This one is Embossed on top Patented 26 August. 1851. This is very similar to the one shown in the patent drawings see this link: http://reference.insulators.info/patents/page/?patent=8316&type=U&pages_drawings=1&pages_text=1&page=1 The color is off clear and this piece is a bit hazy. The LRI is 1 11/16" tall, and 1 5/8" across the base. It is missing the metal point on top. The square hole is about 1 1/4" deep. Purchased in 1996 from the Bill and Jo Dreggors collection.