but dismissed him after six months for incapacity. Said Napoleon, "Laplace ne saisissait aucune question sous son véritable point de vue; il cherchait des subtilités partout, n'avait que des idées problematiques, et portait enfin l'esprit des infiniment petits jusque dans l'administration." Desirous to retain his allegiance, Napoleon elevated him to the Senate and bestowed various other honours upon him. Nevertheless, he cheerfully gave his voice in 1814 to the dethronement of his patron and hastened to tender his services to the Bourbons, thereby earning the title of marquis. This pettiness of his character is seen in his writings. The first edition of the Système du monde was dedicated to the Council of Five Hundred. To the third volume of the Mécanique Céleste is prefixed a note that of all the truths contained in the book, that most precious to the author was the declaration he thus made of gratitude and devotion to the peace-maker of Europe. After this outburst of affection, we are surprised to find in the editions of the Théorie analytique des probabilités, which appeared after the Restoration, that the original dedication to the emperor is suppressed.
Though supple and servile in politics, it must be said that in religion and science Laplace never misrepresented or concealed his own convictions however distasteful they might be to others. In mathematics and astronomy his genius shines with a lustre excelled by few. Three great works did he give to the scientific world,—the Mécanique Céleste, the Exposition du système du monde, and the Théorie analytique des probabilities. Besides these he contributed important memoirs to the French Academy.
We first pass in brief review his astronomical researches. In 1773 he brought out a paper in which he proved that the mean motions or mean distances of planets are invariable or merely subject to small periodic changes. This was the first
