Mengoli, Peter

, an able Italian mathematician in the seventeenth century, concerning whose birth there is no trace, studied mathematics under Cavalieri, to whom the Italians ascribe the invention of the first principles of the infinitesimal calculus. Mengoli was appointed professor of “mechanics” in the college of nobles at Bologna, and acquired high reputation by the success with which he filled that post. His principal works are, “Geometriae SpeciosgR Elementa” “Novae Quadrature Arithmetics, sen de additione Fractionum” “Via regia ad Mathematicas ornata” “Rerrazzione e paralasse Solare” “Speculation! de Musica;” “Arithmetics rationalis Elementa” “Arithmetica realis.” Of these Dr. Burney notices his “Speculationi di Musica,” a desultory and fanciful work, published at Bologna, 1670. An account of this treatise was given in the Phil. Trans, vol. VIII. No. c. p. 6194, seemingly by Birchensha. The speculations contained in Mengoli’s work are some of them specious and ingenious; but the philosophy of sound has been so much more scientifically and clearly treated since its publication, that the difficulty of finding the book is no great impediment to the Advancement of music. He was still living in 1678. 2