He graduated in 1787 after two years of study and then from 1788 he was employed by his old school, the École Royale du Génie of Mézières, as a draftsman and technician.
Siya ay nagtapos sa 1787 matapos ang dalawang taon ng pag-aaral at pagkatapos ay mula sa 1788 siya ay may trabaho sa pamamagitan ng kanyang lumang paaralan, ang École Royale du Genie ng Mézières, bilang isang delinyante at technician.