Astronomical Images : Colures and horizons

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 by Franz Renner in Venice in 1478. This particular copy records various past owners, including one (whose name is no longer legible) who had begun annotating his copy in 1521 but then also heard a lecture, in September 1522, by 'the most excellent teacher of astronomy, Luca Gaurico' (a well-known astrologer (1476-1558) who served various nobles, including, later, Catherine de' Medici). The annotations, including the figures, were copied from a subsequent edition of 1488, and are most likely the insertions by this owner from the early sixteenth century. In this section on the definition of colures and horizons, a diagram is copied in the bottom margin of the right-hand page.</p>