Cambridge University Library


Keeping Time

Illustration of a water clock

Ch'en Yüan-ching (fl. c. 1300 AD). Tsuan t'u tseng hsin ch'ün shu lei yao Shih lin kuang chi. Chien-yang, 1478.

Calendars of the Far East

Different types of clepsydra - water clocks, which measured time by the gradual flow of water - were developed throughout the ancient world; some were vessels that allowed water to escape, others worked by letting water in. The clepsydra shown here is of the inflow type, with three compensating tanks between the reservoir and the receiver; the time is indicated by the rod held by the statuette of a Buddhist monk.