Imser Planetary Clock, ca 1554-61

Imser Planetary Clock, ca 1554-61

Commissioned by Otto Henry, Count Palatine and Elector of the Holy Roman Empire, and later sold to Emperor Ferdinand I, this planetary clock is unsurpassed in its complex mechanisms and was celebrated as a technical marvel in its time. Designed by mathematician Philipp Imser, its delicately engraved faces provide an overview of the entire cosmos at a glance; the clock represents the apparent motion of the planets in real time, visualizing even the subtle nonuniformity of that motion as seen from Earth.

Along with accurate astronomical displays, this piece features five mechanical figures (automata) powered by the clockwork. This video shows the female figure that circles the tower once an hour, her outstretched arm serving as the minute hand. Over the course of the hour, she passes four doors that reveal in turn the three ages of man (child, adult, elder) and a skeleton—a reminder that time is up. The videos also feature the sound of the movement and the chimes.

Images: Technisches Museum, Vienna

Commentary: Making Marvels: Science and Splendor at the Courts of Europe, Metropolitan Museum of Art, New York