CAVALIERI, BONAVENTURE, an eminent mathematician of the seventeenth century, a native of Milan, and a friar of the order of the Jesuati of St Jerome, was professor of the mathematics at Bologna, where he published several mathematical books, particularly the Method of Indivisibles. He was a scholar of Galileo. His Directorium generale Uranometricum contains a great variety of useful practices in trigonometry and astronomy. His trigonometrical tables in that work are excellent.