Prism paralleloscope

A prism paralleloscope is a piece kit used by artillery units as a gun aiming point.

Its purpose was to function as an aiming point in the horizontal plane when laying for indirect fire artillery.

The prism paralleloscope entered service with the British Army in the late 1950s.

This case was mounted on two short metal vertical poles so that it was about 2 ft (0.6 m) above the ground, these vertical poles were held together by two horizontal rods slightly shorter than the paralleloscope case.

These early versions were a mirror about 3 ft (0.9 m) long and 4 in (100 mm) wide, mounted on a tripod about 3 ft (0.9 m) high and positioned a few yards (or meters) away from and to the side of a gun on its dial sight side.