This friend introduced Arago to Poisson who was five years older than Arago and had been appointed at an assistant professor at the école Polytechnique in the year before Arago entered the school. Arago and Poisson became friends, not really behaving as student and teacher.
Ang kaibigan ipinakilala Arago sa Poisson na limang taon ay mas matanda kaysa sa Arago at had been hihirangin sa isang assistant professor sa école Polytechnique sa taon bago Arago ipinasok sa paaralan.