[Trade Journal]
Publication: China, Glass & Lamps
Pittsburgh, PA, United States
vol. 26, no. 38, p. 7, col. 2
ENTIRE GLASS INSULATORS.
A new style of insulator for electrical use in [sic] is made entirely of glass, and is designed to be adjusted to trees, particularly for assisting to suspend wires already strung. It is made by the Ajax Line Material Co., of Chicago, and will hold wires up to one-half inch outside diameter. The insulator is made of a single piece of glass toughened by annealing, and provided with a slot which the wire cannot leave by accident. It has a concave ribbed back, which fits snugly to the tree and keeps it from sliding.