Eloy Mestrelle was an employee of the Paris mint in about 1560 when attempts were made there to replace the hand hammered method of making coins with a mill and screw press. The new technology met with resistance and Mestrelle left Paris for London; he may also have been engaged in counterfeiting in Paris and need to leave in a hurry.
At the Royal Mint he was funded to build the machines again and in July 1651 Queen Elizabeth visited the mint and spent many hours examining the new process. However the technology was slow, the coins may have regularly, if not always, become stuck in the collar and needed to be removed by hand. In 1572 the Warden of the Mint discontinued the experiment citing that the new method was ten times slower than the old.
Mestrelle lost his position and he was later hanged for counterfeiting. Screw presses would not replace hammered coins until 1663.