Stefano degli Angeli

(11 Sept 1623 -11 Oct 1697)
   Stephano Angeli studied mathematics at the University of Bologna. He taught literature, philosophy and theology at Ferrara from 1644, and then transferred to Bologna in 1645 where he came under the influence of Cavalieri.
    After leaving Bologna, Angeli continued his contacts with Cavalieri by correspondence. He also corresponded with a number of other mathematicians including Torricelli and Viviani.
    Angeli was Rector of a religious establishment in Rome (the Jesuate order) from 1647 to 1652. Then he moved to a monastery of the same religious order in Venice before being appointed professor of mathematics at University of Padua in 1662. In fact the Jesuate order was disbanded in 1668 but Angeli continued in the priesthood while holding the chair of mathematics. He remained in this chair until his death in 1697.
   Angeli"s many works were on infinitesimals and he used them to study spirals, parabolas and hyperbolas. While in Venice he published De infinitorum parabolis (1654), De infinitorum spiralium spatiorum mensura (1660) and De infinitorum cochlearum (1661). Gregory studied with Angeli in Padua from 1664 to 1668 and learnt from him about series expansions of functions. Angeli examined fluid statics based on Archimedes" principle and Torricelli"s experiments. He published Della gravita dell aria e fluidi in 1671 while holding the chair at Padua. He also considered the motion bodies falling towards a rotating Earth.