An extremely RARE large American ship's five burner whale oil mast head lantern circa 1851

There are only a handful of similar examples still in existence and those are in the leading maritime museums. This is probably the earliest signed American made ships' whale oil lantern on the market today. It is marked "William Porter, 232 Water Street, New York, Maker" and the burner is marked "H & J Sangsters Patent, June 1851." It stands over 20" high and is extremely heavy. The hand blown glass is original. An amazing survivor!!