|Prague Astronomical Clock (HERE)|
Most of the first clocks were not so much chronometers as exhibitions of the pattern of the cosmos. Clearly the origins of the mechanical clock lie in a complex realm of monumental planetariums.
The medieval Prague Astronomical Clock at left was installed in 1410 - more than 130 years before Copernicus published ‘On the Revolutions of the Celestial Spheres’ in 1543. It is the third-oldest astronomical clock in the world and the oldest one still working (HERE)