CAVALIERI (Bonaventure), an eminent mathematician in the 17th century, a native of Milan, and a friar of the order of the Jesuits of St. Jerome, was professor of 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 great variety of most useful practices in trigonometry and astronomy. His trigonometrical tables in that work are excellent.