BALL LIGHTNING

Greymouth Evening Star, 14 May 1934, Page 3

BALL LIGHTNING

PROVED TO EXIST. Professor J. C. Jensen, of the Nebraska Wesleyan University, U.S.A., has published the first authentic photographs of ball-lightning, says a writer in the Manchester “Guardian.” These unique photographs have settled a discussion thousands of years old; whether ball-lightning or thunderbolts really exist. From time to time accounts of phenomena described as ball-lightning have been published, but the objectivity of the occurrences remained uncertain. The ball-lightning was usually seen during violent thunderstorms by excited and inexperienced observers. There was the possibility that the observers were perceiving a subjective effect due to. over-stlnuila- . ion of the eyes by excessively bright lightning flashes. It is possible for tho eyes to see round spots of light owing Yo the stimulation of (he nerve connecting the eye with the brain. Hence meteorological physicists were cautious of accepting the many stories of ■he occurrence of ball-lightning.

Prefer,Bor Jensen has.not only succeeded in securing several photographs of ball-lightning; he has succeeded in obtaining two photographs simultaneously of the same balls. The possibility of two cameras or plates going wrong at the same moment amt producing the same faults is remote, so the certainty of Professor Jensen’s achievement is indeed great. His account of his observations has been given In the American journal “Physics.” For a number of years he has been engaged in research. on

lightning and has contributed papers., oil (bis subject, which add to the well- j known work of G. C. Simpson, B:inerj;, i U. T. R. Wilson, Schonland, and others. lie lias groups of instru- i meats for registering tho tracks and cihcr features of thunderstorms. His | photographs of ball-lightning have , been secured during years of ohserva- | tion, in which he Ims taken thousands i of photo.' raphs of ordinary lightning. No ono could have been belter qualified or prepared to obtain ball-light-ning pictures. In the course of his routine he took photographs of lightning during a storm on the early evening of August 2d, 193(). The day had been sultry, with local thunderstorms to the south. Two cameras for photographing the lightning were arranged in a window on (he fourth storey of a building. As the storm approached cold air rushing before tho cloud was seen to lie tilled with a, swirling mass of dust. Brilliant flashes began to descend from, tho cloud to lhe earth. Al 9.40 p.m. tho observers began to Like photographs. Professor Jensen noticed that m the wake of a. flash that carried negative electricity 7 from lhe cloud to the ground “a shapeless mass oi. lavendei | colour seemed to float slowly down-j wards.” He was s engaegd in the

manipulation of his apparatus that he was net able to watch the unexpected phcnomeno'.i with close visual attention. but he noted that the rose-colour-ed mass seemed most, luilliant near the ground and gave Hr impression of :i gigant i<‘ display <>! hreworks. I ' <> m three balls of lighi ui'u; seemed to rial about one hundred feel along electric power transmission lims situated s;x hundred yards from the observers, and tell to the ground air! disappeared wbh loud report. The first five of the /holographs Liken from 9.40 p.m. . how i!ie Irills. They were spread over .tn interval of three minutes. Aleasurcmenis show

ihai. one ball was twenty-eight, feet, in dmmt-ier ami another forty-two feet. 'iTi- ir height above the ground was aliimi. ninety-two feet. Professor Jensen does not at press 4 offer any theory of the nature of j) hnh-l'Tlilirng. He remarks, how(•ver. ibai descriptions of ball-lightning ofmi', Hiut the ball seems to be ccmiie-'lrd 'Mill chimneys, Hj-eplaces, and v im'-. qiwUs. Those dre the riles of dm; 1 -laden air. lienee the balllightning may be due to the clecirilicaition of a. vortex of dusty air by the electric discharges from a thimderi cloud.