This is an early 20th century ship's lantern by William Harvie of Glasgow, Scotland. It is a non-electrified ship signal lamp that was used as the masthead light. The copper metal appears to have been re-coppered at some time later in the 20th century. The back cover is marked Telford Grier Mackay Limited Glasgow 1908. Telford Grier Mackay was also a ship lantern maker. It appears that this is a 'marriaged' piece in which the back cover on the original may have been missing and the back cover was a suitable replacement that just about fits. The estimate factors in that the back cover is a period replacement by a different maker and the restoration and is based on actual recent past recorded auction sales of comparables.