On Saturday I found this glass insulator sticking out of the leaf clutter in the woods along an old railroad area. I did some research and it's C. D. & P. Tel Co. which operated 1874-1879.
They used to run a lot of electric wires near the train tracks. That was a good place to find them. As the old poles rotted down these things would fall down near the side of the roadbed. The ones that didn't get shot with our 22's that is. When we found out people would pay money for them we started saving them. People would epoxy them upside down to a coaster and use them for candle holders. I think my brother still has a box of them in his attic. No he won't sell them. He is a collector not a seller.
Very cool find, my grandfather used to work on the Great Northern Railroad and would find insulators alongside the tracks, I have a couple boxes of them but none as old as yours