François-César l. Courtanvaux marquis de (1718-1781)
Details
Type of entity: Person
Name: François-César l. Courtanvaux marquis de
Date of birth: 1718
Date of death: 1781
Source of information: Special Collections
Profile
François César Le Tellier, Marquis de Courtanvaux, was born in Paris in 1718, scion of a family famous for providing two government ministers in the reign of Louis XIV. François César was destined for the army and in consequence he only received the minimum of formal education. At the age of 15, he saw his first military campaign, as aide-de-camp of his mother’s brother, the maréchal de Noailles. In 1740, he was appointed as Colonel of the regiment Royal but in 1745, he had to retire from the army because of ill health. Disinclined to a life of idleness, he devoted himself to scientific study, pursuing successively natural history, chemistry, geography, physics, mechanics and astronomy.
He married at the young age of 14, and had two children, a son Charles-François, marquis de Montmirail, and a daughter, Félicité-Louise. His son inherited the father’s love of science and in 1761 was appointed a member of the Académie royale des sciences, becoming its president for 1763. Unfortunately Montmirail died in 1764 and Le Tellier became a member of the Académie in his place. He in his turn went on to hold twice the position of president, in 1769 and 1775.
In 1767, the Académie held a competition to design a chronometer which would keep time on board ship. Le Tellier offered to test the performance of the entries submitted. He oversaw the design of a corvette and spent over 3 months at sea before publishing in 1768 a book summarising the results. The Académie awarded the prize in 1769 to one of two chronometers submitted by Pierre Le Roy.
During his lifetime, the marquis de Montmirail had conceived the idea of building a collection of all the travel accounts books ever published, together with a summary of the most interesting features of each and an evaluation of their merit and veracity. Le Tellier continued this enterprise after his son’s death and became something of a bibliophile. At his own death in 1781, his library comprised nearly 4.000 items, of which over a quarter related to travel accounts or the associated natural history. Most of the library was sold at auction in 1783.