Joseph Sauveur (24 March 1653 – 9 July 1716) was a French mathematician and physicist. He was a professor of mathematics and in 1696 became a member of the French Academy of Sciences. Life Joseph Sauveur was born in La Flèche, the son of a provincial notary. Despite a hearing and speech impairment that kept him totally mute until he was seven, Joseph benefited from a fine education at the Jesuit College of La Flèche. At seventeen, his uncle agreed to finance his studies in philosophy and theology at Paris. Joseph, however, discovered Euclid and turned to anatomy and botany. He soon met Cordemoy, reader to the son of Louis XIV; and Cordemoy soon sang his praises to Bossuet, preceptor to the Dauphin. Despite his handicap, Joseph promptly began teaching mathematics to the Dauphine's pages and also to a number of princes, among them Eugene of Savoy. By 1680, he was something of a pet at court, where he gave anatomy courses to courtiers and calculated for them the odds in the game called "basset." In 1681, Sauveur did the mathematical calculations for a waterworks project for the "Grand Condé's" estate at Chantilly, working with Edmé Mariotte, the "father of French hydraulics. Condé became very fond of Sauveur and severely reprimanded anyone who laughed at the mathematician's speech impairment. Condé would invite Saveur to stay at Chantilly. It was there that Sauveur did his work on hydrostatics. During the summer of 1689, Sauveur was chosen to be the science and mathematics teacher for the Duke of Chartres, Louis XIV's nephew. For the prince, he drew up a manuscript outlining the "elements" of geometry and, in collaboration with Marshal Vauban, a manuscript on the "elements of military fortification." (In 1691 Sauveur and Chartres were present at the siege of Mons by the French.) Another of the prince's teachers was Étienne Loulié, a musician engaged to teach him the "elements" of musical theory and notation. Loulié and Sauveur joined forces to show the prince how mathematics and musical theory were inter-related. Remnants of this joint course have survived in Sauveur's manuscript treatise on the theory of music, and in Loulié's Éléments. In the years that followed, Sauveur taught mathematics to various princes of the royal family. In 1686 he obtained the mathematics chair at the Collège de France, which granted him a rare exemption: since he was incapable of reciting a speech