The second post in this series show a beautiful teal blue CD 133.4 that was found on the Chicago Northwestern Railroad as it ran East out of Boone, Iowa toward Ames, Iowa

This post shows a Teal Blue CD 133.4 with the following details:

CD-133.4 Patent /Dec.19 1871 (Front Dome) - Medium Script 3 (Back Dome - No Mold Mark) - Teal Blue (A Few Bubbles /Microbubbles / Crude Overpour / Cull Stones) - Measurements: 69 mm Wide x 98 mm Height.

The back of this insulator is shown in the following post: [id=617028730]