The strap-shot consists of a round ball attached to a sabot of the same calibre, by means of two strips of tin passing over the shot at right angles, and fastened to a third, which is soldered around the sabot.  One end of the sabot is arranged for attaching it to the cartridge, the other being hollowed out to receive the shot.  The supposed advantages of this arrangement are, 1st, a diminution of the windage; 2d, the gun may be loaded with greater rapidity; and, 3d, the cartridge is transported with greater safety.

The case or canister-shot is prepared by filling a tin canister with grape-shot or musket-balls, and attaching it to the cartridge by means of a sabot.  There being two sizes of grape-shot, and one of musket-balls, we have three kinds of canister-shot calculated to reach at different distances.  The three sizes of shot are frequently mixed in the same canister.  This projectile is particularly effective against lines of infantry and cavalry, when the distance is short.

The grape-shot is composed of small balls arranged round an upright pin attached to a plate of wood or iron.  The concave cast-iron plate is preferable, as it increases the range of the shot.  The balls are covered with canvass, and thoroughly confined by a quilting of strong twine.  This shot is used for the same purposes as the canister.

Light and fire-balls are formed of an oval case of sacking, filled with combustible matter, and attached to a culot of cast-iron.  The whole is covered with a net of spun-yarn.  Light-balls are used to light up our own works, and are not armed; fire-balls being employed to light up the works or approaches of an enemy, it is necessary to arm them with pistol-barrels, in order to prevent, any one from extinguishing them.  When made of very combustible materials, and used for setting fire to wooden structures, they are denominated incendiary balls.

Carcasses are employed for the same purpose as incendiary balls; they are of two kinds:  1st, the shell-carcass; and, 2d, the ribbed-carcass.  The first is composed of a spherical shell, cast with five fuse-holes, one being at the top, and the other four in a plane perpendicular to this and at right angles with each other; the shell is filled with matter highly combustible.  The second is formed of iron ribs connected by iron straps, and attached at the ends to culots of the same material, the whole being filled with combustible composition.  This is more expensive than the shell carcass, and cannot be fired with as great accuracy; it is now seldom used.  Carcasses may be armed in the same manner as fire-balls.

Smoke and suffocating balls are used to drive an enemy from galleries and mines.  They are thrown by hand.