Remembered primarily for his invention of the barometer and his discovery of atmospheric pressure, Evangelista Torricelli worked extensively with Galileo Galilei, refined the method of indivisibles introduced by Bonaventura Cavalieri, and wrote the famous Opera Geometrica.

Torricelli was born in Faenza, Italy on October 15, 1608, the oldest of three children and the son of a modestly successful textile craftsman. From a young age, the boy demonstrated impressive mathematical talents, so his family sent him to be tutored by an uncle who was a monk of the Camaldolese order. The uncle gave Torricelli much of his early education, after which Torricelli began attending philosophy and mathematics courses in 1625 at the Jesuit school, Sapienza College (the University of Rome), back in Faenza.

His Jesuit teachers were so awed by Torricelli's aptitude that in 1626 they sent him on to more advanced studies in Rome at a school run by a former Galileo...