Cassini, Jacques

Born Feb. 18, 1677, in Paris; died Apr. 15, 1756, in Thury, near Clermont. French astronomer and geodesist. Member of the Paris Academy of Sciences (1694). Director of the Paris Observatory (from 1712). Son of G. D. Cassini.

Cassini was one of the participants in the measurement of the great arc of the Paris meridian (at the end of the 17th century and beginning of the 18th century). He was the first to carry out measurement of the angle of a parallel (1734). In the controversy about the shape of the earth, he supported for a long time the erroneous viewpoint that the earth is elongated along its axis of rotation.