Discussion on “the effects of transient voltages on dielectrics” (Peek), San Francisco, Cal., Sept. 16, 1915. (see proceedings for August, 1915)

J. C. Clark: Prof. Harris J. Ryan has recently performed an experiment which, in a qualitative way, strikingly il ustrates the principle of the energy time lag brought out in this recent work of Mr. Peek´s. Referring to Fig. 1, H is a large helix carrying 8–10 amperes at a frequency of 90,000 cycles per second. The oscillatory circuit LC is mounted so that its inductance L is coupled inductively with H, and a needle gap G is connected across the circuit LC. C is a moving plate condenser capable of smooth adjustment, so that, by turning it to a proper position, the circuit LC will be tuned to the frequency of H. It is found that when C is turned by hand moderately fast from one end of its range to the other, no discharge whatever will take place at G; but that, by moving C quite slowly through its range, G will discharge at the position of C corresponding to tuning for circuit LC.