“On July 16th, 1789, at six o’clock in the morning, the Observatory was invaded by 300 armed men, and while keeping all the exits under surveillance, someone ran to the Maillet road [Cassini’s[SH1]  residence] to inform Cassini about this unexpected visit. An officer, accompanied by six men, showed the authorization to carefully search the Observatory, where it was thought that flour, gunpowder and rifles had been hidden. The director, ordered to accompany them during this visit, followed them to the Observatory.” Nothing was found, but many instruments were damaged. Other searches were organized, but also with no success. Although he was an aristocrat, Cassini IV, who had the support of the local inhabitants, lived through the Revolution unharmed.

caption : Map of the underground - credits : Observatoire de Paris