The Prutenic Tables of Erasmus Reinhold, published in 1551, were the first set of astronomical tables to use the Copernican model of the solar system. Reinhold left a detailed account of his derivation of the parameters used in these tables in his "Commentarius in opus Revolutionum Copernici." The present work is based on an analysis of this unpublished manuscript, which was rediscovered early in this century. In particular, this work analyses the geocentric distances of the sun and moon as found in Ptolemy's Almagest, in both the manuscript version and the Nuremberg edition of...