Boulton helped deal with the shortage of silver, persuading the Government to let him overstrike the Bank of England's large stock of Spanish dollars with an English design. The Bank had attempted to circulate the dollars by countermarking the coins on the side showing the Spanish king with a small image of George III, but the public was reluctant to accept them, in part due to counterfeiting. This attempt inspired the couplet, "The Bank to make their Spanish Dollars pass/Stamped the head of a fool on the neck of an ass." Boulton obliterated the old design in his restriking. Though Boulton was not as successful in defeating counterfeiters as he hoped (high quality fakes arrived at the Bank's offices within days of the issuance), these coins circulated until the Royal Mint again struck large quantities of silver coin in 1816, when Boulton's were withdrawn. He oversaw the final issue of his coppers for Britain in 1806, and a major issue of coppers to circulate only in Ireland. Even as his health failed, he had his servants carry him from Soho House to the Soho Mint, and he sat and watched the machinery,which was kept exceptionally busy in 1808 by the striking of almost 90,000,000 pieces for the East India Company. He wrote, "Of all the mechanical subjects I ever entered upon, there is none in which I ever engaged with so much ardour as that of bringing to perfection the art of coining."