High-Voltage Phenomena in Thunderstorms

Lightning phenomena are analyzed in the light of laboratory experience with high-voltage phenomena in the atmosphere. Special emphasis is placed on the effect of space charges in producing high local stresses when mobilized through channels of high conductivity caused by high temperatures. A detailed analysis is included of the steps through which air at atmospheric pressure passes when, due to applied electric stresses, its electric properties change from those of a non-conductor to those of a highly conducting body,-perhaps many times as conducting as a metallic conductor at ordinary temperature,-and then again resumes its original nonconducting properties.