FIGHTING THE U-BOAT.

Manawatu Standard, Volume XLII, Issue 1017, 9 November 1917, Page 6

FIGHTING THE U-BOAT.

NEW YANKEE TRICKS. - TELSA’s ELECTRIC LAY.' BCTIEME FOR BLINDING SEARCH- ■ LIGHT. Aniorjg- the thousand .of suggested raclhqtls ;«f • lisfiimff slilhiKsrirms— most; ol them, .by ■ persons who have nofc even-, nulinienf-ar.y knowledge- of tho conditions with'whicli they are utteinplmg’ to deal—a - few stick out, with every ‘ appearance of being practical. The August number of Iho. “.Ivleclneal J'.xjierimeuier” foutuVes three of ihese; one byits editor,'one by Nilcola'Telsa, and one by It; Hartnian, a- New York electrical ongin-oo-v,'inventor oi the subniurino an cl other devices. , ■ , All have the merit of novelty. Mr I esm.jS, invention 'is • a-, way;, .of tlotocluig , sub-, marines before t hey can be seen. I hat ol Mr. il. Gerns-baclc, .editor.of tins. Idectncat Tixpcrimentei’, is a met-hod-of blinding , the submarine, so that its, commander cannot take aim. with his torpedoes. .That of Mr Hartman is a. small submerged fort, eontainiug* torpedo tubes, for iho protection, of the- entrance- to- harbours frorri attacks by. .submarines. . ; Rumoui-s have been printed that.;. Mr. I cs a had invented an electrical raythat- would destroy ■ submarines ■at a considerable <hs-. tnnee.' These rumours, while distorted, arc based upon actual facts/ Air Tesla’s device L- a tremeiidouslv powerful elect, Vie. ray, that, while it will not destroy a, submarine will reflect back. from it. in such a way as to reveal its presence and position, thus making its capture or ’destruction a comparatively easy matter.. Describing it to If. Win field Sccdr, Mr. Tesla said ‘ “If We can shoot out "a coneoulrated ray eompri’drig’ a stream .- of.. jniniue ' eleelrie cliaVges, vibrating electricity at Lremen-. dons’frequency, say a million cycles per second, and dheu intercept, this ray after it had been reflected by .a snljniariuft hull, lo.r example, and, cause) this intercepted .ray to illuminate a. [iuorescent screen, (similar to (he X-ray method) oii’ the saine or anotlie.r ship), then our problem for locating tho hidden submarine will, have been solved. SCREEN TO ■ RENTAL ‘SUBMARINE. , “Suppose, for example, that a vessel is .fitted with such an' elect-rid May propcctor Tho avdrag-e ship lias-available, say, 10,000 to .15,000 hor-sepower. The- exploring ray could be .!laslicd ’.out intermittently, and thus is would-bo possible- to hurl. forth a verv formidable beam of .pulsating oled-nca! energy,’involving’ a discharge of hundreds of thousands "of horse-power. “Imagine that the. ray lias been shot, out and that- in sweeping through tho-water .it encounters the hull of a submarine. .AYhat happens? Just- this: The. ray Would bo reflected, arid by an appropriate device- we would intorcont .and translate tins reflected ray, as, for instance, by allowing the ray to impinge on a phosphorescent, screen, acting in a similar way to the X-ray screen’. Ihe iav would bo invisible to the unaided eye. i '“Consider that, a- concentrated ray from & s«arelilig’ht.is .thrown on a .balloon -at night. When .the, spot of light strikes the balloon,-, the latter at once become visibly, from many dift'oi-enl- angles. The same effect woukl.be created with the electric ray if properly applied. When the ray struck the rough hull of a submarine it would, be reflected, but not in -a- concentrated beam—it would si) roi id out: which is just what we want. Suppose several vessels are steaming along in company ; it becomes evident that- several M them will intercept the reflected ray, and aceordingly, ho warned of the presence oj (lie- sulunarihe or submarines. “The Toutbus are clover, you know, very very clever., but we- shall beat them.” said Dr. Te.-.i.’i. eonlideiiiiy. TH E BLINDING MOTOR LA AIT.

I Mr (.!t-nisb;ii:l:’sidea L even more. picturesque. ‘-There is.our. dead Burn, way ol making ■a ship torpedo-proof, and iliap is by makingit invisible.'’ lie v.'riu-.=._ “Nq one will deny this. For if the submarine. commander can’t pli quarry he ean’l Uirpedo ii. In order to imclerstand what I mean let. us try a lew very simple experiments : - ' “LightUp a powerful aulo-.soarchlight._io-nighl..° The.auto must,bo in the dark.. Now station yourself . fifty yards away. .Do not look directly into the. shaft, of light. Dan wbu 101 l .where the driver site?. You cannot. •You siniply- scq the, light, shaft, .that.is‘all. But you Oiui’t soc whoi'O tlio car is, and whether it be the rigid, or the .left .searchlight that is lighted. . ““Now then, imagine lor a inuiulo that you are the .submarine commander, with your eye. glued to - the as yet. submerged _ pensscope. Slowly and cautiously you raise the periscope tube till; it. is a. foot or 'more above the water. . Rapidly you. .turn it m a-circle to scan .every point- of the horizon, 'Nothing but .blue sky and the ocean. \ou keep on turning. Suddenly like: a. bolt on hghining conies a. bail of white tire that makes vour eyes water. •• “ ‘Doimcrwetter !’ y6u fj>iy presuming fliat you are a. German U-b6afc commander. Down conics the periscope, while you wipe vour eyes stupidly. . “Now to torpedo a ship yon must know several things. First., you must know how far a wav it is from you. Second, .you. must know in .what direction the ship is ■travel-' ling Third. "you must know its speed,..;“And with a. powerful searchlight, trained full on your periscope you would,; qC.couvse, know where the ship) was, hutyou.couid not possibly know how far it was from you, nor if the searchlight was on the bow or the stern. . . . ■ ■ - “Alv idea, then is .this: Mount ondim ship four powerful searchlights.. High, up_i.il the crow’s nest: arc two observers .scanning ijio water with their glasses. .The instant- the top of a periscope .is observed, let. ns-say : on the port side,; the crow’s nest .gives the ■position, to the two port .searchlight. attendants. By means of a loot-operated .swit-cli. the • current is turned into /the searchlight 'instantly, and the latter is trained upon the periscope. . , , “The main Teciniremonls ol I ho plan, are very powerful electric .searchlights. flinidrods of thousands of candlmpower must bo used, otherwise I,ho scheme is foredoomed tp failure. ’Perhaps" large parabolic mirrors lo reflect the simlighL onuld be ;nsod with fair, cloudless-skids, .for there L no stranger oi- more blinding light than sunlight. On a clear-.day this would bo perhaps preferable In nsimr electric searchlights. FI.GATING .FORTS. The submarine fort has'.just boon_ patenled by Mr Hartman. It is ■ a. vertical cylinder of. steel, of from 25 lo 30 inches inner diameter, divided into three' compartments, the middle one of which is for.tho operator. The upper-compartment..contains a, powerful electric searchlight; the lower a. storage battery. .there aie also ,dc\icos for supplying the operator . with oxygen, and for absorbing (ho carbon, dioxide ex-_, baled by him. IV a tor pressure gauges,

volt and ammeters, switches, -telephones, etc-., are provided for his use, ] A small motor operating a, propeller enables the man to turn his “fort” around.; The idea is to lower several of'these “forts” into;, the ,sea,-, suspended from steel ropes,; outside- tlie entrance to a harbour. life aoarcldight would then explore the surrounding waiters, and Iho operator would watch for U-boats., On seeing one he could either telephone .its... position - to Hhosjpgashore,, or could discluu’ffri.i.siaall, , - torpedoes ,f at it from the torpedo tubes.