The fifth and youngest child of Jewish parents, André-Gustave Citroën was born in Paris on this day in 1878. He developed a passion for engineering as he watched the construction of the Eiffel Tower, leading him to study at École Polytechnique in Palaiseau, France. During a visit to Warsaw in 1900 he witnessed a carpenter working on a set of gears. He purchased the gear patent and further developed it, leading to the invention of double helical gears, which are used in rear axles, transaxles, camshaft timing gears and many other applications. In 1906 Citroën become director of Mors automobiles. His success in the industry inspired him to found Citroën automobile company in 1919. Citroën would become the fourth largest automobile manufacturer in the world by 1932. Following overspending in development of the Traction Avant model the company declared bankruptcy and it was was taken over by Michelin tire company in 1934. André-Gustave Citroën succumbed to stomach cancer the next year and is buried in Paris. André Citroën (1878-1935). US Library of Congress’ Prints and Photographs Division. Digital ID ggbain.356991951 Modèle 15 SIX D Traction Avant. The Traction Avant was manufactured from 1934 to 1957. It’s development sent Citroën into bankruptcy, but would prove to be an incredibly successful car.