Blaeu’s user’s manual for globes, spheres and sundials
By BLAEU, Willem, 1652
Institution Astronomique de l’usage des globes et spheres…
- Author: BLAEU, Willem
- Publication place: Amsterdam
- Publisher: Joan and Cornelis Blaeu
- Publication date: 1642.
- Physical description: 4to. (205 by 160mm),  ff. 277pp., numerous diagrams and woodcut illustrations within text, contemporary marginalia to title and a few leaves, some light dampstaining, final leaf with lower part cut off, contemporary vellum, title in manuscript to spine.
- Inventory reference: 12215
The Institution Astronomique is divided into two parts, the first following the improper hypothesis of Ptolemy, the second following the true Copernican hypothesis, similar in arrangement to Galileo’s Dialogo. Blaeu explains that he devotes a great many pages to the Ptolemaic system only because it is simpler for neophyte astronomers to grasp; once they have worked through the first set of exercises, they should be well equipped to understand the more complicated Copernican system.
Willem Janszoon Blaeu’s reputation as the greatest globe maker of his time was largely based on his majestic pair of globes, first issued in 1617 and revised several times in the next 30 years. These globes, luxury objects intended for the libraries of wealthy, educated men, depicted the most current geographical information, thanks to Blaeu’s close ties with many Dutch explorers. Blaeu was also an avid astronomer, having studied with Tycho Brahe at the observatory in Hven. The popular Institution Astronomique, first published in Dutch in 1620, appeared in both Latin (1634) and this French translation; it was republished repeatedly over the course of a century.