Although these guns are not yet introduced into service, they probably will be. The construction is the same in principle for the body of the gun as in the old breech-loaders, with slight modifications. The breech mechanism is almost identical with the French, the modifications being in the gas-check, which is of the general Broadwell type. MUZZLE-LOADERS (ORIGINAL). [Illustration: Armstrong 10-inch Muzzle-Loader (Original Construction).] These guns consist of a steel solid-ended tube, reinforced by a number of coils connected by hook-joints. The coils are of wrought-iron bars, rolled into hollow cylinders and the turns welded in order to give a circumferential direction to the grain. Over the breech and powder-chamber a forged breech-piece fits, the grain of the iron running longitudinally. The base of the A tube is supported by a solid wrought-iron piece screwing into the forged breech-piece. A narrow spiral gutter is cut around the A tube throughout its length, and carried out at the cascabel screw-thread. By means of this, in case that the steel tube gets cracked through, the leakage of gas gives warning by blowing out at the breech. Some of these guns (7-inch) have the shunt groove, and the later ones the Woolwich groove. _Modified._ The modified construction consists in abolishing the forged breech-piece, giving the steel tube a greater thickness over the powder-chamber, and decreasing the number of coils, whilst their thickness is increased individually. The guns are also given a greatly increased length of bore, and the powder-chamber is enlarged in diameter to permit the insertion of a heavier charge. Plain grooves. At present the Elswick Company is engaged in supplying the Italian Government with breech-loading 100-ton guns. The breech-block is of the French type, and arrangements are made for moving the block as well as loading by hydraulic or steam power. The 100-ton gun has no carriage proper, its trunnions resting in heavy blocks on the fixed slide, being connected in rear with hydraulic recoil pistons which are themselves connected in such a manner as to equalize the strain of recoil. The movements of running out and in and loading are all performed by hydraulic power. The vent of the 100-ton gun is axial both in the breech and muzzle loader. _Armstrong Projectiles_ (see page 209). _Armstrong Fuze_ (see page 211). _Armstrong Breech Mechanism and Rotating Belt._ [Illustration] [Illustration] The points of peculiarity of the Armstrong breech mechanism are: 1st. The face of the breech-block is made slightly convex so that the gas-check springs back when the pressure comes on it, throwing the edge outwards, and making a wedged joint. This comes free again the moment that the block is started. 2d. The rear of the shaft holding the gas-check in place is held by a spiral spring, so that in turning the block to lock it the gas-check is not revolved in its seat. CARRIAGES.