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can bear the heat, the sand, &c. which adheres to the cannon is beaten off with large hammers, and it remains for at least twenty-four hours before it is cool.
The cannon, being now entirely solid, is taken away to be bored and finished. In order to perform this, its breech is fastened to the axis of a water-wheel, which, by means of a regulating shuttle, turns the cannon with such velocity as the workman requires. It runs upon a fixed frame; and after the muzzle is cut to the proper length, (which is done by applying to it a sharp cubical piece of steel, forced against it by means of a lever) the borer is applied. This borer is a long iron rod, or rather beam, shod with sharp pieces of hard steel, and fastened to a moveable carriage, which runs upon small wheels in grooves exactly parallel with the proposed bore of the gun; and by means of a horizontal rack on each side, passing through a hole (or rather a long box) in the fixed frame to receive it, and which has a small wheel with teeth or cogs corresponding with those of the rack, and a long lever applied to its axis, the borer with its carriage is pressed against the gun with a force answering to the weight which is applied to the end of the lever acting by means of its cog-wheel upon the rack. The cannon all this time turning