Tin coinage
In Devon and Cornwall, tin coinage was a tax on refined tin, payable to the Duchy of Cornwall and administered in the Stannary Towns. The oldest surviving records of coinage show that it was collected in 1156. It was abolished by the Tin Duties Act 1838.
Method
After smelting, the tin was cast into blocks which were taken to the Stannary towns to be proved. Initially irregular in shape, by the 19th century these blocks became standardised as bevel-edged rectangular cuboids weighing. The blocks were marked with a stamp identifying where they had been smelted. At the stannary town the prover, a duchy officer, struck off the corners of the blocks to check the quality of the metal. If proved and the duty paid, a duchy seal was affixed and the blocks permitted to be sold.In the 16th century proving took place only twice a year, at Midsummer and Michaelmas, but afterwards took place quarterly. Under Edmund, 2nd Earl of Cornwall the duty paid in Cornwall was a halfpenny per pound weight. Edward I fixed it at four shillings per hundredweight, at which it remained throughout. The duty in Devon was less at one shilling, six and a half pence per hundredweight. The earliest surviving record of the coinage dates to 1156 when Richard de Tracy had permission to collect the revenue for the following four years.
In 1213 the revenue was farmed out to a third party for 200 marks in Cornwall and 200 pounds in Devon, indicating that at this point the Devonian revenue was much more valuable than the Cornish. By 1337 the income to Edward, Duke of Cornwall was 4000 marks in Cornwall, though this was a bumper year and more usual incomes were 3000 marks. The same year brought a revenue of £273 19s 5d from Devon. By 1471 the revenue was £1,705 0s 5d in Cornwall and £190 17s 11d in Devon and in 1602 was £2,623 9s 8d and £102 17s 9d respectively. The combined income may have been as high as £6,000 by the time of Charles I and was recorded at around £9,620 at the start of the 19th century. At the time of abolition in 1838 the income was between £11,000 and £12,000.