Zhang Heng's water-powered armillary sphere
Esfera armilar movida por agua de Zhang Heng
- Date
- 125 CE · confidence high
- Place
- Luoyang, Henan, China
- Credited to
- Zhang Heng
- People
- 👤 Zhang Heng78–139
- Field
- Cosmos & Earth
What it is
An armillary sphere that turned by itself, driven by a water wheel fed from a clepsydra, reproducing the daily motion of the sky. It is the first astronomical instrument continuously driven by water power.
The exact transmission mechanism has not survived; some authors doubt it worked autonomously.
What it led to
- Chinese hydromechanical astronomical clockwork
- synchronisation of an instrument with sidereal time