Vintage 2 X PYREX Glass Insulators

An antique clear glass insulator made by Pyrex - U.S.A. In great condition. Embossed around the sides: Pyrex T.M. Reg. U.S. PAT. OFF Made in U.S.A. Pat. Appd. For J Y. Height: 4 inches. Width at the base: 2 5/8 inches. Weight: 447 grams. The great majority of glass Pyrex insulators for the U.S. market were made between about 1922 and 1951. Vintage Glass insulators were first produced in the 1850s for telegraph lines, then for telephone and power transmission lines. They insulated and protected the wooden poles from the electricity coursing through the wires.