Milled coinage

[1] Leonardo da Vinci's notebooks showed there was a better way[2] and Donato Bramante, the architect who made the initial plans for St. Peter's Basilica, developed a screw press to make the lead bullae attached to Papal documents.

Aubin Olivier went to Augsburg to learn the technique and Henry II of France made him chief engineer of a mechanized mint in Paris, called the Moulin des Étuves, on 27 March 1551.

Having perfectly round coins made it easy to detect clipping, but the coiners' establishment would have none of this and within a decade the Moulin des Étuves' ex-employees were finding work in Navarre and England.

Eloy Mestrelle undertook the technology transfer from France, but when the great recoinage ended, mint authorities found him redundant and in 1578 he was hanged for counterfeiting.

Yet another Frenchman, Peter Blondeau, provided machinery for a proposed coinage designed by Thomas Simon with Oliver Cromwell's portrait.

Its most significant impact occurred when Philip II of Spain used his personal funds to build a mint at Segovia which used this technique to convert silver from the Americas to coins efficiently.

[14] Matthew Boulton had backed Watt's development of the steam engine, and he used it to power coin-making machinery at his Soho Manufactory.

[18] The Spanish Milled Dollar, and its successor the Mexican Peso, were widely used in trade with the Sinosphere, where coins were previously cast.

The subsequent French rulers of the area had a coinage based on the Spanish Milled Dollar struck at the Paris mint.

[20] Likewise, Spanish Milled Dollars and Mexican pesos became the primary currency used for trade in large parts of southern China during the mid 1800s.