Bailly, Jean-Sylvain

(1736-1793)

   astronomer, historian, revolutionary

   Born in paris, Jean-Sylvain Bailly was early recognized as a brilliant astronomer and mathematician. At age 26, he was nominated to the Academy of Sciences, with his main work as an astronomer being Essai sur la théorie des satellites de Jupiter (1766). in this work he applied Newtonian physics to the theory of Jupiter's moons. Bailly's five-volume history of astronomy is his best-known tome. Combining scientific writing with scholarly wisdom and journalistic clarity, it includes Histoire de l'astronomie ancienne (1775), Histoire de l'astronomie moderne (3 volumes, 1779-82), and Traité de l'astronomie indienne et orientale (1787). Bailly was appointed to a royal commission to investigate the work of the Austrian physician Franz Frederich Anton Mesmer and his practice of mesmerism, which claimed to induce trancelike states. Bailly's report would discredit Mesmer's hypothesis of magnetism and pave the way for the foundation of modern psychotherapy. Elected to the Académie Française in 1784 and to the Académie des inscriptions et belles-lettres in 1785, he was one of only two people appointed to all three of France's royal academies. Politically, Bailly served as secretary of the General Assembly of Electors in Paris at the beginning of the revolution (1789). He was named deputy from Paris to the estates general and became third president of the Third Estate. He would be the first to swear the Oath of the Tennis Court (see revolution of 1789), then became president of the National Assembly. Bailly's defiance of the king made him a popular hero, and he was named mayor of Paris by acclamation after the taking of the bastille. His proclamation of martial law, however, after the riot of the Champ-de-Mars in July 1791, in which he ordered troops to fire on the crowds, led to his downfall. in 1793, he was arrested and falsely accused of plotting with the king and queen. Shortly after, Bailly was executed. His three-volume Mémoire d'un témoin de la Révolution, published in 1804, describes many of the events of the times.