Charles Julien Brianchon

Charles Julien Brianchon was a French mathematician and chemist who lived from 1783 to 1864. He entered the École Polytechnique in 1804 at the age of eighteen, studied under Gaspard Monge and graduated first in his class in 1808, after which he served as a lieutenant in Napoleon's artillery. In 1818 he became a professor at the Artillery School of the Royal Guard at Vincennes. He is best known for proving Brianchon's theorem in 1810, and for his 1817 book Mémoire sur les lignes du second ordre, a study of second-order curves that is available online at the Internet Archive. His work belongs to the study of second-order curves in the generation after Monge.