The Works Of Messrs. Schneider And Co.

XXXIX.—QUICK-FIRING- COAST-DEFENCE GUNS. \ CERTAIN number of points selected for coast | defence, and especially for “ armour-piercing coast batteries,” have to be armed with guns of high power and flat trajectories, permitting a rapid concentration of fire against a target. It is important in inany cases i that coast-detence batteries should be in a position to compete thoroughly, under conditions approximately equal, with quick-firing naval guns, while it is necessary f to take into considemtion the ease with which modern | fleets can perform their evolutions. A special dass of | Schneider - Canet quick-firing guns contains a complété series of calibres, from 37 millimétrés (1.456 in.) to 24 centimetres (9.449 in.), for. carrying out this pro- gramme to the best advantage. This dass of materiel has been adopted for regulär service by varions Govern- ments, especially by Russia and Japan, the two latter countries having acquired the right to reproduce the type in their own arsenals. As a rule, these guns are similar to those used on board ship, as regards construction and breech-closing devices, but tliey are frequently of longer calibre, in order to obtain higher muzzle velocities and flatter trajectories. The mountings are also similar to naval mountings ; but as coast-defence guns have to fire under great angles, both positive and negative, the mount- ing is either placed upon a concrète base or upon a cône built up of plates and angles. As the guns of this dass are similar, except in dimensions, to the naval guns already described, we shall select for the following descriptions a few only of the most interesting types that embody particular devices, and are placed upon special mountings. 12-Centimetre (4.724-In.) 26-Calibre Quick - Firing Coast-Defence Gun (Fig. 874, Plate CL.).—Tbis has been adopted for regulär service in Japanese coast defences. j The programme that had to be fulfilled according to the | Japanese artillery stipulations, stated that the gun should be of medium power, (muzzle velocity 600 metres only = 1968 ft.), quickly trained and fired by a limited number of men. In connection with this Order, the Japanese Government established compétitive trials, in which the Schneider-Canet ordnance obtained the first rank, and was I definitely adopted. The following are some leading data : The mounting is fitted with a shield which protects the working parts and the gunners. The mounting consists of four main parts, namely : The built-up base, in the shape of a truncated cone, stayed inside and bolted to the firing platform, the loading platform being in the rear ; the bed- plate, fitted to the base and provided with roller balis, the central pivot being joined by ribs to the circular ring • the slide which rests on the bedplate on tlie balis and con- sists of two cheeks made practically vertical, the latter being provided with under trunnion plates strengthened in the middle by stays, the cheeks joined together by a stiff plate ; the gun carriage, which consists of a cast-steel jacket, in one piece with which is cast the lower part of the hydraulic recoil cylinder ; the trunnions are in the front part of the jacket ; while inside, gun-metal rings at both ends serve to guide the gun during recoil. At its lower part, over a part of its length, tlie carriage is made with a gap forming two slide paths to guide the butt end, which draws the recoil piston-rod with it. A transverse bar with buffer is placed in front, to check the travel of the gun when it runs out again. The recoil cylinder is on the Schneider-Canet system, with central counter-rod. It acts as follows : During recoil the gun draws along with it the recoil piston, its rear surface presses 011 the glycérine in the cylinder, and forces it to flow through the annular vent cut round the central rod and through the lateral vents cut round the piston. The glycérine flows to the front part, the valve which establishes a communication between the two ends of the cylinder being raised. The inside capacity of the cylinder decreasing by a quantity equal to the volume of the rod which penetrates it, the corresponding excess of liquid moves the bottom of the cylinder, which acts as a piunger ; this moves the transverse bar and presses down the recuperating springs. When the recoil is spent, the springs, in relaxing, drive back the transverse bar and the cylinder bottom, thus forcing the glycérine to resume its former position ; but as the valve is closed, it can only flow through tlie narrow vent in the valve seat, the gun returning, therefore, slowly and without shocks. The training gear, both for vertical and horizontal Weight of Gun ... Length of gun ... Weight of mounting ,, base ... ,, shield... Maximum angles of elevation ... Training ... Weight of projectile „ powder charge, French smokeless powder Muzzle velocity ... 1620 kg. 3570 Ib. 3.120 ni. 10 ft. 2’f in. 2780 kg. 6127 Ib. 1800 kg. 3967 Ib. 1500 kg. 3306 Ib. - 7 deg. + 20 deg. - 7 deg. + 20 deg through 140 deg.|through 140 deg 18 kg. 40 Ib. 2.8 kg. 6 Ib. 560 m. 1837 ft. ' angles, is of the ordinary type, and so need not be j described. 12-Centimetre (4.724-In.) 40-Calibre Quick-Firing Coast-Defence Gun.—This gun is on the same system I as the preceding one, but is of a much greater power. The mounting is provided with a platform, and consists I of five main parts : (a) The base, made of plates and angles, carries the I firing platform, and contains the roller patfh. At its