Astronomical Images : Armillary sphere

Johannes Sacrobosco

Astronomical Images

<p style='text-align: justify;'>Very little is known about Johannes Sacrobosco except that he was probably British, taught astronomy at Paris University, and died there in the second quarter of the thirteenth century. <i>Sphaera mundi</i>, his major work, was an extraordinarily popular astronomical textbook for several generations. Manuscripts of it circulated through all the main European centres of learning. It was first published in 1472 in Ferrara, and went through dozens of editions up to the mid-seventeenth century. This edition of Sacrobosco's <i>Sphaera mundi</i> was printed with Georg Peuerbach's <i>Theoricae novae planetarum</i> and Johannes Regiomontanus's <i>Disputationes contra Cremonensia deliramenta.</i> It is illustrated throughout with woodcut figures that draw closely on those from the 1488 edition, also printed in Venice by Joannes Lucilius Santritter and Hieronymus de Sanctis. Indeed, it appears that the same woodblock for the 1488 edition was used here for the armillary sphere. It illustrates the Arctic and Antarctic circles, tropics of Cancer and Capricorn, the equinoctial circle, the ecliptic (as a band with zodiac signs), oblique horizon as well as the poles of the World and of the ecliptic. The Earth is at the centre.</p>