Engineer of the Northern Railway Company (1914), he was responsible for adapting this network to defense requirements during the Great War. After the world conflict, he undertook the reconstruction of the devastated lines. Expert with the National Economic Council (1926), he was entrusted with the management of the public rail network (1928-37). Concurrently, he held the presidency of the Compagnie Générale Transatlantique (1931-32) and the Conference of Directors of the major rail networks (1934). He organized the (National Compagny of Railways) SNCF in 1938. Minister of Armaments for Daladier, then for Reynaud (1939-40), he declared himself in favor of the continuation of the struggle. President of "L’entr’aide française" (1944), he was entrusted with the Ministry of Reconstruction and Town Planning (1944-46). General administrator, government delegate to Atomic Energy Commission (CEA) in 1946, he was elected member of the Academy of Moral and Political Sciences (1946)