WATER WIRELESS TO DETECT SUBMARINES.

Oamaru Mail, Volume XL, Issue 12541, 12 May 1915, Page 8

WATER WIRELESS TO DETECT SUBMARINES.

(By Cleveland Mofiidt.'* About the middle of December, IPH, there returned i'rOiy abroad an America u inventor, Professor P-, A. Fessenden. who reported to his associates in I Ui<! Submarine Signal Company, of Boston, Massachusetts, that one of the great European Powers (.1 am not at liberty to say which one), after thorough tests, had decided to equip severalof the. battleships with the Fessenden eletcric oscillator, an ■instrument that promises to change the conditions of naval warfare, especially the relations of battlesihps and submarines. He announced, furthermore, that another great Power was' hi active negotiation tor this American invention, the practical value of which will probably be demonstrated with startling effect in cue of the non-distant sea battles. To put it simply, this Fessonden oscillator is a .submarine _ sounding apparatus that sends its signals through the water, not through the air. one result being that these signals travel more swiftly than they would through the air. since sound moves through water at the rate of -1100 feet a second, while through the air it. moves at the rate of only 1100 feet a second. Professor Fessenden\s system of submarine signalling is really a kind of water wireless, destined, perhaps, to as important n development as .aerial wireless.

STRANGE APPARATI'S. A Tow weeks ago in Boston I hud a alk with Professor Fessonden about lis invention, at the factory of the Submarine) Signal Company, a grimy nd resounding establishment, the irthplace of submarine hells, scores ot vhich are now clanging forth their I'arnings under tin? -sea, electrically oi meumatically, on buoys or lightships paced along the perilous ocean fringe.if many lands. ) found the profes.soi n a laboratory"room lilled with strangt apparatus, electrical instruments. ; ncdol of his improved iceberg detector md various other indications of an in -■entire mind. All his life Prei'.' or Fesseuden ha: )een an active ex : ;.vr in new fields o knowledge. For years he was asso •iated with Thomas A. Edison. H< ivas one of the pioneers in wireless tele graphy. and his system of wireles: transmission is \\sei\ in the great Ar lington towers at Washington. Als< his system of electric power transmis sion was used by the Canadian Govern ment in distributing the energy of Nia gara Falls through the province of On tario. For years he -was professor o electricity and physics at the I'niver sity of Pittsburg. 1 have never met man more keenly interested in mor different kinds of things. In one corner of the factory in fenced-off space we came to the new born oscillator, a smallish metal affaii no bigger than a sewing machine, wit many copper parts for the clectricn connections, and a drumhead of soli steel, twenty-two inches in diametc five-eighths *of an inch thick, thn vibrates astonishingly under the clcctri current and gives forth a sound of tci rifying loudness. "But it will be unendurable on .'hip, a thing like that, sounding all th time," I said. HUNDRED MILES RANGE. The inventor .shook his head. "Who you hear the oscillator sounding on vessel you will scarcely notice it. Hei wo are right at the source of souiu but on a ship the oscillator is deep dow in the hold and is submerged i water.'' , "AYould these vibrations be tram mittcd through the water to a considci able distance?" I asked. "To o. very considerable distauci 1 AVe have already received them at distance of thirty-two miles, but, th; is only a beginning—like the first wir less message" across the English Cliai ue'l, which" seemed wonderful fiftee rears ago, but is nothing to-day." "Do you think it will be possible 1 transmit these water vibrations ore say, a hundred miles?" "I have no doubt of it, perhaps sev nil liuedred miles, with larger o.scilh tors and more powerful currents.'' ' "And you will be able to send me sages in this way through the wall itself, with no wires or cables''" "Exactly. It. is simply a matter i leaking the oscillator toot out dots ar dashes according to the code. Now y< ,«ee the importance of these oscillate in naval warfare, for a battlesh equipped with such instruments (•;■ talk to its own submarines win they are miles away and submerge! gaud can actually direct their mov * ments against an enemy's vessels." "But this has never- been actual accomplished, has it, the control submeraed submarines from a battl ship?"" j RECEIVING SIGNALS. ! "Not yet. but it .soon will be aecoii plished. ' We have already put oscill tors in several American battleship the Wyoming, the Delaware, the Uta the Florida, and in four of the I'niti States submarines, the 1)1. and D-. tl Kl and K2 ; and we are now in.stallit them in battleships of a great torch. Power." I asked about the method of liste : ing at a distance to these water wir j less signals, and Professor Fessendt i explained that this may be done in i temporary way with the help of • microphone lowered, for instance, fro a lightship, or from a vessel at aneho This microphone is connected with : ordinary telephone headpiece, throuj. which a listener on the deck may hei signals sent through the water by ; . oscillator miles away. i "As a permanent listening arrang ' ment," continued the inventor, "we u the os'.illator itself, which is really kind of telephone." "Does a vessel need more than oi oscillator?". j "Yes, it needs two, like two ears, oi on cither side, 'which allow it to fix tl direction froni which.a signal come j This is done by a delicate ivistrumei ' that takes account of differences in tl intensity of a- given signal as heard I i the two electrical ears, one of wliicl . on the more favorable side, hears tl ; signal more distinctly than the othe ! A ship's, officer has only to adjust th instrument and then read oil' on a di. the exact point of the compass frowhich tile .signal comes." i "Then a battleship, as it receive water wireless signals from one of i own submerged submarines, could to in what direction that submarine lay? i "Within a few degrees, yes. In sue ! experiments our errors in fixing th ' direction have not, usually exceeded ha I a point of the compass." | "How about the distance of a sul merged submarine from a. battleshiucould the battleship tell that?" | "Yes, approximately, by the' inter • sity of the sound received, for, c; course, the oscillator's loudness grow loss as the distance increases. Ther j will be a distance indicator with a dip | graduated in thousands of yards, an- ! an officer will read off these di.stanc | indications just as he notes the point i of the compass." j "Your invention increases the terror lof the submarine," I said. "It leave j the Dreadnought practically helpless." j Tlie professor shook his head. "Tha is true for Dreadnoughts not equippot j with oscillators, but for others that an ' able to listen with electrical ears, tin submarine becomes far less formidable The oscillator makes it possible for ; j ship's officer to hear the propeliei i movements of an enemy's .submarim while it is miles away. With, our exist ing apparatus we can detect such pro. poller sounds at a distance of tw< i miles, and we have a sound amplifying i device that will extend this distance U live miles or more." | SAFETY FROM ATTACK'. "Does that mean safety for battleships from submarine attack?" "A great measure of safety, yes." "Then those three British cruisers that were sunk by German submarines could have escaped if they had carried these listening oscillators?" "Unquestionably." "What would they have done?" "As soon as they hoard the.propeller noises of the attacking submarines,, which would have been some time' before the, German- torpedoes were launched, they would have.'changed their courses and cone ahead at full speed. That would have baffled the enemy; for .submarines are slow-going craft aud_ only dangerous when their presence is not susoected. It is even possible that the British cruisers, knowing by dial indications the approximate distance and direction of the sul) merged German, vessels, could have de~

stt'oycd them by launching torpedoes of UieiV own/'

An illustration ol the tact that the propeller and engine sounds of a submerged submarine may bo detected by si distant vessel running along the swan surface Mas furnished several yeara ftg«. ""hen ilio Submarine Signal Company actually demonstrated the thing iii Newport hnrbor at the rcrjUfist of a United States juaya! officer. "Do von moan to tell me," asked the incredulous officer, "tlmt if one uf our submarines submerges nnd- runs back mid forth out of sight on the lower levels, voti can hear her in a vessel at the surface and follow hereby means of your listening apparatus!'" STARTLI.NO TEST. ''Certainlv we can." .said the signalmail. '•Go'ahead and sink your .•.libmarine. I'll show you." So thev lmvde the test, and lor sumo • >me a swift launch equipped with watt'r wireless microphones circled and ! zi"zai"'i''(l about Newport harbor euidecf bv sounds from the depths picked up'and magnified by the eleetrical ears. . "You're wromi! !w»c lost her, declared the olikvr pr."-<eiiifly. 'lbo sMbmarino is nowhere noa'r I;* 2 1 " 0,'. j know the course she was to 'jatei>. . The simialniiin insisted he iv«o riglil, however; and a little later tin* submarine came *<> the surface at the very njiot indicated t'y the listening appavaIn JfiW. 19.1 I. at tin' request of theGovernment, new tests were arranged for outside of .Newport harbor betweew tlu- '"rnted States submarines M ami K" hoik Of which wore equipped with improved o.'c Mia tors placed on ttic laiperstructure oi fhese submarines These trials extended over a fortnight, during which \lm\p. the. oscillator wa~s thoroughly levied in various ways. The two submarine, ivnuld run out iil'teeu or twenty miles from Newuort and mancouviv off Point, .h'dit i, send, in. and receiving in turn- Or <h»o would sink to the bottom and he I hr« . ..vblle the other darted back and forth •if iliu'her leveb, signaling »" *»*' u . mc - Or again, thev would .start at a given point and fJm, ««' on iwo legs of a. sixtv-decroe triangle, until they Mere man'v miles amirt, and the oscillator would be busy every minute.

SPKEI) OF .SIGNALS. As ihev f.;aiiiod experience, the operators found tii.it, t)i".v wore able to trans11,it tlio.se water .vireless communications at tlu- rat.' of ten words * minute ami receive them without a mistake over a distance t>i ciuht miles. And for shorter distances they could mmul J's fast, as twenty-five words a. minute. The submarines exchanged signals at a distance of thirteen wiles. Ho clear were the tooting that the rrew.s heard them distinctly without, telephone headpieces when the vessels were .six or seven miles smart. "AVe not oiilv succeeded ni and receiviii'.' \<m<l distance water wireless niesi.n«'es between submarines, said Professor Fessetldeti. "but at short distances, tin lo half H mile, we were .able to talk'with the human voice trow, or.e submarine' to the other. .1 would ?av to the transmitter, for instance: ' Please ask Captain So-and-So to come to the 'nhono.' and a moment later by wator wireless. 1 would hear the Captain's voice askinii what I. wanted. Th- professor pointed out an advantage that his signalling system enjoys iu°war over the aerial wireless system owimr to the fact that the masts and antenna' of the hitter, belli!-' exposed on a battleship, may be shot away by an enemv. whereas the oscillator, tar below the water line and fill.' irom injurv. could keen on sisnallin- .it the whole superstructure of the ship was shot awav. Furthermore .at already explained", water wireless oilers the only means of communication during action between submarines, or between submarines and battleships.