[Letters to Editor]

Abstract

THE point raised in the foregoing letter is one of considerable interest in connection with the origin of the electrical phenomena of thunderstorms. The fact that thunderstorms are usually accompanied by clouds of a special character and heavy rain is common knowledge, and after Wilson's discovery of the difference in the effectiveness of the positive and negative ions as condensation nuclei it was generally assumed that condensation produced the necessary separation of the positive and negative electricity, and was an essential feature in thunderstornis. Simpson in his recent paper on the “Electricity of Rain and its Origin in Thunderstorms” makes splashing and breaking up of actual raindrops a necessary part of the mechanism of a thunderstorm.