The gun is fired by means of an automatically-cocked percussion apparatus. A safety device prevents any shots from being fired until after the breech is closed. The carriage is provided with a hydraulic recoil-cylinder fitted with a spring return. It is also furnished with a "spade," which is placed under the stock at an equal distance from the trail and the axle, and which is of the model that General Engelhardt has adopted for the Russian Artillery. During a march this spade is turned back and fastened to the stock. The carriage is likewise provided with a road brake, which is to be employed in firing only when the nature of the ground is such that the spade cannot be used. The gun is placed in a bronze sleeve that carries the brake cylinders and the various other connecting pieces for the return spring and the aiming apparatus. The hydraulic recoil consists of two cylinders placed laterally and at the height of the axis of the piece. The axle has the peculiarity that in its centre there is a wide opening in which are placed the cradle and the gun. It is provided with two screw trunnions, around which the pivoting necessary for lateral aiming is effected. This arrangement of the gun with respect to the axle has the effect of greatly diminishing the shocks that firing tends to produce. Elevation and depression are accomplished by rotating the axle in the wheels of the carriage. This is done by means of a crank which, through an endless screw and pinion, controls a toothed sector attached to the sleeve. Pointing in direction is done by means of a lever known as a tail piece. Mounted upon the axle there are two small sights, forming a line of aim, that permit of bringing the carriage back in the direction of the target as soon as a shot has been fired. All that the gunner has to do is to give the piece a slight displacement laterally with respect to the carriage by means of a hand-wheel, which turns the gun 2 deg. to one side or the other. The line of aim is found by a back and front sight arranged upon the right side of the sleeve in which the gun is mounted. The back side permits of aiming while the gun is being loaded. It carries a small oscillating level that indicates the elevation of the gun during rapid firing. The weight of the carriage, without wheels, is 1,146 lbs. and with wheels, 1,477 lbs.