WW1 MILITARY COMPASS, 1915

A prismatic Compass has a prism above the scale to enable accurate readings.
The cover hinges up and has a hairline across its glass front, this is lined up with a sighting slot on the other side.
Viewing through the sight and aligning the hairline with two distant known landmarks one at a time, enables the user to obtain their position on a map, by creating a triangle between the position of the two landmarks, and the compass readings taken and drawn on the map.

Donated by Francis Pitkin, this item was used by Mr Pitkin's father

A1033