He never fully abandoned his mining career to mathematics. He worked at the [[Ministry of Public Services]] as an engineer in charge of northern railway development from 1881 to 1885. He eventually became chief engineer of the Corps de Mines in 1893 and inspector general in 1910. | He never fully abandoned his mining career to mathematics. He worked at the [[Ministry of Public Services]] as an engineer in charge of northern railway development from 1881 to 1885. He eventually became chief engineer of the Corps de Mines in 1893 and inspector general in 1910. |