Porcelain multi-part electrical insulator, ca. 1912
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This insulator is constructed of three parts: the upper dome with the saddle at the top and the two conical skirts at the bottom.
Insulators such as this one were used on high-voltage transmission lines of up to 69,000 volts.
Insulators are necessary to keep the current from "leaking" out of the line.
The Locke Insulator Manufacturing Co. produced insulators of this style and glaze from 1909-1918.