Su Song astronomical clock tower
Torre de reloj astronómica hidromecánica de Su Song
- Date
- 1092 · confidence high
- Place
- Kaifeng, Song China
- Credited to
- Su Song and Han Gonglian
- People
- 👤 Su Song1020–1101
- Field
- Knowledge & symbols
What it is
A 12 m tower with an armillary sphere, a celestial globe and automata driven by a water wheel regulated by an escapement and an endless power-transmission chain. The most complex astronomical machine of the medieval world.
Looted by the Jin in 1127 and never rebuilt; known from the treatise Xin Yi Xiang Fa Yao.
What it led to
- the Chinese tradition of astronomical clockwork (Guo Shoujing, 1276)
- the first documented chain-drive transmission
- a historical comparison with the European mechanical escapement
Built on
- Water clock (clepsydra)c. 1500 BCE
- Toothed gearc. 270 BCE
- Zhang Heng's water-powered armillary sphere125 CE
- Yi Xing's hydromechanical escapement725
- Yi Xing and Liang Lingzan's clock (725)
- gears
Made possible
- Jagyeongnu self-striking water clock1434
- chain drive transmission
- motorised armillary sphere