The limber is formed of four futchells,--the outside ones of flat steel, the inside ones and the splinter-bar being of angle-iron,--a platform-board, and a foot-board of oak. The axle is of hollow wrought iron; wheels same as for carriage. The futchells and splinter-bar are all riveted together, and the cast-steel limber-hook is riveted in between the inside futchells: the axle is secured to the bed by three bearings. The pole lets into an iron frame and is held by two bolts with threads and nuts. The single-trees, of metal, are hung to eye-plates under the ends of the brackets. The ammunition-chest is made of steel plate and carries 300 rounds in two compartments, one of which holds 100 rounds packed in ten steel feed-cases ready for rapid firing. The limber carries the following implements: A set of intrenching-tools, axe, water-bucket, traction-rope, cushions for seats, etc. THE CAISSON. Light. Heavy. Weight with limber empty Lbs. 1430 2409 " " " loaded " 3091 4356 Number of rounds 1100 1100 [Illustration: FIG. 85.] The caisson (Fig. 85) consists of the limber, which is identical with the gun-limber, and the caisson-body, carrying two ammunition-chests similar to those of the limber. It is of steel and iron, with brakes like those on the carriage. There are two foot-boards, and it has arrangements for carrying the spare wheel, intrenching-tools, spare pole, single-trees, and other accessories. RANGE TABLE FOR LIGHT FIELD-PIECE. Angle of jump, 4′. Charge, 2.8 oz. Mean weight of projectile, 1 lb. Initial velocity, 1319 ft.-sec.