Another man Cave moment. Kelvin & Hughes 1917 Bronton Compass natural Sine boxed and working

Found this today in a charity down the posh part of Swansea, South Wales the Mumbles where Catherine Zeta Jones lives.

Kelvin & Hughes 1917 Bronton Compass natural Sine boxed and working in what appears to be a walnut case. I don't know what a sine is?

Just been reading up on fakes so I hope I haven't been caught but I love it anyhow.

The kelvin & hughes london 1917 antique brass bronton compass. They are manufactured from the finest antique brass. The pocket transit is a relatively simple instrument which provides horizontal and vertical readings; it has adjustable sights and also can function as a plumb bob. The pocket transit is commonly used in geologic mapping, surveying and claim staking for measurement of the altitudes and structural features