Abstract :
THE MECHANISM of the electric sparkover process lately has become a much discussed problem. Townsend´s theory of the formation of electric sparkover has been challenged and at least in some respects found wanting. Several well-known investigators have given ample evidence that the sparkover process is very complex; that the speed of formation is in the order of 108 cm. per sec. instead of 104 or 105; that polarity and shape of electrodes, ionization, space charges, voltage gradients air pressure, temperature, and other factors enter into the problem. The results of investigations on the early stages of electric sparkover throw light on certain phases of the initial or kindling stage of an electric spark formation, but a comprehensive explanation of the mechanism or process involved in the formation of electric sparks or sparkover still is lacking.