It was the year 1540 when Petrus Apianus, a German humanist noted for his impressive work in mathematics, cartography and astronomy, published and dedicated this masterful work to Emperor Charles I of Spain and V of Germany. His interest in these sciences prompted the sovereign to finance the mysterious manual and then become its patron and grant him titles in order to protect the opinions of an intellectual dangerously advanced for his time.
The Astronomicum Caesarum is considered one of the masterpieces of 16th century printing. Its lavish illustrations designed on movable discs of hand-colored cardboard and stitched with thread expose nothing less than the evolution of the universe and the laws that govern it.
In it, Apianus offers instructions for the use of the movable discs or volvelles, with which he perfectly imitated the use of the astrolabe and which he used, for example, to calculate the exact date of birth of Charles I and his brother Ferdinand.
The work is recognized as one of the best astronomical treatises of the 16th century because of the simplicity with which it tries to explain these sciences to the reader, accompanied by luxurious illustrations and diagrams. In addition, he was able to identify the routes of some comets, forecast eclipses and predict the horoscope of royalty. Something so unusual and surprising at the time of the Renaissance that has led him to survive and be appreciated to this day.
Art and science merge in this book of which 111 copies are preserved around the world. Only 25 of them are in perfect condition or with most of the movable discs or volvelles preserved. In 2020, in an auction in the United States, 260,000 dollars were paid for one of these copies.
This compendium of ideas on astronomy is presented in a simple form with the sole intention of facilitating the reader’s understanding, but without leaving aside elegance and exquisiteness in form.
Thirty-five paper engravings with movable discs make up the printing of a manual that has made history for its content and the visual richness that is evident in each of its pages.
Apianus, with his knowledge and the publication of this work, is undoubtedly part of a scientific revolution that at the time was challenging to God and the Church and that over the centuries has become key to understanding the world and breaking with the thinking based on divine laws.
A book is a treasure. And the Astronomicum Caesarum is a good example of this saying, both for its valuable content and for the exquisiteness of its forms.
