ACTION IS PRACTICALLY INSTANTANEOUS
CD 1963101 E&MP 25.041
Lighting a 1000-watt lamp with a match. Light from the demonstrator's match starts a current in a photoelectric cell, which in turn permits a current to pass through the thyratron tube (large tube in the center).
The thyratron then allows the current to pass through the 1000-watt lamp, lighting it. But all this takes much less time to happen than for you to read about it, for the action is practically instantaneous.