Gauges

In gunnery, are bra rings with handles, to find the diameter of all kinds of shot with expedition. Also instruments of various kind for verifying the dimensions of cannon and projectiles and the various parts of small-arms. Modern small-arms are made on the interchangeable principle , each part being accurately made to gauges. This principle has revolutionized the manufacture of small-arms. It was first introduced at the U. S. armory, at Harper’s Ferry, by Maj. Wade, of the Ordnance Corps.