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Babbage, Charles, 1792-1871

"On the Economy of Machinery and Manufactures"


The mint which was sent a few years since to Calcutta was capable
of coining 200,000 pieces a day. Medals, which usually have their
figures in higher relief than coins, are produced by similar
means; but a single blow is rarely sufficient to bring them to
perfection, and the compression of the metal which arises from
the first blow renders it too hard to receive many subsequent
blows without injury to the die. It is therefore, after being
struck, removed to a furnace, in which it is carefully heated
red-hot and annealed, after which operation it is again placed
between the dies, and receives additional blows. For medals, on
which the figures are very prominent, these processes must be
repeated many times. One of the largest medals hitherto struck
underwent them nearly a hundred times before it was completed.
130. Ornaments for military accoutrements, and furniture.
These are usually of brass, and are stamped up out of solid or
sheet brass by placing it between dies, and allowing a heavy
weight to drop upon the upper die from a height of from five to
fifteen feet.
131. Buttons and nail heads.


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