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