Skilful provisions are made against the various contingencies likely to occur in action. A wheel may he shattered by the enemy's shot, and the gun thereby disabled for the moment: this accident is met by supporting the piece upon a handspike, firmly grasped by one or two men on each side, according to the weight of the gun, whilst a spare wheel, usually suspended at the back of "the tumbril," or ammunition waggon, is obtained, and in a few moments made to remedy the loss, as represented above.
The extraordinary rapidity with which a gun can be dislodged from its carriage, and every portion of its complicated machinery scattered upon the ground, is hardly to be believed unless witnessed; but the wonder is increased tenfold, on seeing with what magical celerity the death-dealing weapon can be put together again. These operations will be readily understood by an examination of the Illustrations. In that at the foot of page 175 the cannon is lying useless upon the earth; one wheel already forms the rude resting-place of a gunner, whilst the other is in the act of being displaced. By the application of a rope round the termination of the breech, and the lifting of the trail of the carriage, care being previously taken that the trunnions are in their respective sockets, a very slight exertion of manual labour is required to put the gun into fighting trim. That we may be understood, we will add that the trunnions are the short round pieces of iron, or brass, projecting from the sides of the cannon, and their relative position can be easily ascertained by a glance at the gun occupying the foreground of the Illustration where the dismantling is depicted. To perform the labour thus required in managing cannon, is called to serve the guns.
Cannon are cast in a solid mass of metal, either of iron or brass; they are then bored by being placed upon a machine which causes the whole mass to turn round very rapidly. The boring tool being pressed against the cannon thus revolving, a deep hole is made in it, called the bore.