AMMUNITION FOR 3.2-INCH GUN. The ordinary friction-primer is used for radial vents; for axial vents an attachment is made to the friction-primer of a thin brass wire about 18 inches long, looped or coiled for convenience, and having one end fastened in the loop of the friction-wire, and the other around the head of the body of the friction-primer. The cartridge-bag is used, but experiments are now being made with metallic cases. (This proposed metallic ammunition for 3.2-inch guns comprises a projectile weighing 16½ pounds, with a suitable charge of smokeless powder to give an initial velocity of 1450 ft.-sec.) Charge of powder { 3¾ pounds I. K. { 3½ " sphero-hex. Weight of projectile filled 13½ " Bursting-charge of shell 7 ounces Bursting-charge of shrapnel 3 " Shell, shrapnel, and canister are used. =Shell.=--The base-percussion-fuze shell (Fig. 42) is made of cast iron in one piece, having a band of soft brass or copper forced into a recess on the outside, ⅝ of an inch from the base. The body and half of the head are painted black; the half of the head nearest the point is painted vermilion. =Canister.=--The canister (Fig. 43) consists of a hollow cylinder of malleable iron, with one end closed by a cast head. The case is filled with from 222 to 226 balls, and a metal cover is inserted. Around the case are several slits, their ends overlapping to secure the thorough breaking up of the case on discharge. [Illustration: FIG. 42.] [Illustration: FIG. 43.] There are several small holes in the head, through which a portion of the gas of the exploded powder-charge enters, drives forward the balls, and assists in disrupting the case. Total weight of a round, 11 lbs. 10 oz. This projectile is painted black. [Illustration: FIG. 44.] =Shrapnel.=--The Frankford Arsenal shrapnel (Fig. 44) weighs 13-10/16 lbs. Exclusive of filling it consists of three parts, viz., head (_d_), body (_a_), and base (_b_). The head is made of cast iron, bored and threaded to receive the fuze, and contains a powder-chamber which is lacquered to prevent danger of premature ignition by friction. The body is made of lap-welded wrought-iron or low-steel tubing, and is weakened for fracture by circular and longitudinal grooves on the inside. It contains 162 hardened lead balls, ½ inch in diameter, which are assembled in circular layers and held in position by cast-iron separators, which increase the effect of explosion by furnishing additional fragments. The base is made of cast iron threaded to screw into the cylindrical case, and is so formed as to provide a support for the copper band to prevent deformation of the case at this point from shock of discharge, _c_ is the rotating band. This projectile is painted, body black, head vermilion.