Stock Certificate for Société des Moteurs Gnome et Rhone

Louis Seguin founded the Gnome engine company in 1895. The Gnome firm initially manufactured internal combustion engines for industrial purposes, and later as automobile engines. In 1898, the company merged with the firm of a hardware manufacturer, Maurice Thevenin, and was renamed the Société des Fonderies de Cuivre de Lyon, Macon, et Paris, Thevenin Freres, L. Seguin et Cie. Seguin separated out the engine manufacturing operations from the rest of the company and established the Société Anonyme des Moteurs Gnome in 1905. When automobile engine sales decreased due to the recession of 1907-1908, Gnome began manufacturing engines for other purposes, including aircraft. Gnome displayed its first rotary engine in late 1908 and, by March 1911, had expanded its factory to meet demand for the engine. By late 1913, Gnome was manufacturing engines in England, Russia, and Italy. The Société des Moteurs "Le Rhone" was founded in 1912 by Edouard Martin to produce rotary engines in competition with Gnome. Sensing a dangerous rival, Gnome offered Rhone very good terms to sell and the two companies began operating together under the name Société des Moteurs Gnome et Rhone in June 1914 although legal issues were not concluded officially until early 1915. Rhone engines were especially popular for military aircraft during World War I and were manufactured in Great Britain and the United States. After the War, the Société des Moteurs Gnome et Rhone attempted to diversify by producing different types of engines, automobile parts, an agricultural tractor, motorcycles, woolen textile machinery, sewing machines, and marine equipment. Only motorcycles and aviation engines were successful due to various problems with these plans and the recession of 1920-1921. In 1922, the Seguin family left Société des Moteurs Gnome et Rhone and new management took over. Bankers Henry Bauer and Charles Marchal, along with Paul Louis Weiller, took leadership of the company. The Société des Moteurs Gnome et Rhone, under Weiller's management, remained a top aviation engineer manufacturer until nationalizing under the name of S.N.E.C.M.A in 1945.