ABSTRACT
Mathematician, born in Bamberg, Germany. Became a Jesuit in Rome, and wrote a number of textbooks, including a version of Euclid's Elements, a commentary on the Sphere of Sacrobosco, and books on algebra, the astrolabe, and practical arithmetic and geometry. He participated in the commission for the reform of the calendar that led, in 1582, to the institution of the Gregorian calendar
