Giles' glass knob insulator

An Improved Glass Insulator Knob.

In the accompanying illustration is shown a glass insulator which it is claimed possesses a number of features which are considered improvements upon some of the old types of glass insulator. As will be seen, the groove for holding the wire is V-shaped, so that all sizes of wire can be wrapped about it and held with equal firmness. The insulator is made both in clear and opal glass, which is especially prepared. It is placed upon the market by W. A. Giles, of Pittsburg, Pa.