Louis Bertrand (mathematician)

Louis Bertrand was a Genevan mathematician, born in Geneva in 1731 and dead there in 1812. The son of a merchant and banker, he studied in Geneva and under Leonhard Euler in Berlin, and later worked in Bern and London as well. He was professor of mathematics at the University of Geneva from 1761 to 1795 and its rector in 1783, and he sat in Geneva's Council of Two Hundred and in the National Assembly of 1795. In 1778 he published Developpement nouveau de la partie elementaire des mathematiques, in two volumes, which contained a demonstration of Euclid's postulates that became famous before non-Euclidean geometry arose and influenced most nineteenth-century treatises on elementary geometry. In 1774 he also published a work on public instruction that openly opposed Horace Benedict de Saussure's plan for reforming the College of Geneva.