Bearing Circle, US Navy, Mk I Mod 2, 1943, in Wooden Case
This is a WWII-era US Navy Ships Bearing Circle, Mk I, Mod 2 in its original wooden case, made in 1943 by The Lionel Corporation. This model has two adjustable vanes (peep and far) with prism for viewing compass bearing and spirit level. The Bearing Circle was placed on top of a magnetic compass or gyro repeater and used to measure bearings of terrestrial objects. The Peep vane and Wire vane are lined up with the object of interest, whose bearing is subsequently read on the compass rose using the reflecting prism that is integral at the bottom of the wire vane.
From US Navy: