Argues, Gerard Des

, a geometrician of the seventeenth century, was born at Lyons in 1597, and died there in 1661. He was the friend of Descartes; this friendship was of service to them both Descartes instructed hisfriend, and Des Argues defended his master against | Fermat and Bourdin. He wrote, 1. “Un Traite de Perspective,” fol. 2. “Traite des Sections Coniques, 8vo. 3.” La Pratique du Trait,“8vo. 4.” Traite de la coupe des Pierres,“8vo, an excellent work on stone-cutting. 5.” Maniere de poser l'essieu aux cadrans solaires.“6.” Maniere de graver en taille douce, et a l'eau forte." All these treatises are said to be written with precision, and in a better style than might have been expected from his time. ¹