When Lalande was looking for a new assistant in 1783 to undertake observations for a new edition of his Traité d'astronomie, he turned to Delambre who was his best student.
Kapag Lalande ay naghahanap ng isang bagong assistant sa 1783 upang magsagawa ng mga obserbasyon para sa isang bagong edition ng kanyang Traité d'astronomie, siya nabuksan sa Delambre na kanyang pinakamahusay na mag-aaral.