CAVALIERI, BONAVENTURE (1598-1647), an eminent mathematician, a native of Milan, and friar of the order of the Jesuits of St. Jerome, was the professor of mathematics at Bologna, where he published several mathematical books. The most famous of these are entitled Directorium generale Uranometricum; Geometria indivisibilibus Continuorum, &c.; Trigonometria plana et spherica, and Exercitationes Geometricæ.