SPEAKING OF SPEED

CD 2478067 E&MP13.002

Electric Arcs

Dec. 1937

This glowing tube, one of the famous Westinghouse Ignitrons, can switch on an electric current and switch it off again in ten millionths of a second -- a period of time that bears the same relation to a second as a second bears to a two-weeks vacation.

Such quick action is needed in many modern electrical operations, notably electric welding.

The earliest tubes of this kind could handle only small currents, but Westinghouse engineers have developed large ones, like that shown, which can switch with ease 700 kilowatts of power - enough current to operate 28,000 household electric refrigerators, of light a string of electric lamps, spaced one foot apart, nearly five and a half miles long. 

Original Caption by Science Service
^©Westinghouse