William Clarkson

XI. The lag in electrical discharges

Abstract The variation of the “ peak ” voltage in the intermittent discharge in discharge-tubes of scrupulous cleanliness are considered, and possible causes, both in the gas and in the electrodes, are sought for and applied in explanation. Experimental results would agree with a “ corona ” lag, a theory of which is developed, if a slow “ build up ” is assumed. This assumption is shown to be justified from results obtained by a method, here described, for measuring the time of duration of a “ flash,” or condenser discharge. The small preliminary discharges often preceding a “flash” are explained on the fame assumption, due to the form of the “ corona characteristic.” Possible causes of this slow “build up” fire discussed, and it is tentatively associated with the apparently inevitable modification of the cathode surface by the filling gas.

XXXVI. On a critical resistance for “Flashing” of air discharge-tubes

Abstract The paper deals with a continuation of work on the “flashing” of discharge-tubes and the resistance relations necessary for the maintenance of “flashes.” (For diagram of circuit see fig. 1.) It is shown that there is a “critical” resistance R c for the air discharge-tubes used, below which no flashing may be obtained, given by the relation where E is the charging voltage, V b ′ is the effective lower critical voltage, and ψ (V b ′) is the current voltage function, under the conditions of the experiments. A tentative explanation of the variation of the voltage intercept for the linear curves between the critical resistance R c and the charging voltage E, with the capacity across the dischargetube, is put forward.