Underground alternating-current network distribution for central station systems: General light and power supply of Chicago: A study of underground distribution systems for the city of New Orleans

E. R. Thomas: I would like to discuss a few things on the flicker problem which came up in Mr. Kehoe´s paper. In Fig. 6 of his paper, there is a plot of some data that were collected on the flicker of incandescent lamps. This subject of lamp flicker dates back to the old problem of 25 versus 60 cycles, or what minimum frequency can be used for lighting. In the study of that subject we are indebted primarily, I believe, to Messrs. Kennelly and Whiting for their thorough research on critical frequency, which was made with a specially arranged Bunsen photometer.⁴