Abstract :
No longer will it be necessary to keep airplane landing fields brilliantly lighted all night when a new invention only recently demonstrated is perfected to the point of being manufactured in quantity. The noise made by the hum of an airplane 1000 ft. in the air closed the switch that lighted a bank of flood lights at Bettis Field, McKeesport, in the first demonstration of the sound sensitive automatic lighting apparatus developed by T. Spooner, an electrical research engineer.
