HOTCHKISS GUN, a gun consisting of an inner tube over which is shrunk a jacket, the latter being extended at the breech and enlarged to carry the breech mechanism. The breech-block moves vertically in a slot cut through the extension of the jacket. The firing mechanism is carried within the breech block, and the block moves vertically and falls of its own weight, the mechanism for opening and closing lifts the block up in closing and keeps it from falling open. The block is opened by means of a crank having a stud on the end which fits in a slotway in the right side of the block. When the crank is turned, the stud sweeps through its arc, and the block is carried up or down with it. The rocking-shaft carries the hammer and has a toe, which turns the rocking shaft and retracts the hammer. When at full cock the firing system is caught by a gear actuated by the rear spring. During this movement of the crank, owing to the curve of the slotway, the breech-block does not move, but as soon as the hammer is cocked, the block de scends, and as it moves down, the car tridge-case extractor is moved directly to the rear, starting the cartridge-case from its seat, and then throwing it out of the gun. In loading the gun, the charge is
entered in the chamber and pushed home till the head of the cast fetches up against the hook of the extractor. The block is closed by a reverse motion of the crank. As the block rises, the forward, upward edge pushes the cartridge and extractor home. When the breech is closed the cocking-toe is in position to allow the cocking-arm and hammer to act in firing. Pulling the trigger fires the charge. The recoil is taken up by a coiled spring carried in a small cylin der below the gun. The naval gun is mounted with its trunnions resting in a pivoted yoke which turns in a pivot stand.