A Lensatic Compass is still primary function of taking accurate bearings for land navigation. The military use the functions of this compass to help direct Artillery & Mortar fire due to it accurate bearings though it sighting wires.
There three major components on a Lensatic Compass:
The Cover: Protects the compass rose dial. It contains the compass sighting wires and luminous sighting dots for night-time navigation.
The Base: Is where all movable parts of the compass reside. The floating dial rotates indicating direction each time the compass maintains a level position.
On the floating dial there are the Bearing figures on the edge of the dial depict the directions east (E) and west (W). Within the center lies the directional arrow. This always points in the direction of north (N). East falls at 90° and west at 270°. There are also two scales. The outer scale denotes miles and the inner scale denotes degrees. The inner scale indicator is in red color.
A bezel ring is also inside the compass base. This ratchet device will turn 120 clicks on a full rotation. Each individual click represents 3°. A short incandescent line works with the north-directional arrow in navigation.
This line lies in the glass face of the bezel ring. The floating dial contains a fixed black index line as well. The final component of the base is a thumb loop. This simply attaches to the base as a handling mechanism.
The Lens: This is what reads the floating dial. A rear-sight slot works with the front sight wires in the cover helps with Navigation and to locate objects.
In addition, this slot protects the compass when in the closed position. This works by a lock and clamp system. The rear-sight mechanism must remain open at a minimum of 45° in order for the compass floating dial to work.
This is the compass I use as I think it is a more accurate and it gives you more information like miles and degrees on the same compass. It looks like a harder compass to learn but most people, I know use this compass as it is more fun to use.
Source by Archie Summers