a rotary, variable, air dielectric condenser is constructed. A central rotary knob and shaft have rigidly mounted thereon one set of serai-circular plates, which may be turned so as to inter- leave with a corresponding number of fixt or stationary semi-circular plates. The con- denser is provided with a scale which is sometimes calibrated to read in m.f., direct, or else a calibration curve is supplied with the instrument. Low-priced condensers are not usually calibrated, but the capacity may be computed for any position of the rotary plates by means of the formulae in the third installment of this series, above re- ferred to. One terminal leads to the fixt plates, while the second terminal leads to the rotary plates of this tj'pe of condenser, and in fact this applies to all other similar t)pes of variable condensers. A variable condenser of the moving cone type which has been used considerably in laboratory work is illustrated at Fig. 3-A. This con- denser involves the use of male and female conical members, arranged in the manner indicated, so that the inner cone can be raised or lowered by a precision screw ad- justment, and the distance between its end and the bottom of the conical chamber of the fixt electrode, as well as the thickness of the air space surrounding the small cone can be varied, and likewise the capacity. Another simple form of variable condenser which has been used extensively in various types of receiving sets, both domestic and foreign, is shown at Fig. 3-B and utilizes one fixt and one sliding brass member, or other non-magnetic metal tubes. The slid- ing tubular member is sometimes provided with an indicating needle which reads over a scale secured to the base of the instru- ment. This condenser has a fixt thickness of dielectric, but the length of the active condenser insulation is variable to quite a The Principal Types of Radio Receiving Condensers Are Here Illustrated and Their Action fine degree. and Use Described for the Benefit of the Student. Fig. 3-C shows what is commonly known as an "adjustable condenser." In this form principal types of condensers found in mod- as at "A," while the balance of the alternate of condenser the capacity is varied by means well as metal leaves are connected to the opposite ern radio receiving apparatus, as of a special switch provided with a multi- circuits. terminal '"B." their use and connection in these fingered blade, so that the capacity of each Referring to the diagrams herewith, Fig. Before going any further, it is well to unit switched into circuit is retained as each 1 fixt and variable condensers note that the metal charging plates or shows how successive unit is switched in. are represented in diagrams and hook-ups leaves of any condenser merely serve to either {Continued on page 796) of radio receiving apparatus ; Fig. 1-A distribute the electric charge from : 767 March, 1918 ELECTRICAL EXPERIMENTER high A SECRET RADIOPHONE. A GOOD SUBSTITUTE FOR A without being rebuilt to suit the PRACTISE BUZZER. power. This idea was original with me, By Seefred Bros. benefit other amateur the hook-up of the and I hope it will of this article is to show how The drawing shows The object much as it has myself. of current is the radio men as can use a Radiophone and still not in- apparatus. The source one "Trans- This device should not be used on A. C, the radio-telegraph. The voice 110 volt D. C. power mains. The terfere with but on D. C. It pro- tlie is very clear, due to duces a note resembling fact that there are not "N A A" on the 100 disturbances any other K. W. spark set. The while talking. going on tone heard is due to the ghostly The voice has a pulsatory nature of di- experiment sound. This rect current as pro- by us was carried on duced by a dynamo. for several years, and Contributed by good re- has given very PAUL G. WATSON. sults. It will usually only work in the day- AN IMPROVED time in cities, as the RADIOPHONE arclights on street cor- ARC GAP. quite a ners interfere Herewith is described bit at night. an improved arc gap is out- Following an for use in radio-phone line of the talking and work. The carbons instruments Hook-UpA= Aerial B^Battery, G = Ground hearing In the Above Diagram of Radiophone are of the ordinary and S=Secondary of Spark Coil, and R Telephone Receivers. 1. The larger the an- P^Prlmary hard variety that can tenna, ground, coil, and could be called such, con- be found in most any dry cells. The ad- source of current, the greater the distance. former" (if it 1" coil having its vibrator vantage of having grooves sawed in each higher the resistance in the re- sists of a spark 2. The it keeps the with a piece of wire) connected in end of the carbons is that the better it is. shunted ceivers volt along the edge to the end (micro- series with a bank of 16 C. P. 110 arc from running 3. Long distance transmitter The mica lamps, which are in parallel. The key is an and burning the mica sheets. phone) is preferred. from old fuses. The would ordinary telegraph key and the 'phones are sheets can be obtained 4. Dry batteries are all right, but carbons high resistance 'phones used in rubber bands are placed around the prefer a storage battery for larger coils. the regular, to hold them in place and still keep them radio work. . The volume of the sound can be varied m insulated. GOOD BEARINGS FOR. ROTARY two ways. The more lights in parallel the is impossible to GAPS. louder the sound, or if it Battery corOons diminish the number of lights and the core When rotary gaps are to be mounted of the spark coil is accessible, its removal separately from the motor shaft the ques- or partial removal will cause a smaller volume of sound in the phones. This method of substituting a power current for over that of a buzzer has several advantages '0SMc p lampimn/r 110 V. DC _I ^parA CO/7 Unique Hook-Up For Learning the Code By Connecting Spark Coil to 110 Volt D. C. Circuit. as Photograph of Finished Bearing For Rotary other methods utilizing the light current Spark Gap. a source. First, it does not click when the key is deprest as most of the other methods tion of obtaining suitable bearings must do. Second, an Omnigraph or other form be considered. I have de\ised a simple of automatic transmitter can be used with it bearing which does not necessitate the making of a pattern and casting, which process is usually expensive. fitted into a threaded hole. In turning Obtain full two inches of 1-inch square out the bearing be sure and drill the holes Hook-Up and Detail of Novel Carbon Arc brass rod and saw off the piece into two thru the sides of the rod which were man- Gap For Radiophone Experimenting. equal parts. These rods must be exactly ufactured square, otherwise the bearing blue- one inch square. Center them in a lathe will not be true, since it is impossible to The color of the arc should be of a glare chuck separately, and drill the hole desired. purple to give a smooth tone. A white carbons are After taking from the chuck it is necessary is not good as it shows the least to ream out the hole. Drill a hole at the hurningT The carbons must be at the results. In top of each bearing block and fit a small 1/32" apart to obtain best strong, oil cup into same. This cup should have a this way the voice will be clear and faint. find piece of felt fitted into it to keep the oil while the arc will be very We from running out too easily. Obtain tvvo that it is better to have the carbons placed sheets of brass 2"x2%"xV&" each, and drill side by side instead of end to end, as it a hole in the corner of each for screw keeps the arc running back and forth on the fastenings. smooth round side of the carbons, and keeps the arc The bearing is complete after the brass them cool. Otherwise by having in sheet is soldered onto the bearing block. at the ends of the carbons, it stays one Do not solder around the bearing block place and tends to heat up and burn the but apply the heat directly to the sheeting carbons. and apply the solder between the bearing We have experimented with this radio- block and the sheeting. If the lathe work phone for three years and have succeeded is done accurately the bearings will matcli in talking thirlv miles distant. exactly. Working Drawing of Rotary Spark Gap Bear- Contributed "by SEEFRED BROS. A necessity for each bearing is a mov- ing, Fitted With Oil Cup. block on the able collar held against the to study up thoroly file a brass surface absolutely accurate. The Now is the time shaft. This collar can be made by turning accompanying drawings show the general on Radio and Electricityl You v^ill find out on the lathe from 1" round brass stock design of the bearings and collars. hundreds of valuable articles in back %" wide. Into this is drilled a hole the Contributed by F. MAC MURPHY. numbers of the "Electrical Experimenter.' size of the shaft. A small set screw is ^ 1 — 1 — 768 ELECTRICAL EXPERIMENTER March, 1918 eeNSTRVIQTER ( 1( ( m \ gni—iF?n[T— r—if— —ii—ii—ii n w ni— —ii— —ii 1 \ Electro-Static Experiments By FREDERICK \ ON LICHTENOW PART I attractive and repulsive forces the "Electro" ll'imshiirst type is required oppositely charged, as quickly released THEpeculiar to Static Electricity enable for the successful reproduction of the fol- under the neutralizing spark, attracted again the person experimenting in this lowing experiments, which will help the under the new charge and so on, which, field to perform "stunts" which he novice in grasping the principles underly- assisted by the springy element existing in could not possibl}' produce with the ing them. it. will cause it to vibrate at an incredible ai'd of anv other kind of electricit\'. How- E.xperiinent No. 1 — ("Opposing" chains). speed. Here is a simple and yet quite pro- nounced way of showing the repulsive ef- I'drassoo// fect on like charged bodies. Two very- ,e.y fine mre light and equally long brass chains, such as are usually found around static instruments t\.. for connection purposes, are suspended side by side by the'ir respective ends as shown in Fig. 1. They must hang well off the table Brass cnoins and under just enough tension to form only a slight downward curve. The electrodes of the machine are then set beyond sparking insu/ofing sfana distance when with a few turns of the crank handle the chains will be caused to press Stjfic the other, sideways, each strongly repelling lUac/i fig 1 in which position they will remain for some time after the machine has been stopt, grad- ually and slowly falling back into normal The Experiment of the "Opposing Chains." position with the leaking away of the static Which Shows in a Striking and Novel Manner The Static "Vibrator" — a Very Fine Wire Is the Repulsive Effect on "Like" Charged charge. Suspended by a Clip, as Shown, Just Above Bodies. The Two Chains Are Both Charged If the discharge balls are brought within a Charged Metal Ball. A Small Static Ma- Positive. sparking distance, so that sparks may pass chine Works This as Well as All the Other Experiments Here Described. at certain intervals, the chains will set up ever insignificant these may appear to the a rhythmic motion—separating upon being Experiment No. 4. ("Cushioning" ef- uninitiated, for the true experimenter they charged, meeting again upon neutraliza- — fect of spark). carr>' a deep meaning back of them. Ex- tion as long as the plates are rotated. — This experiment not only affords a spec- perimenting in Static Electricity is playing Pen- Experiment Xo. 2. — (Static "Ball tacular way of lighting Geissler tubes and with the electricity of the earth in micro- dulum"). form. This fact alone throws a vast amount causing them to swing at the same time, Figure two shows the apparatus needed the of fascination into this odd and yet so but it offers a good chance, for study in this experiment, which clearly illustrates natural branch of electrical science. of the "cushioning" effect of the static the principle of alternate attraction and Static Electricity evidences itself in prob- spark. neutralization, helped along by the weight of equal ably more ways and certainly requires less Two medium sized Geissler tubes of the ball in gathering momentum, which (of rarefied and not the apparatus for its production and experi- length the gas in the end effects the pendulum motion. mental conduction than any other form of heavy liquid type) are suspended a couple This latter, naturally, continues as long as experimental electricity. A rod of glass of inches or so apart from insulating stands the machine is working. Both balls consist and a piece of silk or a sheet of hard rub- connected to the respective poles of the of solid brass and should be kept in a well ber and a piece of fur, together with some static machine (Fig. 4). polished condition. The smaller, swinging bits of tissue paper, are sufficient apparatus With the passage of the electric charge ball, ]/2 inch in diameter, is suspended by ' other, be- for the practical study of its elementary they will at once approach each a piece of very thin copper wire. Syi or principles. ing attracted as a consequence of their 4 inches long, having a loop on its upper small as opposite polarity, when upon meeting by A static machine, however, such necessary free movement. end to insure the their lower globes the spark discharge will 1 inch in The larger one, measuring diam- take place thru their entire lengths, strongly is whole is eter stationary, while the sup- lighting them up for the moment. Being insulating stands. ported upon No sparks released under the effect of the neutraliz- must occur across the static machine gap. Experiment 3. (Static "Vibrator"). No. — jeiss/er'ude {7>ectiL'in a/eJ Working under the same principle as that involved in experiment No. 2, the static vibrator, as I will call it, forms an- iWic other highly interesting piece of apparatus. The smaller ball is here replaced by a short piece of very fine, perfectly straight copper wire, about Z'/i" long, held rigid in a clip as indicated in Fig. 3. The free end of this horizontally placed wire must reach nearly across the entire width of the brass ball, without however touching it in the least, and center upon it. Both should be sep- arated by a gap of from 14 to yi inch, this depending entirely on the size and condi- tion of the static machine employed. With Experiment to Demonstrate the "Cushion- The Static "Ball Pendulum," a Simple and ing" Effect of the Static Spark. Two Geissler the discharge rods set far apart and ma- Illustrated. Pleasing Experiment. It Illustrates the Prin- Tubes Are Freely Suspended, as will immedi- ciple of Alternate Attraction and Neutraliza- chine put to work, the wire Wheti Set Swinging the "Spark Cushion" tion. atelv be attracted to the ball, since both are Prevents Their Touching and Breaking. March. 1918 ELECTRICAL EXPERIMENTER 769 ing spark', tliey fall hack into their former is placed another nut (F; with its corners diliicult experiment to construct a card- positions only to he attracted to one an- pointing midway between the nuts on the compass especially designed for spinning. other again with the approach of the new circumference. A copper brush (E) is Make the magnetic bar rather thin, also charpe (Fig. 5). This in repetition causes placed near enough to (F) that the points beveled and rounded as shown to reduce a sort of swinging niption on the part of will force it back a short distance. This will air-resistance, .\ttach it on top of tTie card, the tiihes. which in the end —one would make contact with the point (C). The (it is underneath in the dory-compass) and standards (U) are then put on and con- drill a hole nearly thru from below to form nections made as in the diagram. The the socket for the pivot. The pivot may action is as follows: When one of the points of (F) push back the brush it closes the circuit and makes (.'\) a magnet; tSM (A) theti turns the rotor by pulling on the iron nuts. The circuit is opened just be- A fore each nut reaches the magnet. The momentum of the rotor brings the next 'c/csler tubei nut in position. If the motor does not start Ofmedium sizs at once spin the armature with the finger. VL Q- Contributed by CLIFFORD BROWN. vl 1 \ ^ AN EXPERIMENT IN MR. MACE'S MAGNETIC CURRENTS. By Thomas Reed. hsueting stands The very interesting articles by Mr. Mace on "Magnetic Currents" calls to mind, I Mac/) and I believe explains, a phenomenon well known to skippers of small boats, which has '^ Fig 5 ,-- never been satisfactorily accounted for. I EC refer to the "spinning" of a card-compass. Interesting Experiment with Compass-card and Needle, Which, Under Certain Condi- The "dory compass," so called, is com- The Swinging Geissler Tubes—a Beautiful tions, Will Spin for Long Periods. and Striking Experiment. Every Time the posed of a magnetic bar attached to a cir- Tubes Approach, a Spark Jumps Between cular card imprinted with the compass- be a fine steel sewing-needle. The card, 5" Them, Lighting Them Up Momentarily. points. The card, of course, turns with of thin bristol-board (say diameter), They Then Fly Apart, the Action Repeating the magnet, should be as perfectly circular and flat as Itself as Long as the Static Machine Is and the points are read off Worked. against an upright line inside the case, possible. In operation, it should be covered called the "lubberline." with a bell-glass to shield it from air-cur- think at least must lead to their striking still, it in the partial — Xow very often, as the boat thrashes rents ; better place ; do. Every hard together but they never about in a choppy sea, the card begins to vacuum of an air-pump. resulting spark acts titne they meet, the spin. It takes on a rapid rotary motion as if it a cushion placed between were of something like 200 R.P.M. in its hori- AN EASILY MADE ELECTRIC them : in fact, they sometimes seem to zontal plane, and keeps it up indefinitely. SOLDERING IRON. cling together for the instant, while the I say "indelinitely." because I have seen .\ny experimenter owning a small 110-volt discharge is taking place, which on the it for go minutes at a stretch ; but as it is step-down transformer, having a secondary other hand forces them always to a fresh a great anno\ance to the skipper, depriving voltage of 15-20 volts, will find the solder- start, in this limiting the momentum way him of the use of the compass for the ing iron here described very useful. When gained by the tubes on each trip. They time being, he always stops it as soon as once heated it remains at an even tempera- will perform in this manner as long as the convenient, by canting the compass case ture until the current is turned off. To machine is in action, the terminals of (which normally is kept level by gimbals) make it, first procure a small soldering which are to be separated beyond their till the card drags on the bottom, and the copper, of about the size shown. Wrap spark limit. rotary motion is destroyed by friction. two layers of thin mica around it. and working out these static "stunts" I On In the better class of comjiasses, the case fasten temporarily with a string. The had in mind not onb' the beginner, but the is filled with a transparent li.4uid (alcohol winding should be of No. 22 or No. 24 less capitalized experimenter who, unable or oil) in which the card and its magnet German silver resistance wire, the length to buy the more expensive auxiliary ap- are immersed, preventing the spinning. of which is best determined by experiment paratus, not be satisfied with the aver- may A plain compass-needle, without a card, Start the winding about '/^" from one end. rr.n of experiments belonging in the age will not spin. The card seems to act as leaving the lead several inches long, and paper-tin foil-pithball class. tissue a fly-wheel, carrying the needle past some spacing the turns about 1/16". (To be coYitinucd) sort of dead centre. When as much wire as nossible is put on. Th e spinning seerns to be initiated by cover with a laver ot mica and wind a SIMPLE BATTERY MOTOR. a successcession of "yaws" as the boat is swung similar layer o\ir this. Fasten the end off her course cross-seas. ; H.rewith I give a diagram and descrip by These cause securely, and bring out . jther lead. The a wide oscillation the tion of a small battery motor. This motor of needle ; and once whole winding is new covered w'ith several, is quite simple and is easily constructed, these are wide enough, the fly-wheel action layers of thin .sheet asbestos, and a layer besides being very powerful for its size. comes into play, and the card starts spin- of fine copper or iron wire is wound tightly ning. I It can be made in any size, but the small have never seen it stop of its own over this to protect the inner coils. sizes give the most satisfaction. The mag- accord, and I believe it would go on until The leads are covered with asbestos for stopt friction net (A) is made by fitting a machine bolt by developing at the pivot. several inches and are then soldered to a In short, I believe V/:" long thru the Yi" upright (H) and that here we have a flexible cord which passes thru a hole in winding the bolt with No. 26 insulated mag- case of perpetual motion—except, of course, the handle. If difficulty is encountered in for friction, net wire. The rotor (B) is a cylinder of which would eventually make winding the German silver Avire, due to its the pivot stick. > wood, V/2" in diameter and Yz" thick. On This is a bold statement, springiness. it should first be annealed by because the possi- bility of perpetual motion is denied. Cord Leads Pro.'eciiye iVindir^ But this is not per- Asbesfos ; (letual motion in the :Asbesfos Solder . old sense of a force acting against itself; we are merely util- izing an earth-force to produce an effect, exactly as a wind- mill utilizes the wind. .\ reference to the Construction of Home-made Electric Soldering Iron. It Can Be Made Simple Form of Battery Motor of Interest to from a Standard Copper Tip and Handle, as the Drawing Shows. the Young Experimenter. diagram will show- how I imaumc 'lie its circumference and at equal distances result to be brought about, in accordance passing a current thru it u.:til heated to are placed four iron nuts (G). These can with Mr Mace's theory. In our latitudes, a dull red. If the iron becomes too hot be screwed on with flatheaded iron screws. the earth's magnetic axis is very appreci- in use. the current should be limited by an The shaft can be made of any durjible ably inclined, which would seem to aid the external resistance, consisting of several metal, as it has no electrical fimction to effect, and perhaps wholly account for it. coils of No. 20 German silver or iron wire. perform. On the shaft, close to the rotor. It would be a very interesting and not Contributed bv AN EXPERIMENTER. ; 770 ELECTRICAL EXPERIMENTER March. 1918 A Speedometer for Small Battery Motors By STANTON C. MOORE 4" somewhat to do this, but that can be easily A N easily constructed speed indicator, or stock, about x 7". The motor, A, is trued up again. Now heat the nail about f\ more properly speaking, a speedom- fastened at one end with the shaft set half of its length and flatten it out. File it eter, for battery motors, that can exactly parallel with the center of the base. j\ on both sides and with a hack saw -^ -^ be made from the odds and ends Part B is made of hard, close-grained smooth 1" a slot the length of the flat part. that are usually found in the ever- wood (such as mahogany), in its larger make The arms, D, may be made of iron, if useful scrap-box, will no doubt commend diameter and J4" thick, with a hole bored fit tightly and your junk-box refuses to yield brass, about itself to the "Bugs" who, being debarred thru the center to very 1/32" thick and 2" long. Width at' one end 3/16", tapering to l/s" at the other. File them up neatly and drill a hole 3/32" from the large end of each, large enough to take No. 2 three-eighth inch, round- headed, brass wood screws. For the weights, C, cut from a piece of sheet lead, about J/J" thick, two pieces yi" x 1" and fold them in the middle. Drill a hole in the small ends of the arms and slip the folded pieces of lead down over them. Hammer the folds together and you have two arms with a lead weight on the small end of each, the lead sinking into the holes in the arms, thus fastening the weights securely. To make a neat job file the corners off and smooth up. Five-eighths of an inch from the large end, near the edge, drill a small hole, g. Fig. 3, thru which to thread the cord, G. These arms are fastened at their large end as shown in the drawing, with a No. 2, three-eighths inch, round-headed, brass wood screw a washer being placed between the arm and B to minimize friction. The center of the screw should be Is a Neatly Worked Out Direct- Read ing Speed Indicator For Use Testing Small Battery Here %" from the circumference of B Motors or For Giving a Steady Indication of t he Speed, Where This Essential. It Can Be Calibrated to Read R.P.M. if Desired. and 3/16" from a line drawn thru the center of the two guides, H. from using their radio sets, are engaged accurately on the projecting shaft of the A small staple, F, made of round wire in Electrical Experimenting. motor. This hole must be bored exactly at is now driven into B so that it spans the While working with a certain device I had right angles with the face of the part so that motor shaft. (I say round wire staples occasion to make and break a circuit at when mounted on the shaft it will run advisedly, because if you use the square certain intervals and also be able at will to absolutely true. It must be noted that in this wire kind such as is employed in tacking alter the intervals and jump to any one of device the slightest movement in any of the down floor matting and linoleum, the sharp four different degrees of rapidity. I tried parts is communicated to the pointer and edges will cut the cord which we are to an electric clock, but in order to change the multiplied about ten times. For this reason thread thru it.) Drive it in all but about period of make and break it was necessary the utmost care must be taken to make every 1/16". to stop the pendulum to slide the bolts up or part as accurately as possible. Otherwise Take a short piece of stout cord, some- down the rod. This was fatal to the device the vibration will cause the pointer to wob- thing on the order of a good quality fish- I was working with, so after trying various ble to such an extent that even an approxi- other schemes, I adopted a modified form of mate reading will be impossible. commutator driven by a toy motor. By Parallel to the shaft hole, 3/16" from it, varying the speed of the motor with a rheo- bore two holes just a trifle smaller than the stat the periodicity could be changed with guides, H. These guides are made from ease. However, I found that to get any one six-penny finishing nails but l]4" long and of the four degrees of speed that I required, forced tightly into the holes just bored on it was necessary to use the "cut-and-try" either side of the shaft hole. They should method of putting in or cutting out resist- be in perfect alignment with each other and ance until the proper speed was secured. with the shaft. This was even worse than the clock On these guides is fitted the slider J. This arrangement had been, but the logical thing is made in the form of a flat-bottomed "U" to do in this contingency was to devise a of brass, preferably, or iron about 1/32" method of determining quickly and with thick and about 3/16" wide, with holes certainly just when the right motor speed drilled in each leg to take the guides H. It for the desired periodicity had been ob- should slide smoothly on the guides but tained. Hence the speedometer here de- without too much play. A hole is drilled scribed. in one leg to take the link, I. This hole The drawings are presented mainly to should be exactly midway between the holes give a general idea of the principle and the for the guides so that the centre of 1 coin- relative proportion of the different parts cides with the center of the shaft of the rather than exact dimensions, as these de- motor. A very small hole should also be pend largely upon the size and power of the drilled in the center of the opposite leg to motor on which you wish to use the device. take the cord. G. However, as it might be of assistance in To make the link, I, cut a six-penny fin- determining what size to make the various ishing nail about V/i" long. File the under parts to suit your conditions, I give in the side of the head square with the shank and Detail of the Direct-Reading Speed Indicator it as smooth as possible as this joint following directions, the dimensions of the make Fly-Ball Governor Mechanism and Needle speedometer which 1 am using on an "Ajax" is where most of the friction comes, and Actuating Means. motor. These, of course, are arbitrary and this of course, should be reduced to a mini- may be varied to suit conditions and the mum. The top of the head may he ing line, and put one end thru the small material which you are able to dig out of rounded as shown for the sake of appear- hole in the back of J. Tie the end into a the "scrap-box." ances. Insert this in the hole drilled in J to good sized knot so that it will not slip The base is made of half-inch mahogany receive it. You will have to bend the slider (Continued on page 805) — March. 1918 ELECTRICAL EXPERIMENTER 771 My Electrical Laboratory By WALTER BOCK (Special prize $5.00)* are six photos of my chemical reagents. look of HEREWITH The things that at least 15,000 meters so it is said. shop and Electrical "Lab" includ- like the noses of some "one-pounders" are The contractor must guarantee transmis- ing myself—one—"Stript for action" the tops of my file handles. sion from the French station to the Ameri- and the others "all drest up and Last but not least comes my bench with can station (on any day of the year; of nowhere to go." The photos more than 300 wood and metal working lO.fKX) words per 24 hours. Moreover, the show most of my electrical apparatus. tools such as twist drills, hand drill, drill transmitting and receiving apparatus will All told I have approximately SO pieces of press, adjustable tool grinder, and so forth. be adjusted in such a manner as to allow of the same, such as spark coils, Tesla and To the left is my 30 drawer stock cabinet, continuous transmission and reception at Oudin coils, Leyden jars, glass plate con- containing machine and wpod screws, nails, the minimum speed of 4,000 words per hour. densers, magnetos, dynamos, motors, volt- bolts, nuts, springs, contacts, binding posts, Adjustments permitting musical transmis- meters, ammeters, polarity indicators, paper ad infinitum. sion and auditory reception at the speed of condensers from .0165 to 1 mf., rheostats, 50 words per minute are also provided for. fixt and variable inductances, Geissler tubes, *See announcement in Feb. 1918 issue, Transmission by the French station of storage batteries, interrupter, etc. page 701, wherein we asked for special signals destined for reception in the United Owing to the fact that space is limited, article, with several photos describing your States of America, and the reception by the (my shop measures 12 feet by 14 feet), I "Electrical Laboratory." Tell us in not French station of signals from the United have to put away all apparatus that I am more than 500 ifords ivhat you do in your States, simultaneously and independently, thru using to make room for another "Lab." Make your article interesting and will be correctly and efficiently carried out experiment. Therefore I have no fixt elec- be sure the photographs are good and clear. trical "Lab." The table of my chemical Address the Editor. "Lab" serving the double purpose. One CAMP MEADE PICKS UP RADIOS photo shows the "Lab" table with twenty- FROM NAUEN. BE- Meade's wireless operator (at Bal- five of my forty or so pieces of chemical RADIO COMMUNICATION Camp a apparatus, such as thistle tubes, test tubes, TWEEN FRANCE AND THE timore, Md.), Jim McGarrity, caused STATES. excitement recently delivery tubes, retort, Erlenmeyer, and UNITED tremor of when he an- nounced that he had just picked up several Florence flasks, chemical balance, c.c. grad- A radiotelegraph station destined to estab- messages the great wireless station at uate, mortar and pestle, etc. lish direct radiotelegraphic communication from Xauen, Germany. The messages were all To the right of my "chem. lab" is one of between France and the United States of official code, therefore my book cases containing some fifty elec- America will shortly be establisht by the in the German and deciphered here. trical, chemical, and mechanical books French Government. It will be situated could not be by anyone officers would among others—three volumes, of the on the West Coast of France and will main- The headquarters not believe first to Electrical Experimentkr (I have them all tain permanent and continuous radio-com- Jim at the distance Nauen being and by night between more than 4,000 miles. He silenced them as far back as April, 1915) ; the Model munication by day Library series and Henly's Formulas. An- France and the United States. It will ra- by displaying the messages, which were im- other photo shows some of my 140 odd diate continuous waves with a wave-length mediately forwarded to Washington. 772 ELECTRICAL EXPERIMENTER March, 1918 How to Make a "Blinker Light" for Motor Boats Important Notice to Subscribers Every small sailing or engine-driven bored four holes of }4-inch diameter in the Due to the congestion existing at the water craft should be equipt virith an ef- bottom, and put the arrangement together present time in all railroad movements^ ficient "blinker light" for signaling to with two thin 2j4-inch brass screws, I had my lamp. Of the also on account of the fact that many train four 54-'nch holes clerks have gone to war, there is a con- on the bottom, two gestion of mails all over the United States. are used for the It may happen that your magazine %vill he fastening screws slow in reaching you, and this delay may and two for ven- be from a few days up to several weeks. tilation. I did not Kindly hear this in mind before sending insert the glass in in a complaint, as the magazine will surely the bottom piece of reach you in due time. Only after not mahogany until the having received a certain copy for a varnish was dry, period of three weeks should a complaint as this piece should be sent in. be easily remov- You will confer a favor upon the able for replacmg publishers not to write until this time has the bulb or clean- elapsed, thereby saving them a vast ing the glass. amount of clerical labor. When it came to fastening the light, HOW TO GET A PORCELAIN I wanted it to set KNOB FOR RHEOSTAT. little ahead of a I was recently in need of a knob for a above the mast and rheostat and thought I would try an old would it, so that it porcelain door-knob which was not in use. interfere with not To construct this knob first procure a porce- the halyards, etc. lain door-knob with a set-screw in it. Next took a I therefore take an old buggy bolt and the head off waste cut piece of and as much of the bolt as desired. As 1/16 inch brass in Fig. 2, file one end square so as to fit 6 inches thick, in the door-knob and leave the other end inches long by Hi threaded for the lock nut. Procure a piece wide, bent it to L of brass and cut it into the shape shown shape for a brack- in Fig. 3, which is 3^" long and fi" wide et and bored holes at the larger end, with a square hole in it in it to correspond to fit on the square shank. Fig. 2. In Fig. with the holes in 4, "B" represents the switchboard and "D" the bottom mahog- is a copper strip with a hole in the center any piece. In using A copper wire can be soldered on this the long fastening copper strip for connection. In Fig. 1 screws mentioned "CC" are washers and "B" is the switch- above, I put them Here's a Simple and Effective "Blinker Lioht" For the Small Motor board. I have been using this for some or first thru the brass. Boat and Launch. It Can Be Operated From a Few Dry Cells time, and it is giving good results. Messages to Be Signaled illustration Storage Battery, the Telegraph Key Enabling (The Contributed by in the Morse Code. shows the brass be- CLIFFORD LUNDQUIST. fore being bent and Other craft or to shore. Such a blinker without the screw holes for fastening it small holes light is described by H. A. Jackson in to the mast.) The other two Motor Boating. correspond with the ventilating holes and allows the lower end of the This simply made lamp can be used with the large hole weather-proof fixture and the wires to pro- equal facility whether it is to be per- ject thru. If it is desired to use this lamp manently fixt at the mast-head (which is on a halliard, omit the bracket and provide much the better way) or hoisted on the a screw-eye for the top piece of ma- yardarm halliard whenever wanted. hogany. Keeping in mind that the lamp should not be too large, must be seen all around The rest of the outfit consists of a send- Arm the horizon, and should be neat in appear- ing key, dry or storage battery, and wires or- ance, I first tried to buy a plain glass tube to connect. The sending key can be an of about 2-inch inside diameter and equal dinary push button, or a regular tele- latter is about twice length—but found it impossible to obtain. grapher's key. The A friend then suggested the kind of glass as expensive as the push button, costing it is much that is used in oil cups, and my troubles in the neighborhood of $1. But were ended, for I was able to get a glass more satisfactory and the light can be of 5^-inch wall thickness (heavy enough made to burn steadily (and so used for an to withstand any usage), 2)^-inch outside anchor light) by pushing in the right hand diameter, and 2ji-inch length, at a cost of arm (see illustration). twenty-five cents. (A good glass cylinder The wiring is also very simple, but as the would be one such as supplied on certain wire is to be used for outside purposes, it radio receiving condensers.) should be well insulated. If attached to From the waste pile in the boat yard I the mast and painted with a couple of then picked a 3-inch square piece of ma- coats of yellow paint, it will not be noticed hogany which was awaiting consignment and the paint will help the insulation. Con- to the stove, and with a lathe rounded off nect the two wires to those projecting riq.3 the top neatly and cut a groove in the lower from the bottom of the weather-proof fix- side 5^ -inch in width and depth and of a ture, leading one wire directly to the stor- diameter equal to that of the glass. I then age battery (or if you have no storage the other to gave it three coats of spar varnish, and battery to one dry cell), and while the last coat was wet, inserted the the left binding post on the sending key; post and let it dry. I then had the top also run a wire from the right binding ^fcim glass ^. and sides of my lamp. For the bottom, I to the dry cell or storage battery. Then, "AD -> '^, X selected a similar piece of wood, left it by pressing down the key, you will light V <^ the ' flat on top and bottom, and on the top cut the light, and by releasing it will cause '^ ^4ii the bottom of light to go out. A 2 c.p. bulb will be amply a similar groove to receive Piq. 4 the glass oil-cup tube. The center of this sufficient, and the voltage of this bulb bottom piece has a hole bored to J^-inch should, of course, correspond with the amount of power used. With such a "blin- diameter for taking a weather-proof tube If You Have a Porcelain Door Knob At socket like those used to decorate large ker light" equipment, communication can Hand Here's a Good Use For It—as a Rheo- Control Knob. Christmas trees outdoors. Having also be carried on at considerable distances. stat March, 1918 ELECTRICAL EXPERIMENTER 773 Siphons—How They Work By I. W. RUSSELL and J. L. CLIFFORD is for con- flask there is SIPHON an instrument a valve controlled opening. right spirit, consists in putting a series of vessel to an- veying liquid from one By stopping up the longer arm and apply- questions to nature. The result of the ex- A level is usually other at a lower and ing suction to the upper aperture, the periment constitutes nature's answer, and word itself siphon is in the form of a bent tube. The started. The valve is then closed when this is correctly interpreted our the word "sipho,' mean- and the siphon will comes from Latin then act the same as knowledge of the universe in which we live principle siphons has type 6. ing tube. The of For safely and easily handling and of which we form one tiny part be- for centuries ; even acids the siphon in probably been known shown Fig. 2 has been comes more complete. Now if experiments the ancients were acquainted with the sim- pronounced by Prof. C. D. Dilts, an au- are to .lead to fresh knowledge they must apparatus. thorit>' plest forms of this interesting on siphons, to hold the greatest pos- he performed methodically. So far as the the greatest use sibilities. Altho the siphon enjoys When the siphon is inserted into confirmatory experiments suggested in text- handling in laboratories, for the purpose of a bottle of acid the liquid rises into the books are concerned, the conditions are ex- other applica- tube. acids, it has a great many By blowing in the small tube, the plained by the. author of the book, and the have been de- valve at is tions. Innumerable forms the bottom closed and the acid experimenter has little to do beyond carry- all purposes. Pipes is forced of the vised and adapted to out siphon tube. With ing out the instructions as carefully as pos- water of an aque- this arrangement used for conveying the there is absolutely no sible. But original experiments need to be duct over hills and following the contour of the sides are often called siphons, but do not necessarily depend for operation upon the principle of the instrument de- fined above. The simplest form of siphon as illus- trated in Fig. 1, consists primarily of a bent glass tube with arms of unequal lengths. In starting this siphon the tube must either be filled with water previous to inserting it in the vessel or, after being placed in the vessel a suction applied to the lower arm. To explain this flow of water from the siphon, let us suppose it to be filled by either method described above and immersed in the liquid. The pressure then at the end of the shorter arm tending to raise the liquid in the tube, is the atmospheric pressure less the height of the liquid in the shorter arm. In the same way the pressure at the end of the longer arm is the weight of the atmosphere- minus the pressure of the column of water in the longer arm. Since the column of water in the longer arm is longer than that in the shorter arm, the force acting at the end of the shorter tube is less than that of the longer; consequently a flow of water takes place proportional to the dif- ference between these forces. The flow- will therefore be more rapid in proportion to the difference of level between the end of the longer arm and the level of water in the vessel. In Fig. 4 is shown a type somewhat simi- lar to the first. It consists essentially of a bent tube with arms of equal length. Besides the methods outlined in connec- tion with the first system, this siphon may be started by plunging quickly into a ves- sel filled to the brim with water. The siphon must be handled skilfully in order not to break the tube and cause the column of water to be forced over the ridge in the tube. Another method is to stop one end with the thumb and inserting the free end A Study in Siphons. These Clever Mechanical Devices Are of Interest to Every Electrical into a vessel filled to the brim with water. Experimenter For the Purpose of Transferring Acids, Electrolyte From Carboy to Cell or Vice Versa, and Other Work. Upon removing the thumb, the water rises in the tube and is carried over the ridge by its surplus momentum. danger of drawing acid into the mouth. well thought out beforehand, and w-hen this A commercial form of siphon intended A siphon of great scientific interest but of is done it remains to arrange the manipu- for transferring acids from one vessel to small commercial value is what is known lative details with a view to getting a clear- another is shown in Fig. 5. The principle as the automatic siphon illustrated in Fig. 3. ly defined result, unafltected. as far as pos- is nearly the same as the first with ex- The tubes are arranged as shown in the sible, bv disturbing causes. this ception that the siphon is started by apply- drawing. When siphon is inserted in a Contributed by H. J. GRAY. ing suction at the exterior arm. With vessel containing water, the water rushes this siphon, however, there is danger of in at the lower aperture and causes a pres- some of the acid reaching the mouth. In sure in the larger tube, which causes the Fig. 6 is shown what is known as the water coming up in the lower tube to be AUTHORS!!! forced into sil^hon fountain. A flask is partially filled up the siphon tube, thus creat- All matter intended (or publica- with water and glass tubes are arranged as ing a flow. There are many types of siphon? tion—not only by us, but by any shown in the figure. Upon inverting and with other than those shown here which are be- the shorter arm immersed in the liquid of yond the limits of this article to describe. other magazine or newspaper as some vessel, a flow is occasioned. As the As this is an intensely interesting subject, well—should be written on one side water is drawn out by way of the longer the serious reader will be highly repaid for of the paper only and in ink. If it arm a vacuum is created in the flask, caus- any labor exerted in experimenting along isn't, somebody else must copy part ing the water to rush up the shorter tube, this line. thus forming a fountain. of it off on another sheet before it A commercial form employing this idea METHOD IN EXPERIMENTING. is given to the printer. is shown in Fig. 7. At the top of the Experimental w-ork, undertaken in the : 774 ELECTRICAL EXPERIMENTER March. 1918 A SPECIAL GOLD-LEAF ELECTRO- tremely delicate. The piece of gold leaf After these short explanations the con- SCOPE FOR RADIO-ACTIVE about an inch long by Si wide is attached jurer passes the bettle to the audience for EXPERIMENTS. to the brass strip by a tiny drop of shellac. examination to show that there are no THERE have appeared lately in this It is possible with this electroscope to see threads or similar devices hidden anywhere. magazine several articles on Radium the gold leaf and the strip on the scale be- He also shows that the glass plate is not and Radio-Activity. In these articles hind and notice the position before and prepared in any way, and the plate may also the experiment of discharging a gold-leaf after charging. be past on to the audience for examination. To use this electroscope charge with a After this, the performer puts the plate glass or hard rubber rod excited with silk back into its former position, and passes or catskin, and notice the position of the a stick, which he borrows from the gold leaf on the scale. Leave for about audience, between the back of the plate and fifteen minutes, and if the conditions are fa- the curtain E, which is about 6 inches vorable, and the electroscope well made, the behind plate A. He now places the beetle leaf will be in the same position as before. on square No. 1 and the beetle will cling Take some Radio-Active substance (the to the p^te. Members of the audience writer used Uranium nitrat and Uranyl are now requested to call out different chlorid) and put upon a grounded copper numbers and the beetle will slowly move to plate. Charge the electroscope and place the square bearing the specified numbers. over the plate and notice the position on the For instance, if the beetle rests on square scale of the gold leaf. After a few minutes No. 1, and No. 9 is called out, the beetle again notice the position of the leaf. The will move from 1 to 5 and from 5 to 9. electroscope will be discharged. The alpha If the beetle is asked to go back again to particles emitted by the Radio-Active sub- No. 1, then it may take the following way: stance have ionized the air, permitting the 9 to 6, 6 to 3, 3 to 2, 2 to 1. This proves charge on the electroscope to leak away to that the beetle can move in any direction. the grounded copper plate. In this w/ay it Small additions or multiplications are also is possible to measure the Radio-Activity of carried out by the ever obedient beetle. diflferent substances by the rate of dis- After the performance the beetle and glass charge oflf the electroscope. The writer has plate are again past to the audience for also found that an E. I. Co.'s Spinthariscope examination. with the lens removed, would discharge the The explanation of this trick is as electroscope. Radio-Active salts (such as follows : As mentioned before, behind the all Uranium or Uranyl compounds) can plate A at a distance of about 6 inches is Appearance of Finished Electroscope Espe- easily be secured at any chemical supply a curtain E. Fixt to the back of this cially Designed for Conducting Experiments curtain is a piece of cardboard F, the same in Radio-Activity. house. size as the plate A. This cardboard is also divided into nine equal spaces and the electroscope by some Radio-Active sub- position of the cardboard is exactly behind stance is mentioned. This is an intensely the plate A. The performer's assistant is interesting experiment, but the ordinary stationed behind the curtain, holding in his flask electroscope is not suitable for this ex- hand a powerful electro-magnet G, which periment. With the usual electroscope is connected by means of wires H to a there is no convenient way of bringing the resistance J, and a few storage battery Radio-Active salt near the electroscope and cells K. As the assistant hears the leaving it for some time. Besides there is numbers called out by the audience he no way of measuring the collapse of the moves the magnet G to the number required. gold leaf, and the ordinary electroscope in The body of the beetle D contains soft Sie possession of the amateur will not hold iron wire and the powerful magnet G its charge suflSciently well. Because of these attracts the beetle and supports it in this difficulties I constructed a special gold manner. The body of the beetle should be leaf electroscope, which, under ordinary as light as possible, and the beetle when conditions, will hold its charge several hours completed may be about one inch long. and which lends itself especially well for Thin iron wire should be used to form the experimenting with Radio-Activity. body and when finished, the beetle should As may be seen in the photograph, the be painted a bright golden color. To make electroscope is housed in a rectangular box the trick more effective, the room may be 3" of %" quarter-sawed oak. The box is darkened and the light of a 50-candlepower 5" square at the top and about high. Ttiere f/ffj lamp may be directed onto the glass plate A. is no bottom to the casing, and in the front This would show the gold color of the there is a glass window to permit the ob- Details of Electroscope For Radlo-Actlve beetle more brilliantly and the beetle will server to watch the collapse of the gold leaf. Experiments. It Employs a Single Gold look almost life-like when moving. Leaf as Shown, the Movement of Which Is Directly in the rear of the box there is an Measured on a Transparent Scale. opening about the size of the front window. Over this opening a piece of semi-trans- This electroscope besides being useful for parent paper is glued, on which a scale experiments with Radio-Active substances is drawn as in Fig. 1. This should be put is a valuable asset to any experimenter's on after the rest is finished so that the scale laboratory. may coincide with the gold leaf. Contributed by L. CLIFFORD. The construction of the top of the box is JAMES illustrated in Fig 2. A piece of fairly thin brass or phosphor bronze strip about 3^4" THE MYSTERIOUS BEETLE. By. C. A. Oldroyd. long and f^" wide is smoothed well. Any slight cut or jagged edge is apt to cause This illusion is worked by electricity, leakage. This strip is bent at right angles and will never fail to keep the audience half an inch from the top, and put thru an spellbound. The effect is as follows inch hole cut in the center of the top. The The performer shows a glass plate about top of the bend in the strip should be even one foot square which is suspended from with the surface of the wood and should two silk cords B (see sketch), which in not touch the wood at all. The hole should turn join the ring that is supported by the then be filled with melted sulfur. Be sure cord C. The glass plate A is divided into to heat the sulfur gently, and do not allow nine squares, each of which contains a it to burn as this destroys its insulating figure starting, of course, with No. 1. qualities. When the sulfur is hard sand- These figures and the division lines of the paper the top so that it is possible to see the squares are painted with black varnish. The top of the strip. The top is put on with performer shows a "beetle" which, so he thumb screws to facilitate removing and explains, he received from an Indian con- putting on the gold leaf. jurer. The beetle will cling to the glass Gold leaf can be purchased either at a plate without having any visible support, sign painter's or a paint and varnish store. and will also occupy the squares of the The Mysterious Beetle Is Not So Mysterious After All For He Is Moved From Square to glass plate — It would be best to find out when you buy A, whose numbers are called Square By Means of the Electro-Magnet In it, how to handle gold leaf, since it is ex- out by members of the audience. the Manner Apparent. — March. 1918 ELECTRICAL EXPERIMENTER 775 OPENING A LAMP CIRCUIT WITH A PISTOL. An Automatic Electric Railway A simple way to run a miniature cable ing on the position The effect caused by this hook-up is as of the motor field wires. railway mechanically and electrically is When motor runs in direction shown in follows : An incandescent lamp bulb is mounted on a cigar box which also has on it two upright wires, and a small wire connecting tliem (about No. 36). The up- rights and the lamp are connected in series, and they are connected by a lead wire and plug to a lamp socket. The current is turned on, and then the operator walks away some distance, produces a pistol, fires (?) at the wire, cutting it (?), when. Presto! the light goes out! The way this effect is produced is shown by the diagrams herewith. In diagram 1, the current from the ordinary 110-voIt lighting circuit passes thru a switch, a fuse, Lr{^V^v a fine wire inside of a bottle containing Vortob/e hydrogen and air, an electro-magnet, a strap Resistance key or push button, another fuse, and the ffheosfa/ other blade of the switch. The switch used Armature Leads is a D. P. S. T. with a fuse block. The bottle will be described later, and the electro-magnet consists of about 10 or 15 feet of No. 18 B. & S. gage bell wire wound on a ^-inch diameter iron core about three inches long. The apparatus at Fig 3 is the cigar box with the lamp socket and wires men- tioned above. The lamp socket is of the type with a hole in the center thru which a screw passes to hold it down. The screw rH'I'i'If used must be about an inch longer than is needed to pass thru the socket and box cover. On the lower part of this, below Relay A r-mature the nut fastening the socket down, is placed a brass nut with a brass lock nut under An Automatic Electric Railway That Electrical Experimenters Will Find Interesting. As it. In securing the socket make sure that the Moving Car Travels Back and Forth On Its Rails, It Trips Electric Contacts Which Serve the binding post connecting with the lead to Control a Relay Reverser Connected With the Driving Motor. from the lighting circuit is the one that shown in the diagram. The apparatus must diagram, the pow-er of the car closes the from the center of the socket. comes The be operated by a series-wound motor for "make" contact, which in turn energizes uprights may be of iron wire and are bolted the connection scheme shown, its armature the relay coils. This causes relay armature to the cover. The shove-bolt or down being connected to the contacts on the relay to come forward and this action reverses screw for the one nearest the socket must armature. The field of the motor, thru a the direction of the motor. On the reversal be long enough to extend about an inch variable resistance, is connected to Nos. I of the car's motion, the "make" contact below the lower side of the cover of the and 2 contact screw; No. 1 screw being opens again, but current is not cut off from directly connected to No. 3 screw, while relay coils because No. 5 contact screw No. 2 contact is connected to No. 4 screw. being directly connected to battery, thence ^/rre W/re The "make" contact is connected directly thru "break" contact and relay coils, keeps in series with the relay coils. No. 5 contact them energized. The opening of the Lamp screw is directly connected to the battery, "break" contact by the car cuts off the cur- Socket thence to "break" contact, to relay coils, rent from relay coils, releasing the relay and back to battery. The contact screws armature and bringing motor back to opposite each other are connected to op- original position. This action may be posite sides of the motor field. The forward repeated as many times as desired. The and backward motion of the relay armature variable resistance or rheostat contrqls the causes the motor to reverse when the relay speed of the motor. coils are energized, or vice versa, depend- Contributed by ARTHUR PRIEBE. •"' Spjrm'gi-- box. After the nut to fasten it to the box pose. The insert shows a convenient stand Fiq.3 on, on another one, to avoid "spilling" out the gas while jim cover has been put put j//(7C then a thin iron plate, and a nut on the generating it. I the plate between Now that the apparatus is completed, 'Lamp bottom. Then we have two nuts which when tightened will hold the magnet must be hidden under the thing it. This plate must be long enough to on which the box is to be placed. I put it just miss the bolt which comes thru the in my overcoat pocket on the bench by a socket and as wide as the box, allowing hatrack and put the box on my overcoat enough room so that it can move freely The jar must be hidden near the place Elec/ro Switch without scratching against the sides of the where the gun is to be fired, and the strap Mocfmf box. Then the brass nut on the bolt key placed where the operator can touch it thru the socket is screwed up until it comes with his hand or foot. Fiq I within almost a paper thickness of touch- The operation is as follows : When the Bolfle -of plate. However, it must not touch. key is closed, the current excites the magnet, Hydrogen and ing the Then the other upright is put on. which pulls down the iron plate short- Air- ^ The method of collecting hydrogen is circuiting the lamp. This throws the full shown by Fig. 2. An ordinary iron pan is 110-volt circuit on the fine wire which Fic^ 4 used, in which there is placed a salt solu- breaks as tho it had been severed by a tion and two lead electrodes. The nega- bullet. However, the resistance of the first tive electrode is put into the bottle which circuit is so low that there is a heavy rush is filled with the salt solution. When the of current which fuses the wire at its current is turned on, by electrolytic decom- weakest point, which happens to be in the position, hydrogen goes into the bottle. The bottle. This fusing causes a spark which bottle should be filled about 'A full of gas. ignites the hydrogen and makes the noise Fiq.2 It is then taken out, and a cork with two required to replace that which the gun wires bound to it having a fine wire con- would make if it were really fired. strands of No. 36. The two circuits may be on the It Seems as If the Bullet Severs the Fine sisting of about two same or Wire Next to the Lamp, Extinguishing It B. & S. gage wire across them, is placed different lines, because they are only con- But Does It? This Trick Is an Excellent in the neck. An ordinary olive bottle has nected by magnetism. One For Parties, Amateur Theatricals, Et for this pur- Contributed by S. Cetera. It Will Puzzle Them All. been found very satisfactory GEORGE GARY. ! 776 ELECTRICAL EXPERIMENTER March, 1918 TN/T? til fYJT^ 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 thi.'s 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 drawnngs. Use only one side of sheet. Make sketches on separate sheets. FIRST PRIZE, $3.00 SECOND PRIZE, $2.00 THIRD PRIZE, $1.00 LADIES! WATCH YOITR "SNAP LAMP "SOCKET" FROM A MAGNETIC PHONOGRAPH FASTENERS'! THEY MAKE GOOD SAFETY PIN. STOP. SWITCHES. I herewith submit my idea of an emer- I have found that by placing a pair of rig- The experimenter who is continually gency electric lamp socket. This socket ordinary electro-magnets, such as found in ging up different apparatus, will find that a may be quickly constructed from a safety few "snap fasteners" soldered to different pin of large size. It may be placed any- where. The pin is fastened down by a A'^re ^_>,_(. tack or screw and is bent as shown in the sketch. The lamp is then screwed into the ^^ ^^^ fffsfeners pin. Contributed bv ELLSWORTH EDGERTON. rrire ^~. Jnop fasteners usa/as t'lna/ngposr .'a', and J is a standard or any other convenient place. Are you looking for a rheostat? Then vibrating bell. is follows ; the examine the drawing which shows a rheo- The action as —When Contributed by HROLF F. LUCK. door is opened contact is made at A. The stat made by sticking a brass or copper rod wood screw is to adjust the movement of into each end of a potato. The resistance the spring which makes contact. When is regulated by bringing the rods close to the wire screen is pushed, it makes con- each other, or by drawing them apart. If tact with the copper plate. Either the this rheostat is used for a continuous period screen or the door will operate the buzzer of over one hour, it will be found neces- alarm, as they are connected in parallel. sary to replace the potato by a fresh one, as the current passing from one terminal to the other tends to bake it. This makes Door- ^^^^^ ^^^ a very cheap and simple rheostat, even -2'x4" Brass3prjng Copper Pla^e To House Current 'Buzzer Suffering Mackerel! Yes, It's Another "Rain ffesisl-ance- Alarm." And it Works. Yep! ^ —•\^AA^ 5^/fch Two pieces of Wire Pushed Into Opposite EXPERIMENTERS ! ! Provides Chicken Thieves!! Beware When This Elec- Ends of a Potato an Emergency Rheostat. tric Alarm Is Hooked Up to the Chicken Coop. Don't forget to write up that little "stunt." It maywin a prize. considering the cost of "spuds," which are The switch is to disconnect the buzzer when about $4.00 per bushel. WTiy not grow Address all manuscripts to the the door is opened for the day. some "rheostats?" What next!! Contributed by Editor, Electrical Experimenter, Contributed by VICTOR C. MAZYLEWSKI. 233 Fulton Street, New York City. RUDOLPH P. KRAJICK. Ma 1918 ELECTRICAL EXPERIMENTER 777 greater tension on the armature spring. A Remarkable Magnetograph These directions are intended only to Herewith is submitted a print of a spool heads should be laid out and drilled Mipplement the accompanying sketches. 1 "double" magnetic field of a horse-shoe before assembly of the spool. In order to have actually made the cut-out herein de- magnet. The cause of this peculiar field is insulate the windings, it is necessary to glue sci-ibed, and since it has been in operation, that the steel from which the magnet is a thin piece of fibre to each of the heads. I have not had a single bit of trouble. In made was faulty and order to keep out dirt, therefore causes an it is well to make a unnatural field. How- cover for it. It can be ever, there seems to be used on automobile a break in the original lighting plants, etc. magnet, which is a Contributed by single piece magnet. DAVID MATHESON Contributed by H.'\L r. BRANAMAN. A GOOD FILTER STAND. A "REVERSE CUR- Those who follow the RENT" CUT-OUT "Experimental Chem- FOR BATTERY istry" course in the CHARGING. Electrical Experi- The following is a menter and conduct description for making the experiments will a reverse current cut- find the apparatus de- out for use with six- scribed in this article volt charging systems. very useful. The material that was The base (C) is six used in the cut-out did inches square and cut not cost anything, the from oak ^-inch thick. parts and pieces being .'Xt each corner small selected from my col- pieces of 54-inch dowel lection of "junk." (D) are inserted in The magnet spool holes bored ^-inch consists of an iron bolt deep. The round up- with two pieces of right (A) is f^-inch in sheet brass for the diameter and secured ends. The top end is in the base by a screw threaded so that the This Photograph of a Magnetic Field Is Unique in That It Shows th e Relatively Large (S). !" the Flux a Horse-shoe Magnet by a Faulty Piece head will turn down ^''^"9« Magnetic About The piece (M) is of ofJ!'"2?""''Steel. A "Soft Spot" in the Steel Might Cause Such a D sturbance. and jam into place. ^^-^^ ^-inch thick x 6 inches long x 2 inches .\ b o u t an inch of thread should be left outside to make and to wrap 2 layers of paper .iround the wide. To this bar is glued the piece (F), winding easier. The bottom end has a core. 2 inches square and 1 inch thick. A wooden set screw is made and a half-inch hole in shoulder cut on it and then the sheet The mountings are made of sheet brass. head (F) as shown in drawing. A hole large brass riveted on. The bottom spool The support for the armature and its enough for (A) to slide thru is bored thru should have extending tabs on it, so that it spring must be made separate from the the base without (M) and (F). Two 154-inch holes, H can be screwed to wooden spool head, because it would be practically the and H' are bored in (M) to hold funnels. damaging the windings. All holes in impossible to bend this tab over after the .'X wooden rosette (B) may be added. windings are in place. The contact plate Contributed bv D. S. HARDING. head. The Cuiou/ must be insulated from the spool A Series contact spring must be insulated from the armature. The armature and tension spring were taken from a DeVeau buzzer, but this com- bination may be readily made if such a combination cannot be secured. The chief point is that the tension on the spring is adjustable by means of a threaded rod and nuts. The contact spring should be made of spring brass with a flexible con- ductor soldered thereto. There are two windings on the cut-out. The inner is a high resistance "Shunt" winding, and should consist of about J4 pound of No. 32 magnet wire. (I obtained this wire from a field winding on a fan motor.) Between the inner and the outer windings there should be several layers of paper. The outer winding is a low resis- tance "series" winding and should consist of three or four layers of No. 18 wire. Insulated (I have found bell wire very satisfactory.) The outside of the windings should be well covered with tape and shellacked thoroly to 3older exclude dampness. The connections should be made as per diagram. Make sure to have the connec- tion at .\, make the two windings in parallel aiding, not bucking. The other end of the scries winding should be connected to the contact plate. The connection from the contact spring goes to the line. .Adjustments: Tighten tension on spring until the cut-out will release when the charg- ing current drops to zero. Then turn down the stop pin until the cut-out will operate A Compound Wound, "Reverse Current" when the current builds up to charging Here Is a Good Home-made Filter Stand for Magnetic Cut-out for Battery Charging. It value. In making these adjustments, be the Amateur Chemist and Photographer. It Is Automatic in Its Action and Prevents a sure that the armature does not come in Built Any Size Desired and Made to Storage Battery from Discharging Bacl< Thru Can Be it Carry 3 or 4 Funnels. the Dynamo. contact with the core as then will take ! ! 778 ELECTRICAL EXPERIMENTER March, 1918 LIGHTNING EXPERIMENT. A SIMPLE 110-VOLT RHEOSTAT. A DRY CELL LAMP MOUNT. I was much interested in your article on Take a porcelain tube such as is used Procure a reflector (A) from an old "Thunder-Storms and Lightning Rods" by for house wiring. Procure an 8-32 machine- "miner's" flashlight and make an 8-32 screw Terrel Croft in the August issue of the screw, about 1 inch long, with a head that hole in it near the outer edge. Fasten this fills the center of the tube, leaving about Vi to the negative pole of the battery with inch of the thread projecting beyond the end. a regular battery nut. Make a brass spring Fasten the screw in with sealing wsix, tak- clip (B) about ^ of an inch wide, with Chargecf ing care that the head on the inside of the U(/der?jor tube is not covered. Put a binding post on the screw. Take ground carbon about as coarse as the sand from No. 2 sandpaper and almost fill the tube with this carbon. Plug the end with a wooden plug and bore a small hole thru the plug. Now take a piece of stiff wire slightly smaller than the hole and a little longer than the tube. This rod is to increase or decrease the resistance at will by simply pushing it in or pulling it out. The sealing wax, binding post and carbon I obtained from old dry cells. Spar/r-^ Contributed by ROBERT EASTMAN. Porcelain Tube ;HltW!l!tHitiMiiniMilllinlllnt{nll g Binding Posl 5hff Wire Uachine Scretv A Home-Made Dry Cell Flashlight. It Can Be Constructed From Odd Parts and Gives A Practical Demonstration of the Efficiency Excellent Results. of "Lightning Rods." The Leyden Jar Dis- charges to a Cup of Alcohol, Igniting It, if Wooden Pluj Ground Carbon an 8-32 screw hole at one end. Bend as Lead Wire Is "Ungrounded." shown and fasten on the carbon terminal ^^i-|.;;.v...^^: Electrical Experimenter, and therefore -..;:..... V.Z of the battery. To turn ofiF lamp turn clip to one side, breaking the circuit. take pleasure in submitting the following s,:^^ For flashing fasten a piece of spring brass experiment, which I believe will explain Seafinq Wax- to clip as thoroly the effect of the lightning rod. (B) shown in the figure. This is operated with the thumb. This outfit can A small wooden building is made, thru easily which passes a brass rod extending to be adapted to extended carbon types A Simple 110 Volt Rheostat Made of Porce- of dry cells. about 2 or 3 inches from the ground, lain Tube Filled With Ground-Up Carbon. Contributed P. B. beneath which a metallic container filled by KINGSLEY. with alcohol is placed (a tin box cover will do). When a charged Leyden jar (or a CHARGING STORAGE BATTERIES MINIATURE RECEPTACLE. In the sketch is spark from a static machine) is approached ON 550-VOLT CIRCUIT. A a wooden base 1}4 to the top of the rod, a spark will instantly Charging storage batteries on a 550-volt inches in diameter and ^ inch thick. B are ignite the alcohol, but when a chain or wire D.C. circuit can be easily accomplisht, as and B small brass strips J/^ of an inch wide and inches long running to earth is attached to the top, it shown in the diagram, by using incandes- yi making contact the center will be found that the alcohol will not cent lamps in series with the battery so as with point of the bulb, and the other being soldered to the wire spiral in catch fire, thus proving the efficiency of the to reduce the voltage. Use lamps of 110- the socket. lightning rod. volt rating each in series of five, being sure wooden C is a piece of wooden dowel stick inch thick, Contributed by EDGAR SINCLAIR. to have the lamps in each group of the ^ with a hole for the same candle-power and current consump- bulb to fit in snugly. A wire in the shape -^ of a spring is fastened inside the wooden WHO SAID SHOE-NAIL tion. The lamps may be sixteen, thirty-two, socket SWITCHES!!! or even higher candle-power. The higher by means of a pin bent so as to be used as a staple, and one end is soldered In the September issue of the Electrical they are in candle-pow-er, and therefore in Experimenter, there was a request for lo a spring contact B. Arrange the wire some genius to come forward with an elec- in C so that good contact is made with trical use for old "shoe-nails." The said the side of the bulb. genius has arrived! Hail, hail!! Glue the wooden shell C to the base A. Shoe-nails make excellent contacts for If small brass machine screws can be tapt multi-point switches, such as those used for in strips B and B as binding posts, it will look than receiving transformers, loading coils, etc. neater to put a hole thru brass The nails are driven into the panel and the parts for the wire to pass thru, the leads are soldered to the projecting and twisting the wire around itself. Method of Charging Low-Voltage Storage Batteries From 550 Volt D. C. Circuit Thru a ' Bank of Lamps. the ciirrent which passes thru them at full voltage, the greater will be the charging current for the battery. Contributed by PETER J. M. CLUTE. Constructed From Attempt No. 1 At Utilizing Shoe-Nalls For EXPERIMENTERS ! ! Miniature Lamp Socket Switch Points. Even Mr. Hoover and Dr. Wooden Shell and Base, In Which a Wire Garfield Must Rejoice At the Economics forget Spiral Is Secured to Form Screw Thread For Exemplified. Don't to write up that Lamp. little "stunt." It may win a prize. ends. panel should thin and of If good contact is made all around, the The be Address all manuscripts to the some hard substance to get proper results. receptacle will work as good as one bought Editor, Electrical Experimenter, Next I from the dealers. Contributed by THEODORE SEXTON- 233 Fulton Street, New York City. Contributed by WALTER SCHRODER. : : March, 1918 ELECTRICAL EXPERIMENTER 779 I FOR FIREPROOFING ANY KIND brushes will tend to peel or turn black. OF FABRIC. Hints are ^iven in the illustration for at- Wrsinkiesi A very good formula for this purpose is taching the "pigtail" connectors. as follows Contributed by H. W. SECOR. Boric acid, SO grams. Borax, 60 grams. noren pigfoi/ Water, 1,000 cu cms. Paint or soak fabrics in the solutibn; then either hang up to dry or press fabric with a hot iron. Contributed by ALBERT W. PUTLAND. COPPER-PLATING CARBON MOTOR BRUSHES. It is usual to thoroly copper plate the better class of motor and dynamo brushes cop. s/ieZ/r/Vefs Copper or EDITED BY SlGERNSBACK made of carbon to improve their surface I p/ug i^reir conductivity, and this may be accomplisht Under this heading we publish every month Details of Method Used In Firmly Securing the useful Information In Mechanics, Klectrlcity in following manner Pig-tall Connections to Carbon Brushes. and Chemistry. We shall be pleased, of The carbon brushes are usually cut from course, to have our readers send ug any flat carbon plates of the desired thickness recipes, formulas, wrinkJes, new ideas, etc., HAND GRENADES. 12 useful to the experimenter, which will be and measuring by 12 inches. They are It often happens in a laboratory that duly paid for, upon publication, if acceptable. in strips, cut out which are then sepa- some inflammable acid is accidently spilled rated into the proper lengths by means of or some chemicals which do not agree be high speed carborundum or corundum RESTORING THE COLOR OF a mixed. A very bad explosion or fire is MAHOGANY. wheel about /4 inch thick and 12 inches usually the outcome of such mistakes. in diameter, rotating at high speed. A sanitary and safe device can be made by Add Yi ounce of Alkanet root, cut small, The brushes are first washed thoroly the experimenter at the cost of a few cents to a pint of linseed oil and when this has and after drying they are dipt in pure which will end chemical fires as quick as stood for about 5 or 6 days add J^ ounce paraffin, when they are placed in a bake they begin. powdered gum arabic and 1 ounce of shellac oven and heated at 110 to 115° F. tem- It consists of a mixture of chloride of varnish. Let this mixture stand near the perature for 20 to 30 minutes. calcium, twenty parts; sodium chloride fire for a week and tlien strain. Wash the They are copper plated by immersing in (common salt), five parts, and water, mahopany well with soap and >vater, before an electrolyte bath. For small tanks the eighty-five parts. Several small thin bot- polishing this recipe. recipe with This bath is prepared by mixing two pounds of tles are purchased, filled with this mixture, should be handy to experimenters for pol- copper sulfate with one gallon of water and corked. ishing the bases their apparatus. of and adding ammonia until the precipitate When a fire occurs, one of these grenades Stain. Dissolve Sienna Mahogany Burnt first formed is just redissolved. This should be thrown in such a way that it will vinegar. in colors the solution blue. Potassium cya- break in or near the fire which will quickly To make paper transparent. By dipping To o ro/f ffj/n ^bat - be extinguished. Contributed by the paper in fresh-distilled benzine, paper EDWARD G. WILSON. becomes transparent. This is handy for Copperbor experimenters who desire to trace designs RADIO-ACTIVITY FROM GAS without using ordinary tracing paper. The MANTLES. paper becomes opaque as soon as the ben- Here is an interesting experiment on zine evaporates and it will be necessary to Radio-activity. I obtained some Welsbach moisten paper again. Ink will not run on gas mantles and powdering them and_ placed its surface when damp. the same in a cardboard box. I then put a Contributed by H. HORTHINGTON. key in the powder and covered it with a piece of cardboard, on top cif which I laid a piece of sensitized photographic paper CEMENT FOR CELLULOID. with the sensitized^'^urface down. The Small celluloid articles can be repaired 'lecfm/i/fQ 'Copper ^noae above operations .were air done in a dark with this simple cement. Dissolve one part room lighted only by a ruby lamp. The of camphor in forty parts of alcohol and Copper Plating Carbon Brushes In Electro- box was then covered and left in a dark add an equal quantity of shellac. lytic Bath. room for one week. At the end of this The cement is applied hot to the parts period I/found that upon developing the nid is then added until the blue color to be mended and the parts are held to- photographic paper that there was an in- disappears. This bath should be used at gether until cooled. distinct impression of the key on the same. a temperature of 122° F. to 131° F. An- Contributed by The radio-active rays which are a property other bath, which may be used cold, is THOMAS W. BENJAMIN. of the rare metal, Thorium, a small quantity composed of a copper sulfate solution with of which is contained in these mantels, had 1/10 of its volume of sulfuric acid. Jts past thru the cardboard and affected the density should register 1.197. This bath LUMINOUS FISH BAIT. sensitized paper. cannot be used for metal objects attacked All fishermen know that a light will at- Contributed by R. E. RAPP. by the above chemicals. tract fish. The present device comprises Pure copper anodes are placed in the a small bottle or vial wound with wire TO CUT THE TOP OFF A bath, and these may be cut from pure HOW spaced one-eighth of any inch apart. Two BOTTLE. copper sheets about inch thick. The hooks are swiveled to the end of the bottle Vf, Cut a piece of filter or blotting paper carbon brushes are held by spring clips, with fish line, tying it to the main line in two narrow strips, moisten same and resulting in about Yi inch of the brush 'above the bottle. A luminous mixture is paste around the bottle, each piece of paper remaining unplated, but this is all right, then made. Heat some olive oil on the parallel to the other, leaving between them as the unplated edge is the one ground stove for about fifteen minutes, just sizzling a narrow space, marking the place where down to fit the commutator curvature, and and not boiling; then mix in phosphorus you want to cut the bottle. Now hold the the plated surface not neces- copper need bottle over the flame of a spirit lamp and sarily reach the commutator. turn slowly so that the bare space is heated The electric current required for a V^ire Protection evenly; after about a minute the glass will Swivel small plating tank is 15 to 20 amperes at break quite clean and will only need to be 4 volts, and regular electro-plat- Hb»*^ 3^2 to a filed smoothly to take off the sharp edges. ing generator is best employed. The Contributed by G. M. BLUM. Hooks. brushes are plated from 4 to 6 minutes gen- Bottle erally, hut this will vary with the tempera- POLE INDICATING SOLUTION ture of the electrolyte and the amount of FOR BATTERIES. Attracting Fish by Means of a Luminous current used. Formula. Water, 1 teaspoonful; Bait and Hook. — A little experimenting will soon tell as Phenolphthalcin, 3 drops; Potassium Ni- the size of a small pea. Put in the bottle to how long the brushes should be plated trate, 1 teaspoonful. and cork. This is a fine bait for bass and and as to the proper strength of current. Directions for Use.—Dip wires into can be used to an advantage at night. It It should be possible to regulate the lat- solution, and the one which is negative can be used in winter fishing when the ter by means of a rheostat. If the plat- will color the solution about it red. lines are placed thru holes in the ice. ing is done too rapidly by using too strong Contributed by Contributed by RICHARD ANDRESS. a current then the metal deposit on the BENSON FREEMAN, JR. 780 ELECTRICAL EXPERIMENTER March, 1918 Experimental Chemistry By ALBERT W. WILSDON Twenty-Second Lesson APPLICATIONS OF ELECTRO- the equation SO, = SO3 + O, the o.xygen cathode, in a vat containing a strong solu- CHEMISTRY. being liberated and set free, while the tion of copper sulfate acidulated with sul- ELECTRIC REFINING OF METALS. former, SO3, having a strong affinity for furic acid, and a bar of copper forms the process of electrolytic refining water, combines with it to form sulfuric anode, as was the case in the refining pro- THEof metals, altho wide in application, acid, which at once dissolves from the cess. Copper is deposited on the grafite has as yet been chiefly restricted to anode to form copper sulfate, which is cathode of wax to any desired thickness, the refinement of copper. The metal + + and it reproduces faithfully every projec- has been obtained as "blister" copper ionized to Cu and SO., and the operation tion, indentation and line of the original. from its ores, sulfids, oxids, etc., containing is rendered continuous. No new supply It is permitted to remain in the bath from of sulfuric acid or of copper sulfate is needed. The bar of irnpure copper be- comes reduced as the refined metal in- creases at the cathode. The tank house of one modern electro- lytic plant for refining copper is 600 by 200 feet, contains 1,600 depositing tanks, each liaving 2Z copper anodes, each of which A weighs about 400 pounds. These are put •anode C-calhode in place by means of cranes, and after be- ing allowed to remain in the tank for about 43 days the remnant is taken out as scrap and resmelted. The cathodes (refined Fig. 108 copper) are taken out every 7 days with the employment of cranes, a tankful at a Molssan's Electric Furnace. Space Is Pro- vided at "B" for Substance to Be Electrically time. Slimes are removed once in three Arrangement of Apparatus for Electrolysis Melted. In Such a Device Small Diamonds of Copper, Etc. A-Anode, C-Cathode, Both months. The liquid contains from 12 to Have Been Made from Carbon. Immersed in Solutron of Copper Sulfate with 209f copper sulfate, and from 4 to 10% of Sulfuric Acid. sulfuric acid. three to eight hours, depending upon the thickness desired. The film of copper does many impurities which it is necessary to The electrolytic refining of zinc and remove. A solution of copper sulfate with nickel have also been tried on a large scale not adhere to the wax or grafite, and can be hydrochloric acid. sorne sulfuric acid is put into a vat or tank, but liave not been as yet entirely successful. easily removed by hot moulds, back is which is connected with the source of elec- The zinc deposit has a tendency to be .\fter removal from the the thing layer of tin foil is melted tricity, and a bar of thick plates of the spongy and readily oxidizable and the cleaned, a on it, and finally it is filled with molten crude impure copper is then suspended in nickel ores require previous smelting and the solution, and made the anode. The contain many impurities. type metal to render it rigid. The face is cathodes consist of very thin plates of the then of rigid copper, which is mounted on suitable called a block. pure copper. (See Fig. 105). /I -cordon anodes a wooden support, electrotype is The curent causes the copper ions from B-isrbon a far .+ .^. .4. .+ S-moHena/i/miii/m This copper harder and more cc7f/ioc^e a\ a\ a\ a durable than metal. the copper sulfate in solution to deposit on lasting and type the copper cathode, while the sulfate ions Copper is practically the only metal used for electrotyping. Recently a process was at the anode form a complex reaction, the invented for electrotyping by steel, which result of which is to dissolve off more n is much harder and more lasting than copper from the anode, thus tending to its drawback lies in fact that keep equilibrium in the solution. The im- copper, but the it it will never entirely purities from the copper anode gradually rusts, and probably supersede copper. settle in the bottom of the tank, and only Li pure copper collects on the cathode. Electroplating. Mif- rig 107 Electroplating is the electrolytic deposi- lions of pounds of copper are refined by tion of one metal upon another. It differs this process each year in the United States, Modern Method of Obtaining Pure Aluminum from electrotjping in that the deposit of and since the beginning of the Europeari by Electrolysis. A Set of Multiple Electrodes (Carbon Anodes-A) Are Inserted in the Ore War the output copper or other metal is fixt permanently has increased to a very to Be Reduced as Shown, the Molten Alum- on the surface of the base metal, which marked degree, having chanced from a pur- inum Accumulating at "D." forms the cathode, and is not removed, as ity of 95 or 98% to practically 100%. This was the case of the former process. The IS called electrolytic, or refined copper. The recovery of metallic tin from scrap chief metals employed for electroplating Native copper from Lake Superior does tin plate is another application of electro- examples not lytic refining that has developed quite are ; gold, of which work are need this refining, and usually sells for been e?:tensively in recent place gold-plated watches and cigarette cases, etc., a fraction of a cent a pound higher than the years. It takes electrolytic variety. in alkaline solution and the tin goes into silver, used to plate knives and forks, etc., Theory. solution as an alkaline stannat. nickel, copper and platinum, and such The The electrolytic refining of silver and its alloys as brass and German-silver. theory of this action is that the copper separation from gold and platinum The cathode, which may be iron, copper, sulfate molecules break up into con- brass, bell metal, or other base metal or copper and sulfate ions by solution. When tained in the silver bullion is also exten- the current sively practised and is gradually supersed- alloy, is first very thoroly cleaned w'ith passes, copper ions deposit as copper ing the method of "parting" by nitric acid. sulfuric acid to rid the surface of all traces atoms on the cathode, (C in Fig. 105) sulfate Electrotyping. (Continued on page 801) ; ions at the anode (A in Fig The process of electrotyping is almost the 105) become sulfate radicals, and at once break down into SO3 and O, represented by same as that described in refining copper. Most books are now printed from electro- types, as are the entire pages of this journal, and they are also employed for printing maps, illustrations and numerous periodicals, etc. The type is first set up, making pages of the size desired. An impression is made of the type or wood cut in a mineral wax, which is composed of a mixture of bees- wax, turpentine and grafite, so as to have an exact opposite of the face type; that is. the projections of the type form indenta- tions in the wax. The plate is called a case, and is impregnated with a fine coating :jy How Silver-Plated Articles Are Coated with of powdered grafite Sectional View of the Gigantic Hydro-Elec- Precious Metals by Electrolysis. The Spoons. which affords the con- tric Plant at Niagara Falls. A Case of Utiliz- Etc., Form the Cathode, a Bar of Silver ductiny surface. These impressions are Serving as the Anode. ing the Chemical Action of the Sun's Rays hung from copper hooks, and form the Indirectly. March. 1918 ELECTRICAL EXPERIMENTER 781 Our Amateur Laboratory Contest is open to all readers, whether subscribers or not. The photos are judged for best arrangement and efficiency of the apparatus. To increase the interest of this department we make it a rule not to publish photos of apparatus unaccompanied by that of the owner. Dark photos preferred to light toned ones. We pay each month $3.00 prize for the best photo. Make your description brief and use only one side of the sheet. Address the Editor, With the Amateurs'* Dept. "Electrical Laboratory" Contest As announced in this department in the February issue, we are desirous of publishing each month a special article describ- ing an exceptional Amateur Electrician's experimental laboratory. Such a laboratory will be found illustrated and described with several excellent photos on another page of the present issue. For prizes and instructions in preparing the articles and photos see the February issue. We now wish to say a few words with regard to the present laboratory contest. We are pleased to bring to the attention of all Radio and Electrical "bugs" two ex-radio amateur enthusiasts, who are shown in the photos at the upper right and left corners of the group. At the left we have a photo of the wireless set used prior to the war by Miss Edith Charmont of Cleveland, Ohio, and who has now joined the American Red Cross. She will probably go across the ocean and join in the "big game" before long. We are pleased to introduce a well-known ex-radio amateur—9 TL—known to his friends as Forest Longbrake, of Sheffield, Mo., but more recently of the 313th Field Signal Battalion at Camp Dodge, Iowa, and who expects soon to "go across" to France. Mr. Longbrake mentions that be has done lots of long distance work in the good old amateur days, with the set illustrated in his laboratory below. Once more—don]t forget to read the important announcement in the February issue. Address all photos and manuscripts to the Editor "With the Amateurs Prize Contest." A GROUP OF REPRESENTATIVE AMERICAN AMATEUR LABORATORIES. Electrical Laboratories of,... 3—Chas. P. Mc- Radio Stations of, Miss Edith Charmont, Cleveland, Ohio; 2— Forest Longbrake. Sheffield. Mo. 1— Nebraska, Carroll Whitney, Laughiln, Cadiz, Ohio (First Prize); 4— Ralph P. Anderson. Selm:, Calif.; 5—Vernon Clements, Elmwood, 6— Waterloo. Iowa; 7— Frank Hennlnger, Pawnee, III.: 8—Scott E. Vance, Hlllsboro, Ohio. 782 ELECTRICAL EXPERIMENTER March, 1918 ^TEST k^TENTS Door-Light for Autos areas. Means are provided, such as ner shown. The diametrically op- device is provided with electric motor (No. 1,248,930; issued to Albert C. by an electric blower, for remov- posite quadrants are connected to stabilizer, and the various electrical Schulz.) ing the ionized air and metal gases opposite sides of the battery so as features involved in the operation An idea capable of wide applica- from between the edectrodes and to be electrified, negatively and posi- and orientation are controlled from tion and providing electric light on simultaneously cooling one electrode, tively respectively. the surface of the water by means the step of an auto whenever the while means are provided for re- of electrical conductors leading door is opened, while the light on taining the heat or the other elec- Electric Piano Player downward thru a well insulatea the closed door lights up simul- trode, to permit the generation of (No. 1,249,157; issued to Alcide H. cable. The outfit is provided with taneously, and thus illuminates the cathode rays. Maitre and Victor H. Gaston a shock absorbing member at its Martin.) lower extremity in the event that Automatic Electric -Light Buoy the device mi^ht be lowered too rap- (No. 1,248,850; issued to H. Hart- idly in some instances. man.) The main object of this device is Stereoscopic X-Ray Apparatus to provide an independent and auto- (No. 1,250,093; issued to William D. matic electric light buoy of simi)Ie Coolidge.) construction, which can generate its The invention requires the use own electricity for lighting a lamp of two X-ray tubes, connected in a at its mast head without batteries certain manner to a high tension or other apparatus requiring con- transformer, while the successive stant or periodical maintenance. The images produced by these two X-ray device comprises certain mechanical tubes on a fluorescent screen are features whereby motive power for viewed in proper relation, first by driving a high tension magneto is floor of the car. .The lights are supplied with current from the car's This patent deals principally with storage battery or from dry cells, a unique electromagnetic interrupter and are controlled by automatic for producing musical sounds such switches mounted behind the doors. as by vibrating the strings of a The circuits are inter-wired so that piano or other instrument. The de- the lamps light in the manner above vice is claimed to damp out false described. A glass window is placed ^nbrations, and to suppress extrane- in front of the lamp as well as ous noises, so as to give a pure underneath the lamp, so that the sound. The electrical interrupter light shines in a horizontal plane as contacts are subjected to the vibra- well as a vertical one. tions of the spring. There is also provided an independent spring pressing one of the contact members into engagement with the vibrating Electric Ice Cutter musical spring, so as to cause the (No. 1,250,010; issued to Germain sonorous vibrations of this Poucban.) string to faithfully react on the interrupter clever invention intended for A contact spring. use in hotels, restaurants, etc., for the purpose of cutting ice into small Combination Magneto and Horn blocks or cubes for table use. The (No. 1,249,255; issued to H. R. inventor provides in this device one Van Deventer.) or more sets of wires which are A combination dynamo or mag- heated by electricity and to be kept neto and auto horn of simple de- in contact momentarily, and thus the sign. The magneto is driven con- hot wires melt their thru the way stantly as in the regular auto equip- ice. By using a suitable number one eye of the observer then ment, and the horn is mounted and perfect at one end of the magneto frame as by the other, in synchron- ism with the current impulses so tuAfaAkt as to produce the effect of an image seen in stereoscopic relief. derived from the constant wave ac- Electric Boiler tion of the sea. A heavy weight (No. 1,251,116: issued to Ora E. is mounted on the main shaft of Sarr.) the mechanism so that as the buoy This invention appertains gener- pitches about on the waves, this ally to electric boilers, and aims to weight follows the law of gravity provide an improved fonn of elec- and swings back and forth. The trically heated steam generator, magneto is connected in series with wherein steam for operating an en- a lamp of the Gcissler tube type, gine or other device is produced and a suitable condenser. of sets of such wires, the ice may Electric Ore Detector as is be cut in as many planes de- (No. 1 ,248,380 : issued to Rupert shown. By means of a sliding gear sirable. In cutting it into cubes, it Nelson.) and a lever connected with a control must be cut in three planes at right Different metals can be substituted rod and handle, leading up to the angles to other, in tnis each and for the electrode that is inserted driver's seat, it becomes possible to case the inventor provides three sets bring a pinion into contact with a of parallel wires, the wires of each stud on the diafram of the horn set to so positioned as to cut be and thus- cause it to operate. the ice in the manner above de- scribed. Submarine Movie Camera (No. 1,250,582; issued to H. Hart- man.) High Tension Rectifier (No. 1,251,269; issued to A. Mul- vany and E. Kennedy.) The high tension rectifier here shown is intended particularly for use with X-ray tube circuits, for the purpose of converting high ten- sion A.C. from the secondary of a step-up transformer into a high potential uni - directional current. WirtER into the earth, so as to determine whether the ore is positively or by the passage of an electrical cur- negatively electrified with relation to rent thru water, circulating around the electrode, thus ascertaining into and between a series of oppositely what class the ore belongs. The charged electrodes in the form of apparatus ernployed for the purpose metal plates, these plates being sus- includes a source of current such as This apparatus for provides the ended in the water within the a battery and a quadrant type elec- taking of submarine pictures This rectifier takes advantage of the motion E oiler. The patent covers special trometer, connected in the at various depths of the sea. electrostatic field intensities sur- up man- The means for suspending the electrode rounding electrodes of different COPIES OF ANY OF THE ABOVE PATENTS SUPPLIED AT 10c EACH. plates within tne boiler. March. 1918 ELECTRICAL EXPERIMENTER 783 Phoney Patents Under this headinf u-« publUht electrical or mechanical Ideas which you haven't a smell of the Patent yet. After they have allowed the Pat- our clever inventors, for reasons best known to theni8elve Prize Winner. SKUNK GASSER. "Well, I've Been Skunked," Will Soon Be Heard Among the European Trench Inhabitants—at Least Just Battalions of as Soon as I Can Get Official Washington to Consider the Merits of My Sure-fire Hun Destroyer. Several Hundred Tame Skunks Are Hitched to Small Two-wheeled Carts, Each Containing a Dynamo, Motor, Storage Battery, and Spark Coil. Dynamo Charges Battery, Which Runs Motor. Motor Drives Cart. Skunk Can't Stop Once Spark Tickles Him. The Limburger-lovers Are Soon "Skunked" and the Sammies Do the Rest, inventor, Rex Purcell, Mo. Valley, Iowa. •^^^^.^^^..^^>VvVfr\'^^'y.^y^^^^'^l.JJ'^^^.^^y^.^'.>^,.^^,\;Mm^M^mmm^^^^^^^^^mm/^:^A>^ - 1 HEfiTER FOR BflTH Z~COCKTM ^/^TER MOTO/?' SHmERFORmRNING ^FLYWHEEL Z- WINDOW OPENER EYE-OPENER ,|?5 4 -B/fCK SCRMCNER 5-REWING L/)MP G-ELECTR/C E/7A/ l-ELECTRJC ^e/7rER Q-BR/CR THROWER FOR CH/^5/NG /^OC- S)-/fL/)RM CLOCK TURN/iL CATS STO/ifi6E 8f) TTBfSY HYDROELECTRIBED. Do You Sleep? Sure You Dol Weil, Here's the Latest Convenience for All Those Who Hit the Hay, either Peri- odicaily or Regularly. Just Before Retiring, Turn on the Water-valve Suppying the "Mattress Bellows." You Rise as You Snore, and While Sleeping Produce a High Pressure in the Bellows. This Water Pressure Runs a Turbine Connected to a Dynamo. The Dynamo Charges a Storage Battery. The Latter Furnishes Electric Current Free of Charge for Electric Light, Heater, Cock-tail Mixer, Fan, Alarm Clock, Ad Lib—Ad Infinitum. What More Could Mortal Want? Inventor, John Renault, Angers, France. : : : : 784 ELECTRICAL EXPERIMENTER March, 1918 QUESTION>^^ BOX This dejMirtment 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. 2. Only one side of sheet to be written on; matter must be typewritten or else written in in!;, no penciled matter considered. 3. Sketches, diagrams, etc., must be on separate sheets. Questions addrest to this department cannot be answered by mail free of charge. 4. If a quick answer is desired by mail, a nominal charge of 25 cents is made for each question. If the questions entail considerable re- search work or intricate calculations a special rate will be charged. Correspondents will be informed as to the fee before such questions are answered. SUPERSENSITIVE MICROPHONE, SQUIRE'S WIRED WIRELESS. ly to a single wire, and each 01 these sta- (894) A. E. Glazier, of Oakland, Cal., (896) Cyril Thorn, of St. Louis. Mo., tions are tuned to a separate or individual requests asks frequency. The transmitters of each of Q, 1. Will you please publish a diagram Q. 1. In number 9 of Hawkin's Electri- these stations are equipt with alternating of the interior parts of the Super-Sensitive cal Guides, on page 2337. a method is ex- current generators supplying currents of Microphone such as is used for detective plained whereby you can telephone or tele- frequencies corresponding to those used in work and explain parts of the same; how graph over a single wire, without using a the receiving stations, so that by means of return wire. It is called Squire's Wired a switch one can control the frequencies Wireless. As it does not describe fully how very easily. When the party desires to ob- Carbon aiofram this is done, I do not understand it. and tain a certain station, he merely throws «ould like to know how it works. over the switch controlling the frequencies to the particular frequency of the desired "station, iiiiiiiiiiiiiiiiraiiiiiiiiimiiiiiiiiiiiiiiiiiiiiiiiiig and thereby he is able to communi- cate with said station. No two different I ODD PHOTOS WANTED AT frequency currents can interfere with each m $1.00 EACH ! ! ! B other : thus the selectivity of the system. The first station might have a frequency H \ uw is the time to make your s of 30,000 cycles per second; the second B Kodak pay for itself in a real practi- s station a frequency of 33,0()0 cycles per lUefa/ s/je/i Carbon cup Carbon ixiJ/s cal g way. We are after interesting H second, etc., etc. B photographs of out-of-the-ordinary B H electrical, radio and scientific sub- Sectional View of Super-Sensitive IVIicro- g WAVE METER QUERY. phone as Used in Loud-Speaking Telephones H jects and are willing to pay $1.00 cash g For Detective Work, Interior Telephone for every one we can use. Please = (897 > John Halson. of Baltimore, Md., Systems, Etc, g B bear in mind that for half-tone re- wishes to know production in a magazine, a photo- Q. 1. How to utilize the wave meter for does it differ from the telephone trans- I graph should be particularly sharp obtaining the wave length of distant sta- mitter? / g a and clear. coxirse, a subject tion. A, 1. The diagram herewith gives the H Of if happens to interest us particularly schematic arrangement of a super-sensitive = A, 1. The manner in which you can well, zve can have the photo retouched. microphone as fised in detective work. The H apply the wave meter for measuring the For the general run subjects, how- essential parts /of such a microphone are H of H wave length of a distant station is by ar- ever, it does not pay to go to such the container, (usually made out of metal, g J ranging the apparatus as indicated in dia- expense. Therefore, please take pains the carbon dij^fram and a carbon cup. A J gram. The received signal is first tuned to to properly focus and expose your very high gradle of polished carbon balls arc M B the required wave length of the distant pictures. It often happens that a used in this carbon container, and the car- g station by varying the various inductances s really mediocre subject well photo- = bon diafram of which is so adjusted that =J and capacities in the receiving circuit. Then graphed wins approval over an ex- they touch this diafram very lighth'. m g by introducing a buzzer excitation circuit cellent subject poorly photographed The main difference between an ordinarv g in the secondary circuit as indicated, and .-Ind don't send us plate or film "nega- telephone transmitter and that of a super- s receiving this excitation current in the lives" ; send unmounted or mounted sensitive type, is the way in which the car- B wave meter, resonance between the secon- "prints," perferably a light and a dark bon grains are utilized. In the super-sensi- M dary and the wave meter will indicate the one. tive rnicrophoines. carbon balls and a car- M wave length which was originally received As to what to photograph: Well, bon diafram are used, together with a fair- S by the receiving set. By referring to the that's hard for us to say. We leave = ly heavy current and a low resistance tele- original calibrated curves of the wave meter that up to you, and every reader now phone receiver, having a resistance of H the wave length of the distant station is thus has the opportunity about 5 ohms. to become a re- g obtained. porter of the latest things in the realm H Q. 2. What causes a double humped of Electricity, Radio and Science. M resonance curve in an oscillatory circuit in ELECTRO-MAGNET. But, please remember—it's the "odd, (895) W. C. Mace, H a transmitter? Marshfield, Ore. novel or practical stunts" that we are writes A. 2. Too close coupling between the interested in. Every photo submitted M 1. Please give Q. in detail specifications should be accompanied by a brief de— secondary and primary circuit results in a for an electro-magnet g necessarv to pull an scription of 100 to 150 words. Give double humped curve. iron lever thru 90 J degrees into a horizontal the "facts"—don't worry about the position. There is very little g resistance on style. We'll attend to that. Enclose ^ this lever; approximately an equivalent of stamps if photos are to he returned H three pounds' pull. I would like to know and place a piece of cardboard in the ijVVA the amount of wire, size of wire, size of envelope with them to prevent mutila- B soft iron core and amount of current neces- tion. Look around your tozvn and U ..-Z ^ci> sary. I have unlimited current. see what you can find that's interest- B A. 1. A suitable electro-magnet for ob- ing. H taining results such as \ou desire is speci- Address photos to —Editor "Odd | fied below : ' r.-rl- The soft iron core should con- Photos," Electrical Experimenter, m ^ec-ofrec sist of a soft iron '2 bar inch in diameter 233 Fulton Street. .Wew York City. h'ayemefer, arcc//^ and 3 inches long. Fiber bobbin ends 2 inches in diameter are placed at each end ^ of this iron core, and then fully winding .*K. 1, The operation of Squire's Wired the intermediate space of said bobbins with Wireless is dependent upon the transmis- No. 21 B. & S. D. C. C. copper magnet wire, sion of alternating currents of different Circuits Used in Determining the and the ends of Wave this winding should be (above audibilitv') frequencies over a single Length of a Received Signal By Means of brought out thru two holes protruding thru line. the Wave-Meter. the end bobbin. The winding should be Let us suppose that the equipment is to carefully protected by covering it with tape. be utilized for the transmission of telegraph ILLUMINATION QUERY. Voltage used 12 volts and current about .75 and telephone messages. Several telephone (898) Paul Johnson, of Detroit. Mich., ampere. and telegraph stations are linked electrical- desires to know: ; — — March. 1918 ELECTRICAL EXPERIMENTER 785 Q. 1. What disadvantage has a frosted glass upon an incandescent tungsten lamp? A. 1. There are several disadvantages from usins frosted glass on tungsten lamps; namely, the increase of tempera- ture within the bulh due to multiple reflec- tions of the irregular surfaces produced by the frosted glass, which naturally decreases the life of the filament due to the operation of the filament at higher temiieratures. Secondly, the decrease of surface illumina- tion produced hy such a lamp, due to a gath- aCUOPEHA CYCUOPHXA ClCU)PQ» QCLOPEDU aCLDPHH* CYCLOPEDU aCLO ering of dust in the fine irregular sections of tiie frosted glass. APPLIED APPLIED / ^^^^^^^fjjj^jgj^ APPLIED APP Q 2. What are getters in incandescent lamps? BHTRiCfn- flECTRICmr V ' .\. 2. Getters are chemical compounds which are used to absorb the vaporized tungsten produced by the heated filament ElEMEKIVj DYNAMOS and retransferred back to the filament in order that the filament will be kept at the aomoony' cuaiutKnt V o METER S DESICN 7 some thickness as it was originally. This retransformation is a chemical process, and very little is known about it, as the com- mercial companies are keeping it secret. However, it may be said that originally, when the incandescent lamp was begun, that halogen members of the chernical group were utilized, viz. : bromin and iodin. Q. 3. What is a micron? A. 3. A micron is the unit of intensity of illumination and is numerically equal to one one-thousandth of a millimeter. ELECTRIC OIL AND WATER FINDER. (899.) Mr. Phil Buracker, 828 Down- SEND NO MONEY ing St., Denver, Colo., asks for data on USE THESE ELECTRICAL BOOKS SEVEN DAYS Q. 1, A special form of "Hughes' bal- ance" for locating underground ore, etc. AT OUR EXPENSE A. 1. Concerning special fonn of the Uy merely lilling in iuul mailing the coupon below you can get this complete set of the Hughes' Induction Balance for locating C'yclopediii of .\pplied Electricity on trial. Pay only small shipping charges when metallic masses buried in the ground, etc., thev arrive. Use these books for seven full days before you make up your mind we would suggest that you read the article whether or not you want them. If you keep them, you may pay the special adver- appearing in the .'\ugust, 1916, issue of tising price in easy installments of .$2.00 a month. If you don't want them, you may The ELEl.TRR.^L Experimenter, copy of send thiiu l>ack at our expense and you won't be out a penny which we can supply at 20c. This article contains the basic principle A MASSIVE ELECTRICAL LIBRARY— NOT HANDBOOKS upon which all such apparatus, of no mat- These se\'en splendid volumes contain all the knowledge you need in order to earn ter what size, should be designed. With big money in the electrical field. They are not thin handbooks, but thick, eneycloi)edia- regard to the size of the inductance coil, size volumes, handsomely bound in half morocco leather, gold stamped. Each one these can be of any dimension desired, but, measures 7 by 10 inches, and is 2 inches thick. of course, the size of the wire and the This big size permits the use of large and comprehensive illustrations, plates, dia- number of turns on each coil will have grams, etc. Over 3,000 cuts are contained in the Cyclopedia's 3,.5O0 pages. to be judged by experiment to a large ex- tent. Considering that the coils are made will be a revelation to The completeness of the Cyclopedia Read These Subjects with fairly large number of turns in in plain, simple a you. Everything electrical is explained Elemenls of Electricity proportion to their size, then the problem English—every technical ])oint is made clear. Each volume Electrical Measurement* —Underwriter!' Beatllre- of exciting these coils properly is mostly is carefidlv cross-indexed for instant reference. ments—Theory. Calcula- a matter of experiment, and one which can Uon. Design and Oon- For this sum—an insignificant structlon of Generalon be solved quickly. and Motors — Dynamo- electrical a Week I this wealth of El e c t r i c If a buzzer fitted with an auxiliary bat- SOc Machinery L Ig h t i n fr Machinery information is yours. But you don't have to send us a penny tery contact is used as described in the Power Transmission- until you have used the liooks for seven days. Then, if you Electric Balln-ays —Power article above mentioned, to excite the two stations — Switchboards to them, send only .$2.00 a month SOc a week— primary coils of such an apparatus, then decide keep and Swilchine — Storage until the special advertising "price of $19.80 has been paid. Baitorie^—Applied Elec- it is but necessary to increase the battery tri'-ChemistO" — Electric price of these pay-raising books is $86.00. Elevators— Electric current of batteries in this ex- Tbe regular Weld- or number ine and heatinR — Wire citing circuit thru the primary coils, and antl Wireless Teleeraphy. the sensitivity of the entire outfit checked Consulting Service Free up by approaching the coils with a metal .\ year's Consulting Membership in the American Technical mass as iron or other Society -regular jirice $12.00—wiU be included with all or- such an tank any « American of Technical Society metal object of fair size which may be at ders for .[ limited time. The advice of an entire corps Dept.E-7443 Chicago. U.S.A. hand. clictrical experts is yours to help you in your progress— J / Please semi me theCyclopedia The diameter of the two coil bobbins foi- a whole vear FREE! I of Applied Electricity for seven or forms used on the French "shell locat- days' examination. — f I will pay ing" balance measure about 2!/2 feet in Send No Money Just the Coupon net shipping charges. If I de- cide to buy, I will send you $2.00 diameter, and one primary and one sec- lliese ItooUs for yourself before you buy. Re- See / ill seven days, and the balance at ondary coil are wound on each of the two member, you don't risk a penny or assume a single t the rate of J2.00 a month, until bobbins, these bobbins being supported obligation. The books will be sent to any one with- t tl9.80 has been paid. Then you will send me a receipt showing from a transverse bar carried on a light boimdaries of the United States or Canada, / that in tbe > Uic set of books and the tl2.00 con- two-wheeled truck so as to be readily expense if they ;md they may be returned at our ,t sultine membership are mine and fullv pushed along the ground when in use. paid for. If I think that I can get along fail to plea.s'e. But you must act now ! This / without Q. 2. What is meant by the term "layer be continued indefinite- the books, I will return them generous offer cannot after seven on layer ?" days, at your expense. ly. .Send the coupon now. .\. 2. With reference to the term "layer Name. on layer." this simply means to follow the AMERICAN TECHNICAL SOCIETY usual construction in winding electro-mag- Dept. E-7443 CHICAGO, U.S.A. , Address. nets or other coils and when one l.iyer has been wound on, the second layer is wound _/ Reference. You benefit by mentioning the "Elfctricat Experimenter" when writing to advertisers. : 786 ELECTRICAL EXPERIMENTER March, 1918 over this in the usual manner, back and forth until the required number of turns have been placed on the coil. Q. 3. Is there any form of electrical oil and water locater? A. 3. Yes, an English concern has evolved a ver>' successful electrical ap- paratus for this particular purpose, which has been approved and used with success by the engineers of the British govern- ment both in England and in foreign coun- tries ; particularly in India, where it has heretofore been extremely difficult to suc- cessfully locate flowing water in order to bore the necessary wells, of which a very large number exist in that country. The principle on which the instrument works is the indicating of the presence of currents which flow between earth and at- mosphere, and which, seeking the path of greatest conductivity are always strongest in the vicinity of subterranean water courses, the waters of which are charged with electricity to a certain degree. In taking obser\'ations, wooden pegs are Whether You Are Drafted or Not placed at internals of twenty paces in a direction usually S. E. to N. W. The in- you cannot afford to shut your eyes to the fact that one of the most strument is tried over each of these pegs in turn, and should the needle move on important branches of the Army, Navy or Aviation branch is WIRE- any one of them, tests are made all round LESS : particularly for entering the Signal or Aviation branch of the it, and the spot where the greatest move- Army. When called to the cantonment you must know wireless, and ment of the needle is obtained is where know it well. There is no branch requiring more trained men than the the boring should be made. If the needle wireless section. does not move, subterranean water does not exist under the spot where the instru- SPECIAL WAR RATES ment is fixt The instrument indicates water courses Send stamp for catalog giving facts. Resident classes open the entire year. flowing underground in a natural state, [NATIONAL RADIO SCHOOL, 14th and U Sts., WASHINGTON, D. C. and not water pipes or sources that have PHONE NORTH 2153 sprung up to daylight Observations should always be taken on a fine, calm, Navy Needs 1000 Operators NOW clear day between 8 and 12 in the morning and 2 and 5 in the afternoon, these being the hours of greatest activity' of the verti- L cal earth-air currents. Send us stamped and self-addrest envelope and we will gladly give you the name of the concern '-''' '^ making this ' * 1 C Complete apparatus. Junior Deaf-Phone \:Impaired Hearing THE MICROPHO JUNIOR DEAT-PHONE is a super-sensitive iDstrument which has been developed to meet the demands for a practical and efficient hearing device at an extremely MISCELLANEOUS QUESTIONS. low price. It is equal to any S:;o."(i instrument made and superior to most of them. SPECTRUM OF The outfit consists of One Super-Sensitive THE AURORA. Transmitter with cord connector; One Super- D., Sensitive (900) A. San Francisco, Cal., writes Ear Piece with small black cord ; One the "Question Box" Black Single Headband : Black Case and Two IMPROVED Q. 1. Is an>'thing positive known about Super-Sensitive Microphone Only $7.50 the nature of heat lighting? A. 1. With reference to the exact na- This LDstruinent is offered at an eitremely low jrice. It is escellent for buildine your oun radio ture of heat lightning, nothing specific is aiupUfler. Can also be used ia manv ejperinieiits known concerning this phenomena, but it where a sensitive microphone is reQuired is generally conceded that heat lightning NEW DETECTAGRAPH $15 is nothing more nor less than the reflec- This detecting instrumeDt of marrelous sensitiviiy tion of powerful lightning discharges at a can be used for detecting secret conversations. Out- fit consists of Sensitive Transmitter. 25 ft. Black considerable distance. Cord, Receiver. Headband. Case and Battery. 2. of the Send for one Today and Convince YourseH DETECTAGRAPH $15 Q. (o) Has the spectrum MICROPHO-DETECTOR COMPANY Gaston Boissonnault, President Aurora ever been determined exactly or is 26 Cortlandt St:. NEW YORK Makers of Super-Seniitlve Microphone Apparatui it variable? (i) Can a gas be rendered luminous under the influence of heat alone, and if so is its spectrum identical with that of the same gas illuminated by YOUR CHEMICAL LABORATORY. CHEMCRAFT an electric discharge in a vacuum tube? Contains more and better experiments, more chemicals and apparatus and (f ) In the event of gases not being known the biggest value. The original and best chemistry sets. to be luminous under the influence of heat alone can we explain the explosions You will be more than pleased with Chemcraft when you find what interest- how of incandescent hydrogen witnessed dur- ing and wonderful experiments you can work with it and how much fun you can have. And don't forget about the ing total solar eclipses, and how can we explain the illumination of in Chemcraft Chemist, which is free to gases there all owners of the No. 2 or No. 3 sets. neubulae? {d) Are such things as phosphorescent gases? Chemcraft No. I. Price $1.25. West of the A. 2. (a) The spectrum of the Aurora Mississippi and Canada. $1.50. has been measured by different investi- Chemcraft No. 3. Price $5.00. West of the gators, but owing to the rapid and sudden Mississippi and Canada, $6.00. changes in the coloring as well as the ex- tent of the the varies Get Chemcraft from your dealer, or if he cannot Aurora spectrum supply you send direct. We pay postage. likewise. However, several interesting points have been discovered in this direc- tion, particularly in regard to the presence The Porter Chemical Co. of certain rare gases in the upper region Dept. B. of the Aurora. Hagerstown, Md. Chemcraft No. 2, Price $2.50. West of the {h) It is possible to gas lu- Mississippi and Canada, $3.00. make a minous under the influence of heat alone. You benefit by mentioning the "Electrical Experimenter" when writing to advertiser!. . ; : : : ; 787 March. 1918 ELECTRICAL EXPERIMENTER and the degree of luminosity depends upon eral other leading experts on this class of QUICK, RELIABLE, EASY the pressure of the gas due to its expan- device. sub- sion, etc. The spectrum of this illu- (fc) This is a somewhat complex ject and we would suggest if you have minated gas is the same as when excited SHORTHAND by any other means, such as by the appli- not already consulted back issues of the would do cation of electric current. General Electric Review that you LEARN IN 5 interesting (c) The explosions of incandescent hy- well to look up some very selective reflec- drogen witnessed during total solar eclipses, articles on the subject of HOURS year and also the illumination of gases in tion which appeared therein about one Absolutely astound- nebulae are undoubtedly due to the pres- ago. ing — the quickness, ence of nascent hydrogen and also oxygen, In general, it would seem reasonable to certainty and ease with in a certain I. which by the electrical disturbances occur- suppose that the molecules which you learn K. neutral when they ing in these gases cause sudden molecular structure cease to be Shorthand. No long the application of ; "Talk ai fait aj you explosions. This is most probably due to are set into vibration by period of study high like. J am taking it gase- some external means, such as by the rays expense eliminated — the electrical bombardments of the down in K. I. light ous ions, this causing the gas to become from an X-ray tube or by ultra-violet here's the genuine Shorthand" luminous. from a spark gap, arc light, etc. method it worth your while to (d) So far as we know there is no You will find treat- Try This Specimen Lesson such thing as a phosphorescent gas. consult several of the newer books molecular structure, and we take Q. 3. (a) Where can I buy a book treat- ing on in 5 Minutes of the very ing such subjects as unipolar lamps illu- pleasure in suggesting one minated by High Frequency Currents latest works in this direction entitled "The liere'sX, p ond.lhlc Is o a Writ-e Fleming valves, Cooper-Hewitt lamps used Electron—Its Isolation and Measurement of Some of Its as valves and vacuum tubes containing and the Determination the two tOGCtlier, and you havc^O ££_ Millikan, three electrodes used as detectors for Properties," by Prof. Robert A. in this you sin- Hertzian waves, (b) In the study of se- one of the foremost scientists Here's A th To nekc path research. Our lective reflection there is a point I fail to branch of philosophical supply copy of v/rite |0 and ^dth these two ecsy grasp. We are informed that certain sub- "Book Department" can a ply stances possess systems which vibrate with this book at $1.60 prepaid. movcir.ents of your pencil, you hp.ve well defined periods. These systems re- trfde sword thot needs 16 pencil flect light falling on the substance only THE BELL TELEPHONE SYSTEM. Pa., asks: movements- when writteh in longhand. when the incident light is of the same fre- (901.) L. Slack, of Pittsburgh, information quency and in this case reflect it totally, Q. 1. Kindly give me some Here's It so it is cesy to iv^ite at, tfip and pnt. \ <\ y ffinging Su&scnders /Insider magne/o Calling Msmber's ^^ Already you have learned four K.I. Jac/f P/ag) JacA '.P/uff .<^horthnn(l si^ns you won't forget. With the other sifns and easy di- i3[[: rections you can leern to irtoicete DBr: every word in the dictionary in to twentieth of the time 'fe- Repesfmg quprter quired in ordinnry Tiriting, as rn p- . coil idly OS words are spoken'. Guarantee You Can Learn Kinging /reg If you have learned the above in 5 ^nsn'er/ng^ 2m(ai/K/i, minutes you should learn the whole sys- tem in less than S hours ; after which you develop speed with ordinary practice. $5,(XX) '^ Operafcrs sef Ca//j/7g s/ffna/ reward on superiority of K. I. Shorthand. /amp Take down speeches, talks, Typical Circuits of Bell Telephone Exchange, Showing Position of Repeating and Retardation telephone^" jrtiessages, Colls, Lamp Call Signals, Et Cetera. order J^-^ermons make yom- memo- randa quickly. Keep producing the phenomenon of selective re- as to the external and internal wiring of private diarj'. Im- flection. V\'e further know that when these the Bell Telephone System. prove your efficiency. reside in the A. 1. It would be impossible for us to natural periods of vibration Golden oppor- infra-red the vibrating system is no longer give you full details, and especially a com- tunities now for an electron but a molecule. Now a mole- plete wiring diagram, of the Bell Tele- those who learn cule is generally neutral as opposed to an phone System in this column. shorthand. Prefer- electron, which is negative electricity. However, we are herewith giving you part ence is given in em- How then can the vibration of a neutral of the circuit as used in the central ex- Prepare jar government ployment to those molecule reflect light since reflection is due change. It shows clearly how the various work who use it. to the radiation produced by vibrating elec- repeating and retardation coils are used. trons? Are we to suppose that neutral K. I. SHORTHAND COURSE radiate energy when in vi- molecules can TELEPHONE RELAYS. entitles you to free correspondence tuition bratory motion, or are to suppose the (902.) H. Wood, Iowa, asks: we J. to improve work in your own occupation. molecules cease to be neutral when vi- Q. 1. What is the state of the work now brating? done by the telephone relay? FREE BROCHURE TO YOU 3. 1. Bell Co. is now A. (o) We would recommend Dr. A. The Telephone Let us send you FREE, our new bro- Nikola Tesla's book entitled "Experiments using a very successful form of telephone chure of the wonderfully easy-to-leam K. I. with Currents of High Frequency and Po- relay of the Audion type on their long Shorthand. The total cost, including special tential" which contains much valuable in- distance lines, between the eastern and correspondence, will be only five dollars formation on unipolar lamps lighted by western coasts. If you talk from New under 30 days' money-back offer. Fill out high frequency currents, etc. For infor- York to San Francisco, your "voice" passes or copy coupon below and mail to us mation concerning the Fleming valve and thru one of these Audion relays. promptly. A postcard will do. Mention other valves of similar type, would rec- Also the "Brown" Microphonic Relay has we Electrical E.vpcrimcnter. Address ommend that you consult any of the mod- been used quite successfully in England ern hand-books on Radio-telegraphy, in- for several years in telephone and other KING INSTITUTE cluding the excellent work of Dr. J. A. work. There have been many patents taken 8 So. Wabash Ave. 154 East 32d St. Fleming, which we can supply at $10 net. out in the past few years on electro-mag- CHICAGO or NEW YORK An exhaustive article describing the exact netic forms of telephone relay, and if you mode of operation of the Audion appeared are intending to carry out research work Send FREE BROCHURE EA-300 of K. I. Short- in the August, 1916, issue of The Elec- on this device, we would strongly suggest hand with piiarantee to mc, postpaid. trical Experimenter, page 251, and which that you have a patent attorney make Name is one of the most authoritative that has search of the patent office records, and appeared on the subject, the article having furnish you with copies of all of these Address been past upon by Dr. de Forest and sev- patents taken out in recent years. You benefit by mentioning the "Electrical Experimenter" when writing to advertisers. : 788 ELECTRICAL EXPERIMENTER March, 1918 COST OF RUNNING ELECTRIC LAMP. Important Book (903.) G. H. B., New York, inquiries: Q, 1. How many kilowatt-hours will a 25 watt, 110 volt, Mazda lamp consume, Iturning 31 days continuously and what will Sent FREE it cost to operate? A. 1, A 25 watt, 110 volt Mazda tung- Tells about the many chances for men with electrical sten lamp, burning continuously for 31 training. Shows how you can master a paying- profession while you hold your present job. Tells how other men have days will consume 18.6 K. Vi'. hours of trained in spare time and are now making attractive, steady electrical energ>- and at 10c per K. W. H. incomes. The book is free. Also a Personal Analysis which your bill for this lamp would be $1.86. will show just what qualifications you have. Send now. This is computed as follows : The 25 watt lamp would consume .025 K. \Y. H. per Be A Successful hour (25 -^ 1,000, as there are 1.000 watts per hour to 1 then K W. H.) ; .025 X 24 X 31 = 18.6 K, W. H, in 31 days. At 10c per K. W. H. the bill figures out at $1.86 Electrician (18.6 X $0.10 = $1.86). Electricity is a great and fascinating calling. It ie one of the great professions of the future. What Edison has done shows its PROCEEDINGS OF AMERICAN possibilities. Think of Dr. Steinmetz, once an immigrant without INSTITUTE OF ELECTRICAL friends or money, now consulting engineer for General Electric ENGINEERS. of And Prof. Pupin who got §250,000 for one electrical invention. All Partial List cannot rise like these men, but any man who knows electricity thor- (904.) .1. Ii. Cartinill. \\". Va.. wants to oughly has no limit upon him. The field is so large that there is a de- Subjects know : mand for trained men as inventors, engineers and experts in a score of Fundamental Principles of dilferent branches. Good wages made in ordinary electrical work. Q. 1. Where he can procure the Ameri- Electricity and Magnetism, Large sajaries paid to expert electrical engineers—and the chance to go into the can Institute of Electrical Engineers' pro- Dynamos, Motors, Lighting electrical contracting business. Get your training now. Here is the opportunity. Circuits, Power Circuits. Bell ceedings. Circuits and Wiring. Automo- bile Circuits. Wiring Buildings, A. 1. You may procure copies of the Electrical Signs. Burglar Complete Course By proceedings of the .'American Institute of Alarms. Ignition Systems. Me- ters, Storage Batteries, Lamps, Electrical Engineers by writing to the Sec- Equalizers, Con t rollers, Switch- retary. Mr. F. L, boards. Telegraphs.Telephones, Mail on Easy Terms Hutchinson, c/o the In- Telautographs. X-Rays, Trans- This stitute, 33 West 39th Street, New York formers. Calculating Wire important subject made clear. Personal instruction under Sizes, Electrical Heating, In- Prof. Albert Wood Wicks. E. E., one of America's well known electrical City, and the monthly Proceedings are stallation of Elect ricalSystems, experts. Learn while holding your present job. Earn money before you worth $1 a copy. Electrical Testing, llluminatinc finish the course. No advanced education required. The instruction Engineering, Maintenance of first starts with simple principles and take you through our course. _ Prepares you Electrical Apparatus, etc., etc. to start right. Take this course up now. Study at home in spare time. PHOTO-ELECTRIC CELLS. Send for Boole (905.) T. T. Gentry, Lexington, Ky„ and Personal Analysis asks Don't put this off. It costs nothing to get this infurniatiun and surely it will show you the way to a better future. Write for the Book and Personal Analysis now so you can find out what qualifi- cations ynu have. Today. WICKS ELECTRICAL INSTITUTE ligM royi 81 W. RandolDh Street Dept. 302 Cliicaao. Illinois PLUMBING AND HEATING l^Jr^^l^u SAVE 1/3 .^ ~- ^^ . ^ Goh onomerer Soit ira/er so/uf/on 6/ass YOU CAN INSTALL YOUR OWN PLUMBING AT LOW COST Bac/r pla/e (pol/shed) Get uur Handy Man Buok. Every home-Lwner needs it. Shows new home improvements and everj'thlng in guaranteed plumbing and heating supplies exclusively at wholesale a-)a' per/brafec/j prices. Any handy man can install with our free easy installing plans and instructions with the help of our service. Construction of Photo. Electric Cell. It Gen- CUT TO FIT HEATING PLANTS erates Electricity Light Strikes It. Our 40 years" experience enables us to furnish heating I'lants. OUT TO FIT, bathroom When lutflts, etc.. with new, original, easy installing featurfs. combining quality, economy, simplicity and ease of installation. Our $500,000 plants behind our guarantee. WRITE TODAY. Q, 1. How to construct a photo-electric THE HARDIN-LAVIN CO., 40 Years at 4541-51 Cottage Grove Ave., Chicago cell ? .A,. 1. Regarding the construction of light-sensitive copper oxid (photo-electric) THE "LITTLE PET'' cells, these are usually constructed of two thin copper plates immersed in a salt water IS unquestionably !/u- engine you solution, one of the plates (front one) be- have always wanted. Ideal to run ing blackened by oxidation over a gas or small electric power plants, for charging storage batteries, electro- other flame, and the other (back plate) re- plating for the laboratory, for the maining polished. A sensitive galvano- workshop, drive bench lathe, meter can be connected across the two grinder, saw. washing machine, plates, and when light is thrown on the etc. cell, the galvanometer will be deflected. Operates on either gaso- Refer to the September, 1916, issue of lene or City gas. this journal, page 316, where extensive Coil built into engine, countershaft and alt gears safely housed. Ready to run when you unpack ii, only technical data is given on such cells. In battery to be connected. Any speed from !;oo to 1400 R.P.M. can be had Instantly, while engine ii running. one type tried out and there described in Step on foot pedal to start engine. Automatic oiling, no grease cups, an ideal home motor safe and dependable, detail, the voltage produced in strong sun- will last for years. Cost to run ij^ cents per hour. Engine has 2" bore and 2" stroke. Gives over Yi H.P, Weight 60 lbs. light was 1/10 volt and the current about Send for free catalog £. 1 —2.000 ampere. This was with a small Price complete $33.00 El^GIN GAS MOTOR CO.. El^in, 111. cell having plates but 3 by 4 inches. It was found that if the cell was left short- -FOR ACTIVE SERVICE- circuited in the dark while not in use, the efficiency of the light reaction would then be greater upon exposure than when left open- ffl»©''VULCAN*'»E You beneiit by mentionino the "Electrical Experimenter" when writing to advertisers. " . —! Ma 1918 ELECTRICAL EXPERIMENTER 789 ARC LIGHTS VS. SERIES INCAN- NEW AUTOMATIC FIRE DE- DESCENT LAMPS. TECTOR. This new electric fire detector is a (907.) W. D , inquires: com- charges which pact little device to be used in either dwell- Q. 1. As to relative YOU MIND should be made for series incandescent ings, factories or warehouses, piers, etc., to lamps in place of arc lamps tor street give warning, by means of any alarms or lighting? WANDERER A. 1. In the first place, we cannot give you the exact data desired as we do not CONCENTKATION of mind, of tlTort. Is a great factor in your endeavor and one know the total watts consumed by the no can successfully concentrjte and apply series arc lamp men- 600 C. P. 4.4 ampere himself If his body Is not in perfect health. tioned. The mind would reflect the ailing condition of Figuring, however, on 70 volts per se- his body and Impair his ability. arc and with a current of 4.4 If yuu are only 50% of the man you ou«ht to tw; ries lamp if you have let your Titallty ebb away without culti- amperes you would obtain a total consump- vatlDK till- r».-S(turc«« wllhlri you; If you have let rour> atlf riHi tlumi ^lly9lcaUy until it affccta you mentally: arc. tion of 308 watts per y'»u iiave Ijec-ii neslcctful of your bodily needs. You The inverse ratio between the 100 watt well know that a weak deblliuted system affects tbe memory. Ueittroys your ambition, makes you unequal series incandescent lamp and the 308-watt to any taj«k and compela yoQ to drag alotiB tn a list- less fastiion. arc lamp is therefore 32.45 per cent, and I will ytur (the rate per put efflclenor up to Uie notch where it this percentage of 87.50 ousbt to be; no matter what your condiUoo now Is or annum for the arc) gives $28.42 per annum your position : I will makr- vou once more gain a keen, vivid relish for work and pleasure and enable as the equivalent rate which should be paid you to have such conirol of your mind that every lamp, sood thought. Instead of going to waste, you can for the 100 watt series incandescent cash in on. per k.w. considering the same base price I will make you vital, vigorous, snappy, energetic. M enthusiastic— ambitious: I will make you do more hour. wlLh less effort : I will make you feel the tingle of Speaking in a general way and without Simple Form of Electric Fire rich, red blood flowing in your veins; I will make you ilirill knowing any of the details governing the Detector Operating Upon the feel the of your nature and increase your Principle That Air, When life; I will make you splendidly healthy, strong, operating conditions of your local electric virile, physirally able, memally capable, better Ui Heated, Rapidly Expands. body, better in mind— all distresslna the results of youth- light company, we would advise that This Causes the Device to ful fi>lly will lit' nullified and will vanish. series incandescent will prove the least ex- Close an Alarm Circuit. to maintenance as pensive with regard I Will Revitalize, Rebuild You compared to the arc lights. It is our annunciator system to which it may be con- Through a Course of opinion that the method of computing the nected, of a fire in its early stages so that a equivalent rate to be paid by the city for fire extinguishing equipment can be brought incandescent series lamps as above out- into use before the fire passes beyond the lined is not fair in all cases, owing to the first critical few minutes. It gives an alarm jtrongfortism fact that the electric light company may in ten to thirty seconds; automatically ad- be operating under much less favorable justing itself to the usual changes of tem- It will regain for you the powers you lost, or attain conditions in your city as compared to the perature occurring within the enclosure in for you powers you never operating conditions in the other city svhich it is located. One detector will take possessed. It mil restore your vitality. It will make care of 300 to 500 square feet. The device you realize the life that is worth living. BAROMETER QUERY. is thoroly protected against injury by a guard, which is placed over the sensitive (908.1 Guy B. Admire. Missouri, asks: portions. I Guarantee Q. 1. See first experiment at Fig. 1, These detectors may be put in with one is the right ; a partial vacuum produced at or more on a circuit on their own independ- Results top of the tube. Say the atmospheric pres- ent system or they may be connected to the sure pressing raises the water in this down present call-bell system, or they may be So confident am 1. ihai tube 15 inches. But in the second experi- connected, by of an auxiliary fire-alarm I place myself under obli- use gation to produce or return ment there are 2 square inches instead of box, to tlie present fire alarm service in the your money. I guarantee to give you greater health and one; would it raise water 30 inches in this building. In private installations, the wir- strength and nervous energy tube ing is not influenced by regulations or un- and ambition and vitality. I guarantee promotion of a A. 1. In reply to your query concern- usual requirements ; the ordinary bell wir- healthier funciioning of all the organs of yotir body ing the height of a liquid in a barometer injury is ing properly protected against and the action of your brain tube, would say that this is a function sufficient, as only battery current is used, and that you will be more which depends upon the atmospheric pres- efficient, more capable, more or it may be installed with a complete sys- able in your work, I guar- sure and upon the density of the liquid in tem of aiuuiuciators and fire alarm bells, antee you more confidence In yourself, more ambltioD and dash and spirit and the barometer tube, and has nothing to do either with or without the wiring under more happiness. I guarantee you a cleaner, more whatsoever with the cross-sectional area be wholesome and a stronger body and clearer brain. 1 constant supervision. This system may guarantee to strengthen your heart, your bowels. of the tube itself. connected to any manual fire alarm system your stomach, sexual organs—all the muscles of your body, internal and external: to improve your by an auxiliary transmitting fire box. thus circulation, your lung capacity and your symmetry making the present system automatic. of figure. I guarantee that you will be refreshed, in- vigorated, energized and vitalized. Further. I guar- The detector consist of a hemispherical antee positively, that If after you have faithfully .^or.-jaj followed the Course and followed my Instructions, air reservoir, the flat side or top of which /acuum and find that no beneficial results have occurred, n is formed by a flexible diafram. This that I will refund in lull to you every cent of money that you paid to me for your Course. reservoir contains air at atmospheric pres- See Coupon —Check what aliment interests you ; sure and when the surrounding atmosphere Mail It to me and I will send a practical talk to n you about the disorder. It will not cost you anything quickly, the dome, rises in temperature and will put you on the right road. which is a rapid conductor, becomes heated Send 6 cents in stamps to cover mailing expenses and receive my book "INTELLIGENCE and expands the air in it, causing the dia- IN PHYSI- CAL AND HEALTH CULTURE". It is written for pressure fram to project outwardly and close an your interest ami welfare, electrical contact, which acts as a switch 2 i-^:« : l£^in closing the circuit of whatever fire alarm LIONEL STRONGFORT system it is connected with. To prevent Physical and Health Specialist false alarms being turned in by the natural md 465 Park Building Newark. N. J. changes of temperature within the enclosure Fig 2 r/ffi in which the detector is located, a com- Mr. Lionel SiJongfort. Sevark. .V. J. pensator is made part of the device. Sir : You may foncard vovr hook. "IXTELLtGBSCE Diagram Illustrating Querist's Problem, In IS PHYSICAL AXD HEALTH CVLTL'RB." I en Which He Asks If Greater Area at Base of dote 6 cents in ttampt for mailing rrpprwr. / marked Barometer Does Not Cause Greater Height NEW RADIO RECORD. X before the tubfect on tehieh I icould lik^ a praetieci of Liquid to Be Supported as Shown. talk. iS'< It is reported that just recently the Mar- Brunswick. ..Colds Neuritis .Constipation Heartweakness coni wireless plant at New . .Catarrh Neuralgia Biliousness Poor Circulation sea level the atmospheric pressure will At . .Asthma . Flat Chest .Torpid Liver Skin Disorders N. J., "picked up" a message from the support roughly about thirty inches of . Obesity Deformity . Indigestion Despondency Cavite naval base, on the Philippine Islands, . .Headache Insomnia .Nervousness . Round Shoulders mercurv or about 34 feet of water. . .Thinness . Im potency .Poor Memory Lung Troubles adjoining the city of Manila, a distance of ..Rupture ShortWInd .Rheumatism Increased Height 10,000 miles. But Tuckerton comes to the Flat Feet Vital Losses .Youthful-Errors Oevetopment A new pocket lamp, which carries its own front with a longer reach than that, the electric generating plant and requires no dry report being that several times this fall and battery renewals, remains lighted as long as winter, messages have been grasped out of the dynamo is kept in motion by a lever the air that were sent from New Zealand, operated by the thumb. just about the antipodes from us. Vou benefit bv menlioiiinf] the "Electrical Exferinutiter" nhcn nTtting to aJverliserr. . : : : 790 ELECTRICAL EXPERIMENTER M8 1918 Moore's Universal Assistant and Complete Mecbamc TELEPHONING TELEGRAMS. OOHTACTB 1016 PAOE3, 500 ENORAVmS, AJTD OVER 1,000.000 Conservation is the watchword of the Inddstrial Facts, CAix:uL4TioN3, Reckhtb^ well telephone com- Pboczsses, Trade Secrets, fob hour. Telegraph as as EVERY Business! panies are losing experts by the thousand.- to the United States Government, which rOB STEBLTNG VAlfE. ELEflAXCE. AND LOW COST, THIS WOBI IA8 !»• COSfEEU IN TUC ENULISU LA»eCAeE. has urgent need of their services. This has POSTPAID PRICE $2 00 resulted in many branch telegraph offices « for Oo. fltMffi. Cl»fl •a being placed in the hands of persons who Mo- FulMfUllilirlll mtajiKjr are not e.xpert telegraph operators. In olniTft kll»l.»PUiorcorVkJ . liiur«t •» the e.xample pliii"R^;bii^r Bafrt"«l WoQMJ, WIU*. Ltoli of im« U Acllou (or l«U, ai«i Unjrj Law* lOHNSON SMITH & CO.. Oept. 925 54 W. Lake St., CHICAGO A for Adams N for New York B for Boston O for Ocean MAGNETIC C for Chicago P for Peter RECTIFIER F-F BATTERY BOOSTER D for Denver Q for Queen Patented E for Edward R for Robert April iS 1916 Full Wave A. C. Rectifier F for Frank S for Sugar BE YOUR OWN SERVICE STATION G for George T for Thomas H for Henry U for Union For Public or Private Use I for Ida V for Victor The Booster can be carried to tlie battery wherever It Is the attachment plug 13 for John W for William located and Is ready to work when J most connected to a lighting or power circuit. It otters the K for King X for X Ray efficient aiid satisfactory means for chareing aU types of stor- age batteries where only alternating current is available. L for Lincoln Y for Young We furnish complete portable Charging Rheostat with am- for Mary Z for Zero meter and current regulator for service on D. C. circuits. M Example: If the name "B. C. Dvorak" $24 Complete, and up is to be transmitted, telephone employes F. O. B. Cleveland shall pronounce the name and then say "B THE FRANCE ;,MANUFACTURING CO., aeveland, Chi* for Boston" and pause, "C for Chicago" , and pause, "D for Denver," "V for Victor," J Ask your dealer or write for Bulletin No. 12 "O for Ocean," "R for Robert," "A for .\dams," "K for King." l^abiUm and Radioactive Substances FOR EXPERIMENTERS MARCONI PRAISES AMERICA. CarnOtite (Radium Mineral) The American Pitchblende found in Colorado, Senator Guglielmo Marconi, who has from which Radium is extracted. been appointed head of the Italian perman- conduct experiments, such as affecting photographic A generous piece, enough to ent mission in America, made the follow- plates thru opaque material (similar to X-Ray pictures), first made by Sir \\ . remarks recently in addressing the Crookes and Mme. Curie, is furnished in neat wooden box. ing Price of one specimen of Camotite as described above, sent prepaid $0.25 Carnotitt Italian senate on Italo-American relations used for above Sensitive, prepared Photographic film (X-Ray work Elm) to be "The Italian mission to the United States experiments furnished for $0.10 each extra^ a.gain realized during its journey the great Radium Very powerful! Brilliant S^abiUm— Radioactive Salts, containing one microgram pure friendship and sympathy existing there for darki white luminescence in the ,•• , , glass tube. l (protected/ . . j byi,„ us and the great assistance the United 10 Milligram of this most carefully prepared Radioactive Salts, sealed in are furnished. a metal container), with which everv Radium experiment can be conducted, States is ready to give us. Price of one tube of Radium Salts as described, sent prepaid $1.00 "The friendly feeling and concrete meas- contents of this tube can be mixed with special sulphides to form real Radium paint. The ures adopted by the American people in Small bottle of Special Sulphide with liquid adhesive, prepaid $0.51 Send for one of these preparations today. Stamps or coin accepted. favor of Italy deserve our entire gratitude. SIDNEY SPECIALTY CO. 233 S. FULTON ST. NEW YORK CITY We must consider the spontaneous .Ameri- can intervention in the war with special satisfaction." Sterling Electric Heating Pad Thii eirtplional pad helps make the eleclrieal bomfsale. reliable, alwaifs ready. CALIF. ELECTRIC PLANTS TO olA. heairy. It Ifl a welaome iiicceesor to that dlsairreffthle dhIsuw*, tin COMBINE. clmnay. hot water bag whli* needo consLam rsfllllng, may Wm n dli- charg* sealdlDg water and whleh "cooia off* Juat ai eoBfort c«nB«a. Representatives of electric light, heat and Th« Sterling pad wlni Qul«b friends bj Its good wort In all aillag wndlUoau Ijeneflted by the continuous appUoatlon of heat, auch u BpraJaa. twitbarh^ power plants serving 38 counties in north- cranips. chills, grippe, uneumonla. InBomnla. InflanunaOlvD. T^acl^ache. ueu- ern and central California have agreed to ralrla, rheumatism, poor clrcuiatloD. and mUBCular afOlctlMW from foot to head and from babyhood to old age. allow their electric generating plants, both It may be uied anywhere at any tlBM in th« heme, hotal m hospital. hydro-electric and steam, to be operated T^le Sterling pad la safe, cannot overheat and la mad* douMy dancaryrotrf by two most clever automatic th«rmoatata Independent of the heating ««K«r«l. under one head, it was announced recently. Tmi can pay more but you c«nnot buy more in a Heating pad. Fully P. M. Downing, chief engineer of the ffuaranteed. pr„ Literature and Siwcial Introductory Oflor. electrical department of the Pacific Gas and Agents Wanted In All Opep Twrltary. Electric company, it was announced, has THE STERLING ELECTRICAL CORPORATION, Chnrth AveDoe, C* West aaili Sired, OcTeUnd, Ohio, D. S. A been selected to have full charge of all of Branchea in parta the warld. all of the plants with authority to carry out their efficient operation with rigid economy of fuel oil. and to cease the operation of as Marko Storage Batteries many of the steam plants as may be found compatible with proper sen'ice. This plan is to be carried into force and jor all purposes where a high grade storage battery is required effect at once, and to continue for the dura- tion of the war and during such further PAUL M. MARKO CO. time as would be deemed in the best inter- The Mark O'Quality & \ T.^tt'i^i^'A.^.o^ ests of the public. I'ou benefit by mentioning the "Electrical Experimenter" when writing to advertisers. March. 1918 ELECTRICAL EXPERIMENTER 791 SUBSTITUTE FOR THE LE- CLANCHE CELL. According to the BuHctin de la Societe d' Encourayemcnt pour I'lndustrie Nation- ale. Prof. Fery describes a new type of wet primary cell that he has elaborated. The Leclanche cell, depolarized by manganese ELECTRICAL MACHINERY, by Terrell dioxid, is the most common type at the Croft. First Edition, cloth bound, 318 Prof. Fery conceived the pages present day. ; numerous illustrations ; 5}4 x iYi idea of doing without manganese dioxid and inches. Price $2.00. Publisht by Mc- depolarizing the cell with the oxygen of the Graw-Hill Book Co., New York, 1917. air. Hitherto, attempts in this direction had Another work from this author not met with much success owing to the zinc of practical electrical books and one that will be thoroly ap- electrode being vertical in position, giving preciated by the practical man. The manv chap- rise to certain disadvantages. ters and sub-divisions cover all phases of electrical machinery that one constantly overcome these defects, and use the comes in contact To with. Practical applications and theories have given air as the depolarizer. Prof Fery has been arranged side by side so that the student, to $150 MONTH as well as the advanced worker, PAY $100 the zinc electrode the form of a horizontal is able by means U. 8 GOVERNMENT WANTS ^^'Scnd of the diagrams and explanations to grasp the plate placed at the bottom of the cell. The Railway Marl Clerks—City Mall Car Coupon essentials of modern electrical practise. A com- riert — Poetofflce Clerks — Clerks Below is vertical, being separated carbon electrode prehensive idea of its scope may be gained from at Washlnoton. D. C. franklin lastitflle zinc a thin sheet of felt or an the following list of chapters: THOUSANDS MEN AND from the by Dcpt. MI03 Principles, Construction and Characteristics of WOMEN WANTED ebonite cross piece. Rochester. N. Y. Direct-Current Generators and Motors; Manage- Common education suffl ^^ filled out Local action in a cell of this type is prac- ment of Direct Current Generators, Starting and clent. Send coupon ^^^^ This coupon, u iminedlaiely. We "^^^^dlrected eutiiles the sender lo Controlling Devices for tically eliminated, and the quantity of zinc D. C. Motors; Troubles ooach candl- ^^^^^^^ 'i*^ sample examination Ques- and Testing of D. C. Generators and Motors; dates ^^^^ lions: (2) a free copy of our boot. dissolved is 1.24 grammes per ampere-hour. free Principles, Construction and Characteristics of ^^ -Government Positions and How to Get The voltage on open circuit is 1.18. Alternating Current Generators; Management of ^ Them"; (3) free list of positions now open, Genfcrators; Induction and ''and (4) to consideration for Frt-e Coaching Repulsion Motors; Syn- ^tfiT the pxamlnatlon luTf cht-ckfi. chronous Motors and Condensers; Management of ~ and Starting and COUPON'^ SUNDAYS AND THURSDAYS SET Controlling Devices for A. C. Railway Mall Clerk to SI 800 Motors; Troubles and Testing of A. C. Generators ..Postoffice Clerk $600 to SI 200' ASIDE AS "LIGHTLESS and Motors. . .Poitofflce Carrier S800 to $1200 A truly motor and generator book, and one . Rural Mall Carrier .... S500 to SI 200 Bookkeeper i$900SIOOO to &I800 NIGHTS." which will find a ready welcome by all electrical ..Customs Positions .... ($800 to SI 500 ..Internal Revenue r$700 to $1800 To further conserve coal and other fuels, ..Stenographer [SHOO to $1500. Administration, . Clerk in the Departments at the United States Fuel PERPETUAL MOTION, by Percy Ver- Washington [$1100 to $1500] amending its former orders permitting the ance. Cloth bound ; 360 pages ; illus- Name , restricted nightly operation of electric signs trated ; 5>4 x 8 inches. Price $2.00. Pub- Address M 103 displays, put into effect a and has now lisht by Enlightment Specialty Co., St. ^^^H Use this before you lose it. Write plainly, ^^^m schedule of "lightless nights" on Sunday Louis, Mo. and Thursday of each week. A very excellent work on Under the new order, it is forbidden to a much discust sub- GROUND ALMONDS ^i^.'/'lZ'/ ject. For centuries the struggle for the means consume coal, oil, gas or other fuel for Atnaiingly Prolific— Easily Grown Frsm'Seed I ---. of self-motive power has progrest and yet today Tt,.. r,r 'l ',:. 'fl.. tor th«t i« MOST EXCELM'M t--.-:iii.l illuminating or displaying advertisements, in the Twentieth Century we are as far as ever designat- away from the solution. of'"'tjro"n color. It k- notices, announcements or signs And aaylbiOR from '2<'- The numerous chapters cover a wide range, ing the location of an office or place of busi- giving data on most of the known attempts at ness, or the nature of any business, for elec- perpetual motion. The vast history of the sub- tric searchlights, or for external illumina- ject has been boiled down and a comprehensive Fly Plant I Weather Plant digest given, on the different methods by which Shoo tion for ornamentation of any building, or various scholars sought the solution to the prob- lights in the interior of stores, offices or lem. Also chapters on why the various devices other places of business when such stores failed Among some of the more important chap- ters may be noted the following: are not open for business, excepting such Devices intended to operate by means of lights as are necessary for the public safety Wheels and Weights; Devices employing Rolling JOHNSON. SMITH & CO., Dept. 92S, S4 W. Lake St.. Chicago Weights and Inclined Planes; Hydraulic or as are required by law : nor for excessive and Hydro-Mechanical Devices; Magnetic Devices; street lighting intended for display or ad- Liquid Air as a Means of Perpetual Motion; Radio vertising purposes, whether such lights are and Radio-Active Substances; List of Numerous maintained by the municipality or others. Inventors and Their Devices and a final chapter on whether the question will Dr. Garfield, Fuel Administrator, has also ever be answered, besides discussions and opinions of eminent scien- Treat Yourself requested that, in compliance with the pa- tists on the subject. WITH HEALTH GIVING triotic spirit of the order, householders A book for all interested in Mechanics, and those who have a strong mechanical bent. This shall observe the "lightless nights" by burn- book does not contain any new matter, but aims VIOLET RAY ing as few lights in homes as it is possible rathpr to orovide a fairly broad digest of th" principal perpetual motion schemes proposed from to get along with conveniently. Health time to time in the world's history. It will prove Electricity from your light transformed Into the I interesting reading for all those interested in the Sirpnolii^orket n L greatest healthgiving agency subject from the layman's viewpoint, the treat- Beauty science — Violet WIRES TO RUSSIA ARE SEVERED. ment kno«-n to being non-mathematical. Ray —powerfully effective, yet sooili- Ing and gentle In action: 110 volts Cable and telegraph lines to Russia have without the slightest shock: pleasant been cut, American Minister Morris, at RADIOTELEGRAPHY—War Depart- and perfectly safe. ment, Office of the Stockholm, reported on January 29th, and Chief Signal Officer, RenuLife Violet Ray the only remaining routes of communication Paper Covered, 6x9 inches, 135 pages, with Petrograd now are thru Persia and price 30 cents. Publisht by Government High Frequency Generator Vladivostok. The land telegraph lines were Printing Office, Washington, D. C, 1917. severed, Mr. Morris reported, at Haparanda tlie lowest priced, most very handy book and the cables at Viborg. He gave no in- A which should find a great TreaB effective instrument of many friends among radio men. Into this small significance. " the kind in the world. dication of the volume has been compiled all the chief points of radio equipment, formulas and calculations such Used and endorsed by as one expects to find only in a more expensive physicians and beauty book. BIG POWER PLANT AT NIAGARA can re- The work starts with the fundamental princi- specialists. Vou IS PROPOSED. ples of electric charges, static fields, currents, ceive the benefits in the magnetic fields, etc., and then branches out into privacy of your own power circuits, calculations Three bills designed to provide for the and the functions of only the various instruments, with many curves and II nntifj home, heretofore construction by the State of a hydro-electric illustrations which are of great help in mastering Skin Diiiaiii procurable through cost- plant on Goat Island, Niagara Falls, were the art. ^y treatments. introduced in the Legislature at Albany, on Considerable space is devoted to hook-ups of all ^EuTeu" standards sets as used by the U. Signal Write for particulars January 16th, by Senator Gibbs of Buffalo. S. Corps, with notes on gasoline motor sets and complete Co. Provision would be made for a bond issue operating instructions. RenuLife Electric 532 Marquette BIdg., Detroit, Mich. of $3,000,000 if the measure should be ap- Several chapters dealing with wave meters, tun- ing, damping and decrement are verv thoro, en- proved by the voters at the Fall election. >pre- abling the uiiinitiated to ^rasp the calculations of lentatlvea to demonatrat* to doc- As proposed by the bill, the plant would be radio quantities very readily. tors and Individuals. Earn $50 a operated either under State management or All in all it is a very handy manual, well worth H-eek up. We giro full Inatnictlons. the trifling sum asked for it and should Get our proposition. by lease, and would be capable of generat- find a ready demand from "Radio-bugs" as well as pro- ing 500,000 horse power. fessionals. You benefit by mentioning the "Electrical Experimenter" when writing to advertisers. — : 792 ELECTRICAL EXPERIMENTER March, 1918 EX.WIPLES IN BATTERY ENGINEER- program. Therefore, we cannot look to ING, by Prof, F. E. Austii:. Cloth stearfi to solve the power problem. Evi- bound, 5 x 7^"; pocket size; 90 pages. dently our only lasting salvation is in water Price $1.25. Publisht by the author at power. Hanover, N. H., 1917. "Water power can be divided into two zones : western and eastern. The bulk of Another very good book by Prof. Austin is this the eastern power is located at Niagara SCIENCE latest pocket manual on Battery Engineering. Falls, a potential possibility of Usually very little space is devoted to this impor- perhaps tant subject in electrical text-books and it is only 6,000,000 horse-power, 3,000,000 available touched on lightly. without affecting its scenic grandeur. We The increasing application of primary and stor- have heard the great exponents of western age cells and the greatly extended adaptations power proclaim if possible in the near future form valid reasons that there is a shortage why battery students and engineers should have of power in the east, come to the west, an adequate knowledge of the principles of "bat- where there are some 13,000,000 horse-powei tery engineering." undeveloped at the present time. This work covers all the working theories and The power could practical applications in a series of lessons cover- be developed at a cost to per ing the same in easy and gradual steps. The mit a selling price equivalent to Niagara importance of chemistry is treated on, as it has power some five or ten years ago. But is much to do with the final success of the materials located involved, etc. power so far from the industry's center Many practical formulas and examples are given of gravity cheap at any price? calculating internal resistance, heat losses, for "The electrochemical industries at Niag electro-motive-torce, amperage, efficiency. etc Various arrangements of battery circuits are also ara Falls consumed practically all of thi given. power developed on the American side (ap It is a good book for all electrical and radio proximately 250,000 horsepower) plus ap- students and is of particular interest now, espe- proximately 150,000 horsepower imported cially as storage batteries are being adopted more widely every day to automobiles, aeroplanes, sub- from Canada before the outbreak of the marines and radio equipments. war. Owing to the increased activities on the Canadian side, the Canadian government has found it necessary- to exercise certain NOVEL ELECTRIC TARGET. rights which it retained, and a great per- centage of the power coming to this coun- To enable a rifleman to see where his try from Canada has been cut off. The bullets go an Ohio inventor has designed industries, therefore, at the falls find them- a target which, when hit, extinguishes selves in the predicament of having installed light lights in front of it and shows a from equipment, but no power to operate it. It r^BOOK the back thru the bullet hole. is doubtful if at the present time 70 per cent of the installed equipment at Niagara Falls AVIATION is under power. In other words, the plants ON are not turning out as much today as they 3,000,000 H, P. AVAILABLE AT United States Government has were previous to the war. It was found THE for new NIAGARA WOULD appropriated $166,000,000 COAL. necessary in Buffalo, but 20 miles away, to airplanes. Tliousands of trained men SAVE build a steam plant of 120,000 horsepower. once trained in the Prin- are needed at —men This being a public service corporation, il ciples and Mechanics of Aviation—men who can {Continued from page 753) was necessary to produce power serve as airplane designers, builders, assemblers, regardless repairmen, mechanics, inspectors, contractors a large user of sulfuric acid, increased its of the cost, but when a mobile industry is heed the call? Our and instructors. Will you demand fifteen times normal since the be- affected, there is nothing for it to do bul book tells of these opportunities and is sent ginning of the war. move and this is happening. you free—prepaid. "Where will this important industry ob- "The best hydraulic talent in America ad Trained Men Needed at Once tain the power necessary to meet this vast vises us, that it is possible to develop ai The Curtiss Aeroplane Company expects to in- demand? Electric power enters into the Niagara Falls 3,000,000 horsepower withou: crease its working force from 7.000 to 20,000 men. The Standard Aero Corporation. PlainfleJd, New Jersey, cost of these products varying from two in the least affecting the scenic grandeur working night and and hundreds of other factories are per cent to 60 per cent. The cost of ferro of the most wonderful cataract in the world day to suppb" machines. The airplane companies need a half a million men right now. The demand ia tre- silicon, for example, is about 50 per cent By the proper location of submerged dams, ever to consider the wonderful mendous. Did you stop at the rapid deterioration of the possibilities offered ambitious men in the profession of power. Hence its cost must be kept a Horseshoe Aeronautics? This new billion dollar industry will soon minimum. It must be kept at a minimum Falls would be eliminated and the certain take its place along side of the auto- •••I Be a pioneer in are in direct competition with suicide of this wonderful cataract stopt. • ,^ mobile industry. because we •, this industry. Tou may be the fu- foreign countries where the governments V ture "Henry Fwd" of Aviation. "The crest of the Horseshoe Falls is mov- Aero National . « » *» r> insist on a complete development of the ing back at the rate of seven feet a year. Institute \ Send the Coupon water power resources and where real con- The length of the crest in 1842 was 2,030 Dept. B7443 \ Tust put your name and ad- structive legislation is used to aid the cause Morton Building \ dress in the coupon right now feet and now has increased to 3,020 feet. •• and receive our free book Chicago,r'k,:»'>nn rilinoisiiiinnic of conservation. Conservation by the way .,^ ^j^^, ^^ Science of Aria- The farther back the erosion goes the wiU tell you plank in a Gentlemen . —Please \ tion. We that is conservation, and not a more rapid it becomes. At the present rate, free •, how you can learn at •end me absolutely political platform. and prepaid your new *• home the Principlea of the Horseshoe Falls will be completely book on the Science of •• Aviation. Tear out the are but sources of power eliminated in the next two or three genera- *< mail at "There two Aviation : also particulars fo coupon and brfore this of- your mail course in the Prin- once— First, coal ; second, water. Daily we read tions and we will have nothing but a rapids Aviation and special fer Is withdrawn. ciples of headlines complaining of "shortage of fuel.' to replace the same. The installation of limited offer , Do— it right away \ N'OW. The most optimistic prognosticators tell us the above mentioned dams would then, *•, National Aero JVome. the mines will disgorge but little over their therefore, accomplish a double benefit ; that '•, lostitute Dept. B7443 usual amount this year. Decreased labor is, preserve the beauty of the falls to- \ MortoD Butltfiog supply is not the only cause of the shortage. gether with developing half of this potential \ Chicago. Illinois It is well known that every ton of steel power. Some have asked for the use of requires a ton of coal in its manufacture. water as limited by the Burton treaty, i. e., The production of steel is without prece- 36.000 cubic feet per second on the Canadian How to Make Money dent, and so its consumption of coal. Our side and 20.000 cubic feet per second on the mighty effort should be to prevent addi- .\merican side, but this is simply a drop with an OLIVER tional uses of coal and in fact diminish the in the bucket and would in no way affect the Many bo.vs pay for their own Oliver Type- domestic consumption in favor of the steel serious power shortage that now tends to writers by doing work for others. Easy to learn if it possible to obtain ruin ohe of our most promising industries One for school work—wins better marks. Then industry. Even were when you grow up typing is a decided advantage. coal at prices permitting steam-electric de- to say nothing of embarrassing our entire We send you an Oliver for five days' free trial velopments, the apparatus for this purpose manufacturing position. then you pay $3 per month If you keep it. You could not be obtained in less than three to "Engineers have calculated that to develop can earn more than it costs every year. Writ* to- day for our free trial blank, catalog and full par- four years. The war program of this coun- 3,000.000 horsepower at Niagara Falls would ticulars. Boys everywhere try is such that the total capacity of the save for posteritv- 100 tons of coal per X> are profiting by our liberal «\ manufacturers building this class of appa- minute or 52,000,000 tons of coal per year, liV plan- M^ ratus has been requisitioned for that length sufficient to change the situation from a THE OLIVER of time which may even be extended. The shortage to a surplus in the coal industry TYPEWRITER COMPANY shortage of power menace is with us now Furthermore, it would assist in the freight 673 Oliver Typewriter BIdg. Chicago. 111. and its solution must be obtained in far car shortage, releasing 62,000 cars for use Canadian Price, S62.65 less time than that to save us from a des- elsewhere, thereby changing the situation perate serious embarrassment of our war again from a shortage to a surplus," You bcitefit by mentioning the "Electrical Experimenter" ultcii uriting to advertisers. . March, 1918 ELECTRICAL EXPERIMENTER 793 CHEMICAL EXPERIMENTERS! No. 2115 Set of five Beakers $1.30 No. 2112 Erlenmeyer No. 2127 Desiccating Flask $0.30 Jar $1.30 Reagents and Chemicals lb. $0.^ Cupric Sulphate, tech lb. 0.' Ether Formaldehyde, tech. (Formalin Glycerine ch. pure lb. 0.' Hydrogen Peroxide, tech lb. 0.; iodine, Resublimed Iron Chloride (Ferric) Iron Sulphate, tech Lead Acetate, tech Lead Nitrate, tech Litmus Paper, blue Litmus Paper, red Manganese Dioxide, tech Mercuric Chloride The Livest Catalog in America' Our big. new c.vclopedia No. 19 is waiting for you. Positively the most complete Wireless and electrical catalog In print today. It contains the greatest chemical experimental assortment of any catalog in print. There are close to 20 pages, containing several hundred chemical apparatus such as Reagent Bottles, Crucibles, Water Bath, Tripods, Blow Pipes, Chemical Scales, Glass Retorts, Chemical Thermometers, Glass Rods, Beaker Glasses, Test Tubes, Funnels, Thistle Tubes, Desic- cating Jars, Wash Bottles, etc., etc. Also a complete line of Chemical Laboratories from $2.00 up to $90.00. Full line of popular chemicals as used by students. 228 Big Pages, 600 illustrations, 500 instruments and apparatus, etc. Big "Treatise on Wireless Te- legraphy." 20 FREE coupons for our 160-page FREE Wireless Course in 20 lessons. FREE Cyclo- pedia No. 19 measures 7x514". Weight J4 lb. Beau- tiful stifT covers. "The Livest Catalog in America" Now before you turn this page write ynur name and address on coupon below, cut or tear out, en- close 6 cts. stamps to cover mail charges, and the Cyclopedia Is yours by return mail. THE ELECTRO IMPORTING CO. |23I Fulton Street New York City||| Potassium Nitrate yi Ih. 0.65 Potassium Permanganate . 0.60 Silver Nitrate cryst 1.25 Sodium Hydroxide (caustic) 0.75 Sulphur (Brimstone) 0.25 Stannous Chloride (Tin) 0.75 No. 2171 Spring Zinc (Mossy) Metal lb. 0.80 H Pinch-Cock $0,20 The Electro Importing Company, 231 Fulton St., New York City. I enclose herewith 6 caM» In stamps or coin for Rblcli please send me jrour latest Cyclopedia Catalog No. 19 containing 228 pages. 600 lUustratiotis and diagrams Including TreatlBe on Wireless Telegraph;. Chenitstry Department, and 20 coupons for your 160 page Free Wireless Course in 20 lessons. NAME AI>DRRSS. STATE. YoH benefit by ttwutiouing the "Electrical Experimentc whe ziriting to adz'crtiscrs. « 794 ELECTRICAL EXPERIMENTER March. 1918 Edited by In this Department we publish such matter as ATTORNEYS those who are in doubt as to certain Patent Advice'* cannot be answered by mail free of ^W^f Invenf10x19 A^^nfed benefit of all readers. If the idea is thought to Tl:~'' 77 ^;'I rc-peat itseU in t3;e present War. The greatest victories witl divulge details, in order to protect the inventor be Will, nut through overpowcriiig iiumbe.s. but Uirough Uie surprise; Should advice be desired by mail a nominal wrought by inveotion. Life and property will be saved for the Nations h. Inveniious. The Government is rtadLv to exreriment with and carefu]!;- Sketches and descriptions must be clear and ex inventions which will aid in winaiug and consider any ending the War Lancaster ten on. The Special War Bulletin just off the press will give you a good idea of wiiat is ucedL'd. We will send it to you fr?e of charge. Located in Wash- & ington, we are in close touch with the proper Gorcmment Officials wh'' should be ap'Toached ^ith inventions fcr use in War time, and we wil: Allwine advise you fiiHy how the disclosure should be sent. Our cccperation with an inventor is. First, to help him establish hi=; rights before sending a sketch, drawing or model to any attorney; Second. 283 STARCHED CLOTHES SPRINKLER. to give a frank orinion whether it will pay to patent his idea, based up Submarines, torpedoes, liying machines, machine guns, immense howitzers, the British "tanks." and an untold number of other GAS STOVE. products of American brains, are dominant factors in the Great (205) Joseph F. Tucci, New York, N. Y., War. We are just starting, our—YOUR—ingenuity must lead to Victory has sent in a sketch of a gas stove, the Uncle Sam the whole civilized World is seeking ideas that will — — aid in the principle of which seems to lie in so-called fight. Can't you help with even ONE of thousands of simple things that will win recognition—perhaps fortune for you? forced draft, also making use of the prin- The need is for inventions of peace, too. Never before was there such a ciple of a Bunsen burner. This stove throws demand for new ideas of all kinds—never before have so many manufacturers, the heat out by means of a hood-shaped top. and other patent buirers, written me for good things protected by OVVEN which also serves the purpose to throw PATENTS. There is, to-day, a market for thousand.-" of ideas—including YOURS. Write for my free booklet and see—read for yourself the hundreds the heat forward instead of upward. The of requests recently received. inventor claims that he thus corrects the You incur no obligation by writing me. My advice costs nothing and I faults of present gas stoves. make no charge for an opinion aa to patentability of your idea If my A. This device appears quite plausible opinion is favorable I will back it up by a Guarantee Contract which protects on paper, but without having it tried out. -^ you fully. If you want to sell vour invention. I will help you and will f advertise it, free of charge, in "INVENTION AND MANUFACTURING." we are at a loss to know whether it will A simple request will bring to you at once, my four free books: —"SUC- actually work as described. We would ad- CESSFUL PATENTS," a 72 page guide telling how to proceed, gives refer- vise our correspondent to have a model ences, etc.; "STEPPING STONES" tells the truth about prizes for inven- tions, gives hundreds of hints of inventions made and if it works satisfactorily, to have wanted, etc ; "PATENT BUYERS" publishes over 400 requests of manufacturers and others who a search made for patentability. want OWEN PATENTS, together with ideas they want; "PATENT PRO- MOTION," tells you how to sell, why some inventors fail, discusses the value of your idea. etc. DOUBLE ENVELOPE. VWite for these books to-day. I will send you a signed agreement that (206) Williams E. King, Monesson, Pa., will protect you before you disclose your invention. submits a very ingenious and what he calls a double envelope, made from a single piece RICHARDB OWEN Paieui Lamyer of paper. The double envelope is supposed to be used for contributions in churches 164 Omen 31d Vou benefit by mentioning the "Electrical Experimenter" ulien Tvritinq to advertisers. March, 1918 ELECTRICAL EXPERIMENTER 795 ^^^^^r Your Ideas May Bring Wealth If Patented. H. GERNSBACK. ^^^^ 1^^^^ Always a Demand for Valuable Inventions. Now is the time to patent a mcriturluus invciuioti. \\ c are constantly is of interest to inventors and particularly to ^^^^^^fl^^^^^l receiving letters from manufacturers and investors who are interested Phases. Regular inquiries addrest to "Patent ^^^^^I^^^^^^H ^^^^^^^^^^^^^ in new devices and specialties that are protected by patents secured charge. Such inquiries are pubtisht here for the HumoT.ibort Mr. E. (hrough US, and can be turned into money through proper handling. be of importance, we make it a rule not to shortage of labor has increased a demand for inventions in all lines of manufacture as far as it is possible to do so. The and agriculture, and charge of $1.00 is made for each question, plicit. Only one side of sheet should be writ* Uncle Sam Wants New Inventions to Help Win the War You should write us today for a free copy of our 104-page book "How to Obtain a Patent and What to Invent," and should at the same time send us a sketch. model_or_ photograph with written description of your invention for our FREE OPINION AS TO PATENTABILITY know if such a device is of any value, and If your invention is paicnlablc. wc will send you our Certific.nc of Patentabiliiy. which of the conception of your invention and may prove of value and assistance if it could be patented. is evidence to you. Our Credit System will enable you to file your application and proceed with- idea is very clever and seems A. The out delay. Patents secured by us are advertised, at our expense, in Electrical Experi- quite feasible. We have seen a double menter Magazine. To protect yourself you should write for our free book and submit envelope before, but not made as described your Invention to us today. by our correspondent. We would for this TALBERT & TALBERT, a search in and other reasons recommend (Successors to Talbert & Parhe will the patent office ; any patent attorney 4287 Talbert be glad to conduct such a search at very Building Washington, D. C. low co>i. DYNAMO. Patents Julius Gemot, Maurer, N. has (207) J., PATENTS sent us sketches as well as description of a procured by a former Examining THAT PROTECT AND PAY dynamo armature, which he thinks will Official of the U. S. Patent Office, Advice Free save not alone an enormous amount of Books and Norman T. Whitaker, Attorney-at-Law If you waut to sell your patent, take It out throuKh my RESIJLTS energy, but will almost run free, thereby «nd Mechanical Engineer, 480 Whitaker office. HIGHEST REFERKNCES. BEST producing free energy ! His contention BIdg., Waihington, D. C. Inquiries invited. WATSON E. COLEMAN, Patent Lawyer seems to lie in the assumption that bringing 624 F. Street, N. W. Washington. D. C. the windings to a certain position on the outside of the armature, no power will be ^--^ Njv =». Z. ^ ^ ^- used in so transposing the windings. Our advice is asked. A. Our correspondent labors under a delusion, and his machine will certainly TENT5 WANTED not work as he states. It doesn't matter ^TRADEWARKSand COPYRIGHli^ if the winding of the armature is outside or inside, if current is produced he must var^esf I^ienl Firm have just so much energy to do it, and ihe World this energy cannot possibly be cut down. in J Our correspondent also seems to think that Before sendinft your invention to any attorney or it is the field coils which absorb the energy, K\\ manufaeturer or (liSLlo.sinc y"Ur '"mention write OF CUNCEITIO.N and for that reason, he suggests some for our tree blanli form I'ROOK in order to protect vour invention and secure your changes in the field coils as well. This, riKlits. This sliould be signed and witnessed and re* ttirned to us, locether witlt a model or alietcti and de- is however, not correct either, for the sim- scriiition of your invention, and we will give a !• iit-L If we ple reason that if you take a magneto which OPINION aa to the patentability of the invention. epnrt the invention patentable ve will funiish a Certilloate has no field coils it does not work any dif- of Patentability, ferent from a dynamo with field windings. This Certificate ot Patentalllllty, together with our hianli form SPECIAL^ proof Proof ot Conception will protect the Inventor and serve as If the magnetic Hux is cut by the windings until the case can be filed In the U. S. Patent OFFER ot the Invention Victor J. Eva of the armature, so much energy must be ifflce. supplied to the driving pulley in order to OBTAINING ASSISTANCE FOR INVENTORS-Our certificate is of great as- get so many watts. It doesn't matter how sistance to inventors wlio require financial aid to obtain patents the windings are arranged, and no matter / BOOKS MAILED FREE how efficiently they are disposed, the dif- OUR FIVE Coupon Br'.on) ,. ference in the power factor saved is very distribution. /(See- - address. Send for these books— the finest publications ever issued for free any small. WHAT TO INVENT HOW• TO OBTAIN A PATENT - --'- list of Inventions wanted and eishty-pane Guide Bo,,l( is a Honk Contains a valuable Our illustrated jrofltable fields of inventions; for inventors and contains 11)0 mechan- suggestions concerning of referencL" tor Inven- Tells how al.-o II i.Tiiiiitii II rcKard'ii.; prUes offered ical movements, illustrated and described. to invent for proat. tloni amounting to ONE |MILLION DOLLARS ELECTRIC NON-FREEZING i LIST OF PATENT BUYERS Contains requests from manufacturers, mail order liouses ana rromoters for DEVICE. tbej- wish to purchase. oalents secured bv us and sucgestlons as to New Ideas cliarge. have recently We place our clients in tnifli with capital tree of We iruni maiiufaclurers. (208) J. D. Browder, Jr., Canadian, received over 300 reduests Okla., has submitted an electric non-freez- MILLIONS IN TRADE-MARKS ing arrangement, whereby he uses a cer- Shows the value of Trade-Marks and information regard- tain number of thermostats which control ing unfair competition i A Sunday news- advertise Our Client!' Inventions Free in a list of \ a heating element of an automobile radi- We Progress. Sample papers, in nianufacturL^-s- journals and in World s palcnu. After ^ ator. The idea l)eing that as soon as tlic Copy Free. We save you time and money in se You benefit by tnentiotiintj the "Electrical Experimenter" when xvriting to advertisers. ; 796 ELECTRICAL EXPERIMENTER Ma 1918 THE THIRD LIBERTY LOAN AND .Mr. H. Gernsback, and this is shown YOU! schematically at Fig. 4-B. Three porcelain rolls are used in this scheme A. B and C INfVENTORS (Continued from page 751) The three rolls are geared to each other by means of gears secured to the shafts of turned into military or naval appliances each roll, but which are not shown for the almost over night The Army and Navy sake of clearness. A thin as well as flexible booths helped to tell the story of how elec- ^AMAZED! sheet of copper or aluminum foil as tricity was mobilized for the def»nse of the also a strip of flexible insulation, such as nation. oiled linen or oiled silk is secured to roller FREE BOOK With thousands of men and women, for- A at the left. These are also secured to / you who would like to in- merly employed in one form or another roller B as shown, and a second strip of vent something — you who of electrical occupation in civil life, trans- flexible metal foil makes connection to have Inventions in m!nd-- ferring their activities to the Government rollers and C. the adjustment you who have been dlsap- B When ~- pointed In vrtiir plea for service, it is hardly necessary to point out knob secured to the central roller B is wiU open a patent—write today for a book that the patriotism that has actuated this class turned, it unrolls the dielectric and one cop- 90 -page book. The most vour eves I My new of workers, .^s the war plans of the United per electrode from A, and also the second published for rree complete patent book ever States are developed and as more and more gradual A straightforward revelation of copper electrode from C, while a distribution. from valuable information. Altogether different places for electricians are made in the Army increasing condenser capacity is produced Free to the usual stuff sent out to Inventors. and the Navy, the men at home are hearing about the perifery of roller B. The arrows SendOCIIU a j»W3**-ai«.postcard. you.vou. the call. in the drawing indicate how the rollers turn when the central knob attached to B is Patent For those who are unable to offer their MyNewKind of rotated either to the right or to the left ' services to the country as electricians or fi • I entered the increasing or decreasing the capacity in field with electrical inventors or engineers, there still iJWlNprvirPTIVV' patent consequence. j[,g i^ga of giv- remains an opportunity to be patriotic. The superior service to inventors. ing a man who is not in service may act as an The diagram at Fig. 4-C shows how a My policy has won out big. My auxiliary to the man who is in the Navy or variable air dielectric condenser may hav< free book explains my personal 1 service to inventors. I do not the Army. How can he do this? Simply its capacity increased several fold by filling entrust your interests to as- by becoming a member of that great army its container with oil. One of the best oil- square advice on sistants. Fair, of "Liberty Loan" subscribers which has your ideas. to use for the purpose is castor oil, which Send Me Your Sketch or Model been growing steadily since last June. has a "K" value of approximately 5. Thus, me sketch. pliotoKraph or model of your iDven- Send wnal if the variable condenser with air dielectric tion for prompt report. Let me prove to you The Third Liberty Loan affords a chance service really meana. has a capacity of .001 m.f., when it has its a hlBh-class patent attorney for the electrician at home to stand by his GEORGE P. KIMMEL, Patent Lawyer container filled with castor oil, its capacit> Washington, D. C. associate under arms. The loan not only 88-C Oriental Building, will be increased to about .005 m.f. Thi^ will buy clothing and food for the man in property is use of considerably in the service, but will help to equip the submarine made laboratory, either for the purpose of in- chasers, the aero plants and the communica- creasing the capacity of the condenser or Book tion systems in which that associate of his "The for increasing the resistance between the is rendering expert help to the Government. the Inventor plates, and thus cutting down brush dis- Do the readers of The Electrical E.\- charges and other leakage, where it is de KEEPS" PERIMENTER realize that the Third Liberty sired to use such a condenser in experi Loan will pay for the Radio that binds to- mental Poulsen Arc circuits, etc. than .Ejether the hundreds of units in the Ameri- Worth more A special form of high capacity, small patent can fleet? Do they understand that the ill other size rotary variable condenser used by one aviator who flies over the Boche trenches books combined. of the leading commercial radio companies and communicates his discoveries to his FREE. in their receiving sets and measuring in- comrades by wireless is supplied with his Write struments, as well as wave meters, is shown outfit out of the Liberty Loan? His equip- in section at Fig. 5-A. This variable con- LACEY & LACEY (Co)itinued on page 798) denser has about five times the capacity of 131 Springer Bldg. an equal size air dielectric condenser, for WulHniton, D. C. the reason that it employs hard rubber as a EitaHllihad IM> dielectric instead of air. THE HOW AND WHY OF RADIO The stationary semi-circular plates are APPARATUS. Patent Secured or Fee covered with thin discs of hard rubber as illustrated, and the moving semi-circular (Continued from page 766) plates slide in between the hard rubber Keturned v "n t i o n f sow Several other forms of condenser are il- leaves in the usual manner. The reason for yearly. We help market yours lustrated in Fig. 4-A, B and C. That at A the greatly increased capacity of this type without cott. Our new book ii is the familiar rolled type of condenser. of condenser is due to the high specific in- Free. Send model or sketch for free opinion. These are formed of one or more dielectric ductivity of hard rubber, which is about 5 A. M. BUCK & CO. layers, made long with respect to their Another interesting form of condenser V& lii Naliinal Bank BU{., Vishiifioo, D. C. width, and which are suitably interleaved which has been used both in this country with two or more metal charging leaves and abroad to some extent, but which must Get up-to-date in House Wir- the whole is then rolled up and tightly built to reliable iNG ! Save Time. Monetv. be very accurately be and Labor and MATERiALby usinR Electricians our as Genuine Blue Print comprest after having been soaked in hot free from accidental short-circuits, is the Drawings, containing all the tfttest diatrrama and connections known in houoe wiring- - -esery diaexam paraffin wax. This gives a high capacity vertical, cylindrical plate condenser illus- and connection up-to-the-minut« as used by first class electricians for wlrinR Bells. Bukguar Alarus, Lights, Annunciators, Fire Alarms in a small space, and enables a large ca- trated in plan view at Figure 5-B. As be- and Electric Gas Lighting. These drawinirs are bound in the form of • flexible book i9 X 12) for convenience in using on the job. Send for pacity condenser to be quickly constructed. comes evident the central rotary knob and tbem, and if they don't make you mare efficient as a wireman and save 70a many times their coat aa a contractor, return tbem and money Substantial terminals for such a condenser shaft carries a suitable rigid member to will bo refunded--yoo can't afford to be without th^m. One Dollab D*flt paid. 9end for clrcatara oo other sets of drawlnsa. are formed of small copper strips about % which is fastened at either end a set of PATENT specialty COMPANY of an inch wide, which are wrapt in sev- properlj- spaced, cylindrically curved plates 462 Sanches Street San Francisco, Cal. eral turns of the tin-foil leaf at the end as which, as the knob is turned, intermesh with Fig. 4-A indicates; this junction may be the similarly curved stationary plates, and riveted. Where a fixt tin-foil and waxed thus increase the capacity of the condenser paper condenser is used, and there are a until they are moved thru 90 degrees. The large number of tin-foil tabs to be joined capacity is reduced by turning the knob so PATENTS together, a very efficient and substantial that the moving plates slide out from with- Send ma juu ideas. Mauufactureri want pitentA I connection is afforded by simply punching in the fixt plates. procure. Prompt, confidential, pergonal Mrrloe by soocesafol patout aiioruev with highest rflfaronoa*. or drilling a hole thru the tabs and passing Honeat It is often desirable in building wave advice and •'The Truth About Patenu" Fr«. a battery terminal screw thru the opening '«D Woodward Bldf.. meters and in certain forms of receiving JR K'FI I V formed and placing on either side of the sets to obtain an extra high variable ca- tin-foil tabs a piece of copper or brass pacity. A common method of accomplish- about yi inch square. When the nut on ing this result is indicated at Fig. 5-C. A LUMINOUS PAINT the screw is tightened up, the tin-foil con- small or medium size variable condenser Make Your Watches, Clocks, Etc., nections will be clamped firmly, and the con- VC, is connected in series with the circuit, necting wire from the circuit may be fast- HiUierto. prac- in shunt with this variable capacity . wc liave »t \»m\ and !cJcrl •UCd in producing thia rrmnrk.it^f.' 1 UMINd'us' I'AlNf. which,jvhich. appapplicf* to ened between two nuts on the screw or else '' "_ ''^*' .. ""''_ , "f^K"''',,.,._••"It* r«y»,, of_. whlla,..»..,li|tht. ri-ndcHriBJ,... , il,1 porf«Ctl»porf«ctlv ViBlbl* there is placed a group of small fixt con- I In the Jark. THE OARKCR THE NIGHT, THE MORE BRILLIANT IT SHINES. Cluite soldered to the screw as desired. •implo lo iiiir. Anyone — y Vou benefit by metttiouino the "Electrical Ext>trimeiiter" when writing to adl'ertiscrs. March, 1918 ELECTRICAL EXPERIMENTER 797 a metal sector as shown at Fig. 5 —C with a series of spring contact fingers. Thus sup- pose the variable condenser VC has a ca- pacity of .001 m.f., and that each one of the. live tixt capacities shown has a similar m.f! value. It is thus clear that we may now obtain any capacity from practically zero up to and including .006 m.f by in- VLf)t IreafeersJ termediate stages. The standard connections for both fixt and variable condensers are given at Fig. on the 6-A and B. A fixt condenser is usually connected in series with a detector as shown ocean front at Fig. 6-A, and is sometimes called the "stopping" condenser. The high resistance telephone receivers used with this circuit in connection with a crystal detector D, are frequently shunted across the fixt capacity as at Fig. 6-B. Either connection of the Atlantic City's Newest Fire-Proof Hotel telephone receivers serves equally well in a majority of cases, but if the capacity across ofifers unusual attractions during Autumn and Winter the 'phones is adjustable or variable, it is considered best practise to connect the Seasons. Luxurious lobbies, spacious verandas, restful sun 'phones across it instead of the detector, as parlors and superb music. A palatial residence for those considerable tuning can be done in this way and maximum strength of signal obtained. seeking rest and recreation. 6-B, a standard connec- Referring to Fig. American and European Plans tion of the variable condenser is across the secondary of the loose coupler LC. The Illustrated literature and terms mailed variable capacity thus shunted across the Garage with accommodations for chauffeurs. secondary not only permits the closed oscil- latory circuit to be adjusted to resonance with the open aerial circuit, but also per- mits a closeness of adjustment or tuning which the usual secondary inductance switch does not give. In any case the oscillations HOTEL MARTINIQUE set up in the secondary circuit by adjusting BROADWAY. 32D STREET, NEW YORK One Block from Pennsylvania Station. it to resonance with the aerial oscillatory circuit, overflow to the shunt detector Equally Convenient for circuit, where part of the current is recti- Amusements, Shopping or Business. fied by the crj-stal detector D. indicated in 157 Pleasant Roems, with Private Bath, the diagram, and is stored up in the fixt condenser. 'The charge which this fixt con- $2.50 PER DAY. denser accumulates during the time of a 257 Excellent Rooms, with Private Bath, single train or group of oscillations, dis- facing street, southern exposure, charges thru the high resistance telephone $3.00 PER DAY. receivers T, thus causing the diaframs of Also Attractive Rooms from $1.50. the 'phones to vibrate at a rate which cor- Moderate. responds to the spark frequency of the 400 Baths The Restaurant Prices Are Most station. transmitting SOO Rooms A new use for variable condensers is " MOMEYINIT" shown at Fig. 6-C. There are here used in THERE'S ^ the role of a capacity coupling between the closed oscillatory circuits. telegraphY^„8Si^ aerial and The hS^ilearn-— ^ diagram shown is that described and illus- — MORSE AND WIRE l-ESS£nf:_ trated in the latest edition of the "Naval Electrician's' Text-Book" by Captain Bul- lard, Volume 1. This arrangement of TEAOH VOURSEUF capacity coupling in the place of electro- in half the usual time, at trifling cost, with the coupling, is in prac- magnetic which used wonderful Automatic Transmitter. THE 0MNI6RAPH. tically all other receiving sets, is strongly Sends unlimited Morse or Continental messages, at any speed, just as an expert operator would. commended by the U. S. Navy experts, and is claimed to be equally efficient to any form Adopted by U. S. Gov't. 4 stylet. Catalogue (roe. of electro-magnetic coupling for short wave lengths, and to be very much higher OMNICRAPH MFG. CO. in efficiency for long wave lengths. In 39L Cortlandt St. New York this hook-up, devised by Dr. Louis Cohen, formerly of the Bureau of Standards Radio Laboratory, the primary circuit is tuned PURIFIER to the incoming wave length in the usual ELECTRIC WATER Brings ft CTTBtal Srrlnf to Frery Homo. manner. The secondary coil L-2 and con- Bettor than the Best Bottled Wfctar Without lt« Cost. Economy— Efflcl»ncy—Safi^. are resonant the same ^ ., ^ , « denser C-2 made to ' Some flrmi apond as much u Jl.800.00 per year "trying to get good drlnkln« wMor— wave length. The aerial circuit energy is Bottled water apoUi In 24 hour* being subject to a process of putrefaction, becomlaf transferred from the one circuit to the other stale and stagnant. STERLING ELECTRIC WATER PURIFIER by means of the two coupling condensers asurea a perpetual eupply of iparUlng. (Tyaial. clear, palatable. bealthfiU water af unquestioned purity . shown and which are secured to a common . . , Its natural action Is like strong aunllght, all germa are Wiled by It. nnnaiura) odon shaft, so that they are simultaneously ad- and colorB are removed. ImpurlUee are precipitated and the hardest water made soft. It Is Belf-9terlll2lng but may be readily cleaned- justed. These condensers are in no sense For Fartory. Theatre. Offlc*. Home. Elsewhere MtHiey 3ai^ftf» and Health Preserrert of the word tuning condensers, and do not Free Literature and Spclal Introductory Offer. Aflpnts Wanted In All Open Territory. vary the adjustments of either primary or THE STERLING ELECTRICAL CORPORATION. Church Av.-.. Cor. West 28th Strut. Cleveland. Ohio. U. S A. secondary oscillatory circuits. They are Branches Ln all parts of the world used for no other purpose than that of transferring electro-statically the energy in the aerial circuit and circulating thru induc- TYPEWRITER SENSATION tance L-1, thence to the closed circuit com- d»oOO A Month Buys prising inductance L-2 and variable capac- L. C. Smith ity C-2, across which is placed an adjust- «P«3 a Visible Writing able stopping condenser BC, crystal detector Perfect machines only of standard alM with keyl>oard of stAndard unUeraal arrangWB«!— has Backspacer—Tabulator— two color ribbon — Ball Bearing oonstrucUon -every oi^eratlng n. and high resistance telephones, "T. coDTsiil«io« Five Days' Free Trial. Fully guaranteed. Catalog and special price sant tree. (To be continued) H, A. SMITH, 738-231 North Fifth Avenue, CHICAGO. ILLINOIS You benetit by mentioning the "Electrical Experimenter" aJi.-n xiriting to advertisers. 798 ELECTRICAL EXPERIMENTER March, 1918 THE THIRD LIBERTY LOAN AND equipment. The Third Liberty Loan pro- YOU! vides these essentials. Thus the loan becomes the The Electrical Worker (Continued from page 796) immediate con- cern of eveo' man and boy in the electrical Needs This Tool For ment must be of the best. He must have industries and in the experimental labora- instruments and dynamos that are better tories. It is no question of Cutting Condenser Plates finance which than those of the German who is up in the has to do solely with the bankers or with air on the same kind of assignment. All the rich investors. Primarily it is a bank- Zip ! And you cut out a this requires money. That is where the ing matter : yes. and it concerns the mobil- condenser plate from plain American at home can co-operate with the ization of billions in credit. But it also is glass with this genuine man who used to work alongside him, and the personal affair of every one in the "Red Devil" Glass Cutter. who now takes his life in his hands to United States. search out the secrets of the enemy. Has manifold uses besides The First Liberty Loan was over-sub- The German scientists who turned their scribed fifty per cent., so that three billions —-handy in repairing win- thoughts toward war many years ago, de- were ofTered where two were asked for by dow and picture frames, vised weapons of destruction which they the Government. The Second Liberty Loan making table tops, lamp- were quick to bring into action in 1914. was for a minimum of three billions, but British and French intellect, which had not more than four a half shades, etc. and billions were been working in the same barbarous chan- subscribed. When the Third Liberty Loan GLASS nels as that of Germany, was forced to imi- is opened, what will CUTTERS the answer of the ''Red Devil" tate the enemy. It did not take many Nation be? Trade. Muk months for our Allies to catch on to this Cut more glass with less pres- new and appalling game. By this time they An order has restricted the lighting of sure and breakage than any have shown Germany how w-ell they have stores and restaurants learned the lesson she taught them in 1914. in Berlin to one-fifth other cutters. Used by all of the degree of The United States has been forced to go to illumination permitted up skilled glaziers. to December, 1916. the same school. Here it was only a ques- To be obtained from hardware tion of turning the unrivalled American dealers, or if not, send 10c for genius for industrial invention in the direc- sainple, style 024. tion of war. The nation has adjusted itself to battle conditions and will fight Germany, cutter booklet free Glasa bomb for bomb, gun for gun, mine for Important Notice to Subscribers mine, 'plane for 'plane, until the enemy lays Smith & Hemenway Co., Inc. down his arms and admits that he cannot 107 Coit Street Irvington, N. J. finish what he started out to do. Due to the congestion existing at the present time in all railroad movements, The best intellects of the nation, hitherto also on account of the fact that many train employed in the diverse industries of the clerks have gone to war, there is a con* NEW BOOK ON country, have been called into consultation gestion of mails all over the United States. by the Government. The Army and the It will happen that your magazine may be ROPE SPLICING Navy are getting the advantage of this "con- slow in reaching you, and this delay may Useful Knots, Hitches, Splices, etc. scription of brains," as the assemblage of be from a few days up to several weeks. How Different Knots fire IVIade and WtiatThey Are Used For inventors at the call of patriotism may be Kindly bear this in mind before sending INDISPENSABLE TO EVERY IWECHANIC AND RICCER called. The greatest minds may be diverted giv- in a complaint, as the magazine will surely PRICE A most practical handbook from private business in the laboratory and simple direc- reach you in due time. Only sifter not ing complete and directed toward the mobilization of the me- tion for n-.aking all the most having received a certain copy for a chanical forces of the nation ; the most useful knots, hitches, rig- period of three weeks should a complaint Over' skilled workers in all the electrical trades grinc splicps. etc. _ be sent in. lOO illustrations. All « may enlist in the Ordnance or the Signal ^y about wire rope ^fN You will confer a favor upon the pub- Corps ; every energy may be bent toward attachments. lash- wja, lishers not to write until this time has r.g, blocks, tackles. J^^'»' war; but unless the Third Liberty Loan is etc. y" Heraldic Knots ff J^ elapsed, thereby saving them a vast illustrated. Of Krent v.tIh? to VVl^ supported by the people as heartily as were rippers, c.impere. Sr^ amount of clerical labor. hanica. first two, all these efforts will be in vain. n Price 20 cents oostpaid, R the JOHMSON SMITH 8 CO., Oepl. 925. 54 W. Lake SI., Chicago Alen cannot fight without supplies and Attention Experimenters!! IkT LAST A NON-TECHNICAL MAGAZINE DEVOTED TO YOUR VOL. 2, NO. 1. JANUARY 1918 i\ OWN INTEREST. JUST CHUCK FULL OF THINGS ELECTRI- 10 Cents Dcr Copy $1.00 Per Ye«r X"^ CAL, CHEMICAL AND SCIENTIFIC, BESIDES ARTICLES FROM THE COLLECTORS WORLD, ABOUT STAMPS, COINS, MINER- THE SCIENTIFIC ALS AND OTHER CURIOUS THINGS, ALL WRITTEN IN A PLAIN INTERESTING MANNER, FULLY ILLUSTRATED. RESEARCH WUST think of getting a "Magazine" containing departments on "General 1 Articles." Under this heading all things of an experimental nature will be %^ discussed. The Dean of the United States College of Chemistry has an article A Non-Technical to appear in this department entitled a "A Course in General Analysis," which is Magazine devoted to alone worth 100 times the subscription price. Money making formulas, interest- the advancement of ing experiments, the latest news from the many Electrical and Chemical Labora- Electrical and Chem- tories, how to make Chemical and Electrical Apparatus, useful things of all kinds ical Research. and description, things you never saw before about Stamps, Coins and Minerals. An "Open Court" to which all subscribers may submit articles of interest to others, ask questions, etc. THIS NUMBER CONTAINS offer, to those THE FIRST OF A SERIES OF my ow FOR OUR very special limited ARTICLES ON CHEMICAL IXI WHO SEND IN THEIR SUBSCRIPTION AT ONCE, WE WILL ANALYSIS, WRITTEN ES- 1 ^ SEND YOU THIS SPLENDID MAGAZINE FOR SIX MONTHS PECIALLY FOR THIS MAGA- FOR 25c. THINK OF IT, ONLY 25c. COIN. NO STAMPS ACCEPTED. ZINE BY THE DEAN OF PRICE $1.00 PER YEAR. ADDRESS THE UNITED STATES COLLEGE REGULAR ORDERS TO OF CHEMISTRY. Zenith Chemical Laboratories - - Publishers DULUTH, MINNESOTA You benefit by mentioning the " Elcctrica! Experimenter" ttheti writing to advertisers. March, 1918 ELECTRICAL EXPERIMENTER 799 EXPERIMENTAL PHYSICS. aftect the plate or film is called the actinic (.Continued from page 760) power. Since all colors do not have the same actinic power, ordinary photographs comparing (a) and (b) in safe "red On do not have true color values. This effect Mesco Telegraph difference light" no will be apparent. One can be remedied by interposing color might hastily come to the wrong conclusion screens between the object photographed that light has no chemical effect silver on and the plate, thus reducing the sensitivity Practice Set bromid, but if now a few drops of a weak of the more actinic colors. A still better solution of amidol, eikonogen, pyrogallic way is to use orthochromatic plates. These For Learning Telegraph Codes acid, ortol, or of any other well known are treated with baths of certain dyes which are to of the test developer added each increase the sensitivity of silver bromid for tubes (a) and find that the (b) we (b), light of their own color. These plates, one which has been exposed to the light, however, have the disadavantage of being rapidly precipitates out fine black particles slower than ordinary plates. which gradually sink to the bottom. (See figure 56 (b).) Evidently the light has Experiment 65 : —The process of making done something to it. Actually the light photographs in Nature's own colors has caused the silver bromid to give off a slight been a problem of Physics rather than amount of bromin and percipitate out a Chemistry. There are several processes minute qiianity of silver. "Nascent silver" now in use for colored photography both (silver just formed) causes the hydrogen for "still" and "moving" pictures, all of in the "developer" to unite with the bromin which depend upon the same physical prin- The Practice Set comprises regular tele- of the silver bromid and thus leave the in- ciples of color. In lesson 10 we found that a graph key, without circuit breaker, a special soluble black silver particles. In the case ordinary white light is composed of violet, hign pitch buzzer, one cell Red Seal Dry of the ordinary "dry plate" or "film," silver indigo, blue, green, yellow, orange and red, Battery, and four feet of green silk covered flexible cord. bromid is mixed with gelatine (forming a and that if we mix these colors white light The key and buzzer are mounted on a more sensitive combination than the silver results. As a matter of fact if blue-violet highly finished wood base, and three nickel bromid alone, since the gelatine absorbs red, and green (three primary colors) are plated binding posts are so connected that the set may he used for five different the bromin given off) hence aiding the mixed white light results. pur- poses. liberation of bromin and the deposition of One may satisfy himself of this fact by List No. Price silver. The plates or films after being ex- dividing a circular piece of cardboard into 342 Telegraph Practice Set, with Bat- posed show no change to the eye but when tery and Cora $2.70 three equal parts, painting the segments placed in the developer, wherever there was with these three colors (see figure 58) and ibinalioo Practice S«l fii leiroiai (be Morsi most light there will be most action, hence .^"' revolving the circular disk rapidly by at- MESCO ConlineBla) Visoal and Asitible Cades most silver and hence the darkest part of taching to a small motor. Because of per- the "negative." Black objects, giving off no sistence of vision tlie three colors will strike light do not affect the negative and the the eye at apparently the same time and the negative stays transparent (white). disk will appear white. In the most suc- This is illustrated by figure 57. If I is cessful of color photograph processes, the photographed the negative will appear as in glass plate is covered with an e.xtremely fine II. Naturally one must remove the nega- layer of starch grains (almost microscopic tive from the developer as soon as a clear in size) some colored red, others green, and image is obtained otherwise the entire still others blue-vioIet, i.e., the primary amount of silver bromid would be decom- colors (see figure 59). The mixture ap- This »utflt li tht anlj rsUabl* Inilrument whleh will posed and a black plate would be obtained. pears to the eye as ivhite. Upon this mix- enabiB atudents te b»<«iDe proflclent operalori In tbt NsTal S«rTlc6. because It Is fr ing out the silver bromid by "hypo" (sodium tive immediately, the silver is dissolved out It It pocket ilze. contarni 2*8 >agM. with ov*r l.OM thiosulfate) and washing, thus leaving the and the silver bromid decomposed into sil- lllustratloni and describes In plain, clear langunge all abeut BelU. Push ButtonB. Batterlei. Talpphone negative with no more silver bromid to be ver. Therefore where light from a red and Telegraph Material. ElMtrle Toy*. Burglar and Fire Alarm Contrlvancas. El«ctrlo Call BrtU. EI*«trlo acted upon by the light. our image is particle struck the plate the silver bromid Now Alarm Clocks. Medical Batteries. Motor Boat Horiii. tixt permanently on the plate or film and was changed to silver, and then the silver Electrical ly Heatad Apparatus. Battery Conneoton. Switohn, Battery Gaugae. WIreleaa Telenrapti l>- can used for prints, enlarge- dissolved out. that the plate is transparent be making so itruments. Ignition Supplies, etc. ments, lantern slides, etc. and on looking thru it one sees the little starch grain. I'.c'.. the same color as the The process of making prints or positives Send for the Catalog Now object. The same holds true for the other is essentially the same as that of making two colors. On looking at the whole plate negatives. The negative is placed flat Manhattan Electrical after development and fixing processes simi- against the sensitized paper (paper with Supply Co., Inc. lar to those of black and white photography, silver bromid and gelatine or albumen) and the transmitted light will fuse the almost New York: Chicago: ST. LOUIS: exposed. Thus light will pass thru the 17 Park Place 114 S. Wella St. 1106 Pine St microscopic spots of color, and one sees the .light part of the negative and not thru the San Franolaoo Ofllee: 604 Ulsalao 8t image of the object in Nature's own colors. black part of the negative in varying de- grees, so that after developing the result is In motion picture work the same prin- really a negative of the negative film or ciple (primary colors) is used. The nega- plate. Referring to figure 57 we see that tives are taken alternately (on black and the negative of II (which is the negative of white film) thru red, green and blue-violet Automatic Repeating Rifle I) is I (which is the original) so that our screens, thus getting pictures of the red. Fires /" prints are e.xact copies of the original. green and blue-violet parts of the objects an on separate films. On projecting the films, 20 Shotsits in L E.vperimcnt 64 : —Different colors affect sil- a screen similar to the disk of figure 5S is >-- ver bromid in unequal degree. Blue and vio- One Loadingadine ^^ revolved in front of the film synchronous let have a very pronounced affect while red regular ;...- \i with the placing of the three films in po- This is a and orange have almost none. It is liecause autdmatic revolvL-r. sition, so that the film of the red parts ^ of this fact that the process of loading and Shoots B. B. shots ob- of the objects is projected thru the red unloading the camera and the process of tainable anywhere, screen and similarly for the others. By the rides and developing are carried out in red light. To same as other persistence of vision these are blended, thus guns. Repeats 20 times verify this, photograph various colored ob- giving the natural colors. This phase of with cno loading. Hand- jects or better still a spectrum (see lesson postod"^ motion pictures is still in the experimental somely finished in gun figure It will 10, 52). be noticed that red - or load necessar;. : ^ itage and a fortune awaits the one who metal. No caps appears black and blue white and the inter- with a sprin;; and shoots with rapiJity and ac- develops a good commercial method, mediates hues shade gradually from white curacy. Simply load with 20 B. B. shot, then especially a method making it possible to to light gray, then darker gray, etc., up to piess the trigger. Nothing to explode — abso- take motion pictures in artificial light. May harmless and safe. Remember, it is not black. If now a print is made of this lutely success reward the efforts of the conscien- mere toy, but the same size and shape as a negative the red end of the spectrum will be s tious workers in this field. REGULAR .\lTTOMATlC. Sent complete with a round of white and the blue end black with inter- thot for ONLY 25c i.ostraid mediate gray. The power of a light to (To be continued) JOHISON SMITH I CO., Olfl S2S. S4 W. LUt Si.. CMUfff Vou benefit by mentiouing the "Electrical Experimenter" when wrifinff to advertisers. 800 ELECTRICAL EXPERIMENTER March, 1918 VISITING ARLINGTON VIA THE meters. In some way or other we started TALC CLUB. to argue about the number of wires in the aerial, and I nearly bent double trying to {Continued from page 763) JKNAEi LEADER count them while "Woody" snapt a picture into the receiving room, and while watch- of me. 'Bet the fellows thought I would ing the outfit work we saw the chap out- topple over, but luckily my stabilizer was The Big Power Motor for Boys J side cut the other fellow off and start to working and I regained normal position A compact, highly effi- cient reversible motor, operate the relay by hand. Afterwards we again. The large aerials were pulled up by perfect in every detul. found out that the chap in question had the means of a steam roller and it was done by The reducing gear, eas- day before been on duty receiving and had pulling up about two hundred feet, and then ily adjusted, transforms taken his message from a boat, to be re- coming back for another hunk. Pieces of the high speed to more layed later on, and that the fellow who did wire lay around and we all brought back a power at slower speed. the sending at the time, made a mistake, so souvenir. This motor is guaran- teed by us to be exactly that was the reason for breaking into the The wires from the telegraph companie*- as represented. transmitting. Some stunt, say we. and Washington Observatory were con- Along about this time "noon" began to KNAPP "LEARNELECnUCS" nected in the receiving room, for it is, no Complete Electrical & Experimental Laboratory pay us a visit and, of course, great interest doubt, known that the time clock that closes $2.75 was taken in watching how the 100 K.W, the circuit for both Arlington and Key set was started up. One operator throws in AT ALL LIVE DEALERS West, Florida, is in the Observatory and a switch and the ammeter climbs to 300. and operates both stations simultaneously. Be- Inilflt oa your dealer showing you the KNAPP line— nothing happens ; then somebody else grabs KNAPP goods aj-e best. If your de&ler emnnet supplj yond this was a large room where there raa. order dire«t. Sand for FRBB Ulutratad catA- hold at last the outfit gets into and working were going to be kept various styles of re- (•fiifl tbowlKx a oompletfi Uii» of Hlectrical Motors and order, but it took five minutes to speed up NoTvltles ranging in yrlce fr«ni lOo up. ceiving sets and form a sort of museum and say, 42 cm, gun-fire has nothing on the KNAPP ELECTRIC & NOVELTY CO. while in one corner was a box full of Aud- noise from the spark when the key is prest. ions ; afterward I told "Dickey" that while 523 West 51st Street, N. Y. City One needs cotton in the ears, and then neither one of us would steal money the some, for when you stand ten feet away temptation to walk off with a couple of and attempt to talk, it's a case of yelling Build a Model of this Curli^s Mili- those bulbs was very strong and he cer- your head off, and ten to one the other tary Tractor used in the U. S. Army tainly agreed to the fact. It's a funny chap don't get you. It is claimed that the thing tho when you look right into it and 1 spark can be heard miles away on a two suppose it is born of the training that an night, of the operators told quiet and one -Amateur receives, namely, that radio sets us that when he goes to see his girl he need good detectors and also that every his let never needs watch to him know scrap of material must be saved in order to when it is ten o'clock. make new sets. "Woody" wanted to get a picture of the Our time was now getting short, so tak- back of the small switchboard, and as he ing a last look we beat it for the car which Build A owns a Graflex camera, we were afraid could be seen coming some distance away, that the noise of its going off would in- and upon arriving at the Monument, the Model War Aeroplane! form the operator who would, no doubt, lt'9 easj;! With "IDEAL" Accurate Scale Drawings and motion on the floor was carried and we Instructions you can build a 3-foot Model Aeroplane that looks demand the film, for at that time some like a real one and that will rise from the ttround by its own started skyward. "Woody" and "Mac" flower and fly 50 to 100 feet. It's great sport, and you can publishing company had bought the rights earn a lot about Aeroplanes and how they fly. Send for the walked up while "Dickey" and "yours truly" Drawings and Instructions for the one you want to balld. to take pictures, so there was nothing doing rode, but as it takes five minutes to travel Curtiss Military Tractor Wright Biplane in the line of amateur photography, but he the five hundred feet we had a nice rest Bleriol Monoplane 25c Corliss Hydroplane told me about his desire, and while he beats Nieuport Monoplane EACH Curtiss Flying Boa) and would have gone to sleep only at the it back of the board I motion "Mac" and Taabe Monoplane i8 for S1.75t Cecil Peoli Racer start the cables that held the car being so "IDEAL" Aeroplane Construction Outfits, "Dickey" to come over and talk to the op- containing all parts and material needed to long, the car oscillated up and down a few build these Aeroplane:^, are sold by Leading erator on duty real loud, thereby hoping to Toy, Sporting Goods and Department Stores.at inches and we thought something was go- $4.00 to $7,011. A-ikyourdeakT for "IDEAL" drown out the sound of Woody's "gun," for Aeroplane Construction Outfits Send for ing to happen. We could hear "Woody" Free List ot Stores which sell these Outfits. by the time the glass plate drops out of and "Mac" yelling as they climbed round Send 5c For This Catalogue the way and the shutter film moves over Tells about Model Aeroplanes and what you and round on their journey upward and need to build them with. 43 pajfes of U9 low price. We have only a limited quantity but air surrounding, Oh ! Boy ! we thought follow. tTailable at this price. Order yours to-day. of Home and Mother, and mutually dropt BODINE ELECTRIC CO. the subject. of St. Two the towers are four hundred feet 2254 W. Ohio Chicago, III. Attention ! ! Mr. Reader. high, and the other six hundred, so you see it would have been some climb, and besides Are a constant reader of this journal? powerful, permanent; lift YOU "***5"*^*-*>1\/lacmtf>fc ^'P* we all wanted to get back again the same about 3 lbs. Educational, use- There is no reason why you should not ful. Sent parcel post $1.00 each. day, for I guess that it would have at taken be—but every reason why you should be- least an hour to climb and do it without GENERA TORS come one, if you are not already. It is dropping on the way up. \\t> ulso have a mirnHer of high grade Holtzer only by persistent reading along certain Cabot Hand Generaton wliich we will dispoee There was a small aerial running from of at bargain i^rices. Give up to 110 volts, A. C. channels that really benefit. midway the highest pole to sta- definite YOU You can make direct and run by pulley If de- down &e sired. Special price $3.00 each. tion and this was used for six hundred The "E. E." brings a wide variety of sub- WATSON ELECTRIC CO. meter work, as the large antenna has a jects to your library table every month 124 S. Michigan Ave., Chicago natural period of about two thousand «rhich YOU cannot afford to miss. You benefit bv mentionina the "Electrical Experimenter" when writing to advertisers. ; — March, 1918 ELECTRICAL EXPERIMENTER 801 Reduction Metals. EXPERIMENTAL CHEMISTRY. of Experimenter's Special Bench Lathe iContiinu-d from page 780) Perhaps the most striking illustration of A Regular laths, not a toy of oxid, and then hung in a solution of a the reduction of metals by electrolysis is the strip of salt of the metal to be deposited ; a preparation of aluminum as it is now car- metal—gold, silver, or nickel— is sus- the ried on at Niagara Falls, where nearly in the solution as anode, to keep pended 5,000,000 kilos (1 kilo equals 2.2 lbs. ap- deteriorating. (See Fig. the bath from prox.) are annually produced by the famous For gold or silver the bath usually 106). Hall process. The principle involved is not EXPERIMENTERS: TMi Is Uke flrat contains potassium cyanid (KCN) together pr&ctlcaj lathe especlaUy designed for all dissimilar to those described above, the kinds of expeiimenUl work. With thla the salt of silver or gold with a little of greatest difference being in tlie solvent and lathe jou can make almost anything de- scribed In this magazine, whether It Is etc., forming a double cyanid (AgCN), the kind of electrodes. A large iron box In the "Const nict(/r" Department or (KCN. AgCN). The current employed is mix- "Hfjw-to-Make-It" Department. Par- is lined on the sides and bottom with a ticular uUf^tlon Is tabes or battery, called to the fact that cardboard furnished either from a dynamo ture of carbon and coal tar, which forms the can be wound nicely with wire by means of this lathe, and voltage according to the metal it can easily be driren by means Of a sewing machine or and varies in cathode (See Fig. 107). Large carbon ter- by a small electric motor. deposited. minals suspended from rods connected with Excellent for small wood turning, fibre taming, etc. Lathe is made from finest materials. Size sereoteeD Inches : In nickel plating By way of illustration tlie electric supply form the anode. The over all—swing 4 inches. U Inohes center to center. Bed IB machined and centers accurately: ihlDTiing weight Is 13 we begin with 5 volts, gradually decreasing consists at first of solid cryolit "bath" lbs. : price $4.50 cash with order. the current to 1 volt; for silver plating 3 (NajAIFe), or a mixture of cryolit and strength Sypher Manufacturing Co., Deparimeni C, Toledo, Ohio volts potential is employed with a tluorit (CaFa), which is put in at the bottom of 50 amperes per square meter of cathodic and around the terminals. When the cur- E. M. F. should surface ; in gold plating the rent is turned on the resistance to its not exceed 1 volt and the current strength passage by the cryolit fuses the latter, after 10 amperes per square meter of cathodic which the aluminum oxid (AUOs), specially surface. The time of immersion varies prepared from the mineral bauxit, impure according to the metal to be plated, the .\1 (OH)s, is fed in. It is first dissolved metal deposited, and the thickness of the \>y the molten cryolit, and then electrolyzed desired deposit. For nickel plating with a into oxygen and the metal aluminum. The The First Electrical Ra$x battery current, the time is from two to latter seeks the cathode at the bottom of six hours; for silver, from eight to twelve the bath where, at intervals, it is drawn off WITH this new Electrical Wonder you get the min- passes to the anode, some pleasant effect of a massage hours ; while gold requires but a few while the oxygen and a share at the same time. This razor is oo the market utes immersion. of it consuming, at the intense heat, part of and we are shipping all points in the United States Due to the tendency to peel, heavy plating the carbon and burning it to carbon mon- and South America. should be guarded against. Before such oxid and dioxid, which escape. This device can be used without electricity like the ordinary safety razors, but is supposed to be base metals as zinc, pewter, etc., can be used Many other metals are now reduced by with alternating current. The blade moves 7200 times silver, they are given plated with nickel or electric processes, as calcium, arsenic, phos- per minute and actually cuts the hair without pulling. object of Price 5io.oo. a light coating of copper, the phorus, and even iron. Calcium was a cabi- the which is to secure firm adhesion of net curiosity a few years ago, listed at Vibrating Electric Razor Co., Omaha, Neb. plating metal. SIO.OO a gram ; but now, owing to elec- Electrolysis. trolysis, sells at cents per kilo. It is quite ELECTRICAL possible that, some time in the future, iron rears fn the fandamentalo of Appli«?d tiectncity. "iTiE Bliss Ei-BCTS]- involve e(tuipi>t-d and Most electrochemical processes ores may be wholly reduced by electricity. CAI. School, with ii3 well sh^pg laboratones, ispecnliarlj «»ll Qokltf1«d to (Iva eond^n^td coura^^o ElecOical electrolysis, the simplest illustration of Many of these processes are electro- which is the separation of water into its ENGINEERING thermic, involving heat to a far greater de- elements. Water was stated to be a non- ifjcludinc Mathematicfl. Steatn and Gm En. gree than usual, electric furnaces being sub- >;irjL--i, Mechanical iTawingr Shop Work uid Theoretical and Fraclical Electucitj-. in kI) electrolyte ; it can, however, be electrolyzed stituted for the bath described above. The brancb«». Studenta actually ojustruct dra»- install wtrins t«9t efficiency of indirectly for an experiment as follows : a ID08, and heat in these furnaces runs as high as 3,500 electrical machineo'- Coare«, with diploma, small amount of sulfuric acid—which is an compli^te to 4.500 degrees. Moissan was the first, or electrolyte— is first mixed with the water, at least one of the first, to utilize the process IN ONE YEAR which is then poured into the electrolytic and invent a furnace, about 1890. This first apparatus and connected with the source attempt is illustrated in Fig. 108, and is a 260 Takoma Avenue, Washington, D. C. of electricity, which may be two or three general type of most electric furnaces. It is Daniell cells, these being the best for this about the same thing as an electric arc light o ; or it be connected, using a purpose may placed horizontally and inclosed. Intense R motor-generator, with a street current. A heat generated between the carbon terminals D motor generator giving a maximum voltage ' or electrodes by the passage of a current is E of 15 and an amperage of 15 is of sufficient -> made use of to melt, to vaporize, to reduce ijp I R size. The electrolytic tubes should prefer- or to combine substances. Refractory ele- Cash with order buys thi* ably graduated. When the current is be ments like platinum, gold, copper, silicon BENCH LATHE N turned on it will be noticed that the gases carbon are fused and even vaporized. O and Swing 3 to. 81d. C. to C. Shipping Wt.IO Lba collect unequally, about twice as much at In this furnace Moissan made minute dia- P«tef Austin 910 W.nrst E E. Muncle i^^. W the cathode as at the anode. A slight vari- monds from ordinary black carbon, the dia- ation is due to the greater solubility of mond being an allotropic form of carbon SMALL ENGINES oxygen than of hydrogen in water. After on Carbon). The substance to (see lesson Perfected Gasoline Engines H, 1 and running the current for a while, with a be acted on, usually in the form of a pow- 1 1.^ h.p.—for Farm and Shop use. Pria Also lighted splint test the gases which escape. der, is put into the central open space be- $19.50 and up. Hydrogen collects at the cathode and oxy- tween the terminals, the space closed, and WASHING MACHINES trial. Send (or Booklel end Special OHe' gen at the anode. the current introduced. We $hlp on SieTtrkropp Engine Co, 1401 19lh Street Primarily it is the acid that is electro- Racine. Wis. Starter for Ford Cars + + Carborundum. lyzed. The solution first contains HH ions This product, next to the diamond, is the Feldman's "Geyser" and was prepared and SO* ions. When the current passes, hardest substance known, Electric Water Heater by Acheson, but its chemical properties were + + InMtantaneout Hot Water HH ions become H: molecules at the investigated by Miilhauser in 1892. It is cathode and rise thru the liquid. The SO* now made by million of kilos (1 kilo equals FELDMAN MFG. CO. ions at the anode become SO< radicals and 2.2 pounds, approx.) annually. Its manu- Bldg. New York City break down into SOa and O. The oxygen facture involved a very simple process, a 1514 Times rises as a gas thru the water, the SOs (be- reaction of silica (SiO=) and carbon, the Your Own Cards, unites firvulars-label.hiHjk.papor. ing the anhydrid of sulfuric acid) latter combining with both silicon and oxy- PrintsIs8. PBESS. L»rg».rRU. Ro. with forms which is again big HjO and HiSO., gen. tao'STO. Save money. Print for others, + -\' 4- Sic 2 pnntit. .\lleasv. ml'»>8 wnt. Write factorr SiO, 3C = -h CO TYPE, paper, cards. again for catalog presses, ionized into HH and SO* ions, to Carbon monoxid (CO) escapes thru the THE PRESS CO., 0-47 Itortdea, CoBik go thru the same process. Thus the end loose openings and burns, with the charac- products are hydrogen and oxygen, and the teristic blue flame, to carbon dioxid (COO water indirectly has been electrolyzed. The -5-1 FREE on reaching the air. The carborundum PPl BOOK ON AVIATION acid remains unchanged in quantity but it - .1.,. ii.'9 new the core of the ter- j;r.-..t iipiortuTini-^ in (SiC) is left around netxled is really tlie acid that carries the current. ;;niu*tr\ . Tnousiin.ls t-f m.'n at once crystalin, iridescent , -frtfltook toH« how. Write In electroylsis all salts in solution minals as a beautiful, the of -0 INSTITUTE. Dt»t 9443 MarttaSI*!- Cfc*eat» water plays an important part. lustrous, metallic lookine sub.stance. Cxf^enmentrr'- uhen writing tn advertisers. Yon benefit by mentioning the "Elcctrtca! 802 ELECTRICAL EXPERIMENTER March, 1918 The furnace is E^™?™"^ about 5 meters long, 2 existence of the Falls, and Congress has PRACTICAL meters wide, and 1J4 meters high, built now past a law limiting the use of the water. ELECTRICAL loosely of uncemented fire brick, and is dis- The electric current is carried for great EDUCATION mantled at the end of each run. The car- distances, even running street cars 100 miles bons are 8 cm. in diameter and 60 cm. long, away. We leai?h by practical work and approved scientific methrxU Prac- arranged in two bundles of about 60 carbons Utilizing the energy of falling water—in- tical Applied Electricity in one each. The charge contains coke. directly year. Commercial Engineering in 34.2% the radiant energj' of the sun—be- iwo years and Electrical Engineer- 54.2% sand, and 9.9% sawdust, and 1.7% gun at Niagara, is now carried on at other ing in three years. Short Trade chlorid Course gires you big advantage If sodium (common salt), the total places where cataracts have been provided drafted. Part time emplo>Tnent weight amounting to 10 metric tons. The by nature. The recent utilization secured for students and positions guaranteed to icrad- of nature's uates. New Term Opens April 2nd. Write for free conversion takes about 36 hours and pro- forces has enormously stimulated chemical Ulttstrated catalog. Mention age, education and course duces about 2 tons. The core consists industries interested in. and led to many discoveries of mainly of grafite around which is a layer Home Study Course—If you canuoi come to tis. or do new chemical processes ; for of all agents, to occupation, we will not want give up your present of the crvstallin carborundum, some 45 cm. electricity best lends itself furnish you by mail at small cost our theoretical courBe. to the generation Will deduct all payinenla made wben ready to enter thick. of other forms of energy. In Canada, our school at Milwaukee. Get full partioulars. Carborundum is used in all sorts of Switzerland, Brazil and other countries, SCHOOL OF ENGINEERING OF MILWAUKEE. abrasive work from the polishing of granite great waterfalls 29-373 Broadway. Milwaukee. Wisconsin. are utilized in this way. It to dentistry, taking the place formerly oc- is even proposed to carrj- the electric cur- cupied by emery and corundum. Acids have rent from the falls of Zambesi in Africa to no effect on it Witwatersrand, a distance of 600 miles, {To RADIO OPERATORS NEEDED Calcium Carbid.— (CaCj) be continued) Govemment Service Merchant MArlne A substance which seems liable to revolu- tionize gas lighting is one of the largest Special course for men subject to furnace products. Slaked lime (CaO) and PRESIDENT'S SPEECH TO WORLD draft. coke (C) are mixed and put into an elec- VIA CABLE AND RADIO. Complete course of inatniction under tric furnace, the terminals in which are, as expert teachers in shortest possible time. (Continued from page 742) usual, carbon. A temperature of 3,300 de- Special Classes for Women grees is obtained, at which the lime melts and thence to India and the East Indies. Complete Equipment—Low Rates—Indi- and the carbon reacts with it, combining Another cable route %ridual Instruction — Rapid Progress — extends from Durban, Dormitories—Employment Bureau. with both calcium and oxygen, the latter on the east coast of Africa, to Mauritius START TODAY forming carbon monoxid and carbon dioxid Island, thence to Cocos Island, to Java and escaping. The calcium carbid is at first the west coast of Write (or Illustrated Booklet. Australia, landing at liquid at the high temperature, then is ob- Perth. New Zealand received the message Y. M. C. A. RADIO SCHOOL tained in lumps of gray, earthy appearance. via the Vancouver cable route. One of the longest straight, uninterrupted 145 E. 86th Street, New York, N. Y. CaO -f- 3C = CaC, + CO cable routes is that from San Francisco to BEST RADIO SCHOOL IN NEW YORK The process was invented by Moissan and the Philippine Islands, via Honolulu, T. H., also W'illson, the carbid having been acci- Midway Island and Guam. dently discovered in 1894 by Moissan. BORE HOLES QUICKER Alaska, too, read President Wilson's <^ When calcium carbid is thrown into water - ^^ and with lees memorable speech, thanks to the cable run- elbow greaae. Vmo it reacts violently with it, liberating the gas the Busby Extension ning from Seattle to Valdez via Sitka, Brace. A perfect acetj'lene, which burns with a brilliant white Drill Over snow-clad mountains and valleys the comer brace, eitonsion flame familiar to most readers, uniform chuck, and breast drill In one tooL Instantly ad- message leaped along telegraph wires to lengths and speeds. Chuck holds round thruout, entirely devoid of the non-luminous justed to variotis the farthermost telegraph city and sQuare shank drills and bits. Often pays for itself in parts of the ordinary gas flame. in this part one Job. Special Price, $3.60 Prepaid of the world St, Michael, on Norton Via insured Parcel Post — CaC= -f- 2H=0 = Ca(0H)2 C=H= Thousands In use. Sold on money-back guarantee. Send -f Sound, It swept across Norton Sound with check or money order for one TO- PAY. Start NOW to H,C2 +50 = H.O + 2 CO the speed of lightning, same time and strength—they're valuable. thanks to the wire- HOWARD R. SMITH. 234 Harrison St.. Nutiay. N. J. Acetj'lene is much in use for lighting less system operating between St. Michael headlights on automobiles, but is being and Nome. This wireless link, belonging gradually superseded by the electric lights to the U. S. Government, is of considerable to a very marked It is LEARN DRAFTSMANSHIP degree. also used in historic interest, as it was first built by many places for lighting fiend for free Test Lesson and valuable information streets and houses, the well-known American radio pioneer. Dr. nw>k|^|-i on Draftsmanship. Leam how you the gas being liberated in small definite Lee de Forest, in the early days of Radio. '^^^ master it at home in leisure time. I* |\tt quantities by water trickling on the carbid. Another frigid clime territory that has Easy terms. Unusual opportunities It burns with a verj' smoky flame unless cable connection with the world, but not LiUUiJUilI F>\llnl now. due to war. Draftsmen earn S25 to gioo a week. Write today. used in a special burner. Being an endo- shown on the ordinary map, is Iceland. A CHICAGO TECHNICAL COLLEGE thermic compound, acetylene easily explodes telegraph line runs across Iceland and its 345 Chicago "Tech" BIdg. Chicago when under great pressure, dissociating into cable route is via Shetland Islands, south- its two elements. It is non-poisonous. ward to Scotland. The preparation of caustic soda by elec- Coming back to the Atlantic Ocean we trolj-sis was taken up in the Lesson on Sodi- find that at present the direct German cables WIRELESS um and Potassium Hydroxid, and little from New York have been cut. These used Th« GoTernment now urgently needs radio men more need be said here about this process. to land at Emden and ran via the Azores, for the Naval Reserve, ATiation and Sl^al which Corps. Our Special short code courses. Day CHEMICAL tiny spots of land, far out in the or Irenlne. prepares you quickly for Govern- UTILIZATION OF SUN'S broad Atlantic, serve join RAYS. to together many ment Service. Students admitted any time. of the most important, long distance cables Send for LATEST prospectus, jtiat out. That these electrochemical industries, and of the w-estern hemisphere, as a glance at EASTERN RADIO INSTITUTE 119 B Beylston St. Boston. Mu8. inany others that might have been men- the map shows. tioned, have centered near Niagara Falls is It has been said that, after the war, the due to the drop of ISO feet or more of the United States and Canada will have an THE MIDGET SLIDE RULE vast body of water of the Niagara River. open in establishing will add. subtract, multiply, dl- sesame trade connec- Tlde: solve problems Involving even For ages all the tremendous energy of this tions with the South American countries. and tmeven roots and powers. Also gigantic falls give* the logarithms of numbers was wasted. A few years ago This presumption has often been based on and the Sines and Cosines, Tan- the idea was conceived of turning a small the mistaken belief that the European coun- fents and Cotangents of all angles, ta operatlMi Is very simple: quick- portion of the water into a canal, a mile or tries would have to send all cable messages ly solves any mathematical prob- so back from the main falls, making an arti- via York, and thence to lem. Durably made of metaL Adapt- New South ed for shop and office use. Pltj ficial drop, by excavation in the earth by the America, via the New York direct cable to the Pocket 3% Inches diameter. side of the river. Price vrith Instructions $1.00 Machinery- was installed, Colon, etc. In this way it was thought that, Your money bark if you are not nalisfied. the water conducted vertically downward perchance, the American merchants would Gikta Sfide Rule Co, ^f3es, Mich. thru penstocks, and turbines placed at the get the tips on commercial deals and beat bottorn, which the 25 meters of falling water the Europeans to it—or at least give them Prepare at once with its enormous - energy set in motion. a run for their money. This is where many to serve w TELEGRAPHY is This energy communicated to the surface people deceive themselves, for there is On land or sea, io army. navy, telegraph or railroad compaoy, by revolving shafts and there used to drive multiple cable service to Pernambuco, S. A., merchant marine or aviation service. Cours-s under tuper- powerful electric dynamos. fiaon of chief instraclors From Marconi Co. and Western The water is via Cape Verde Island, to Lisbon and Udiod Telegraph Co. discharged by a subterranean passage below Cadiz, thence to London, Marseilles, Aden, Landlinc or Radio Complete at the Falls (See Fig. 109). It was a magnifi- and the Far East; not to mention the other EASTERN DISTRICT Y. M. C. A. cent scheme, the immediate success of which ambitious empires in northern Europe, all Marcy Ave., near Broadway BROOKLYN was so great that new companies were of which are plentifully supplied with cable Send for folder F formed—so many as to threaten the very and telegraph connections. ou ) benefit by mcntioninp the "Electrical Rxt Ma 1918 ELECTRICAL EXPERIMENTER 803 CAN ELECTRICITY DESTROY Ingals and I discust the problem for Instructive CHARTS GRAVITATION? hours, but could come to no agreement. REE! The National Geological Society had al- 22 inDruglessHealing { Cdnliiiiicd from pa(jc 743) ready declared the cause to be a volcanic . h' Learn It h' (having practically no mass) rested upon crevasse of prehistoric origin, a layer above by mail vonced education necr^dary. insulators. They were separated from the which had given way beneath the city and Our method mak'^evL-rythintr protective screen by sheets of glass and dropt it to a great depth. I accepted the plain for you. Chirouraclom now in demand. Some of our were grounded to it by heavy copper wires. Society's solution as the only reasonable graduates report makiti tZ.OOO a year or more. The metal boxes were then charged in one, but Ingals scoffed at it. $3,000 to SS.OOO YMrl: every way that the solid lead spheres had "The Mars fever has gone to your brain," You too.caneom m eood iocom«, havo your own ofQc«a, your own These Charts are a slightest change in the I told in been, but not the him one of our disputes. "Sup- noun, be yoor OWA employer In big help in showing this foAclnatinr profcsaioo of how to make Spinal position of the suspended balls could be posing they could have slipt thru the V- drutrlrKe hi-altnir by Bt>inal ad. JuHtrncnt. Wttto for {tc« book Ad)ustment for r«* detected. This would seem to prove con- plane blockade— an obviously absurd prop- which Hhown yoti evcrythinir. lief of Toconvidfi^you quickly we offirr. Calarrfi Haadacha clusively that the "repulsion" and "gravi- osition—why didn't someone see them com- FREE. a*16w.-t of 8 colored An- Epilapay Neuralsta atumical Charta and S16.GO act Favar* Conattpatloe tational nullification" effects that he had ing or going? And why didn't the selenoid of N(.TV(.-, I'ain Arnu and Conctia- Paralyal* IndlKaatlon aionChartft '22chartRin aU). Thia Plaurlay Nauritia produced when the solid large balls were towers indicate their approach ? I suppose U Uk- chancL" you've bL-en looklnir AaUima Dyapapalt and f'lr— the otii>ortunity y.ur iitnt.l- Lumbafo Rhaumatlaat electrically charged, were genuine you know that the plates in those towers Jaundice Cout, ate. based undoubtedly on a true interatomic will record anything coming towards the AMeillCAH UNIVESSITT. Manerre Buililint. Oepl. 18? Ch fodj U ' U» |^a^ the large masses, see Fig. 4, with the result descent." that the gravitational attraction was quickly Ingals was right. Barely eight days after reduced to zero, and not onlj- that but in the complete obliteration of America's third 15 to 20 minutes the small lead spheres largest city, there came hurtling thru the had moved away over one-half as much to air the gripping news of the destruction of the opposite direction^eis the distance they Ramillon, the proud capital city of Mercun.'. nrHEB Mrc. co. had been attracted originally towards the The need for theorizing was gone. The 186 Marren Street large masses. Thus gravitation had not Martians had plainly broken thru the ap- TuLEOO, OHIO only been completely nullified, but it was parently impenetrable blockade and were actually reversed. again wantonly on the rampage. But how? we asked ourselves desperately. What un- DUCK'S BIG 300 pp. ELECTRICAL known force had blood-reddened Mars un- and WIRELESS CATALOG AT WAR WITH THE INVISIBLE. leashed, that could reach across the in- calculable space, unseen and unheard, and, Eblailfld upon receipt of So In suaps {Continued from page 759) or LX>ln which may b« deducted on more omniscient than lightning, select its Qrst dollar purchase. Catalog aeti- wlrelesa instru- I had the eerie feeling of one who be- taJns 160 pages of victims at will? ments aiid 140 pages of electrical holds an awesome vision in a dream, aware The days that followed Ramillon's de- supplies. No bigger or belter r&lue* are obtainable elsewhere. We hare that he is dreaming and unable to rouse struction were like a gruesome nightmare. a coiiiplete stock of ererytMnji Hated himself. All sense of reality vanished be- In this catalog. Wireless erden Every city on the allied planets lived on premptly filled. fore that appalling devastation. tide The the edge of an unseen abyss, cringingly THE WILLIAM B. DUCK CO. was setting in from the bay and the sullen 230-232 Superior St. Toledo. Ohio awaiting the next bolt to fall upon it. waters brought a small wave lapping at On Friday morning, November 10th, as feet. There a splotch my was of rusty London was emerging from the fitful sleep MUSDCALKAZOOl MAGIC FLUTE sediment on the wavelet which, to dis- my of a terrorized city into the broad, full sun- Wondcrfallf Sweft ordered imagination, had the appearance of shine of a new day, a series of short, Toned and Mostcil blood. It might be from some of the in- sharp, ominous explosions were heard in nocents beneath the sea, I thought, and the air above the National Gallery. In baspipf. anare drum. Punch Bnt] Juily. ftc. t*i> i>o'.r% to tin««r. It i* Bimplincy drew back shudderingly. tsclf. PnxliiccB rxci-llrnt muaie. Boutin sudden alarm, those in the vicinity gazed tioC blow lnt» it. buf slnir. apeak, Ikash nr maki: any dnirrd DniLation. Uard vtlh The worst feature was that no one had upward. From out of a clear sky, a shower aatonishinr results >t booctr rnrctinff*, home, cJub or eburch entrrta'nmcntJ. survived to tell the disaster. of thin, red, discs dance*, aercnadea, picnics, outinrB. n- of Camden, metal zigzagged fantas- cunioiui- Juit the Uilno- tor choruici anij tically ahtwB, bicycle and mawhlng clubs, etc. directly across the river, could give no to the ground. £iCk't1i;i:il for vocal or Imtrunicntal ac- comnarvimcnfa, either with or without riatrumml. the *ITcct i« [niiled ins true tionii fo» coherent account it The entire district ^cal lEisCrufncDta.. of what had seen. In from Oxford Street hlo IScp. pd. ll >.k:^ isaliucnent. fact, it had seen nothing that could explain to the Victaria Station became at once a JOHNSON SMITH & CO. Depl. 923. 54 W. Lake St.. CHIUGO the mystery. At ten o'clock in the morn- frantic bedlam. Stampeded humanity ing— it was Sunday, and the neighboring rushed for shelter, and with palpitating ex- cities were smiling peacefully up at the pectancy awaited the direful catastrophe. Convert Yoar Bicycle Into a Motor-Cycle sky—a sudden explosion shook the Earth With fascinated horror they watched the \Vf sell you the motor complete to its very heart. Stunned by the shock, bewildering missiles bound and rebound or furnish you with the finished p.irts from which you can build the residents of from street to sidewalk roll Camden were further be- and clinkingly the motor yourself with few tools. wildered by the shattering glass and the to and fro. We send you the printed Instruc- rush of wind that sent chimneys and roofs Five—ten minutes past. The scarlet mes- tions with blue prints of the drawings for $.25 or full particulars for 3-cent stamp. crashing to the streets. Those who were sengers had ceased falling, and lay gleam- Brown St.. Phila.. P». first able to look about saw a black cloud ing in the bright autumn sun like splotches STEFFEY MFG. CO.. 502S rising to a great height above Philadelphia of blood. Here and there some, more bold It hung there for an hour or more, and than the others, slept out of their hiding meanwhile the surge of angry waters could places, compelled by curiosity to examine MAKE YOUR OWN GENERATOR ! be heard rushing in to fill the void. When these strange visitants from out of the no- We have a complete line of sturdy efBclent generators and alternators from 106 to 1000 the air finally cleared, the terror-stricken where. Gradually London drew a sigh of watts. We furnish these complete, or parts fur- people rushed to the river front and their relief. Traffic and life swrung again into nished ready to assemble with wire and Instruc- hearts sickened within them as they be- motion. Nothing fearful had happened. tions to wind. Send for catalogue. held a troubled ocean rolling over the The metal hail phenomena would soon be ALL AT FACTORY PRICES. region their sister explained, perhaps, those where once city had by whose business BERGMANN MOTOR WORKS. 1283 NIAGARA ST.. BUfFAlO. N. V. been. it was to solve such freakish events. You bcneiit by nientujning the "Electrical E.Tperimcntcr" when writing to advertisers. ! — 804 ELECTRICAL EXPERIMENTER March. 1918 Hardly an hour had past when London's less we agreed to her demands by noon on feeling of reassurance was cruelly shat- Thursday, that hour would mark the doom SEND PICTURES tered. The discs, interpreted by university of New York, and our other cities were e.xperts, were found to be messages from to be similarly damned to extinction. Mars. In one brief statement, the imprint On the Saturday evening following Lon- '.rELECTRlCITY* on the red circle announced the complete don's destruction, I sat in the study of my destruction of the citj' by three o'clock apartment overlooking Van Cortlandt Park. that afternoon. A wail of deepest anguish My mind was spent from a whole day's This latest sensation in elec- like heart-weary'ing discussion and argument in trical advancement—marvel of rose from London's masses and spread today, necessity of tomorrow, the blackened wings of doom over the the Council. Many of the older men had affords wonderful entertain- whole cit>- as the demoniac portent of the advised submission, but several members ment. Affords Instruction in of the coming science. You can evil messengers penetrated the minds of. of the Board Strategy, including myself, send pictures of your friends the people. pleaded for delay. At any moment the keen by electricity over telegraph In vain had the watchers in the Selonoid minds working tirelessly on the problem wires or by wireless. Picture might in this advertisement was sent Towers sprung to their sensitive record- discover the means used by the Mar- and received by this system. ing plates to seek for some indication of tians to reach our Earth undetected. With- Electrical experts and scien- plates out such knowledge, we all admitted, our tists have declared the Leish- the enemy's presence. The were cause hopeless. man Electrical Picture Trans- blank. A message, imploring help, was was mission System is the marvel flashed over the Earth and at once our Alone in my room the mystery tugged of the age. See article December Issue. strongest forces were hurled to the spot. at my mind again and again. It was Sel of Two Machioe PRICE ONLY $15.00 For Complete Huge V-planes, bearing tremendous bat- baffling. In despair I looked about for J. Ogdeo. Uub L. LEISHMAN COMPANY Depi.T. teries; grim little Heliolites (in one of something to relieve the unbearable strain. which I was stationed) with their atomic The reflccto-screen on the east wall caught detonators, and thousands of other craft my eye. It was connected with the leading thronged the air for a distance of fi,ve hun- theaters, and I remember thinking cynically dred miles around and above London. how the people could go on playing even But of what avail our formidable arma- tho the end of the world was in sight. ment, when there was no visible enemy Theresa Carmine was singing at the against whom to direct it? We circled Metropolitan, I noticed by the auto-indica- about in close formation so that not even tor. Switching off the lights, I connected a sparrow could have escaped our reflec- the screen transmitter with the Opera tors, but the air was apparently innocent House, opened the au4ophone, and stretched THE ^ of any hostile ship. myself comfortably in an arm chair before Meanwhile, the cit>' below was in the grip the screen. of a hellish panic. Those who could take The second act of Madame Butterfly, to the air did so immediately, with never a that imperishable story of hopeless love, thought for their treasures left behind. was nearing its end and Carmine stood Others pushed and struggled like mad- looking towards the bay, waiting patiently dened beasts along the streets to escape for the lover who would never return. The from the doomed city. Bruised and wonderful colors of the screen brought out crushed bodies lay thick along the high- vividly the pathetic droop of the slim figure way, like worms after a spring rain, and and the room echoed softly to the sobbing their fellow beings trampled on them un- violins and 'cellos of the orchestra. heedingK' in those awful moments. HANDY BINDER Unstrung as I was by the events of these Unfortunately, the greater part of those anguished weeks, the pitiful little for the EJectrical Experimenter two who cleared the city streamed out into Es- Holds and preserves 12 issues, each of which tragedy touched me deeply. Tears came to can be inserted or removed at will, without sex and Kent, overflowing such places as my eyes and I thought of Ava. I had been tools. Will keep your magazines perfectly for Welling, Grayford, Dagenhow, Grays Thur- unable to see her since the night of the all time or just preserve them like new till rock and Gravesend, where the Martians reception in Paris. Probably the next you bind them permanently. Made of heavy material, extra strongly reinforced had evidently placed contact points for their cataclysm would destroy one of us, I at the back and covered with hand- detonators, in order to tear up the entire thought, and the other would be left alone, some rreen cloth, suitably lettered Thames bed and hasten the deluge from like the little Butterfly, waiting, waiting gold ;50c in the North Sea. Shipping weight 2 lbs. Add sufficient The curtain dropt and the sound of ring- postage, otherwise we will have to send A few minutes before the appointed hour ing applause came over the audophone. The binder by express. we withdrew our army of planes with as operator at the Metropolitan now turned his Order a Binder Tc-day and PreierTe Year MagaziiKs Ez^enneolcf Pab. C«^ Ik, 233 FiHob Street. New Tor many people as we could load on. I bent visu-ficctor upon the audience. Row upon Book Department, k over the glass in the floor of my Heliolite row of exquisitely drest women and men for a last glimpse of London. flashed on the screen. The sight of the smiling, chattering, thoughtless throng An immense throng had gathered on the jarred on my mood and I was half rising o/" Embankment, evidently resigned to the POCKET BOOK ELECTRICITY to disconnect the transmitter, when the dreadful fate, and were listening to the [SPECIAL WAR EDITI ON I view of directly in FREE soothing words of an old man who had a box the center of the DlstrlbutAd as * supplement to oar bi» HandT Bock horseshoe brought me to my feet with a darioB temporary assumed leadership of the mass and like government Bospeasion of wire- cry of surprise. There sat beside her leas. Uata new thinffS to experlfnent wilb. Also inspired evidently direct- Ava motors. Qasbligbts. telesTapo some prophet was apparatus, pozile*. i ma^le ootfitd, books, athletic ffooda. chemical seta. father, a pensive smile on her beautiful fishiQf tackle, ing their thoughts away from the approach- ooreltlea. Handy . In terestins. For face, her eyes shining straight into mine everrbor in America. Ftm on ic«?ue«t. ing terror. Down Cheapside way, other The eiectro-Set Co., noic knotcn a* The view past in a second and I was left The Newman-Stem Co., Dcpt.E.t^ CleveUnd, Ohio groups, crazed by fear, were tearing and gaping at the screen. I had been so en- rending each other in insane fury. My grost in the Martian atrocities that I had last impression—one that I still see vividly entirely lost track of the Venusian com- whenever I close my eyes— is of a large to mission's program. Undoubtedly this SAVE 25% 60% number of women and children kneeling was the day of their arrival in New York, and GRAFLEX- KODAKS on the ground in Regents Park, their arms of course the committee had taken the C&merafi &nd Leiue« of every deaorlptlcCL outstretched piteously to us as we flew by. Equal to new Save money. Write now for members to the opera. Free Bargain Catalog; long stayed, loath depart Book and So had we to In another minute I up on the plane .-.^rir.v r.urdrei^ of roCir.ey - saving barEnios in was 'iliKhTlv use"; and r,ew cameras and supplies. All while there remained the faintest hope of roof and had pushed my little electric from } goods sold on ID days' Free Trial. Money back ' -.It sat'.sfiei. You take no chances dealing discovering the Martians, that we had only h U'i. We rave been in the photographic boSJ- the garage. The despondency of my mood sover It: years. Write Mow reached the explosion Oxford when came. had changed to joyous exhilaration, and I CENTRAL CAMERA CO^ Dept 173 134 S. Wabash Aft, Cycap -Again the dark cloud of destruction spread rose high in the air before turning towards above the Earth, again the swirling waters the Metropolitan. A young moon was high Learn Walchwork, Jewelrywork into and rushed the chasm, and London with in the heavens and New York lay beneath ^ *^"^ trade commanding a good sal- EngT avui^«dVinP its ten million lives was gone. me. bathed in the enchanting glow. Never ary. and your services are always in demand. Address HOROLOGIC.AL Department, This was the culminating tragedy. Se- had the city looked so beautiful, so en- Bradley Institute, Peoria, 111., for our latest catalog cure in her untrammeled power, Mars now trancing; never had it seemed so dear to issued an insolent manifesto. Peace was me. I was conscious of a sudden strong offered us on terms that would make the faith that it would be saved from the IS^oN AVIATION allied planets mere vassals to her will. If despoilers. Learn of the great opportanitiea in this new we accepted, the destruction of our cities The last act had already begim when I v^l.OOO.OOO.OOOindastry.TnoQsands of men needed. would cease, otherwise . Five days' grace entered the box. Quietly I drew a chair Learn bymail— free book telia how. Write at once. — MTIOIIU. A£BO IHSTITUTE. DeplA7443 ientti)Bld«..Ctncage were allotted us to make our decision. Un- from the rear of the box and seated my- You benefit by mentioning the "Electrical Experimenter" uhcn writing to adz-ertisers. " — March. 1918 ELECTRICAL EXPERIMENTER 803 part I' is a wooden standard, %" x solf near Ava. Under cover of the dark- The a Month the bear- ness I prest my lips to lier hand. 1 felt yi" X iy»". To it are screwed master- ings, N, supporting the drum, M, by means The a thrill go thru her as she recognized me, piece of watch and my heart welled np in conleiitnient. of a small pin passing thru it and serving manufacture—adjunt- to revolve ed to thL- si^oDd, positiomi, tern- I hand to my lips. The as a shaft, permitting the drum Again raiscil her tTiru and isochrontsm. En- mystic hells chimed f:iintl.\ and .\va prest freely. I ut factory into yonr choice at thecxuauitODeHWatcbcaaes. my hand warningly. 1 leaned hack, silently A good drum may be made by simiily drinking in the radiance of her presence. passing an ordinary pin thru the center ol Idly my mind pla\ ed with the thought ol a cork, lie careful that tlie top of the drum 21Jewel the hells on her wrist. Mysterious bells, I is even with the center of the motor shaft. like our love from thought dreamily, ringing Solder a short piece of Xo. 28 copper -i^^ Burlington the world The (freat Burlinffton Watch request. heart to heart, invisihle to wire, L, to the end of the link, I. Pass it sent on BJmpIe Pay at rate of $2.50 a month. You get the watch at With a sudden jerk I sat upright. "Aya!" once around the drum and fasten the end thPB.-ime price even the wholesale jeweler maet pay. I whispered. "Come outside with me." to the pin, S, adjusting the length so that Write Today lor Free Watch Book Sf-e hand-='.ome color illustrations of all the oewent there will be no slack when the slider, J, ijlie turned in surprise. flcL^it^ns in wat''hes that you have to ebooee from. is out as far as the cord, G, permits it Y'>ur name and address on a poetcard is enoutfti. !" once I urged hreathlessly. G';t thia olTc-r while it last*. Write today. "At to go. Ohediently she took my hand and fol- BarImgtoi^alcl^^«i^443J9lji^Jt^tt^^ The elastic band, Q (or better, a spiral lowed me to the foyer. It was deserted spring if you can scare one up), is also 1 one of the gilded settees, and led her to fastened to the pin, S, and the other end my mind tingling with the idea that had fastened to the small screw-eye, R. The v?u FREE it Delivered -*-•-- entered tension will have to be adjusted by experi- _ Yourr choice ofi' 44 styles, colort— ' "^r^"^ Tj.!"— ami Riz«^i in the famous line of I spoke in a choked voice, speedometer is completed. "The bells—" ment after the BIlS^'v W>/*'RANGER" bicycles, shown in unable to control the eagerness that was iiaKfejf^'-'^^full i-olor 111 theth ttig new Free Cats- O is a wooden standard, tapered at the all the freight ) log. We i>ay charges must • thrilling me. "Let me have them— I top to about Mt" in widtli. See Fig. 3. frum Chicago to youi town. see— In height it should be just sufficient to 30 Days Free Triah'i°TS? off. one knows \hicycle you select, actual ridinn test "I cannot take them No barely support the link, I. ;irj your own town for a full m'Hith. how the bracelet is fastened." My excite- until you get our great A tack, K, similar to those used in mak- 'Do not buy ment had communicated itself to her and new trinl ojf'-r and low Factory- ing cigar boxes, is placed thru the slot ' Hirect-To-Kider termg and prices. she breathed rapidly. "What is it?" she TipFQ KAMPS, HORNS, pedals. in I and driven almost home, but permit "What have you dis- :..; I intw singla wheels and repair asked eagerly. ;': for of bicycles ting I to slide easily back and forth without parts aU makes at co\ ered ?" alf usual prices. No one else can the slightest trace of binding. This ar- tier such values and such terms. sure yet, but I think— I be- but write today "I'm not rangement permits the lateral motion of SEND NO MONEY — " surge of exultation over- for the bin new Cataloc- It's free. lieve A communicated to the drum, M, and Agontm I to be CYCLE COMPANY whelmed me and I clasped her to me so Wanted thence to the end of the pointer, while MEAD Dept.M-107 Chlcaso tightly that it seemed as if our hearts must preventing I from turning with the motor meet. "Ava!" I cried. "You and I have !" and twisting ofT the connecting wire, L. found the secret of the Martian raids BuUd Your Own PHONOGRAPH pin, cut to the right length, "Where!" she gasped. .An old hat //'j Easy With Our Hth makes an ideal pointer. It should be pushed few hours intereetinc work SAVE I triumphantly. A "On your wrist!" replied dollars and gives thru the drum so that when the motor is saves many In the e.xcitement of the moment, wrought .vou a machine exactly to OVER at rest and the tension, Q, is properly ad- suit your ideals We furnish up by the discovery and the closeness of motors, tone arms, oast- ma- HALF justed, the end will be at "stop" on the her own dear self, I kist her. tt»rial, blue prints and full dial, V, which is supported by the stand- instructions. Plays any rec- "Can the bracelet be touched?" I asked d06 ELECTRICAL EXPERIMENTER March. 1918 This masterpiece contains 160 pages, 400 illustrations. The most comprehensive Wireless Course ever printed. Size of book 5"x9". Printed on extra thin paper, so book Contains 160 pages, 350 illustrations. Size of book can be slipped in pocket. Handsome stiff cloth cover. 6I/2" X 9". Very fine flexible linen cover. FREIE with a year's subscription. FREE with a year's subscription. TTiis is a very limited offer. It may be withdrawn at any time, due to the tremendous cost of paper, which IS JUST DOUBLE WHAT IT WAS ONE YEAR AGO. We only have about 2000 each of these fine books on hand; after they are gone we cannot reprint the books until conditions become normal again. THIS MAY BE TWO YEARS OR MORE. Now is your chance. The publishers of this journal have earned an enviable reputation of giving more than 100 cents' worth for each dollar spent with them. Proht S^e Electrical by this liberal opportunity NOW; it may never be made again. Experimenter HERE'S THE OFFER V Subscribe to THE ELECTRICAL EXPERIMENTER for one year, -w Vv at the regular subscription price of $1.50 per year (Canada, foreign and N. Y. C. $2.00) and we will send you FREE, •^s :s-ls ^^ .^^^^. POSTPAID, either one of the above books. If you sub- <;entlemen scribe for two years. BOTH BOOKS WILL BE GIVEN FREE, POSTPAID. P,„.se e .. t ,. r .^ .— ray subscription ti> THE EUE«'- If you are a subscriber at present, take advantage TRTOAL EXrKUl li ' of this wonderful opportunity t anyway. If .MENTEB fo t ^vO^ you term of year v/"^ do. we will extend your present subscrip- for which I enclose hcri- \V ^_ tion for one year. wltli { \.^ You will iilso scud mc al once This Offer Limited. Act Now. KREE prepaid your book. V\ 12 copies of THE ELECTRICAL EXPERI- EXPERIMENTER PUB. CO. jMENTER malce a book 9" i 12" and 4" thick. 223 FULTON STREET This book will weigh 7 lbs. It is the greatest Electrical and Wireless reference d»l Cf\ NEW YORK work in the world. "PisOVI ^^ CITY And all for \<^ You benetit by mentioning the •Electrical Experimenter" when writing to advertisers. March, i 9 I 8 ELECTRICAL EXPERIMENTER 807 Opportunity Exchange will probably rt-.il VOL Imd more opportunities and barsains in these columns tban anywhere else in the countr>. Most goud things in life arc hard to find after these little and worth going — ads illustrate that point; you alone will be the real loser if vou don't take th- tune to scan through these columns. Advertisements in this section six cents a word for each insertion. Count 7 words per line. Name anil address must be included at the above rate. Cash should accompany all classified advertisements unless placed by an accredited advertising agency. >ii Ten per cent, discount f.ir (. issues. per cent, discount for 12 issues from abi.ve rate. Objectionable or misleading advertisements n..t accepted. Advertisements for the April issue should rcai.ll us not later lliaii February 23. OVER 100.000 PEOPLE READ THIS JOURNAL E.\PERI.MENTER PUBLISHING CO.. IN'C. 233 Fulton Street, .\ew York, .\ -yum'"' zae^ irC AERONAUTICS CHKMICALS BIG PA\ for men and women. Tremendous demand for draftsmen. Pleasant work; salary $100 to $200 a month. Study spare time at home; wc AEKIAL AGE. America's leading illustrate! PREPAID Hit DIFFERENT CHEMICALS. S4.UU will help you secure position when qualified. weekly, presents the latest dev*l You benefit by mcntioiiittfj the " Hlcctrical Experimenter" when writing to advertisers. 808 ELECTRICAL EXPERIMENTER Me 1918 I'HONOGRAPHS TtLECJRAl'H Y VVIRtLESS both MORSE AND WIRE WIRELESS—We prepare you for Signal Corps and TELEGRAPHY— BUILD YOUR OWN PHONOGRAPHS LESS, also STATION At.ENCY, taught quickly. work, radio service. Our instruction includes manufacture them for profit. Drawing, Instruc- TREMENDOUS DEMAND— much greater than radio, buzzer, wigwag, semaphore, and military complete tions, Parts, Price List, Blue Print, etc., supply—PERMANENT POSITIONS SECURED. drill. Prepares you for rapid promotion in service. sent free upon request. Write today. Associated BIG SALARIES — recently raised. IDEAL BIG OPPORTUNITY FOR DRAFT AGE MEN. Phonograph Co.. Dept. El. Cincinnati. WORKING CONDITIONS— short hours, vaca Write today for illustrated booklet and full in- tions with pay, sick and death benefits, etc. —pre- formation. WIRELESS TELEGRAPH DEPART- vailing. GREAT OPPORTUNITIES FOR AD- MENT, GRACEL.\ND COLLEGE, Lamoni, Iowa. PRINTING VANCEMENT. WOMEN OPERATORS also postage. greatly desired by Railways and Western Union. COILS— -^i" guaranteed, send $1 with Cheap living expenses can Alfred Dubs,)S, 1534 Pitkin Ave., Brooklyn, N. Y. YOUR name on fifty "Styloprint cards," 35c. Tuition reasonable. — and largest school established Card case FREE. Imprimatur Press, VValtham, be earned. Oldest — Endorsed by railway. Western Union SPECIAL SALE—On account of financial rea- Mass. 43 years. and' Marconi Telegraph Officials. Large illustrated sons we are forced to sell a large number of the code-learners at the INTRODUCTORY OFFER—100 catalogues free. Correspondence courses also. latest type of WIRELESS SPECIAL reduced' price of $1. & Mfg. Co., Box 725. Noteheads, Name cards, $1. Claude Write today. ENROLL IMMEDIATELY. Dodge's D W Envelopes, Madison, South Dakota. Wehinger, 105 Ludlam, Lowell, Mass. Institute. Lone St., A^alparaiso, Indiana. Scientific Exchange Columns • UNDOUBTEDLY you have at the persent time some things for which you have no further use. Do you wish to exchange them tor something for which you have immediate use? There is no surer and quicker way to do this than by advertising your articles in these columns. The Very people, the Otily people, who could possibly have a. use for your things read this journal. More than 75,000 interested people will see your cohimns ad. It is furthermore the cheapest advertising medium for you in the country. Dealers advertising accepted in Opportunity Exchange The rates are: Five cents per word (name and address to be counted), minimum space 3 lines. Count about 7 words to the line. Remittance must accompany all orders. No advertisement for less than 50c. accepted. We reserve to ourselves the right to refuse any advertisement which we consider misleading or objectionable. Advertisements for the April reach us not later than February 23. issue should « - r, r. The Classified Co!mi:ns of the "Electrical Experimenter' Bring Positive Results. Subscribers experiencing trouble in dealing with anv advertiser should notify the publisher very promptly. OVER 100.000 PEOPLE READ THIS JOURNAL >j^am""' L '* FOR SALE— New $17 Spencer Dissecting Micro- 6 VOLT generator and starting set, good condi- WANTED— Ives Electric Trains for "O-Gauge scope, with mahogany case, $12. $8 large metric tion, will sell or trade for wireless instruments. Track. Also cars, track, switches, crossovers, etc. scales, $5, and S3 scales with weights, $2. Send Wm. Frey, Bedford, Michigan. State what you have, condition and lowest price stamp for description. Reginald Pitts, Hanover, in your first letter. C. E. Robmson, Portland, Conn. Pa. P _ FOR SALE—Adjustable Barbell, Dumbell, Ket- tlebells and Course. All plates 165 lbs. S25. Paid ^vlthout "WANT TO SWAP"? W.ANTED— Motorcvle engine, with or I | S37. T. Voegeli. 2351 Park Ave.. St. Louis, Mo. carburetor and magneto or coil. Write. Harold Do you realize that these "Scientific Ex- FOR SALE— Iver Johnson motorcycle first-class Lambert, Haverstraw, New York. 8 g m change" Columns"* are the World's most re- p condition, 1913 twin cylinder; good running order. = nowned "Swap" market? "THE EL EC- ^ price $r5-Q0. Howard B. Stossel, Front Royal, Va. m TRICAL EXPERIMENTER'* prints 90,U00 = FOR SALE— ^4 H.P. Emerson A. C. Motor. SELL—Motorcycle engine, H. F. TRADE OR ^ copies of this issue; that means that at least ^ Will trade for good rectifier or water motor. All '/, Horse gasoline engine. condensers and outfit for M 180.000 readers see this page and probably answered. A. Hampton, Box 263, Whitewright, 413 Boston St., Gabon, Ohio. ^ Reuben Shumaker. M a great many more. Our readers who adver- ^ Texas. = tise here seldom advertise the same thing g FOR SALE— 15 dial Omnigraph (Morse code), twice—usually within five days after the m volt ^ key and sounder. Harry Baker, Box 48, Green- 2 K.W. 60 Amp. dynamo 110 issue is out the advertised article has been WANTED— ^ p ville. Ohio. or less. Harry D. Morris, Quitman, Mo. sold, or swapped. The many testimonials ^ ^ Complete chemical outfit. Cash or ^ which we print here from time to time are ^ 8 ample proof of the almost miraculous pull- g exchange for wireiess goods. Toth. 1628 First for sale cheap. of columns. Ave.. New York City. WRITE for list of small stuff m ing power these ^ Mass. R. W. Chaffee, 67 Thurston St., Somerville, FOR SALE—$11 Omnigraph; Marko. storage bat- in your attic or workshop \\'rite m Look around g tery ; Crystoloi detector. offer. George M and you will find dozens of long forgotten ^ Dimon, 367 Genesee St., L'tica. N. Y. = articles, useless to you now, but very use- 110 volt direct current motors, 1/^ H.P ^ \\"ANTEE>—Twin cylinder motorcycle eneine, SELL— ful to someone else. At a ridiculously low $15- 1/8 H.P. $6; 150 ohm relay, $2; exhausted M ^ complete. Have various articles to trade. What cost you can either sell or swap such articles. coherer, $1.50; leather tool bag, $2. C. S. Haines, ^ ^ have you ? Benj. McCaul, Ayr. N. Dak. Johnson City, Tenn. BICYCLE outfit, $15. Brand new auto g And remember this fact: The U. S. Postal g MOTOR ^ Laws protect you. No one can "do" or cheat ^ carburetor, $4. Motorcycle Presto tank. $6.50. you. Of 3,495 "ads" published in these col- Joseph Tucci, 122 East 52nd St., New York City. complete out- g ^ MINUTE PHOTO CAMERA with umns during the past five years, only twelve = WILL PAY S8 for a No. 2 Omnigraph (holds engine, or what g fit will exchange for motorcycle complaints were reported to us, and each fifteen dials). Must be in good running order. Hippie Court, Canton, ^ ^ have you- Wm. Smith, 337 ^ and every one was adjusted to the full sat- = Sell a vest-pocket Kodak and daylight developing III. M isfaction of the complainant. g tank to fit vest-pocket for $5. Radio, Gwyncdd Valley. Pa. have old books or m It matters not if you g EXCHANGE—$100 Generating Plant. Engine. Savage automatic 22 calibre rifle, magazines, a kodak, electrical or chemical FOR SALE— ^ ^ Generator, batteries, for Yi to 1 K.W. Transmitter. coil, price $1. George Sump- apparatus, scientific instruments, bicycles. = price $8; J-j" spark M $26 Violin, $12; 3000 Ohm phones. $3; 8 fuse Wash. picture machines, air = tion, Box 25, Anacortes ^ typewriters, moving blocks, each 15c; 2 blocks with fuses, 90 Amp.,. structural toys, etc., etc. All ^ rifles, watches, ^ each /5c; $50 piano music, $20. Other bargains. these and countless others can be speedily Complete Wireless Outfits; pay cash s g Reuben Scholz. Sheboygan. Wis. WANTED— ^ disposed of here. Try it and be convinced. = or exchange photographic goods. O. Ingmar Olc- BARGAINS FOR SALE— Erector, cost $15: Dak. Cias "Search- son, Ambrose, No. liiiiiiiiiiiiiiiiiiiiiiiiin^^ No. 2A "Brownie" Camera; Bicycle light": Hunting Lamp: Electric Lantern; Camp Ax; Bicycle Horn; "Boys' Book of Electricity": Kilowatt transformer; FOR SALE — One $12 takes my wireless and experimenter's appa- Knapp Leader Motor; Striking Bag; Spring E.xer- E. I. Co., Static machine; Brandes superior phones; ratus. Write C. Pfeiffer. 41 Rohn's Ave., Detroit, ciser. Ail practically new. \ ery cheap. Gordon experimental apparatus. and other wireless and Mich. Bennett. Darlington, Md. for stamp. Also Yi H.P. Gas engine. Particulars Amarillo, Texas. Harold Rice, 1409 Harrison St., BARGAINS— First $25 takes $62 worth of wire- less and electrical apparatus, including audion. Useful, and phones, coupler, motor, variable, etc. All perfect FOR SALE—3 novel inventions. time The ad I had in your magazine some condition. Act quick. Write for list. Aubrey nroduceable at low cost. W. M. Seyferlich, 43« answers; they Tholin, 1339 Fifth Ave., Rockford. III. Wrightwood Ave., Chicago, 111. ago brought me 122 different came from all over the United States and FOR SALE—Remington U. M. C. 22 Caliber Indian motorcycle. even from Canada. The advertising columns sell Rifle FOR SALE— Single cylinder Repeating Rifle. Cost $14. _ Will for $9. Ready to run with exception of few repairs. Price in your magazine are the BEST I ever used. in first-class condition. Never used. \Vrite for Mooresville, Ind. further information. Joseph A. Stropko. 9325 $25. W. R. Milner, obtained splendid results for such a small I Buckeye Road, Cleveland, Ohio. ad. FOR SALE— Sending and receiving set. Price Copy of book "Michael Faraday, His list sent on request. Instruments sold separately. WANTED— Yours very truly. Sylvanus Thompson. Also., an Jack Cox, Thomasville. Ga. Life and Work" by LOUIS E. KRIEG, ohmeter of the Roller-Smith type or a Wheatstone Gloversville, N. V. bridge; must be in first-class condition, and include 5 or 6 K.W. Transformer 110 volt 1.U North School Street, WANTED— galvanometer. H. W. Secor, c /o Electrical Ex 10,000 to 20,000 Secondary. Ed. Dick- Primary to PEKIMENTEB. ZH Fulton St., Ncw York City. son, 2014 E. Denny Way, Seattle, Wash. You benefit by mentioning the "Electrical Experimenter ' uhen writing to advertisers. — ryElecfricalMaii L fWits These Books andive dbip fhetn EDpIT for your inspection I If b! 10 Volumes 3500 Flexible Pages Covers 4700 Pictures Handy Pocket- Volume Size $1 Per Volumes 1 Month Just what you need to know to sii6beed in ELECTRICITY electrician, every eiiHiiieer, every mechanic should know EVERY READ THIS PARTIAL LIST OF CONTENTS about these wonderfully helpfid instructive books, which give in — I Contains .148 pages. 3SS illustrations. Elixtrieal plain words a complete working knowledge of electrical engi- N '-'' * siyns and symbols -static and current elecinciiy priiuary cells—conductors and Insulators- rei>istaiice and neering in all its phases. conductivity —iiiaBiietism—Induction coils—djiiamo iirinelples classes uf dynamos—armatures— windings—commutation \ou nm into some new electrical problem almiisl every day. The brushes, etc. M*v Contains "AS pawes. 394 illustrations. Motor i-%\jm 2 information yon need to help vou in your every day work is in A jirinciples -armature reaction — motur startim; calculations—brake horsepower—selection and Installation of dyiiamct and motors— galvanometers—standard cells—current measurement -- resistance measurement — voltmeters ~- watt- meters -watt hour meters—operatiou of dynamos—operation tti motors, etc. No. 3 *'""ta'"s 300 partes. 423 Illustratloiw. Distribution systems— wires and wire calculations— inside, out- H -sKie and underground wiring— pro- AW KINS sign flashers—lishttiing ntiion— recti tiers- -storage battery systems, etc. 4 *''^'"»'"* 270 itages. 379 llluslrations. Alternating ELECTRICAL GUIDES No. current principles-allernatinB current diaKranis iiie power factor— alternat*»r principles—alternator con- These linulcs pliii-c chM-tl-ifil.v al .vuui (iii;iti ends. 'riif.\ cover e\ci.s liiiatiin;ible struction —wmdiiigs, etc. subject, pjinciiile. tlieor.v, iiriililem. Irouhle. and wa.v of doing tilings electricall.v Wq K Contains ?,20 page.*). fiI4 Illustrations. A. C. Motors Ever.v .subject is indexed so tiiat yon can tnrn rijilit to it. Tlie.v are a stnd.v course ' ** —s>'iichronous and induction motor iirinciplcs—A. C. and a reference snide in one, written in iJlain ever.v day lanijuage— no wasted Winds connnutalor motors— induction motors, tranafnnners; losses, construction, -only wluit you need to know—chock full of np-to-the-minufe electrical knowledge. conned ions, tests—converters— rectiflers. etc. Contains 20.S pages. 472 illustrations. Alternating The Kuides are a eojnplete course in electrical engineering. They will help ytni in No 6 " current systems -switching devices—circuit break every detail of the day's electrical work. You can't ask an electrical question that ers—relays^lightiUng pnitiotor ajiparatu^- reRUl.-itini: de\ic« Hawkins tiuides can't answer. ^-synchronous cnmlensers indicatint: devices -meters- -power factor imlicators- wave form measurement — swit.'li board-;, e'c. i^v.Mq 7 Co"'a''>s 31G pages. 379 Illustrations. Alieniatlng Pocket-Size Flexible Covers f current, wiring power stations—turbines: manage- nuut. selection, location, erection, testing, running, care and repair— telephones, etc. The hooks are small eimuKli to slii> into your coat poeki't—hamlsomel.v hound in flrxihlp biaek tovers. Contains :iZ2 pages. 430 Illustrations. Telegraph ^' What Electrical Men Say No ' 8 Votl can carry eacli vohinie with you until you have , —simultaneous telegraphy and telephony- wireless— ^^ mastered its contents, ."i.'.tin pases of actual inforinalloii electric bells— electric lichtlnir-photomctrr. etc; ^ Helped Him Make Good "^ntains and 4.700 illusiratlons. Once you see these books and No 9 * 322 pages. fi27 illustrations. Elec- ^ "'•^ 'II is itiily riRht fur mo to KTom- put them into actual use you will never aKiiin want to be ,, railwa.vs—electric locomotives-car light- ^F Ing—r trolley mciid liialily tliti Hawkins Ciiilili'H. for without them. Try It at our ex]>ense. car operation— miscellane«ms applicntinno - motion pictures— .^ tlit-y hiivo been of thy gr^'atest ussist- gas engine ignition—automobile self .^P starters and lighting ttiu-y to ino in [jliirinu luo in my pres- svstems. electric vehicles el-- ^ fiit position as i^npt-riiiirnilent of Con- ^'""'•I'ns r.l3 pages. .1<11> No4-^v 10A\M illu^lr.iiions. ^^ mrut'lion DepartiiR'nl of otio of Oliio's Klevators—cranes -pumiis -air eom- ^^ JarKosI Elpi-trirul ('ornimiiies. I would SEND NO MONEY pressors— electric heating — electric weMim:- *. ^ THFn Bolderlng and brazing— lllte to see every man have a sot of industrial electro- ^^ Aiinc. p nn Hawldns (iuides." II will cost you nothiiiK to riteive these books—to look lysis—electro plating— electro-iherajvutic ^r «uutL *. uu. (Jeo. Kiieclit, i.'oluiiihus, Oliio. iheni over— ask them all the questions you can think ol —X-rays, etc. 72 Fifth Avenue — use thrill in your work- study pick In- ^^ them — up some Also a complete 12fi-i>iice ro;uly In the Naval Electrical Dept. formation that will increase your eariiinK ability. \Vc ^^ New York. N. Y. reference index of tlio will »liip you the entire set of 10 volumes entirely FREE cntniiletc ^^ "Tlio Hawkins (Iiiidcs uro KTi'Ut lu-lp This is a siiin of our contldenec in the guides. I*ure library. This index lias been ^r ricHse mi.inii nie for to ine III tlio Naval Kleclili-al l>i'imrt- examination a k'old does not object to belnji tested. Keep iheni for planned to render easily ac- a H w k 1 n s nii'iit, which they cover very thnrnuKli- seven days and if you do not decitle that you can't get cesslble all the vast hifnr- T:i.x*irical Jiuides (price ly." C. J. Cornell, ^ aloiiK without them, reiurn tliem to us and owe us tl. Receiving matlon contained in the S. Siiip. Brooklyn, N. Y. nothino. ^^ pafl 7he'in ';;;.';;.b"e"rs''"lf S;?: 10 electrical guides. When you decldp to kee!> them you only have to pay ^^ isfactory I ngr.e to send vou V Superintendent There are over I.S.- seven days and to $1.00 down and remit the halanco of JO. 00 on the easy ^ within further "'«" ^'^" *' •" " '' """i"' ninii i.^i^ "I am now superlnlpndent of the payinenl of $1.00 a month till [taUl for. .'SflO cross refer- ^^ Diinnvllli' Hydro - KIcctric SyatPtiis. Uso this eoupon to net the hooks. It will pay you ences. Ynii find a. and Hawkins (luldes woro a Rrcat heli> limes - many m'er. what you want stonaturp III nit' hi lioldlnt; down a respoiiHlhiB ^^ pO!*l11(HI *' to know sfantly. VV, E. Swarlz. nuiinville. Ontario. THEO. AUDEL & CO. Occupation Wireless Operators ' "I have worked wireless for ton 72 Fifth Ave. New York, N. Y. .yi-flfs hut 1 wish I liad these books .vears hbo. as Ihcy have saved me a iireat deal of trouble," H. Marshall Steamer M & It No, 2. 5END NO MONEY- U5ETHE COUPON Walkervlllo, Ont. 4€ Think Beyond ^ur Job! ^^ "There is not a man in power at the Bethlehem Steel Works today." says Charles M. Schwab, in the American Magazine, "who did not begin at the bottom and work his way up. These leaders rose from the ranks. They won out by using their normal brains to thini beyond their manifest daily duty. "Eight years ago Eugene Grace was switching engines. His ability to out-think his job, coupled with his sterling integrity, lifted him to the presidency of our corporation. Last year he earned more than a million dollars. "Jimmie Ward, one of our vice-presidents, used to be a stenographer. But he kept doing things out of his regular line of duty. He was thinking beyond his job, so I gave him a better one. And he has gone up and up. The fifteen men in charge of the plants were selected, not because of some startling stroke of genius, but because day in and day out, they were thinking beyond their jobs." -TEAR OUT HERE What about you? Are you satisfied just to hang INTERNATIONAL CORRESPONDENCE SCHOOLS on where you are? If so, rest assured that's as far as Box 5375, SCRANTON, PA. you'll ever get. But \f you want to be somebody, to Explain, without obligating me, how I can qualify for the position, or in the climb to a position of responsibility, get ready for it. subject, before which I mark X. Do what you are doing no^w belter than the men a ELEfTRICAL ENGINEER n Bridge Engineer nTRAFFlO TIA\A Make 3«>ur start NOW. Mark and mall this coupon. Occupation _ Employer INTERNATIONAL CORRESPONDENCE SCHOOLS Box 5375. SC:RANT0N. PA. StreetandNo _ City _S^'ff_