Thanks to Jon Baldwin for providing this: it adds more historical detail to the earlier story 'The Daggers of the Fleet'.
During the 18th Century the coinage, unless old and still circulating because of shortage, was all milled coinage. Clipping coins was something that could only be done to a hammered coin. This clipping was something that happened during the Medieval period and carried on until the hammered coins were replaced by machine made milled coins. During the Georgian period in the 18th and early 19th century the term ‘coining’ was still used, but because the coinage in circulation was generally of the milled type with a milled edge on the coin, it was impossible to clip them without the marks being visible. So during that period, the copper alloy low denomination coinage was melted down and cast into moulds made from the silver coinage and then they were dipped in a very thin layer of silver. This was known as silvering and this was very commonplace, especially in somewhere like Belper with a large nailing community that used a miniature forge in workshops or even as most did, in their houses in the hearth to heat the metal. Making copper alloy coin blanks was very easy for them. During my metal detecting in the Belper area, I have found more "silvered" forgery Georgian Bullhead Shillings than I have found genuine silver ones, so that is an example of how widespread and prolific the activity of coining was in the area. I am pretty sure that my Great Great Grandad was probably involved as he was a horse nail maker living and working on Barton Knowle (Bedlam Hill) and was definitely somewhat of a "rogue". The local Constables even located stolen property at his house, and later in his life he had a quantity of gold stolen, and many other unusual goings on. He bought 3 cottages and some more land behind them and had gold in his possession, which was not the norm for a poor honest nailer!
The above picture shows local forgeries found metal detecting. The top line are all forged bull head shillings of George the Third. The second line shows 3 more and also on the right of the second line there are 2 forged bank tokens. Tokens were produced by banks with permission of the Government and the Crown to help with the shortage of coinage. On the third line are 2 more forged shillings and a forged sixpence. The silver coins in the lower group are all genuine bull head shillings. The coin on the bottom line on the left is an example of a heavily clipped late medieval silver sixpence from the reign of Elizabeth the First, dated 1561 also found locally. That does not mean that clipping was especially rife in our area. It was very common across the whole country, even involving Lords and nobility who would have it done discreetly to increase their wealth, as the clippings were then melted down and used for something else or stamped into more coins if they had copies of dies available. Of course the penalties for this activity were very severe, including death by hanging, or hanging drawing and quartering for very serious clipping or hands being chopped off for minor offences. I have written an article recently for a friend of mine who has a website about salt glaze stoneware pottery, and he wanted something writing about the old Belper pottery. You can find it under the Denby section if you want to look, here is the link. http://www.mernick.org.uk/brownjugs/Denby/Belper.htm