CASSINI, JACQUES, son of the preceding was b. at Paris, Feb. 18. 1677. In 1694 he was elected a member of the academy of sciences. He traveled in Italy, Holland, and England, where he formed the acquaintance of Newton, Halley, Flamsteed, etc., and was elected a member of the royal society of London. On the death of his father, he succeeded to the charge of the observatory at Paris, and died April 16, 1756. C. wrote several treatises on electricity-, the barometer, etc. In his treatise, De la Grandeur et de la Figure de la 7erre (Par. 1720), lie attempted to show that thu earth must be a spheroid elongated at the poles. The Newtonians denied this, inasmuch as it was opposed to the ascertained facts of gravitation and rotation, which necessitated the earth's being a spheroid flattened at the poles. As an observer, C. was eminently successful. He determined the periods of rotation of all the satellites of Saturn then known, the incli nation of the planetary orbits, the obliquity of the ecliptic very nearly, and the length of the year, etc.—His son, CtESAR CASSINI, was also engaged in scientific pursuits.
°Assisi, JEAN Domixiquu, Comte de, the son of Caesar Cassini, was h. at Paris, June 30, 1748. He succeeded to the charge of the observatory, and completed in 178g the great topographical map of France, begun by his father. But it having been decreed in 1793 that the observatory should no longer be in the hands of one person, three others were in consequence elected to the superintendence of it along with C., whose conduct on learning this fact showed that he had a greater regard for his own dignity than for the whole stellar universe. Ile refused to have anything more to do with astronomical science, and obstinately kept through a life that lasted nearly a century, and which was apparently so prolonged to test the durability of a French man's disdain. In his 95th year he published a small volume of poems! He died Oct. 18, 1845.