He arrived in June 1788 at the small fortress on the Saône, seat of the artillery school of application. Its commander, Baron Jean-Pierre du Teil, brother of the author of The Use of the New Artillery, quickly singled out this eighteen-year-old lieutenant and entrusted him with work and memoranda usually reserved for senior officers.
What was taught there was the Gribeauval system: lighter guns, standardised, interchangeable, served by trained crews, able to follow the infantry and concentrate quickly. Crossed with Guibert's ideas on mobility and the division, this was exactly the tool Bonaparte would use at Toulon, then Lodi, then for the grand battery at Austerlitz.
Material life was hard. He lived on his pay, brought over his brother Louis whom he fed and taught himself, ate once a day and fell ill with persistent fevers. His Auxonne notebooks, which survive, mix ballistics, fortification, reading notes on ancient history and literary drafts: the mind of someone who files everything.
The Revolution came in through the window. In 1789 the garrison was used to contain grain riots in the region; he watched soldiers disobey and the authority of noble officers collapse. What the provinces showed him then he forgot no more than the firing tables.