Editing Old Sheffield Plate (section)

==History==
The fact that silver and copper could fuse together was almost certainly well known to Sheffield silver makers, as silver based solder (an amalgam of silver, copper and zinc) was widely used.<ref name=crosskey |page=42/> Boulsover's discovery or invention was to find that sheets of silver and copper under high pressure would fuse together when heated to the melting point of the silver-copper [[eutectic]] alloy, then could be rolled out and shaped without the layers separating.<ref>{{cite journal |last1=Charles |first1=J A |title=The First Sheffield Plate |journal=Antiquity |date=Dec 1, 1968 |volume=42 |issue=168 |page=278 |url=https://www.proquest.com/docview/1293830139 |issn=0003-598X}}</ref>  The material could be rolled out to a thinness appropriate for the making of silver items. As far less silver was needed, the price of these items was far lower.
[[File:OSP Telescopic candlesticks.jpg|left|thumb|284x284px|OSP 'Telescopic' candlesticks, {{circa|1830}}, with the 'Orb' Maker's Mark of Blagden, Hodgson & Co. The inner sleeve allowed the height of the candle to be adjusted.]]
It is said that the material was accidentally invented by [[Thomas Boulsover]], of Sheffield's [[Company of Cutlers in Hallamshire|Cutlers Company]], in 1743, but this attribution is probably anecdotal.<ref>{{cite book |last=Crosskey |first=Gordon |title=Old Sheffield Plate, A History of the 18th Century Plated Trade |publisher=Treffrey Publishing |year=2013 |isbn=978-0-9568003-1-2 |edition=2nd |location=Sheffield, UK |pages=12}}</ref>  It was said that while trying to repair the handle of a customer's decorative knife, he heated it too much and the silver started to [[melting|melt]]. When he examined the damaged handle, he noticed that the silver and copper had fused together very strongly. Experiments showed that the two metals behaved as one when he tried to reshape them, even though he could clearly see the two different layers.  

Boulsover set up in business, funded by Strelley Pegge of [[Beauchief]], and carried out further experiments in which he put a thin sheet of silver on a thick ingot of copper and heated the two together to fuse them. When the composite block was hammered or rolled to make it thinner, the two metals were reduced in thickness at similar rates. Using this method, Boulsover was able to make sheets of metal which had a thin layer of silver on the top surface and a thick layer of copper underneath.  When this new material was used to make buttons, they looked and behaved like silver buttons but were a fraction of the cost.

The main centre for the trade was always Sheffield, England, where there was already a substantial manufacturing industry for making small silver items such as buttons, cutlery and snuff boxes etc. Following Boulsover's discovery, the trade rapidly expanded particularly from the 1760s onwards. The other centre of production in England became Birmingham, almost entirely through the efforts of Matthew Boulton.<ref name="mason ed">{{cite book |last=Mason |first=Shena |title=Matthew Boulton: Selling what all the world desires |publisher=Yale University Press & Birmingham City Council |year=2009 |isbn=978-0-300-14358-4 |location=Birmingham, UK |pages=41–46}}</ref> While Boulton's ormolu and solid silver products tend to attract most attention,<ref>{{cite book |last=Goodison |first=Nicholas |title=Ormolu: The work of Matthew Boulton |publisher=Phaidon Press Ltd |year=1974 |isbn=0-7148-1589-6 |location=London |pages=398}}</ref><ref>{{cite book |last1=Delieb |first1=Eric |last2=Roberts |first2=Michael |title=The Great Silver Manufactory: Matthew Boulton & the Birmingham Silversmiths 1760 - 1790 |publisher=Studio Vista |year=1971 |isbn=978-0289702048 |location=London}}</ref> his button and plated wares manufacturing were financially always more important.<ref name="mason ed"/>{{rp|loc=chapter 5}}