This tumbler like glass object has a broken pontil, and three projections on what I assume is the base. Its is 3 3/4" W X 4 1/4" H, and is made of heavy duty glass that appears to be late 19th Century. The original owner and the antique dealer I bought it from didn't know what it was used for, and I don't either. Perhaps it is some kind of electrical glass. Does anyone out there know or have an opinion?