BAILLY, Jean Sylvain, French astrono mer, statesman and historian: b. Paris, 15 Sept. 1736; d. 12 Nov. 1793. Leaving the art of painting, to which he was educated, he pursued poetry and belles-lettres until his ac quaintance with Lacaille, when he turned his attention to astronomy and calculated the orbit of the comet of 1759. In 1763 he was admitted to the Academy of Sciences; in 1766 he pub lished his treatise on Jupiter's satellites, which also contains a history of that section of as tronomy. In 1771 he published a valuable and interesting treatise on the light of the satel lites. Later he wrote also a history of astron omy. In 1784 he was chosen secretary of the Academy, also admitted to the French Acad emy and the next year admitted to the Acad emy of Inscriptions; a rare thing for one per son to belong to the three academies. He es poused the Democratic cause in the Revolution, was elected from Paris, in 1789, 1st deputy of the tiers itat, and was chosen president of the assembly. In July 1789 he was mayor of
Paris and discharged his duties during 26 months of a most trying and dangerous period with great firmness and wisdom. Losing his popularity by repressing rioting and other crimes and defending the Queen, he gave up public life and lived in retirement till seized by the Jacobins and brought to Paris, where he was condemned as a conspirator and exe cuted. Several posthumous works of his have appeared; the most noted are an