English water-clock

From Object Wiki

English water-clock
Manufacturer	(unknown)
Production years	17th century
Production location	England

This form of water-clock or clepsydra indicates hours of equal lengths and was introduced about the middle of the seventeenth century. The example is of English make and of about 1700.

[edit] How it works

It consists of a closed metal cylinder or drum suspended from a stand by means of two cords attached to a horizontal axle, which projects from the flat ends of the drum. The drum contains a small quantity of water and a number of partitions passing from its circumference tangentially to an imaginary circle of about one-third the diameter of the drum. When the drum is wound up, the cords are wrapped round and round the axle and the water falls over the inner and open edges of the partitions into the lowest portion of the drum. The weight of the drum then tends to make it descend, while the weight of the water in the bottom part opposes this motion which would, in the first place, involve raising this water to a higher level. As, however, the partitions are perforated, water can pass gradually from one chamber to another, and the drum descends slowly, the position of the axle indicating the time on a vertical scale.

[edit] Memories

Do you remember stories about water-clocks? Add your memories.

[edit] In the Science Museum's Records

Inv. No: 1894-131