This book places itself among the most important scientific editions of the 16° Century. It is a valuable work representing the final point of the previous editions of pre-Copernican astronomy in Europe and describes the geocentric model of Ptolemy. 

The volume is divided into two parts. The first one is composed of 40 chapters and deals with stars and planets’ movement, as well as eclipses. This part uses graphic tools instead of tables and mathematics tools. The second part has a more scientific nature. The book is noted for its visual appeal. 

Richly decorated, it includes 30 movable tables and 15 unmovable ones. The 30 movable tables consist of graphic compositions, made of overlapping paper disks, which can be rotated letting contents appear or disappear.