#protoclock

Other images of the Kaifeng-based “Cosmic Engine”of the 11th century.

Derek de Solla Price:

“In its final form, as built by Su Sung after many trials and improvements, the Chinese "astronomical clock-tower" must have been a most impressive object. It had the form of a tower about 30 feet high, surmounted by an observation platform covered with a light roof. On the platform was an armillary sphere designed for observing the heavens. 

“It was turned by the clockwork so as to follow the diurnal rotation and thus avoid the distressing computations caused by the change of coordinates necessary when fixed alt-azimuth instruments were used. 

“Below the platform was an enclosed chamber containing the automatically rotated celestial globe which so wonderfully agreed with the heavens. Below this, on the front of the tower was a miniature pagoda with five tiers; on each tier was a doorway through which, at due moment, appeared jacks who rang bells, clanged gongs, beat drums, and held tablets to announce the arrival of each hour, each quarter (they used 100 of them to the day) and each watch of the night. 

“Within the tower was concealed the mechanism; it consisted mainly of a central vertical shaft providing power for the sphere, globe, and jackwheels, and a horizontal shaft geared to the vertical one and carrying the great water wheel which seemed to set itself magically in motion at every quarter. 

*A simulation of the Su Sung astronomical clock tower of 1089 AD, a Chinese water-powered “Cosmic Engine.”

https://en.wikipedia.org/wiki/Su_Song

Su Song (simplified Chinese: 苏颂; traditional Chinese: 蘇頌; pinyin: Sū Sòng; Pe̍h-ōe-jī: So͘ Siōng; courtesy name: Zirong 子容)[1] (1020–1101 AD) was a Chinese polymathic scientist and statesman. Excelling in a variety of fields, he was accomplished in mathematics, astronomy, cartography, geography, horology, pharmacology, mineralogy, metallurgy, zoology, botany, mechanical engineering, hydraulic engineering, civil engineering, architecture, invention, art, poetry, philosophy, antiquities, and statesmanship during the Song Dynasty (960–1279).

Su Song was the engineer for a hydro-mechanical astronomical clock tower in medieval Kaifeng, which employed the use of an early escapement mechanism.[2][3][4][5] The escapement mechanism of Su's clock tower had been invented by Buddhist monk Yi Xing and government official Liang Lingzan in 725 AD to operate a water-powered armillary sphere, although Su's armillary sphere was the first to be provided with a mechanical clock drive.[5][6][7] Su's clock tower also featured the oldest known endless power-transmitting chain drive, called the tian ti (天梯), or "celestial ladder", as depicted in his horological treatise.[8] The clock tower had 133 different clock jacks to indicate and sound the hours.[9]