Giovanni Antonio Magini (1555–1617)

Giovanni Antonio Magini was an Italian astronomer, astrologer, and mathematician. Born in Padua, he received a doctorate in philosophy from the University of Bologna in 1579 before publishing three years later a major astronomical treatise, Ephemerides coelestium motuum. Following the death in 1586 of Egnatio Dani, who held the chair of mathematics at Bologna, a competition was announced to select a successor and Magini was chosen over and above — amongst others — the young Galileo Galilei. Taking up his appointment in 1588, Magini held this chair for the remainder of his life and supplemented his income with work in Mantua for the Gonzaga as tutor to the sons of Vincenzo I.

Magini was well acquainted with the most advanced and revolutionary mathematical and astronomical theories of his day, but nonetheless remained convinced of the essential truth of the traditional world view. While he endorsed the accuracy of Nicolaus Copernicus’s calculations of celestial movements, he rejected that author’s heliocentrism and, in Novæ cœlestium orbium theoricæ congruentes cum observationibus N. Copernici (published in Venice in 1589), set out instead his own geocentric theory which involved eleven rotating spheres.

Magini brought out in 1606 a publication of accurate trigonometric tables and followed this a year later with an astronomical work, De astrologica ratione. He pursued yet another interest in a treatise on the theory of concave mirrors. However, it is as a cartographer that Magini is best remembered today. Not only did he publish an important commentary on Ptolemy’s Geographia [1596], but he worked for much of his life on the preparation of his Atlante geografico d’Italia, a significant and ambitious undertaking to publish a ‘complete atlas of Italy’. This magnum opus remained unfinished at the time of his death and was published posthumously by his son three years later in 1620.