Sauveur, Joseph

, an eminent French mathematician, was born at La Fleche, March 24, 1653. He was totally dumb till he was seven years of age; and ever after was obliged to speak very slowly and with difficulty. He very early discovered a great turn for mechanics, and when sent to the college of the Jesuits to learn polite literature, made very little progress, but read with greediness books of arithmetic and geometry. He was, however, prevailed on, to go to Paris in 1670, and, being intended for the church, applied himself for a time to the study of philosophy and theology; but mathematics was the only study he cultivated with any success; and during his course of philosophy, he learned the first six books of Euclid in the space of a month, without the help of a master.

As he had an impediment in his voice, he was advised by M. Bossuet, to give up the church, and to apply himself to the study of physic: but this being against the inclination of his uncle, from whom 'he drew his principal resources, Sauveur determined to devote himself to his favourite study, so as to be able to teach it for his support. This scheme succeeded so well, that he soon became the fashionable preceptor in mathematics, and at twenty- three years of age he had prince Eugene for his scholar, He had not yet read the; geometry of Des Cartes but a foreigner of the first quality desiring to be taught it, he made himself master of it in an inconceivably small space of time. Basset being a fashionable game at that time, the marquis of Dangeau asked him for some calculations relating to it, which gave such satisfaction, that Sauveur had the honour to explain them to the king and queen.

In 1681 he was sent with M, Mariotte to Chantilli, to make some experiments upon the waters there, in which he gave great satisfaction. The frequent visits he made to this place inspired him with the design of writing a treatise on fortification; and, in order to join practice with theory, he went to the siege of Mons in 1691, where he | continued all the while in the trenches. With the same view also he visited all the towns of FUnders; and on his return he became the mathematician in ordinary at the court, with a pension for life. In 1680 he had been chosen to teach mathematics to the pages of the Dauphiness. In 1686 he was "appointed mathematical professor in the Royal College. And in 1696 admitted a member of the Academy of Sciences, where he was in high esteem with the members of that society. He became also particularly acquainted with the prince of Conde, from whom he received many marks of favour and affection. In 1703, M. Vanban having been made marshal of France, he proposed Sauveur to the king as his successor in the office of examiner of the engineers; to which the king agreed, and honoured him with a pension, which our author enjoyed till his death, winch happened. July 9, 1716, in the sixty-fourth year of his age.

Sauveur was of an obliging disposition, and of a good temper; humble in his deportment, and of simple manners. He was twice married. The first time he took a precaution more like a mathematician than a lover; for he would not meet the lady till he had been with a notary to have the conditions he intended to insist on, reduced into a written form for fear the sight of her should not leave him enough master of himself. He had children by both his wives anJ by the latter a son, who, like himself, was dumb for the first seven years of his life.

An extraordinary part of Sauveur’s character is, that though he had neither a musical voice nor ear, yet he studied no science more than music, of which he composed an entire new system. It was he also who first invented the monochordand the echometer. He pursued his researches even to the music of the ancient Greeks and Romans, to the Arabs, and to the very Turks and Persians themselves; and was the inventor of the term Acoustics, now generally adopted to signify the theory of sounds and their properties. But Dr. Burney does not speak very highly of some of his musical theories.

Sauveur’s writings, vvhich consist of pieces rather than of set works, are all inserted in the volumes of the memoirs of the Academy of Sciences, from 1700 to 1716, on various geometrical, mathematical, philosophical, and musical subjects. 1

1 Niceron, vol. IV, —Hutton’s Dict.?urney’s Hist, of Music.