The outside plates are connected at the rear end by the rear cross piece, into which they both dovetail; this piece is fitted with (1) hollow handles, which are also used for carrying oil, and are closed by milled heads, fitted with camel-hair brushes; (2) a firing lever and spring, the lower end of which fits into the trigger bar, while the upper end is provided with a double button for firing; (3) an automatic double-handed safety catch, which is so arranged that unless it is held up the firing lever cannot be pressed forward; and (4) a pivoted shutter, which, when moved to the right or left, uncovers an aperture through which (when the lock is removed and the crank handle vertical) the barrel can be inspected or cleaned from the rear. The cover is fitted with (1) springs to ensure the extractor dropping on recoil; (2) a gunmetal block to keep the lock down when back, and (3) at the rear end, a lock to fasten it. On the upper surface is the tangent sight, consisting of a stem, a graduated plate and slide. Running through the centre of the slide is a pinion, the teeth of which work in the rack on the stem. A pawl is secured to the pinion by a fixing pin. On the under side of one end of the pawl are teeth, which engage in the circular rack on the slide. When the slide is at rest the stud on the inside of the milled head (nearest the slot for the slide spring) bears on the stud on the pawl immediately over the teeth, being actuated by the slide spring, thus forcing the teeth into the circular rack. This keeps the slide stationary on the stem. On rotating the milled head, this stud is partly disengaged from the stud on the pawl, thus permitting a second stud on the milled head to press on one side of the V-shaped ramp at the other end of the pawl. This action releases the teeth sufficiently to permit the pawl being moved round the circular rack by the action of the stud bearing on one side of the V-shaped ramp on the pawl; this moves the slide along the stem. On releasing the milled head, the spring positions the cover, thus causing the stud on the pawl to become once more engaged with the stud on the milled head and force the teeth into the rack. Recoiling Portion. The recoiling portion (which is mounted inside the non-recoiling portion) consists of a barrel and two side plates which carry the lock and the crank. The barrel is coated with copper to protect it from rust; the gunmetal valve referred to above, which prevents the escape of water to the rear, is fitted just in front of the breech end, which is formed in the shape of a block; this block has two studs, one on each side, called the barrel trunnions, by means of which the barrel is attached to the side plates.