Water clock, Sri Lanka, 646

Record summary

Held and catalogued by Science Museum Group, London (object number L2015-3520), this is a water clock, made in Sri Lanka, Sri Lanka, dated 646. The Atlas places it in the Medieval Period period (500 – 1400) of its Instruments collection. The record is illustrated with 1 photograph.

Assembled from the source record's structured fields. Dates and attributions are given as the source states them; where a field is missing the Atlas leaves it blank rather than estimating.

Catalogue description

Atlas type guide

Water, fire and incense clocks

Before the mechanical clock, intervals and hours were measured by flow and combustion. Outflow and inflow water clocks were used in Egypt, Mesopotamia, Greece, China and the Islamic world; Chinese and Japanese incense clocks burned powdered incense along a maze-like path; oil-lamp clocks with graduated glass reservoirs were popular in German-speaking Europe in the seventeenth and eighteenth centuries.

These timekeepers needed constant correction and could not keep the hour automatically for long periods, but they underpinned temple ritual, legal procedure, astronomy and the earliest monumental astronomical clocks such as Su Song's clock tower (1090s) and al-Jazari's designs (1206).

General guidance written by the Atlas editors about this kind of object. It is not a statement about this particular piece; for that, rely on the source record above and on physical examination.

Read next:Su Song's astronomical clock tower