The Institute Conversazione

Saturday, April 20, 1901
Archived Page: 

266 as in other electric lamps. Mr. Ile\vitt`s gas is mercury vapor. The lights are long and cyl- indrical in shape. r\t the bottom of each lamp is some mercury, from which, when the current of electricity has been run through it. there issues the vapor referred to, The current is transmitted tn the mercury direct, The most peculiar colored light is emitted from the tubes. It is half purple. half green. This, according to the explanation of the exhibitor, is a disadvantage, but it can be obviatcd by the use of counteracting colored shades. The reason the crowd seemed to bc especially interested in the long tubes was the fact that everybody wl\o came into the room had his or her features so dis~ torted that the skin of the face appeared to be covered all over with ghastly, violet-colored erup- tions. The lips that came under the light seemed purplish gray, the pupils of the eye lost their nat- ural hue, whatever it had been, and assumed a green- ish tinge. RYAN AND PHELONIS RAmoanai=HtNu or ALTERNAT ING-ctnuusnr WAVES. Professor Harris I. Ryan of Cornell University and Professor ]. O. Phelon exhibited a most valu- able application of a Braun tube in radiographing of alternating-current waves. This is a method for securing stationary and continuous diagrams or cards of alternating»currcnt values, which are cou~ veniently recorded by means of a simple form of pantagraph, that is run over the luminous diagram and operates a lead-pencil. HUTCHXSON,S Anoornosr. M. R. Hutchison exhibited two instruments known as the alcouphone and akoulalion, and which are in- tended to make the deaf hear. \V. H. Van Tassel of the New York Institute for the Deaf and Dumb brought eight of the deafest boys in the institution for experimental purposes. One lad was born deaf. dumb and blind. He was led to the apparatus and the earpieces Fixed over his head. The operator spoke into the altouphone, which is described as a microtelephonic instrument, so con- l i | > 1 1 P fr .` ,|‘ ‘fir / ` It, _ A \ t FIG. 3. THE INSTITUTE CON\'ERsazxcNE_-ANDREWS' SPARK EXPERIMENTS. structed as to reproduce and largely intensify sounds and still preserve their quality. The boy jumped when \vords were spoken, showing the novelty of all sound to l1im. \\fhen the \vord “hello” was re- peated many times he made an effort to repeat the sound. with only partial success. _-\ phonograph was attached to the receiver and band music was played. A faint smile appeared on the boy’s face and he spelled out the word music with his fingers to his preceptor. He began to keep time with his hands and his face was soon wreathed with smiles. l-le resisted when the cap was removed from his head. Mr. Van Tassel said experiments with the akou- phone on another inmate of the asylum had resulted in great success. ELIHU TnostsoN’s APPARATUS. Professor Thomson showed a dynamo static ma- chine, containing a small direct-current motor, the windings of which are tapped and connected to two rings, giving a primary alternating current for the operation oi a step~up transformer, which gives a secondary current of about 20.000 volts. being capa- ble, however, of regulation through a wide range. The tops of the alternating»current \vaves of high potential obtained from this secondary transformer are used to charge a number of glass~plate condensers in parallel. The rotating frame synchronously driven with the motor makes the connection to the con- densers periodically and in synchronism with thc alternating current. The connection by the rotating frame is alternately in parallel and in series, corr denser plates being charged to 15,000 volts and with io in parallel, giving 150,000 volts when corp nected in series. The machine therefore furnishes from low-pressure direct current, high-potential dis- charges of definite polarity at the discharged termi- nals. A new rotary electrical apparatus. consisting of an iron sphere heavily clectroplatcd with copper and mounted so that it may revolve on any axis oi in any plane. was also exhibited by Professor 'l`hom~ son. Surrounding this sphere are three coils in planes. at right angles to each other. By suitably energizing these coils with polyphase current, the WESTERN ELECTRICIAN sphere may be made to revolve on any axis or in any direction, or it may be said to illustrate a three- diniensiou polypliasc system. This apparatus illus- tiates the principles of the gyroscope and Bohncn- hergcr sphere. r\ third device \vas an illuminated disk mounted nu a shaft free to rotate and having applied to it in special way< alternating-currcnt magnetic fields, the rotations of the disk involving interesting para- dows. .~\xr>tt-was rt-vtdved while illumincd by the discharge, the optical t-ti`eet being a circle of bright radial lines. Under these conditions, the number of primary radii is ob- viously determined by the ratio between the alternii- tions and the speed of rotation, but the character\s~ tics of the primary radii may be changed by n~ianip-- ulati<»n of the apparatus. Referring to the theoretical diagram of high»ire- quency apparatus shown in Fig. 2, when the spark gap is set at a certain length and the potential of ihe transformers adjusted. so that the condenser discharge will only just are across it, the radii will appear as single lines, indicating that the condenser discharges only once during a half wave. See (A). lt-`ig,` 3. If the primary potential is now increased. or it the sparic gap is shortened. the single radii will he seen to open out like a fan into two or more lines, thus indicating a corresponding number of condenser discharges during each half wave. See (B), Fig. 3. To obtain permanent records of the different ef» it-cts. photographs were taken. Fig. 4 shows a snap exposure of the high»frequency sparks during two half waves. Fig. 5 shows a star produced when the tube was revolved at 430 revolutions per minute. During each half revolution eight compound radii were 1'orn1ecl in each half of the circle, corresponding tri eight half waves in a 58-cycle current. "It would be difhcult, if not impossible," says Mr. .-\n` i n!/// l' //30 7~.,~¢.;,1, i ' l FIG. 5, THE INSTXTUTE CDNVERSAZIONE_-ANDRE\\'s' SPARK EXPERXMENTS. chronism and the phase relations of their electro- inotive forces \\'as the exhibit of Mr. Charles L. Clarke. It is also applicable for showing the lag of a current behind the electromotive force. either in the same or another circuit, provided they have equal frequencies, and also for showing the phase re» lations of currents of the same frequency. The in- strument, as exhibited, \vhich is intended for use in lighting and power stations, consists of two synchronous alternating-current motors, which re- spectively drive two stroboscopic disks, the strobo- scopic image formed opposite a scale indicating when the generators respectively supplying current to the motors are in synchronism, or nearly so, and, in the latter case, which of the generators is running at the greater polar speed. V\'hen the generators are in synchronism, the stroboscopic image is stationary. and its position relative to the scale indicates the degree to which the electromotive force of one gen- erator leads or lags behind the electronlotive force of the other. IUISCELLAXEOUS EXHIBITS. Mr, Otto T. Louis sho\ved an electric furnace consisting of several terracotta cylinders, about two inches in diameter and one~half inch thick, around \vhich is wound platinum wire of 22 B. & S. gauge. The wire is put on in four circuits, so that. as the resistance increases \vith the heat, the circuits may be thrown from series to parallel. The cylinders have longitudinal and vertical motions, and are held in position by clamps. Mr. Louis also had an ohm- rnctcr for making direct measurements from 10.000 to io,ooo,oo:> ohms and a 55-centimeter \\'imshurst influence machine. Other exhibits may be mentioned as follows: Mr. E, V. Baillard.-Faraclmeter and bridge for measuring low resistances. Professor George F. Harker and Professor Arthur \V. Gotidspeed.~Radio|:raphs. Mr. A. F. Clift.-»'l`eIpl1erage system for the trans~ portation of freight in small bulk, express matter, mail, etc., by means of an electric motor traveling

WESTERN ELECTRICIAN Vol. XXVIII. The Institute Conversazione. In the dictionary 21 eonversazione is defined as an assembly for conversation, “particularly on literary or scientific subjects." But the gathering at Colum~ bia University, New York. on the evening of April 12th was that and more, being also an exhibikiun of one evening's duration of the latest advances in the science and art of electricity. It was held by the American Institute of Electrical Engineers, with the co-operation of the university authorities, and was .1 brilliant success. The effort to present electrical features of real novelty was satisfactorily carried out, and the attendance was worthy of the exhibits and demonstrations, including such men as Edison, Tesla, Elihu Thomson, Sprague, Bell and Pupin. The affair was held in the Engineering building and Haverueyer Hall, the latter being de- voted exclusively to Tesla's demonstrations. In all there were 32 special exhibits, A collation was served on the third floor of the Engineering build- ing. The committee of ar- EVERY SATURDAY. CHICAGO, APRIL zo, 1901. highly interesting character. Edison's entrance and later that of Tesla were greeted with cheers by the Columbia students. Tesla explained that he was going to use an electric oscillator to produce wave vibra» tions which were to be discharged in various parts of the room by means of a large transmitting cable. The brillianey of the electric light from a large coil was made to decrease and diminish by Tesla rubbing his hands along the sides of the coil. Geissler tubes were made fluorescent, and a beau- tiful effect was produced by waving vacuum tubes charged with the electric current. The later experiments partook of the nature of the results obtained by induction currents. A glass moon was lighted from a huge wire coil, the current passing through the air as in wireless telegraphy. Tinfoil was heated from the center of the coil. Vl/hen the coil was short-circuited, the foil heated so quickly that the demonstrator dropped it with smothered exclamations, BQ( far the most spectac- ular performance was the last. A huge. Hat coil, I0 feet high, was constructed in the front of the room and the current turned on in full force. Sparks No. 16 cylinder. Automatic synchronizing apparatus is pro- vided. ln the experiment arranged for the Insti- tute Mr. Palmer was at the New York end and l\Ir. Mills in Chicago. The accompanying picture (Fig. I) shows the instrument set up in z\ room at the Quadrangle Club of the University of Chicago and was taken on the evening of April Izth, at the time of the test. Mr. Mills, one of the in- ventors. is in the chair in the foreground, with an assistant at his left. The machines will be exhibited nt the Pan-American Exposition by the Interna- tional Electrograph company of Cleveland, of which Mr. Palmer is president. POULSEN’S TELEPX-1oNccx Y £5 -Y-' 'W' YW ' ~ Regting upon the wire_ is S. Barstow, elmirnuxn. and '~ 1 Z; 1 9 [my electrgmagnet' Wlxch E Q; 5 3 cells of battery and pref- ' 'f 'YOF ‘Cry T- M5“`U"v l 535' ;~:‘.' gy erznbly an induction coll. Q “- Rlce and G@<>f1;~2 F- ‘ , 5 'T' ‘_ _` ,_ , - ' \Vhen the transmitter xs bcvcr, The reception com- " "F" "‘j_'E}'l§j§§5%?I »;f4?`i;_- 'fl-_Q14 , 1 , ' 1; ' spoken into. it acts as a mittee embraced :1 long list -j ,V gé TAD 011 the |J0fl€\'Y» CHHSQHZ nf well-lcnown names, with - ` '. .;1.:" lie ~ ' .\ 1 C “ r r 9 " £5 of V.“"ymg Carl Hering as chairman .i~,' 7' ' 'épfféfiz '3f,f, ff, ` - 5 strength' m 1°f0v°1‘f\°“ to Amd R xv PO C as _C Y _ ;:i. ig. Y - ,-gg ' the strength of the sound “_ _Y H` _- D v °bC-éf _f§;.f- ~ -‘$§{¥»`§‘}'“EfE}§~l§L§£'5§_:y§,ifT"‘L`=Ij='_‘» ig` Wi , waves, to pus; through the UU' 5' ‘“‘mEf _~‘l'° U* vi." . ` ' `_17" 1, `f » , _ ‘ I; clcctromzxgnct. The cur- nCCO\\111S of cxhwlufs- ‘ 1 Q ‘V ,_ ‘ » , le; 1 mu causes me magnet PU,,N»S IMWOYEMENT IN ‘ .> R _> . - ' _' , transversely to mngneuzc L0NC_M5T_\NCL TD: . 4 * -‘5 , the steel \\'1re as the drum m,"ON\,_ ‘_j~ V- ‘ - ~ \ ~ Q ` ng ‘il ' ;'e\'ol\'c;. ‘fund the nmgnctic 1"'°f°§S°i1§1-1-.P“1>i“ Qi ’ ' » ' $1 f ,1`le§1‘¥\» 32521- _ _ - A _ -"~. me 10 me wO,dS_Ihe ‘in provement of long-dxstancc ' V ,` , A ' 1] U, - I' d < land and ocean lelcphonv 5* \ Q' l 1 ,gg _ mqgpct ls -[lace m 'ts , _ _ \ I I , -g ~,_”. = . ; .' ` _-. ~ original posmrm and con- consxsung m §1e_0C.111cn 0 _ :~ ,I ` ‘_ _,_ ‘,.l ' ,\i l ‘fl ' d ,- h B U ._. - - , , L , ~.,‘ N ~ _. , .\ Y necte \\1L a e rccenmg mductrmce coils ln Ihe lme »_ »; _ _ -, , _ ~ , = ; ~ - - in distances which are dell- I ‘ ' ‘A ` ‘ ‘ ` ~ `7`f$` ` " mlcphone' The Cylmder ‘S nite small fractions of a ' '_ "Jil r, ` »?“‘__ ' ""\, ' in V '¥ “gm” revo-wed’ and as the current-\\'ave length. This '17 _ 3' A ` ~~~ ' ` , V ' f ' 'F m a g n C t l Z C d Steel “me apparatus was shown in the ' l M ' ""~. 4 ‘ ' \" ` passes before the Poles of basement of the Eu_.,inee1._ > _ \ / -X: ¢ & _I the eleetromagnet xt forms iq building ” _ _ #ts _ _ _ ' 1 /f‘;§;,_ avspecxes of magngLo~elec- ‘ g ` ' _wg -> " - 1 ~ ,‘ _ ,_ me generator, glvlng out '1ESLA'S Ex1>E1<11\1E,NTs. I - V \ ' ‘" currents of electricity of a In Havemeyer Hall, Nik» ;_ ` .¢,§f‘ ‘ strength and direction cox:- ola Tesla performed starv ’ Q f ,_ \'€SDOHdln§ I0 the mH§f\€fl' Hug and 5ugg¢§fiv¢ @?;peri- _ ` if. _ zatlon of the s!§el wire, ments with l-ns osmllator > V 1 ;_vh;Ch §30li\i@iP?Y1q;¥\g]Y hafé -experiments remgrkab e to , ` > ' \ ' ff 3 ff 9 CD U“€ U Sec, yet impggyble ada- l `_ , ' x to the ear and reproduce qualely to describe, An in- ln. __ _,W ` ` - , ._ » _-., ehe sounds and }VOTC|S Oflg' teresting feature of the mally 5P0k€“ “'l}lf* ab5UlUT9 Tesla d€IT|0HSU”2U0Yl W35 ns. 1. THE rNs'rx'ru'r\; coNvzRsAzroNE.-1>x<:'runEf"ta1.EGRAPH MAC!-ima rr cHxcA<;o END ov CIRCUIT. fldellfy' In “dd't‘°"~ there the high tribute paid _ Tesla by Edisorfs presence at his demonstratxon, for Mr. Edisorfs reluctance to attend functions of all sorts is well known, The entrance of Edison was the signal for tremendous cheering on the part of those present, and Tesla’s smiling and evident appreciation of the high compliment paid him by the older inventor was by no means the least inter- esting ieature of the evening, As is often the case where highly scientific demon- strations of an impromptu nature are essayed, and with a short time for preparation or test of appa- ratus after transportation, Mr. Tesla had to suffer his disappointments. In the midst of his most re- markable experiments, and at a point where he had hoped forcibly to illustrate certain remarkable phe- nomena relative to the transmission of energy with- out wires, well known to himself, but it is safe to say, new to the majority of those present, the transformer on the city electric-lighting system, that had been tapped or temporarily installed by the college au» thorities to furnish Mr. Tesla his main supply of current gave out. The manly and patient manner in which Mr. Tesla endured what must have been :\ most trying ordeal won him ihe sympathy of every practical scientific man present. Tl1e'f:\ct, too, ghat he had worked throughout the entire preceding nxght and had brought to Havemeyer Hall nn astonishing amount of heavy yet delicate and intricate apparatus, earned him the thanks of everyone present for his ef- fort. ns he smilingly put it, “not to instruct, but to nmuse." Fortunately for Mr. Tesla. lmwever. he “Ins enz\l1lc<1 to make an exhibition of high-frequency m- duction effccts and of high-tension discl1:\r;;es of a leaped six feet in all directions from the end of the Wire, and the heat was so intense that the insulation hegan to burn. The audience felt uncomfortable and Tesla smothered the flames, remarking that “It’s just nothing.” PALMER AND MILLS’ PICTURE TELEGRAPH. H. R. Palmer's and Thomas Mills’ “facsimile pic- ture telegraph” was one of the exhibits. This in- strument is worked on a system whereby half-tone pictures, sketches, handwriting and the like can be transmitted over long distances by employing ordi- nary electrical circuits. An attempt was made to send and receive pictures to and from Chicago, the instrument on exhibition having been connected with long-distance telephone wires. but the experiment failed this time, although the emcacy of the appliance has previously been demonstrated over long distances. The explanation for the failure was that the induction in the under- ground cables in New York caused the trouble. It is not claimed that this apparatus is entirely perfected for commercial use not that it involves :my new principle in picture transmission, the idea lvcing (0 utilize synchronously revolving cylinders, the one at the transmitting end having the picture 011 a prepared zine plate treated with an insulating <’<\n1nmmrl to break the circuit of a metallic stylus in contact with it. At the receiving end is a dupli- cate machine, in wlmich. however, a pen takes the place of the siylus and produces, on a sheet of paper on the receiving cylinder, the outlines or dots trans- mitted hy the electrical impulses of the transmitting was shown the band form of telephonograph and a dictation machine for ogice use. The band form gives the machine a practical value, as it makes it possible to extend the dictation almost indefznitely. The record is wiped out at the will of the operator, or retained permanently. There is no waste of material. The telephonogrqph zs not yet considered perfect by its inventor, who lS eonstantly at work upon it, The reproduction 15 slmxlar to the sound of the telephone, the buzzing of the phono- graph being Obviated. HEWl11`,S MERcvRY»vAPon LAMP. One of the most remarkable exhibits, clue largely to its importance as bearing upon the future of the m~ ezmdescent electric light was that of Mr. Peter Cooper Hewitt. With a knowledge of the present efficlency of ordinary types of are and incandescent lamps and also ihat of such lamps as the Nernst, Mr. I-le\vilt’s record with his mercury-vapor lamp, pp- elniing at 74 volts with three amperes, consummg a total of 222 watts and giving 700 candlcpower, nr. in other words, giving light at the rate_ of 0,32 want per candle, measured lmrxzontally at rmght an- gles to the tube-such a lresult as thw me:\ns_ some- ihing to the electric-lrm1p mdustry. Mr. Hewitt was 1mtur:\lly very solicilous lhnt those nrescnt should use the nmmctcrs and volimeters for themselves, and many veriflcd the tests. This mercnry»\'npor lnrpp f\pprn¢¢»q on nu-flinnry H5-vnly, cr]\1

April zo, IQOI 207 upon an overhead cable obtaining current by rolling contact wiih a lighter \vire above. Dr. Francis B. Crocker.-Magnetic liquids, with apparatus in operation for showing the magnetic properties of liquids and for measuring their per- meability. Mr. H. P. Davis.-Two switchboard panels, show- ing principally a phase-shifting transformer, 2. power- factor indicator, a. synclironizer, an alternation meter and various new indicating and integrating instru- ments. Professor W. S. Franklin.-Magnesia arc lamp (an electrolytic lamp on the Nernst principle, op- erating on x,ooo volts). Dr. \Villiam E. Geyer.-Incandescent-lamp ex- periments. (Experiments employing incandescent lamps on circuits containing self-induction and ca- pacity). Mr. Caryl D. Haskins.-Power-factor indicator, showing relation between real and apparent energy in an alternating-current circuit, and single-coil astatic instruments, which, instead of using four coils, employ only one. Professor Frank A. Laivs.-Radiographs of al- ternating-current wave forms and oscillatory dis- charges, made by the use of cathode-ray tubes oi the Braun pattern. Colonel Samuel Reber, U. S. A.-\Vireless teleg- raphy in operation, employing methods and im- provements as worked out for the use of the United States government; also field telephone and tele- graph kit used in the Cuban and Philippine cam- paigns. Mr. Martin P. Rice.-New X-ray apparatus, em- ploying a modified form of \Vehnelt interrupter. Mr. L. T. Robinson.-Wave-form indicator, con- sisting of a small synchronous motor in connection with suitable commutating devices, and used for determining the wave shapes of alternating current. Mr. H, F. Sanville.-Copper-splicing machine. consisting of a portable and self-contained splicing press. with independent pump and flexible hose. used for making a solderless splice in wires and cables. forming a cold weld. This machine has an ability to give a pressure of 20 tons per square inch in the weld. Mr. E. T. Schoonmaker.-Floating magnetic field. Mr. Fitzhugh Townsend. - Alternating-current \ra\'»: tracer. (ln this device the Contact is made during one-half of thc period in contradistinction to the instantaneous-Contact method ordinarily em- pl03'\‘\l.) _ WESTERN ELECTRICIAN