Michelangelo Ricci

Michelangelo Ricci (1619 to 1682) was an Italian mathematician and a Cardinal of the Roman Catholic Church, born in Rome to a family of low social standing that came from Bergamo. He studied theology and law in Rome, where he was a contemporary of René-François de Sluse, and learned mathematics from Benedetto Castelli, himself a student of Galileo. A friend of Evangelista Torricelli, he played an important role in the development of the Galilean school and in the debates and experiments that led to Torricelli's discovery of atmospheric pressure and invention of the mercury barometer. Having suffered from epilepsy since birth, he was disqualified from ordination under the canon law of the time but was created Cardinal-Deacon of Santa Maria in Aquiro by Pope Innocent XI on 1 September 1681. His published mathematical work is a nineteen-page treatise, Exercitatio geometrica, de maximis et minimis (1666), on the maxima of certain algebraic functions and on tangents to curves, which was much admired by his contemporaries and republished as an appendix to Mercator's Logarithmotechnia in 1688. He also studied spirals and cycloids.