the present emergency demanded more.  About half a dozen years ago the superintendent of the works here sent to England and obtained a set of rollers, and a workman to operate it, bargaining with him to remain one year at a stipulated salary.  At the expiration of the time engaged for, the workman demanded, instead of a salary, to be paid eleven cents for each barrel rolled by him.  As he had allowed no one to learn the art of rolling the barrel in the mean time, his demand was acceded to; but after the breaking out of the Rebellion four additional rolling-mills were imported, and of course new men had to be taught, or imported, to work them.  The art is now no longer a secret.  There are forty men employed, day and night, running the rolling-mills, but, instead of twelve cents, which was paid for welding, they now receive but four cents for rolling a barrel, with the same contingency of a dollar forfeiture for each one that bursts.  Four persons are employed at each mill, namely:  the foreman, who sees to the heating of the scalps and barrels; the straightener, who straightens the barrel after it passes through the roller; the catcher, who stands behind the roller to catch the barrel when it has passed through; and the fireman.  The rollers weigh two tons apiece, and the five sets turn out one thousand barrels per day, one per cent. of which burst in the proving-house.

The barrel when rolled is left much larger in the circumference, and smaller in the bore, than it is intended to be when finished, in order to allow for the loss of metal in the various finishing-operations.  When it passes into the roller, the scalp weighs ten pounds; when it comes from the roller, the barrel weighs a little over seven; when completed, it weighs but four and a half:  so that more than one half of the metal originally used is lost in the forging, or cut away by the subsequent processes.

The first of these latter is the boring-out of the interior by machines called boring-banks, of which the water-shops contain a large number, in constant operation day and night.  These machines consist of square, solid frames of iron, in which the barrel is fixed, and bored out by a succession of operations performed by augers.  These augers are square bars of steel, highly polished, and ground very sharp at the edges, and terminating in long, stout rods to enable them to pass through the barrel.  The barrels are fixed very firmly in the boring-banks, the shank of the auger inserted into the centre of a wheel placed at one end of the bank, and a slow rotary motion given to the auger, together with a still slower progressive motion at the same time.  By this means the auger gradually enters the hollow of the barrel, and enlarges the cavity as it advances.  After it has passed through, another auger, a trifle larger, is substituted in its place, and thus the calibre of the barrel is gradually enlarged to nearly the required size.  Formerly, six borings were given to each barrel, but at the present time only four are permitted, aside from the rifling, which is a distinct operation, performed at the works on the till, and will be described hereafter.