Early astronomical timekeeper

We all know that clock is a timekeeper. Before we developed clocks, our ancestors have taken many methods to record time. For example, the sun dial of judging time according to the sunshine's place, and using sand filter for marking the hours. But all of these are not the clocks and watches. What are the clocks and watches? A machine or device is to calculate time through producing oscillatory period.

Clocks and watches can be divided into three parts. First of all, slowly leaving out from Astronomical Clock in early stage. Second, moving forward from huge time bell to clocks and watches in miniature. Third, wrist watches' development and utilizing electronic technique. Every stage's development is connected with technical invention of that day. 

The famous British science historian Joseph Needham in “history of Chinese science and technology” has said a section of history that has been flooded almost six centuries. When the Western clocks and watches in the early seventeenth Century were entering into China, in fact, "escapement" embryonic form already appeared in China of 600 years ago. In 1088, China's Song Dynasty scientist Su Song and Han Gonglian and others made astronomical instrument -- "waterborne instrument like a stage", it is "free" and "celestial globe" mechanical timer combined giant mechanical device. About 12 meters high, 7 meters in width, it is divided into three layers, the upper on the armillary sphere, astronomical observations: the middle on the celestial globe, simulating the celestial movements synchronous presentation, the lower is the heart of the apparatus portion, the timing time, source of power in this layer. Because celestial movement take the time as the foundation, and to operate time through a mechanical structure need a device forming a time interval, which produced the "escapement" instrument of the early years.

The great invention of ancient China has the extremely vital significance in world horological history. Thus, china's famous watchmakers, antique collectors, horological historians Jiao Dayu initiated a point of view -"Chinese create watches’ history -- watches is the five great inventions of ancient China".