In 1972, I purchased 17 CD 134 insulators at a local antique store in Boone, Iowa. The owner was a local historian - as most are. The story she told me was that they obtained these insulators in the early 1950's as most of the Boone, Iowa electrical network was upgrade and the oldest system was finally removed from the poles and downtown businesses. The first power plant for Boone, IA was built by the Chicago Northwestern Railroad in 1877 to power their operations. This power plant used local coal as fuel. Shortly after this, a low voltage electrical line was extended to run the electric lights and power local businesses. The homes and some farms in and around Boone were electrified in 1886 to 1890's. The second upgrade took place in the early 1900's and the third upgrade occurred after WWII. Some of the earliest insulators were never removed from some poles and many business until the fourth upgrade in the 1950's.
The first post shows what I believe are the most uncommon to rare insulator from the lot of 17 insulators purchased. This post shows three CD 134 insulators including the following:
CD-134 Patent / Dec 19 1871 (Front) T-HE.CO (Top Dome) - (Bubbles & Microbubbles) Yellow Green - 73mm Wide x 98mm Height (Left Insulator) [id=614871829] [id=614871963]
CD-134 C.E.L.CO. (Front) - (Vapor Milk Streak) Deep Teal Green - 72mm Wide x 105mm Height (Middle Insulator). [id=614872835]
CD-134 Patent / Dec 19 1871 (Front) - (Massive Number of Microbubbles) Light SCA - 73mm Wide x 98mm Height (Right Insulator) [id=614873215]