Nicolas Fatio de Duillier
Swiss mathematician and astronomer.
Born at the château Le Vieux clos in Duillier.
Lived in Paris (from 1683), The Hague and London (from 1687).
Member of the Academy of Sciences in Paris.
Member of the Royal Society in London. Research on the distance between the sun and the earth and on the appearance of Saturn's ring.
Credited as the inventor of a method for drilling gemstones (rubies or sapphires) to use as jewels in watchmaking. Fatio and de Baufre filed a patent for the system. The method, held secret, was to remain an English specialty for some time.
The method which Fatio and his successors probably used is described in Die Kunst, die Edelsteine für die Zweke der Uhrmacherei zu bearbeiten (Dumontier, Weimar, 1845).
Sealing wax is used to fix the stone to a mandrel mounted on a treadle lathe which drives a diamond graver. Other books explain how artisans made their own drills. The surface to be drilled was coated with a mix of oil and diamond abrasive, the stone attached to a support then drilled.
The method, which was kept secret, would long remain a speciality of English watchmaking. Ferdinand Berthoud was the first to adopt it on the continent, in 1768.