Here is a picture of the Surge glass fence insulator made by Hemingray Glass Co. for Babson Bros. Co. Chicago, IL. The one on the far left is a CD 100.5 made by Pyrex. It could have been used as a fence insulator but I think was used as a insulator for transposing wires. I think it would have been a neat fence insulator though. The next ones are CD 100's embossing index 030-clear, 010-Straw,020-clear with the embossing error and another 030-clear showing the correct spelling. Beside that is a Surge insulator pin for the glass pieces. My father remembers a farm once that had all Surge insulators on the posts plus equipment years ago. What a pretty sight that would be to see glimmering in the sun on the farm.