An astronomer, born at Paris; wrote the "History of Astronomy, Ancient and Modern," in five volumes; was distracted from further study of the science by the occurrence of the Revolution; elected president of the National Assembly; installed mayor of Paris; lost favour with the people; was imprisoned as an enemy of the popular cause and cruelly guillotined. Exposed beforehand "for hours long, amid curses and bitter frost-rain, 'Bailly, thou tremblest,' said one; 'Mon ami,' said he meekly, 'it is for cold.' Crueller end," says Carlyle, "had no mortal."