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1940 - insulators first take form as moulded pieces of wet clay, after preliminary drying, they are turned to size on this special lathe, and then glazed and hardened for five days at a temperature of 2400 degrees Fahrenheit in a 400-foot kiln

CLAY "HAT" FOR POWER LINE

CD 1963053 E&MP 23.006

Electric Insulating and Insulators

Dec. 6, 1940

One of 45,000 porcelain insulators, included in a rush order for a large interconnected electric power line in the Northwest, is shown here in the process of manufacture at the Derry, Pa., Works of the Westinghouse Electric & Manufacturing Company.

Turned out at the rate of 6,000 per week -- enough to fill two freight cars -- the insulators first take form as moulded pieces of wet clay. After preliminary drying, they are turned to size on this special lathe, and then glazed and hardened for five days at a temperature of 2400 degrees Fahrenheit in a 400-foot kiln.

Original Caption by Science Service
Westinghouse



National Museum of American History

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