In artillery

Artillery

Originally applied to any group of infantry primarily armed with projectile weapons, artillery has over time become limited in meaning to refer only to those engines of war that operate by projection of munitions far beyond the range of effect of personal weapons...

, capsquares, or capsquires, are strong plates of iron which come over the trunnion

Trunnion

A trunnion is a cylindrical protrusion used as a mounting and/or pivoting point. In a cannon, the trunnions are two projections cast just forward of the centre of mass of the cannon and fixed to a two-wheeled movable gun carriage...

s of a cannon

Cannon

A cannon is any piece of artillery that uses gunpowder or other usually explosive-based propellents to launch a projectile. Cannon vary in caliber, range, mobility, rate of fire, angle of fire, and firepower; different forms of cannon combine and balance these attributes in varying degrees,...

, keeping it in its carriage. They are fastened by hinges to the paizeplate, so that it could be lifted up and down. They form a part of an arch in the middle, to receive a third part of the thickness of the trunnions; for two thirds of them are let into the carriage, and the other end is fastened by two iron wedges, which are called the forelock

Forelock

The forelock or foretop is a part of a horse's mane, that grows from the animal's poll and falls between the ears and onto the forehead...

s, and keys.