The Works Of Messrs. Schneider And Co.

316 MESSES. SCHNEIDER AND CO.’S WORKS. resist main force attacks. It remains down during the shell- ing of the place, and is run up when convenient to fire a volley. It can also be made to disappear and be raised for each round in succession, the manœuvres and the laying of the gun being effected within a very short time. The turret is armed with a 57-millimetre (2.244-in.) quick-firing gun, that lires with a muzzle velocity of 425 metres (1,394 ft.), ordinary shell or grape shot shell weighing 2.720 kilo- grammes (6 Ib.). The range of elevation is through — 5 deg. to + 10 deg., and the turret can be made to turn through the whole circle. The body of the turret consists of a cylinder, 1.400 metres (4ft. 7in.) inside diameter, formed of steel plates, covered by a cast-steel spherical head. It is carried on two brackets, built up of plates and angles, the top flange of which serves as a roller-path for the gun-mounting. The brackets are joined at their lower part by a cast-steel stay-piece, in which the pivot is made to fit. The pivot turns in a gun-metal step-bearing fixecl in a cast-steel pivot-rest ; this rises or descends vertically under the action of the disappearing inechanism. A cast-steel support, placed at the bottom of the turret pit, acts as a guide for the pivot-rest and prevents it from turning round. The cylindrical body is fitted outside with a brass ring, made to slide inside a cast-steel guiding shaft, strongly embedded in the masonry work. The turret, when rising, disappearing, or rotating, is guided at the top by the fixecl shaft, and at the lower part by the pivot and pivot-rest. The lower stay-piece of the brackets forms a platform ; the gunner in charge of the gun sits on a seat, the height of which can be regulated. The non-recoil mounting transmits the effort it undergoes when the gun is fired, to the whole of the turret, which in its turn transmits it to the guiding shaft. The gun does not get displaced through the firing; it can therefore be made to work quicker and with greater accuracy than would be the case were the shoek caused by firing to be taken up by elastic butfers, which do not always resume their former position, and are liable to break. The protective armour is of cast-steel, in one piece ; it is in the shape of a cap made to cover the system. The vertical wall is 100 millimétrés (3.937 in.) thick ; 1.625 metres (5ft. 4in.) outside diameter. The spherical top is 120 millimétrés (4.724 in.) thick, and is made with a slight overhang that fits, when the turret is run down, in a bevel cut in the fore-shield. In the turret armour are cut the following openings : (a) Tn front, the gun embrasure, as small as possible, and an opening for sighting the gun. (b) In the centre, at top, an opening of about 80 millimétrés (3.149 in.) for taking observations; this is usually closed by a brass screw from the inside. (c) In the rear and in the sides, three small openings | 40 millimétrés (1.574 in.) in diameter, to survey the ground during firing. A rod is jointed under the pivot-rest, through which the whole of the movable part bears on a lever, the I other end carrying a cast-iron counterweight. The point of suspension of the lever is above the line that joins the centre of the counterweight and the point to which the lever is jointed ; the counterweight is so designed that the whole system is balancée! when the lever is in a medium position. In this way the turret, when in battery. has a prépondérance which tends to cause it to disappear ; on the other hånd, when the turret is completely down, the counterweight has a prépondérance ; which tends to run it up. A very slight action, there- fore, is necessary to start the rising or disappearing of the turret ; and in order to cause it to disappear com- I pletely, it is only necessary to drive it a little while the power of gravity acts, so tliat the speed obtaineel during the first half of travel compensâtes the prépondérance developed during the second half. This is facilitated by a small winch, which transforms the uniform speed of the crank, in accelerated speed during the first half of the travel, and in slackened speed during the second half. Two seconds only are required to completely lower or raise the turret, one man working the crank. The height of travel is over 310 millimétrés (12.204 in.). When the turret is run down, it rests on the guiding shaft, with the interposition of wood weclges ; a play is maintained between tlie shoulder of the turret cover and the level of the fore-shield. The gun takes up two positions m the turret : when the latter is run down, it is completely inside ; when it is run up, the chase is outside the turret, leaving a space at the breech-end for the gunner. This is obtained in the following manner : The gun is carried by its trunnions on a movable mounting, made to run on the top flanges of two brackets. Two strono- bolts hold the mountinsr when in battery, and prevent all recoil ; these bolts are worked by the gunner, by means of a lever. The tixing of the bolts sets free a latch, and allows the working of the breech-block ; the latch resumes its position when the bolts are driven back, thus fixing afresh the breech-block mechanism. The turret camiot be made to disappear so long as tlie gun is not run in, for when the gun is in battery a latch in the rear of the turret is made to run out on the top of the guiding shaft, thus preventing the lowering. This latch is only run in by the mounting when the latter is brought completely back. The elevating mechanism for the gun is arrangée! in such a way that tlie gun takes up automatically a horizontal position in running in, whatever be the range of elevation at which it has been fired. The required elevation is given by the angular dis- placement of a movable slide, worked by a hand-wheel which the gunner holds in his left hånd ; the hand-wheel drives a screw jointed on the end of the movable slide, through two bevel pinions. When the gun is run in the turret, and whatever be the angle of elevation, the screw runs down the movable slide, and causes the gun to resume its horizontal position. A screw fixes the elevating : mechanism when firing takes place. The gun is trained