Engraving by William Humphrey after a composition by Cunningham. Christopher Pinchbeck (c 1670-1732) invented the copper and zinc alloy for making imitation gold watches, which is now named after him. Cheap and durable, the alloy was popular until the mid 18th century, when its use faded following the legalisation of nine karat gold and the introduction of the electro-gilding proces. Published by William Hebb, Pinchbeck's son in law, on 1 May 1783.
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