Field-Carriages.
The field-carriage is of the ordinary type, consisting of two straight iron brackets, strengthened along the upper edge by angle-irons, and curved to form a sole at the bottom. To this a trunnion socket-frame is bolted. The brackets are braced by transoms and by two side rods. An iron axle bolts to the under side of the brackets just in rear of the trunnion-holes. The wheels are wooden with brass hub-boxes and iron tires. The elevating-gear is of the plain screw and hand-wheel pattern. A limber is provided with this carriage which carries two ammunition-boxes, each of which holds six rounds of shell and the corresponding cartridges (not fixed to the projectile). The carriage itself also carries two ammunition-boxes of the same size.
Field-Carriage.
GUNPOWDER.
The gunpowder used for the majority of naval guns is of the kind known as prismatic powder. Of this there are two classes. The first, for use with the heaviest calibres, is solid; that for medium calibres is pierced with holes longitudinally—for the high calibres with one central hole, and for the medium with seven. Large-grained cannon-powder is used in shell-guns, whilst the usual classes of small-grained powder is used with small-arms and for shell-charges. Prismatic powder is invariably used for battering-charges in all calibres, the gradation with regard to time of burning being obtained by the holes pierced through the grains: slow powder, solid; medium, one hole; quick, seven holes.
PROJECTILES.
The projectiles used in the German Navy are shot, shell, case-shot, and shrapnel. Shot are either solid or hollow for the lighter calibres, and hollow for the heavy ones. They are of ordinary cast-iron, chilled cast-iron, and steel, the solid shot being invariably made of ordinary cast-iron. They are of two different types, according to the style of rifling arrangement. In the earlier patterns, all projectiles were provided with a lead belt extending from the shoulder to within about two inches of the base. To receive and hold this jacket, broad shallow grooves were cut around the circumference of the projectile, the ridges left having slots cut through them at intervals to resist the tendency of the jacket to slew around. The jacket was moulded around the projectile and zinc-soldered. Corresponding with the grooves in the projectile, there were grooves in the jacket to receive the overflow of metal forced back when the projectile took the rifling.