1) Copper plated with silver.
In 1764, the Rev. Edward Goodwin commented on the principal manufactures in Sheffield, and included in the list various kinds of goods … plated with silver. In fact, the trade dated only from 1743 when Thomas Boulsover discovered how to plate copper with silver, partly by chance it is said. He successfully sold silver-plated buttons which were hardly distinguishable from those made of solid silver: his wares were convincing alternatives and much cheaper. He did not patent his find, and other metal workers were quick to exploit the discovery, especially Joseph Hancock, and they established a reputation for ‘Old Sheffield Plate’ that still survives. The occupational term was in use soon afterwards, for example: 1796 Godfrey Machon, silverplater, Broad Lane, Sheffield.