Page:Popular Science Monthly Volume 31.djvu/665

Rh out to windward if the vessel is heeling over, on account of the inclined plane becoming more horizontal, or even inclined in the reverse direction; and should the ship take a permanent list, from a compartment getting full of water, the inconvenience might be very considerable.

In land-service guns, when mounted in barbette, the rising of the gun exposes it and the loading detachment more to the enemy's fire; and in both cases, when placed in ports or embrasures, the ports must be higher than if the gun recoiled horizontally, and will therefore offer a better mark to the enemy's fire, especially that of machine-guns, while the sudden rise of the gun in recoiling imposes a severe downward pressure on the deck or on the platform.

To obviate these disadvantages, the author has contrived the gun-carriage, of which Fig. 8 illustrates the internal construction. The



gun is mounted on a carriage composed of two hydraulic cylinders, A, united so as to form one piece. This carriage slides on a pair of hollow ways, B, and also on to a pair of fixed rams, C, the rear ends of which are attached to the piece D forming the rear of the mounting. There are water-passages down the axes of the rams, and these communicate through an automatic recoil-valve, E, opening from the cylinders, with the two hollow sides B. There is a second communication between the cylinders and slides by means of a cock, F, which can be opened or shut at pleasure. The hollow slides are packed full of cork and water, the latter also completely filling the cylinders, rams, and various connecting passages. By means of a small force-pump, enough water can be injected to give the cork so much initial compression as will suffice to run the gun out when the slides are inclined under any angle which may be found convenient. When the gun is fired, the cylinders A are driven on to the rams C, and the water in the cylinders is forced through the hollow rams into the cork and water vessels formed by the slides B, and the cork is compressed still further. When the recoil is over, the automatic recoil-valve E closes, and the gun remains in its rearward position ready for loading. As soon as loaded, the running-out cock F is opened, the expansion of the cork drives the water from around it into the cylinders, and so forces the