Arago was an exceptionally good populariser, whose course Astronomie populaire attracted all the Parisian intelligentsia as well as various members of the public. The talks were given in various places, most of them quite inadequate, which led Arago to build an 800-seat amphitheatre at the Observatory. He used it until 1846, when ill health forced him to stop. Unfortunately, only a few decorative items survive, since the amphitheatre was replaced in 1854 by the apartments of the new director, Le Verrier.

caption : Blackboard of Arago - credits : Observatoire de Paris