Giovanni de’ Dondi’s astrarium

INTRODUCTION
- Man and the stars
SECTION I
- The dawn of astronomy: Mesopotamia, Egypt and the Biblical Cosmos
SECTION II
- The cosmos becomes a sphere
SECTION III
- The geometry of the cosmos
SECTION IV
- The skies of Islam
SECTION V
- Evangelisation of the cosmos
SECTION VI
- The Renaissance of Astronomy
SECTION VII
- Galileo: the cosmos through the telescope
SECTION VIII
- From Galileo to Newton

Atlas coelestis seu Harmonia Macrocosmica

Zoom

Giovanni de' Dondi's astrarium
Working model; reconstruction by A. Segonds, E. Poulle, J.P. Verdet
Paris, Observatoire de Paris, inv. 404, anc. 20-36

De' Dondi's astrarium is the oldest planetarium that shows the movements of all the planets known in the Middle Ages (including the Sun and the Moon). A single weight-driven motor drives trains of gears that set the seven stars in motion. Each of their trajectories is visualised on a dial. Giovanni de' Dondi's manuscript (14th century) contains an extremely detailed plan of the astrarium, thanks to which it has been possible to build a faithful and fully functioning replica of the lost original of this extraordinary planetary clock, which was considered a mechanical miracle not only by de' Dondi's contemporaries but also by scholars of later generations.