WORLDS STORMS.

Press, Volume LXVII, Issue 20273, 26 June 1931, Page 13

WORLDS STORMS.

AID FOR AIR PILOTS IN PERIL ? TRACING LIGHTNING BY RADIO. FBOU A Sskiaj. Cosexspokdett. J 'LONDON, May 14. S&dio may soon be used to trace the Moree of every thunderstorm in pro-' ~' J free* within two or three thousand " Miles of the observer. If this hope is realised, aeroplane pilots will be able to atcer their course to avoid one of their YOBit perils. Scientists at the Badio Research Sta- " 'ties at Slough (about 20 miles from Loadon) under tho British Government /'j, Department of Scientific and Industrial jag Seaearch are now engaged on elaborate , i': experiments to establish' beyond doubt -• tke reliability of their methods. They ksvo invented one of the most sensir tire and remarkable pieces of appara- • ta» that the wonders of wireless have jet produced. It is called a "cathode »y direction-finder/' and it records, by " flickering of a little point of light, , grery important electrical disturbance * ' ttat goes on in any part of the earth's s.. tfeacsphexe for thousands of miles ■ • Slough station is the only place is the world where the instruments are "f* mfle. They were invented by the jßgfßfintendent, Mr Watson Watt. Two have just been supplied to; the. Badio Board, where they td be used for a new Australian •tamtnduag research scheme. Others f an wader construction for Canada, and I*9 beear.supplied, by special reqv&t, to ihe United States Navy. . | ' ADeioeUre for Lightning. si; 23to?ymuatiis lives in a little -wooden |( kutwiuen looks iuore 'ike a chicken-, | houswlhan a laboratory. Here hyper. &?* sensitive apparatus reacts every time* iiah of lightning on a dis-] nt. _ lory, n ihass of wires and inged in darkness. Scienter a little point of'light, nping ,about like a thing <s like South Germany,*' f storm-tracker. "Nothing . . ah I that's an Atlantic I ehotrid 'say, moving in. ne thing going on down A cinema, which removement of the light, making, a permanent. relistantstorms and depresbpberio lasts only about a h of a second and is re* itely instantaneously. As ) signals a second may be for the Air Mail. lowa only the direction of Scientists want to find its on on the map. So they another exactly similar j er in Scotland, about iOO with a land-line connect-! ions. Time-signals are | ; «the laboratories to syiifiltrut exactly. One mm ra from Scotland an£ the •jeeted simultaneously on • the world. Where two in where that atmospheric ti<sts tan now trace th<j storm within two hours, ir earlier methods it took 'his time -:ould be reduced nates if the Scottish j tire arranged to transmit a over the land line by a txl. already worked out, ed to picture transmission, nake all the difference to teh depend on such i • keep out of disturbed ould also be of great value srec.osts for ships, farmers, ;ourse, are practical appli-; e new method of direction 1 more important, experts le theoretical question of y, and how is an atThey have discovered ospherics are due to elec irges or lightning. The id's object is to study the and higher mathematics s to provide a bacltground--9 oa which the radio euMise his improvements. Waves Go Wrong. tical side of wireless," I "ha* outstripped the iVirele&s waves do certain if ten radio engineers dont This may lead to unforand the big advances ofire likely to come only ) knotvn about the fuada-. r iour- of waves." itiats can sort out the miles which crowd the ether, 186,000 miles per second, re can distinguish different in a stream of traffic. One ield of Btudy is called gation," wliicb means the rhich befall a wave as it goal is sent off, scientists « impulse travels by d«- . One set of waves goes uad, and thi? is picked up receiving sets over short dby ships. Tie otbe* 8 upward and u reflect® 0 !

down again from the upper atmos?>here, somewhat as light is reflected rom a mirror. * 'Night Error' * at, Sea. Many radio troubles are caused by these two waves not joining up again exactly in step. When the peak of one wave coincides with the trough of another, you get what scientists call a "fringe"; and "fading," ' familiar to listeners, results. These fnffges have actually • been photograhed, and two distinct waves can be seen intermingling. "Night error" in direction-finding at, sea is caused by these downcoming waves. It is of£en found; when taking wireless bearings, that direotion-finders are 30 or 40/ or even more, degrees out at night. British scientists have perfected a new type of direction-finder which does not Dick up the parts of the wave pausing these troubles and which thus 'eliminates the error. For longer distance signals, such as those between Empire stations, the "downcoming" wave is the important one. Scientists are studying how it is reflected from the upper atmosphere, called the "Heaviside" layer after a man of that name who first suggested that such a conducting layer was needed to explain the success of radio communication For' years this remained a hypothesis, and it is only within the last ten vears that definite proof of the existence of the layer was obtained by scientists working for the British Radio Research Board Heaviside. then an old man. was offered a medal for his original work, but refused jt because b,v that time ;he was more interested in roses than in radio.

Messages to Mars? » These layers, for the same workers have sliown that there ar® at least 'two of them, at about 60 and 120 miles above the earth's surface) consist of electrons. Short-waves travel further through them berore getting reflected bafck than do .1 ongwaves. There comes a point, scientists believe, when fery, short waves, right through the layer and on in to space. . "If there were any radio communi-i. cation with Mars," • scientist said t me. "that is how it "'would-be done. At Slough they are trying to find —-not with tins shortest wflve which can be sent without gejtme lost. They believe it may lie So ™®T where between the ranges of five ana 10 metres. ..

coming from behind. Apparatus has been designed that will not pick up these back-door waves. Split Seconds. The almost incredible accuracy needed for work on this "wave propa gation" is such that scientists can measure an .effect produced by a time difference oi' a few millionths of a second. They study the angle at which an invisible wave hits an inaccessible layer, made up of .theo.retical particles, as happily as if they were working out a new stroke m squash-racquets. The man in charge of thin work js Professor E. V. Appleton. of Kings College, London. He has an international reputation, and the work under his' direction at Slough is acknowledged to be the finest of its lrind in the world. w . - The last Imperial Conference stressed the fact that, the Empire's progress depends largely on the efficiency of imperial communications. Wireless has become one of the most vital of these. The Empire must be linked in the ether as well as bv sea and air That is why the British Government is supporting a research centre where it is encouraging the British genius for invention to extract the fundamental secrets of radio out of the immense mysteries of space, so that the knowledge gained can be applied to the practical problems of a work-a-day Empire. -