Title page of Clavius' commentary on the Spheres of Sacrobosco, first published in 1570. Revised editions appeared in 1581, 1585, 1593, 1607, and 1611. The book, along with Clavius's influential commentary on Euclid's Elements, was regularly reprinted for many decades after Clavius' death in 1612. The book is basically a presentation of Ptolemaic astronomy, although in later editions the Tychonian and Copernican planetary systems are also discussed.
-Written and last revised 20 December 1997 by paulchar@ucar.edu.
