Primer

A wafer, cap, tube, or other device for communicating fire to the charge of powder in a cannon. The cap or tube usually contains a friction or percu ion-powder. The friction-primer is generally used in the land service. (See Friction-primer .) For service on shipboard, a quill filled with rifle-powder, having on the top a capsule of fulminate of mercury, is generally employed. The capsule is exploded by a blow from the lock-hammer. The tape-primer , used sometimes in blasting, is formed of long, flexible strips of paper or fabric containing fulminate or other quick-burning substance. The electric primer is used to fire simultaneous discharges, both in ordnance and blasting. In firing wet gun-cotton, the small charge of dry gun-cotton used in conjunction with the detonating exploder is called a primer . In small-arms the term is specially applied, at the present time, to the percu ion-caps used in reloading metallic cartridge-cases. The cap is set in a rece in the head of the shell. When the firing-pin strikes the outside end of the cap, the fulminate is exploded by being driven against a perforated cone called the anvil . This anvil is usually a part of the shell. In the Winchester primer , recently invented, the anvil is a part of the primer itself, being inserted upon the fulminate. A shoulder in the rece holds the anvil when the cap is struck.