12 cms long with lignum vitae handle.
Large 3 cms bulls-eye lens ( 4.25 cms including brass ring holder).
3 cms deep.
Unsure if original fixing joint from the handle to the drum or a later repair but perfectly done.
Ask the Dealer
I live in Lancashire (U.K.) and have been a dealer and collector of scientific and nautical instruments for a number of years. My stock has included some fine items from museums and colleges, which were surplus to their requirements. I occasionally purchase some interesting items from abroad, having established some reliable sources.