FRISI, PAOLO (1728-1784), Italian mathematician and astronomer, was born at Milan on the 13th of April 1728. He was educated at the Barnabite monastery and afterwards at Padua. When twenty-one years of age he composed a treatise on the figure of the earth, and the reputation which he soon acquired led to his appointment by the king of Sardinia to the professorship of philosophy in the college of Casale. His friendship with Radicati, a man of liberal opinions, occasioned Frisi's removal by his clerical superiors to Novara, where he was compelled to do duty as a preacher. In 1753 he was elected a corresponding member of the Paris Academy of Sciences, and shortly afterwards he became professor of philosophy in the Barnabite College of St Alexander at Milan. An acrimonious attack by a young Jesuit, about this time, upon his dissertation on the figure of the earth laid the foundation of his animosity against the Jesuits, with whose enemies, including J. d'Alembert, J. A. N. Condorcet and other Encyclopedists, he later closely associated himself. In 1756 he was appointed by Leopold, grand-duke of Tuscany, to the professorship of mathematics in the university of Pisa, a post which he held for eight years. In 1757 he became an associate of the Imperial Academy of St Petersburg, and a foreign member of the Royal Society of London, and in 1758 a member of the Academy of Berlin, in 1766 of that of Stockholm, and in 1770 of the Academies of Copenhagen and of Bern. From several European crowned heads he received, at various times, marks of special distinction, and the empress Maria Theresa granted him a yearly pension of 100 sequins (£50). In 1764 he was created professor of mathematics in the palatine schools at Milan, and obtained from Pope Pius VI. release from ecclesiastical jurisdiction, and authority to become a secular priest. In 1766 he visited France and England, and in 1768 Vienna. In 1777 he became director of a school of architecture at Milan. His knowledge of hydraulics caused him to be frequently consulted with respect to the management of canals and other watercourses in various parts of Europe. It was through his means that lightning-conductors were first introduced into Italy for the protection of buildings. He died on the 22nd of November 1784.
His publications include: - Disquisitio mathematica in causam physicam figurae et magnitudinis terrae (Milan, 1751); Saggio della morale filosofia (Lugano, 1753); Nova electricitatis theoria (Milan, 1755); Dissertatio de motu diurno terrae (Pisa, 1758); Dissertationes variae (2 vols. 4to, Lucca, 1759, 1761); Del modo di regolare i fiumi e i torrenti (Lucca, 1762); Cosmographia physica et mathematica (Milan, 1774, 1775, 2 vols. 4to, his chief work); Dell' architettura, statica e idraulica (Milan, 1777); and other treatises.
See Verri, Memorie ... del signor dom Paolo Frisi (Milan, 1787), 4to; Fabbroni, "Elogi d' illustri Italiani," Atti di Milano, vol. ii.; J. C. Poggendorff, Biograph. litterar. Handwörterbuch, vol. i.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)