CD 135 CHICAGO INSULATING CO. Blue On October 16th, 1883, Bradley A. Fiske and Samuel D. Mott were granted an insulator patent for "a wire groove composed of a series of diamond-shaped cavities". The theory for their design was that the unigue wire groove would have much less contact with the line wire than an ordinary groove, thereby reducing current leakage or "escape" to ground. This shoulder-embossed example was found on a rail line that cuts across the northeast corner of Mississippi. |