Charles de Tinseau d'Amondans

Charles-Marie-Thérèse-Léon de Tinseau d'Amondans de Gennes was a French military engineer and mathematician of the eighteenth century, born in 1748 and dead in 1822. The sixth of seven sons of a noble family of the Franche-Comté, he entered the École du Génie at Mézières in 1769 and graduated in 1771, where Gaspard Monge, his professor of mathematics, drew him towards mathematics, although he followed a military career and reached the rank of brigadier general. In 1772 he presented two papers to the Académie Royale des Sciences, published in 1774. The more influential, on the properties of solids bounded by surfaces made of straight lines, demonstrates what is now known as De Gua's theorem, which led to a polemic with Jean Paul de Gua de Malves, who had published another demonstration thirty years before.