3. Let the breech of the gun be slightly raised, when the breech-casing can be shoved over the lock-cylinder to its place; then screw the casing to the frame, putting, in the meantime, the cocking-ring in its proper place. Revolve the gun to the right or left so that the places for the locks will come on a line with the hole in the diaphragm, through which one lock at a time can be inserted in its proper position; afterwards the screw-plug should be inserted to close the hole.
4. Put on the cog-wheels, replace the crank-shaft, pinion, and steady-pin. Put on the rear sight, and screw on the cascable-plate and hopper, and the gun is ready to be mounted. The piece is mounted on a 3-inch gun-carriage widened between the cheeks to receive it. The ammunition-chests are arranged for twelve trays. For field service each piece is accompanied by one caisson.
THE GARDNER GUN (CAL. 0.45").
Fig. 94.
| Weight of gun | 142 | lbs. |
| Weight of gun and carriage | 502 | " |
| Shots per minute | 357 |
This gun consists of two breech-loading rifled barrels, a ([Fig. 95]), (chambered at the rear to admit a flanged centre-fire metallic cartridge), having their axes in the same horizontal plane enclosed and supported in a bronze casing. The two openings in the front part of this casing are for the circulation of air to keep the barrels cool.
The barrels are without motion, and are loaded and fired by the action of the breech mechanism, which is contained in the rectangular rear part of the casing. This is closed at the top by a hinged cover, c, which is firmly locked in position by screwing up the cascable.