The Palliser chilled shot is used with the muzzle-loading guns of 7 inches and upward. It is of cast-iron, the head as far as the shoulder being cast in a chill, while the rest is in a sand-mould. This shot is never solid, but a space is left large enough to contain a bursting-charge if desirable. By this means a better casting is obtained. With the larger calibres, the cylindrical part of the shot is reduced slightly in diameter to allow for setting up when the projectile first starts. There are four kinds of shells: the segment, common, double, and Palliser. The segment shells are only used with breech-loaders. This shell consists of a thin cast-iron cylindro-conoidal case lined with cast-iron segments built up in layers and leaving a cylindrical powder-chamber in the centre. The base is closed by a cast-iron disc. It is provided with a thin jacket of alloy, which takes in the rifling and gives the twist to the projectile. The common shell is the ordinary cast-iron projectile. In addition to its fuse-hole it is provided with a loading-hole opening on the shoulder. The double shell is similar to the common shell, except that it is nearly four calibres long and its chamber is provided with longitudinal strengthening ribs. It is only used in the 7-inch gun. [Illustration: Zinc Passing-Box.] [Illustration: Armstrong Segment Shell.] [Illustration: Armstrong Shrapnel.] [Illustration: Woolwich Cartridge.] The Palliser shell is similar to the Palliser shot, except that it is slightly longer and has a larger chamber. Fuses are never used with the Palliser shot or shell. The shrapnel consists of two main parts—the cast-iron body and the wooden head. The body is nearly as thick as that of the common shell, and is scored longitudinally in order to permit it to break up easily. The wooden head is covered with a light sheet-iron case which rivets to the body. The bottom of the chamber is the powder-chamber proper, over the mouth of which rests a wrought-iron disc having a hole in the centre, tapped to take a wrought-iron tube. The upper chamber is filled with lead bullets which are set fast with resin. The fuse screws into a hole in the head, and projects into the wrought-iron tube communicating with the powder-chamber. Both the chamber and the tube are filled with powder. Case-shot are of the ordinary form. Up to the 7-inch calibre the body is made of tin, beyond that it is of tinned sheet-iron. For the smaller calibres the bottom is of tin, for the larger it is a wrought-iron disc. The top is in all cases tinned iron. The contents of the case are packed in clay and sand, and there is an interior lining made up of three loose-fitting wrought-iron segments.