Projectile

A body projected or impelled forward by force, especially through the air. In a limited military sense the term is applied to a body intended to be projected from a cannon by the force of gunpowder, or other explosive agent, to reach, strike, pa through, or destroy a distant object. The materials of which projectiles are usually composed are lead, wrought or cast iron, each po e ing advantages according to the circumstances under which they are fired. But the material which combines in a greater degree than any other the e ential qualities of hardne , strength, density, and cheapne , is cast iron, which is exclusively used in the U. S. service for large projectiles. Compound projectiles are sometimes made, so as to combine the good and correct the bad qualities of different metals. To obviate the serious results that may arise from the wedging of the flanges of a cast-iron projectile in the grooves of a rifle-cannon, it is frequently covered with a coating of lead or other soft metal. Cast and wrought iron have also been combined with succe , and also cast iron and soft metal in such a manner as to attain the strength of one metal and the softne and expansibility of the other. Other metals, such as bra , are also used in projectiles of special construction. Projectiles are generally cla ified, according to their form, into spherical, or smooth-bore, and oblong, or rifle projectiles.