Fabrizio Mordente

Fabrizio Mordente (1532 to about 1608), born at Salerno, was an Italian mathematician, best known for inventing the proportional eight pointed compass, an instrument with two arms and cursors that solves problems of measuring the circumference, area and angles of a circle. In 1567 he published a single sheet treatise at Venice with illustrations of the device. He studied at the University of Naples, and at twenty set out to see the world, leaving Naples in 1552 and travelling through Crete, Cyprus, Egypt, Palestine and Mesopotamia, then by Portuguese ship to India, where he stayed three years in Goa before rounding the Cape of Good Hope to Lisbon. He drafted the first design of his compass on this journey. In 1571 he took service at the court of Emperor Maximilian II in Vienna and from 1578 at Prague under Rudolph II, where he met Michiel Coignet and Giordano Bruno, whose dialogues Mordentius and De Mordentii circino praised the compass while also criticising Mordente, who replied in 1586. He later served the Duke of Guise and, from 1591, Alexander Farnese, Duke of Parma, where he published his last mathematical treatise.