Origin of Atmospheric Electricity in Thunderstorms

Abstract

PROF. ARMSTRONG holds that Simpson's theory of the thunderstorm is invalid because its physical basis is unsound. He believes that it is not possible for water-drops to become electrically charged by simple rupture in air. If Simpson's paper (Phil. Trans., A, vol. 209, p. 379, 1909) is consulted, it will be found that the author of the theory has established quite definitely that when water-drops in contact with air only are broken by an air-current, the resulting smaller drops are positively charged, the corresponding negative charge going to the air as an excess of negative ions. The present writer is all the more confident of the reality of this effect, as in subsequent experiments (Proc. Roy. Soc., A, vol. 90, p. 531, 1914), with a form, of apparatus quite different from that used by Simpson, he obtained the same results. Thus, whatever be the grounds on which Prof. Armstrong declines to believe in the possibility of an electrical separation as the result of a “mere division of water-drops against an air-current”, there is no doubt that such a separation does occur: !