The turret-slide is fixed, and forms a part of the turret. The rails incline forward at an angle of 6°, so that out-tackles are unnecessary. The carriage-rollers are of the ordinary type. But one lever is used in throwing the rear trucks in action, as there is not room to work on the inside of the carriage. For running in, two chains shackle to the turret in rear of the gun and pass over a drum in the centre of the carriage. The drum is revolved by gearing. The recoil is controlled by the Elswick compressor. The elevating-gear is the single-screw type. _Turret-Carriage for the 24-cm. Gun, Pattern 1874._ This carriage, intended for a small port, differs in height and shape from the previous ones in order to permit a vertical elevation and depression of the gun-trunnions. It is built on the double-plate plan, with heavy transoms and bottom plates. The four carriage-rollers are arranged in the usual manner, the levers for throwing the rear trucks in action being moved by a tackle. The elevating-gear is fixed to the chase of the gun forward of the trunnions. It is of the ordinary rack and pinion type, but does not connect with the carriage, being hung in a frame which projects from the trunnions. The gun is run in and out by means of the endless-chain gear, the gearing being connected to a long shaft outside of the turret, to which three hand-wheels are attached. These hand-wheels are of course underneath the upper deck, coming out directly under the port. The recoil is governed by a hydraulic recoil piston, the arrangement in this case being identical with the English system. (See English Ordnance.) The trunnions have three positions, the lower, middle, and upper. They are supported in a saddle whose arms travel in a framework in the brackets, being supported by iron blocks inserted through holes in the sides of the brackets. The saddle is raised by a hydraulic press, which is so fixed in the turret that the piston takes against the bottom of the saddle when the gun is run out. The details of this arrangement are precisely similar to those of the corresponding English turret-carriage. The slide-rails are fixed in the turret with a slope to the front of 5°. In addition to the chain nipping-gear and the hydraulic recoil piston, the gun-carriage is provided with bow-compressors on each side. (See English Ordnance.) _Boat-Carriages._