CD 2478086 E&MP15.005
Electric Circuits, Breakers
Electric arcs oscillate and die out ingas bubbles when circuit breaker contacts pull apart under oil.
Drs. Joseph Slepian and Thomas E. Browne, Jr., made this discovery by taking moving pictures at the rate of 2,000 a second through glass windows which revealed the inner workings of the apparatus.
The pictures have shown engineers how to improve protective equipment which switches power lines on and off in a few hundredths of a second
Original Caption by Science Service