Soho Mint was created by Matthew Boulton in 1788 in his Soho Manufactory (grid reference SP051890) in Handsworth, West Midlands, England. A mint was erected at the manufactory containing eight machines, to his own patent design, driven by steam engine, each capable of striking 70 to 84 coins per minute.
The common coinage, copper halfpennies, was subject to severe counterfeiting. No copper coinage had been issued by the Royal Mint since 1754 apart from inadequate issues of halfpence and farthings from 1770-75.
In order to differentiate his proposed copper coins from counterfeits Boulton specified them as follows:
- 2 ounces weight, diameter 8 to the foot
- 1 ounce, diameter 17 to two feet
- 1/2 ounce, diameter 10 to a foot
- 1/4 ounce, diameter 12 to a foot
Their weight in pure copper should be so close to the intrinsic value of the material that counterfeiting would be uneconomic. The diameter was made strictly defined by striking within a collar so that diameter, thickness and weight could be used to prove the quality of the metal.
In 1797 the first, and only, copper twopenny and the first penny coins were produced under contract although the smaller denominations did not follow until later. These coins were comparatively large, having a broad raised rim with the inscription pressed below the surface and became known as the cartwheel pennies. Over 45 million were minted in two years.
- British halfpenny coin regarding counterfeit coinage
- History of the British penny (1714-1901)
- Old Bess, a steam engine at the Mint
- History of mints
- Dickinson, H. W. (1937). Matthew Boulton. Cambridge University Press.
- Old and New Birmingham: A History of the Town and its People, Robert Kirkup Dent, Published by Houghton and Hammond, Scotland Passage, Birmingham, 1880
- A Numismatic History of the Birmingham Mint, James O. Sweeny, The Birmingham Mint Ltd, 1981, ISBN 0-9507594-0-6
- British Coins Market Values, Link House Magazines Ltd, 1993, ISSN 0-86296-100-9
- Victor Skipp, A History of Greater Birmingham - down to 1830, 1980. ISBN 0-9506998-0-2
- Britain's Cartwheel Coinage of 1797
- On Matthew Bolton and the Soho mint
- British Coins - Free information about British coins. Includes an online forum.
- sohomint.info A website celebrating Matthew Boulton, his mint and its products