Jean-Baptiste de La Chapelle

Jean -Baptiste de La Chapelle (* 1710, † 1792, probably in Paris) was a French mathematician, inventor and one of the major contributor to the Encyclopédie to the theme mathematics.

Life and work

The exact lifetime of Jean -Baptiste de La Chapelle are unknown. As in 1751, the first volume of the Encyclopédie, he was in his thirties or forties and lived in Paris. Until at least 1734 he had earned his living as a maths teacher. He had emerged as a translator of medical works and had published several works on elementary mathematics. In 1747, he was inducted into the Royal Society in London and from 1751 he worked as a royal censor.

To cooperate in the Encyclopédie he came about his acquaintance with d' Alembert, La Chapelle as the author of works Institutions de géométrie and Traité Des Sections coniques estimated and recruited him for the thematic areas arithmetic and geometry. Overall, La Chapelle contributed more than 270 articles in the Encyclopédie and was, to the twelfth band in all volumes as contributors represented (his articles are marked with the symbol " E"). According to Luneau de Boisjermain (1732-1801) should Denis Diderot about La Chapelle's work have expressed, this kill his job "a little nimble " and his mathematical articles are those of d'Alembert inferior.

In 1763 published La Chapelle an educational pamphlet entitled L'Art de ses idées communiquer (Eng. " From art to convey his thoughts " ), in which he made ​​proposals, as such topics as language, history, mathematics and religion are to teach.

Wider became famous for La Chapelle in 1765 by his experiments with a life jacket made ​​of cork, which he claimed to have invented. A large audience, he jumped into the Seine and ate, drank, snorted, fired a gun and wrote while he drove to the surface. When he this demonstration three years later, in the presence of Louis XV. wanted to repeat close to the royal hunting lodge in the forest of Sénart, failed the test. La Chapelle was quickly driven away by the current, that Louis could not see what was going on. In 1775, La Chapelle published under the title Traité théorique et pratique de la Construction du Scaphandre ou du Bateau de l' Homme finally a book about his findings in 1776 in 1777 translated into German and Dutch.

Special attraction also practiced ventriloquism from him. On the basis of studies that undertook La Chapelle on a particularly gifted in this art Kramer from Saint- Germain -en- Laye, he wrote in 1772 under the title Le ventriloque, Ou L' Engastrimythe a book about ventriloquism, which is still in the 19. century was considered a standard work on the subject.

For the years after 1775 as no accounts of La Chapelle's life and work are so well preserved. In 1783 he led a lawsuit against one of the sons of his former publisher Jean debure to a lifetime pension of 400 livres. After that trace of him.

Works (selection)

• Discours sur l' Étude of Mathématiques. Paris 1743
• Institutions de Géométrie, enrichies de notes et critiques sur la nature et des philosophiques développements de l' esprit humain; précédées d'un Discours sur l' Étude of Mathématiques. (2 volumes), Paris 1746, 1757
• Traité des sections coniques et autres courbes anciennes, appliquées appliquables et à la pratique of differents arts. 1750
• L'Art de ses idées communiquer, enrichi de notes historiques et philosophiques. London 1763
• Le ventriloque, ou l' Engastrimythe. London and Paris 1772
• Traité théorique et pratique de la Construction du Scaphandre ou du bateau de l' homme, approuvé par l' Académie des Sciences. Paris 1774; New edition under the title Traité théorique et pratique de la construction du bateau de l' homme ou scaphandre ... par M. de La Chapelle. Nouvelle édition du Projet de formation ... precede d'une légion nautique ou d' Éclaireurs of cotes, Destinée à opérer means of débarquemens qu'on avisera sans le secours de Vaisseaux ... par ... La Reynie ... [ Jean -Baptiste -Marie -Louis de La Reynie de La Bruyère ] Paris XIII