Provo-type electrical insulator, ca. 1897Item 74830 info
Maine Historical Society
This style of glass insulator was originally made in 1898 for the Telluride Power Transmission Company in Provo, Utah, which used it to construct a long high voltage line.
It proved unreliable at high voltage, but worked well at lower voltages, and remained a popular technology for 22kV transmission lines throughout the United States until porcelain multipart insulators were developed.