He has, too, a large grist and saw mill, which are put in motion by the
explosion of gunpowder. This is conveyed, by a sufficiently ingenious
machine, in very small portions, to the bottom of an upright cylinder,
which is immediately shut perfectly close. A flint and steel are at the
same time made to strike directly over it, and to ignite the powder. The
air that is thus generated, forces up a piston through a cylinder, which
piston, striking the arm of a wheel, puts it in motion, and with it the
machinery of the mills. A complete revolution of the wheel again prepares
the cylinder for a fresh supply of gunpowder, which is set on fire, and
produces the same effect as before.
He told me he had been fifteen years perfecting this great work, in which
time it had been twice blown up by accidents, arising from the carelessness
or mismanagement of the workmen; but that he now expected it would repay
him for the time and money he had expended. He had once, he said, intended
to use the expansive force of congelation for his moving power; but he
found, after making a full and accurate calculation, that the labourers
required to keep the machine supplied with ice, consumed something more
than twice as much corn as the mill would grind in the same time. He then
was about to move it to a fine stream of water in the neighbourhood, which,
by being dammed up, so as to form a large pond, would afford him a
convenient and inexhaustible supply of ice.
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