Liquid-Driven Escapements
Greeks (Water)
- earliest liquid-driven escapement described by the Greek engineer Philo of Byzantium 325 BCE in his work, Pneumatics, in chapter 31 as part of an automaton washstand
- "its construction is similar to that of clocks" indicates that such escapement mechanisms were already integrated in ancient water clocks
- 723: Tang dynasty Buddhist monk Yi Xing along with government official Liang Lingzan made the escapement to the workings of a water-powered armillary sphere and clock drive
- world's first clockwork escapement mechanism
- Song dynasty (960–1279) horologists Zhang Sixun (fl. late 10th century) and Su Song (1020–1101) applied escapement devices for their astronomical clock towers
- According to Ahmad Y. Hassan, a mercury escapement in a Spanish work for Alfonso X in 1277 can be traced back to earlier Arabic sources