Can Radio Ignite Balloons?

Wednesday, October 1, 1919
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October, I9 l 9 ELECTRICAL EXPERIMENTER Balloons 'T Can Radlno ignite (Couliurwd from [mga 516) WHAT NIKOLA TESLA SAYS Probably no other living electrician could be found today \rho can more authorita- tively state just what effect can be pro- duced at a distance hy radio c\\rrents, than Dr. Nikola Tesla. lle has produced and measured the greatest electrical discharges ever developed by man-sparks 70 to 100 feet in length, which manifested their in- fluence 12 miles and more distant. In a special interview with the Etccrruc/u. Ex- t-|:R1McN'n;n representative, Dr. Tesla said in regard to the present hlimp disaster: “Referring to electrical or radio wave action at a tlisuutce, I know from experi- ence that if proper precautions are not taken, fires of all kinds and explosions can be produced by wireless transmitters. In my experiments in Colorado, when the plant was powerfully excited, the lightning arresters for lwtltfe 1ni/vs around were bridged with contintlons arcs, much stronger and more persistent than those which ordi- narily took place during an electric storm. l have excited loops (coil aerials) and lighted incandescent lamps at a colisider- able distance front the lnliorzitni-y witlnint even using more than tive or ten pct' cent of the capacity of the transmitter. When the oscillator \vas excited to about 4,()00,0t)0 volts and an incandescent lamp was held in the hand ahout jifly or ri.rIy fur! from the laboratory, the filament \vas often broken by the riliration set up, giving some idea of the magnitude of the electro- motive forces generated in the space. The accompanying illustration shows one of my experiments in which I lighted several lamps at a distance of 100 feet from the laboratory, purely hy wireless energy. Such induced currents might easily fire a gas halloon under the proper conditions. When the large transmitter coil, 51 feet in diame- ter, which I had in the center of the labo- ratory, was powerfully energized, butter- flies were carried around in at circle as in a lntrricnuc zunl could not get out, no matter how they tried. l was unalile to satisfactorily explain the gyrntious in the circle, altho I can well understand that the charged coil might, hy repulsion, keep them in the center. Perhaps the most remark- able of all the observations was the pro- duction of sparks in the sand \vlten one walked at some distance from the huilding. At night a contintuius stream of tiny sparks could he seen hetween the hr-els and the earth and ln-t\ret-n the grains nl' sznnl. An- other 'ntost curious ellcct was the action on horses, which shows ho\v very sensitive they are to electric shock. V\’heu l oper- ated with uudamped waves, the oscillator being perfectly silent (no streamers what- ever), a horse at a distance of perhaps one-half u mile, would become scared and gallop away the instant the switch \vas thrown on. I suppose the capacity of the body was sufficiently great to derive a rather strong current thru the legs which would frighten the animal. \\'hcn using damped waves the roar was so strong that it could lie plainly heard ten miles away and despite all precautions, such as using cotton in the ears, one would get a singular sensation in the head as if something \vas bursting, similar to that I ol>st-rved with Riiutgen Rays in 1890 or ’97, when l was opt-rating' with at powerful apparatus de- signed for their production. "In my experiments in New York in the laboratories at 35 South Fifth Avenue and at Houston Street. 1 have exhibited to thousands of people etfeets of loops or coil antennae. In one experiment, for instance, I would tune a coil about 30 inches in diameter with which I would collect at

ELECTRICAL EXPERIMENTER October, l9l9 a a s gm ac %@[email protected]@ s? 516 S at result ut lliu iwiwsl lln~t»r;. lltiu |»t»\vt~t-[nl iutlurt--l <-n|\<~nl~ t-n\;\n;t|- ing funn thc l\la\:l| |{:idi<| Slnliun Chicago produced thc spark that ll\ ignited thc Gomlycnr dirigihlc air- sllip which plunged in llanies thru the roof of a hank ltuilding in that city. resulting in death lur thirlccu |\cl': ll “ 5, li’ _"___ _ . . . . _ _. _ _ _ . ,_ __ . ~ ___-_ __ __.__--> - l fit. _ t tt 4 ‘ _:I-L* .__ ,. 'yr--2: ,~ ‘ I .i-Qt.. - ' " _ ‘ _tgmj _ 1 . ‘ 'W / ~ / ` _ ’ ~ _ _ _ _ ,__ - 1; 1 " " 51/"__ =,,._|. ' _ _ _ __,__ _ _ / __ _ 1 _»- _ _ _ _ ___ `;_- _ _ ,_ _ / _ _ »- _ j. ___ _ , - _f ~..._f___f; _ _ ' _ -- ._ . i nu, -l \ \‘~".1,___’_ _ _ ____ ,I _ _ _ _ _ __, ,_ ,__ ._ __ __ \\ _ -7, t __ _ _{____.____ _ ._ _*___ ___(_%___ _ __ _ _ {_ __ 'T _ _ \ _'- '~'-“_ __ _1_l'1'l1/lil' ~---_ L _ ._ . , 'we ~+ - - - »- - 4 __ _ ___,_ _ *str* ' ~ E l __ * ; J J. L ; 1 1 3 l l rtffi "4 “__ ‘i l ii W i l l i ' it? Ili Ei" _ _ _ _,__. _,_ x _____i_ ; _ _;_ 1; =__ __ ‘ ‘_,,.._~- _ __ _ _ _ , _s_. __;;_;,_ \<_m,.____“__;__ ___,. _ _ _ _ __ , _ - _ _ -_te-~ f i » _ __ ~ _ m; . - t i_______é,/ _ , __ _L_ <§~;_____ ___ ._ - _ ,tl"'_' _ _ lr ti' - - _ _ , ' "" T 'V *75}.i'_»iiiA "6"-~ "<‘ f- ` ' ' :~-if ‘ t .. "7l ‘ti 1 ' .auf/3-~§¥ _ j __ .__ 1% f' _, -,tr , _ »1~“'~ ` "` ' - _ ' _ ta; _ f ,_ l ’=?_§§ '_ fs _1 _ _ »»*_»Li ~ ‘ , ~ ,tri _~ £‘ ‘ _ _ __ T.. _ li--» _ _ - .nt _l 3 \ = . _ 'w ____ e ‘ 1 _‘ _ _,V __- ._q_` -' 7 ___'_ ._.__ _ _ _ _ ts" ~ ~»' =f~'- 2 _ ’ _lat ‘_ Ag "‘ ' °~ “r `i "9 in i A A 'fi _~_».‘L,j,..;..x.£.,_‘ ‘_ _ _ 4 __ _*_ - T- _ _ __ _ I ~ T .- _ ‘~ nltkix _ vw _ ret - - f /‘f"_: __ .- <.¢‘ ,_;”f,_ Sl _/_/ ,-~._ _ ..- __ __ },_ \, ‘_ [ti ` _ t-.~` . '/.' ‘ _ . "t l _ \ - _ _ ' ;_ "__ »f"" ` "“"“ ` '_ ` _ _ _ _ _ ’»_*§/ ~ ~»l _ ~\ \ E' __ #14 ,ff f - 1 ~ ' ` ' ` - ~ ri ' .f _ ‘ is , a- "7 " _ l --"'r ' 7 ff _ _ \ . _ , lag __ _ _ ____ _ ~ _ _ _ \ i _. _“_ _ 5* N _ l _ 1 ~ ;; __ ~ ' l :¥lt”~:‘@,=l.;;_ L _ so _ . 1 -*We __ tif; Ev / t , J l`l . SHN, Ili VT. |'. Cu, Herewlth Are Shown Some of the Plauslbte Reasons Why the Recent Chlcagc "BIlmp' Dlsaster Mlght Have Been Caused By a Spark Induced Ey An Adjacent Radto Station. The Photo tn the Lower Right-hand Corner Shows Three Incandescent Lamps Llghted to Full Candlepuwer, At a Distance of 100 Feet from Dr. Nlkola TesIa's Colorado Hlgh Frequency Power Plant. The Oscillator Was Worked At Less Than Flve Per Cent of tts Total Capaclty. t\vcl\ty-surclt others, naval uunnnnnicatiun ullicr-rs will aid thc authorities in fixing rcsptlllsiliilily fur tllr disastul, lt nas as- \'c|'tailwtl that lcclulical experts had sug- ttcslcd llzix theory, hccausc the hig ship sailcd ovcr or nuar the Tralistlurtatiull liuilding, from thc roof of which arc pru- jcctcd the antennae of thc Naval Radio _ Lieut. F. 5. Mason. ul the Great Lakes Naval 'l`r:\iuill;.{ Station, district cunintnlli- <~atiu;;llt thc tiussiliility of sparks front thc rxllansl ig- niting thc gas hay; very remote, but said he had not formed all opinion as tu thc Cause uf the accident. ((`m|1i1lllt‘d ull /lllgu 591)

ELECTRICAL EXPERIMENTER October. | 9 l 9 any place in a large hall. ncnrly llxrve- quarler; of a'/lower, lighting incan- descent lamps, producing long discharges, streamers, etc. One of my exhibits, which was particularly appreciated, was a coil car- ried on the head which, when resonantly excited, would develop streamers several feet long. "As regards that d¢~plor:\hle necitlcnt tu the blimp in Chicago, of course a powerful wireless plant is capable of setting up, at a few hundred feet distance, electro-motive forces of such magnitude that if there is even moderate rise thru resonance, long sparks may result. In Colorado I drew l- inrh spar/ts bctwreu my body and an iran /ri/tr' buried in Nu: ground about 100 frrt from the laboratory. I think it perfectly practicable to produce an explosion by wire- less designedly at a considerable distance from a wireles transmitter, and 1 look upon the accident as very likely having' been due to some such cause. By taking proper pre- cautions, however, it is possible to entirely eliminate this danger and I have devoted much thought to the subject, having early recognized thc peril to such bags lillcd with hydrogen. According to my ideas, the ac- cident is not so much chargeable to the plant as to the neglect of proper precau- tions on the aérial vessel itself. Such a vessel has a considerable span and the guy wires, gondola and other metallic parts constitute a considerable capacity, so that an appreciable amount of energy can be de- prived from a \vireless plant at a great dis- tance, as it is well shown in the ease with which messages are transmitted to, and received from, aerial vessels. "Why do the naval and other authorities allow such forms of aircraft to use an ex- plosive gas like hydro cn? A short time ago the press was filler? with the wondrous stories of how the U. S. Government ex- perts had perfccted the manufacture of the new! and non-intlammable balloon gas- lnclium, to such an extent that it was very cheap and readily obtainable in quantities. Funny, how these "new" inventions require so long a time to reach the public and those \vho need them. Helium, extracted from illuminating gas, is not new or wonderful at all. My friend, Sir james Dewar, showed me experiments with it over 20 years ago." How radio waves, even at distances of several miles, can cause sparks to occur :inning bales of cotton, lmled with wire lumps, etc.. is slniwn i|\ one of llle necmn- panying illustrations. 'l'hc cotton hnlc wires have currents induced in them every time a radio message is sent from the ship or in its vicinity. This induced current is prac- tically neyer strong enough to heat up the wire, but should one of these wires break and form a. spark gap, then very often the induced current will cause a spark to jump the gap. That is enough to start a fire. Where wired bales are packed close to- gether in the hold of a steamer, in trains, or warehouses, here also radio \vavcs are liahle to cause fairly strong electrical oscil- lations to be set up by resonance in adia- cent loops on the bales, as the diagram shows. Result, a spark occurs, and an- other fire of “unknown origin" has started. M. George A. Leroy, a French chemist. i\\ his municipal laboratory at Rouen, France, very ahly demonstrated that wire- less waves could without doubt cause Gres at a distance. His apparatus is shown schematically herewith. Mr. Leroy’s apparatus has been christ- encd by him the “Igniting Resonator." The apparatus he used consists of a glass bulb having four apertures; one at either side and one at the top anal hnttnm. respectively. 'l`ln° suhstmlce to he tested with tlns ignitcr resonator can he plnccsl in the airtight glass cotnparttuent and tl\e two electrodes very accurately adjusted hy micrometer screws fitted to them. The transmitter comprises a spark coil giving a 15-10-20-

ELECTRICAL EXPERIMENTER October. ' I9 I 9 wireless station of even a fcw kilowatts, that the Editor! would prefer to stay on land than go to sea on such a ship. One of the accompanying photographs shows how a great multitude of close oscil- latory circuits are provided unwittingly in all-framed or rigid gas airships, and even in the non-rigid gas airships there is nsn- ally :i suliicient nmonnl of metal :resent in thc gondola, wires and other fittings tu form one or more resonant circuits, which may cause a spark at an imperfect joint or other gap. It should he remembered. as laboratory tests have demonstrated hc- -yond cavil, that it is not necessary to have a metal wire coil in spiral form in order to have powerful currents induced of suffi- cient strength to cause a spark to jump from it: a straight metallic wire, bar or even tools, lying within a few yards of small high frequency coil, will pick tip snfiicient energy to cansc sparks to jump from them, and they will sometimes glow with a vivid brush discharge when viewed in a darkened room.

October, l 9 l 9 ELECTRICAL EXPERIMENTER inch spark, which was connected with a spark gap, glass plate and tin-foil condenser and a loop antenna or spiral comprising a few turns of heavy \vire, aliunt 2 ft-ct in diameter. Several yards distant, l\Ir. Lei-ny placed his receiving coil or igniting reso- nator, \vl\ieh included a loop or heavy cop- per conductor about three feet in diameter. The action on the device was similar to that of the Ilertzian resonator, i. e., \vhen- ever the spark coil or transmitting helix were excited, allowing a spark to jump the gap, electromagnetic waves were set up in the intervening ether, causing corre- sponding currents to be induced or set tip in the receiving loop, As in the historic experiments of Hertz, this loop \vill gather s\tFficient energy from the etheric waves to cause a small spark to jump a gap con- nected across tlte terminals of tlte loop, as the accompanying diagram clearly shows. Mr. Leroy carried out many diFferent ex- periments with l\is apparatus, placing the glass spark chamber ot' the igniting reso- nator in a bath oi oil or vaseline, which can be heated when desired by incandes- cent lamps, etc. One of the most interesting experiments carried out by Mr. Leroy \vas that with miniature bales of Cotton, which were en- closed in jute wrappers and provided with iron wire hands, in the way cotton is usu- ally packed for shipment. “Spontaneous coinlmstions in cotton wareltouses and in shiplnrlds loaded with cotton or siniilar material, are not always what they seein," says Mr. Leroy, in describing his experi- ments and results with the radio igniter. One of the hoops encircling the bale of ra\v cotton may break or become loose under the action of shock or from some other cause, and the gap created by the breaking of the wire, forms a miniature Ilertzian resonator. When a wireless station situ- ated in the immediate vicinity, or perhaps at some quite distant point, starts in to transmit (and the more powerful the sta- tion the more pronounced the effect and danger from fire of course), currents \vill be induced in the iron wire around the bales or other packages, and sparks may pass between the various metal members, Especially will they he inclined to jump small gaps in the wire which occur in the immediate loop. \/Ve may say right here, that to a layman all of tltis phenomena may seem somewhat far~fetchef.l, and not within the realm of everyday possibilities, but anyone who has experimented with high frequency currents, as generated from even a small size oscillator, will at once be convinced that these effects can and do take place under most unbelievable condi- tions. Of course, one objection that the average electrirzil and radio rrzuler \vill prtibalily think uf, is that if tl\e cnttmt bales, et cetera, arc placed in a steel vessel, that this metallic hull will act as a screen, and that the bales will not have any current induced in their wire loops, but \vhile this lnay be partially so, in some cases it is not always so by any means; especially \vhen the home transmitting station, such as on ship-board, starts in operating. In this case, the steel lutll of the boat is charged whenever the transmitting key is deprest. The secret, if so we may call it, of the production of inflammatory sparks or dis- charges in metallic bodies such as here de- scribed, iies in the phenomena known as “resonance” This means that the nearer the metallic members come in tune with the radio waves, the more pronounced the induction effects prmlnceil in ant' instzntee. lt is uf course readily ctnu~eiv.\|~lt~ that a cargo of cottun bales presents many pe- cttliar conditions of resonance, due to the varying capacities and inductances of the various loops. ln fact, so obvious and pos- sible is this eonditiou, that a wooden vessel carrying bales of cotton or other material having wire or metal members to hol-1 them, and providing she is titled with a