This is an aqua three piece mould CD 127 embossed "W. Brookfield 55 Fulton St. N.Y." on top line in a circle around the dome and "Pat Jan 25. 1870 - Cauvet's Pat Feb 22 70" on the second line in a circle around the dome. There is a circle with a "V" containing a "1" on the top of the dome. This insulator was found on the Central of Georgia Railway telegraph line North or Byron, GA. It had a cut section of old heavy iron wire around the dome. This was the only one which was ever found. I think the three piece mould design insulators are fairly rare.