CESAR FRANCOIS CASSINI

cesar francois cassini, or cassini de thury (1714-1784), son of jacques cassini, was born at the observatory of paris on the 17th of june 1714. he succeeded to his father's official employments, continued the hereditary surveying operations, and began in 1744 the construction of a great topographical map of france. the post of director of the paris observatory was created for his benefit in 1771, when the establishment ceased to be a dependency of the academy of sciences. cassini de thury died at thury on the 4th of september 1784. his chief works are:--_meridienne de l'observatoire de paris_ (1744), _description geometrique de la terre_ (1775), and _description geometrique de la france_ (1784). see c. wolf, _histoire de l'observatoire de paris_, p. 287; max. marie, _histoire des sciences_, viii. 158; j. delambre, _histoire de i'astronomie au xviii'e siecle_, pp. 275-309; r. wolf, _geschichte der astronomie_, p. 451; j.j. de lalande, _bibliographic astronomique_.