L'Académie des Sciences, like the Royal Society of England, had a pre-official existence. A company of scientific men were accustomed to meet weekly at the house of some of the members in order to discuss, in an informal way, the current scientific topics of the day. Colbert, with wise discernment, saw that it would be advantageous to give them official recognition. He induced Louis XIV to bestow upon the newly organized body extensive grants for pensions, experiments, and instruments. Under this provisional charter the Academy met for the first time on December 22, 1666, in the rooms of the Royal Library. From this time forward a regular account of the proceedings has been kept, and for the first time it was called L'Académie des Sciences.
Within the very year of Colbert's incorporating the Academy there was returned to Paris for interment the body of one who, more than any one else, gave life and direction to the Academy during its earlier and more informal years. Although having spent the greater part of his life in Holland, Descartes was a Frenchman, and lived for a while in Paris, where, in fact, many of his greatest physical investigations were begun. Descartes was a ferment. Already in England Bacon had cut himself loose from the Aristotelian philosophy of the school-men. Descartes followed with a similar upheaval upon the Continent. Yet the two philosophies were in no way akin, save in the interest their works aroused for the study of nature. In Bacon's shameless race for state honors his philosophical studies were but diversions; consequently his philosophy was vague and undefined. To Descartes, in his almost ascetic life, his philosophical studies became an all-absorbing passion; consequently his system of philosophy, if not clear in all its details, was pointed and forceful, and swept as if by storm over both the scientific and metaphysical worlds.
Colbert, pursuant of the policy of Louis XIV to make Paris the intellectual as well as the political center of Europe, invited Huygens to leave the Hague and take up his residence in Paris. This he did in 1666, France receiving from Holland this celebrated mathematician and astronomer in exchange for her loss of Descartes, who gave the best part of his life to that country. Huygens was not the only foreigner whom the honors and pensions of Louis XIV induced to leave their native land; Romer, a Danish astronomer, and the great Italian astronomer, Dominic Cassini, being among the most eminent. Since the astronomical labors of these three men were so interwoven and interdependent, they can be considered together.
The Observatory of Paris was established in 1667, eight years before the Observatory of Greenwich was built. The French monarch appointed Cassini as the first director of the National
