Abstract
It has been customary in the study of electrical breakdown and of the motion of electrons and ions in gases to record the experimental data as functions of the parameter E/p. This parameter is being increasingly replaced by E/N, expressed in V cm2, where N is the gas number density (E in V cm-1, N in cm-3). This makes it difficult, however, to estimate quickly the equivalent `E/p' and it is proposed that a solution would be to choose the magnitude of the unit of E/N (the `Townsend') such that 1 Townsend = 10-17 V cm2.
Comments on this suggestion are invited from workers in the field.