Ancient Chinese water clock
The Chinese has a saying, “Time is money, but you cannot buy it with money.” The sentence distinctively expresses the time concept of the Chinese. Yet before the invention of clock and watch in the modern times, how did the Chinese measure time?
The oldest time-keeping machine is called gnomon, solarium or sundial, the basic principle of which is to measure the time through the direction and projection of the sun. It is commonly called sun clock.
Gnomon (Gui Biao) is the oldest and simplest astronomical instrument in ancient China created to observe the length and position of sun shadow so as to determine the time.
A sundial is an instrument that measures time by the position of the sun. Called "rigui" in Chinese, a sundial is a timepiece that indicates the daylight hours ...-more
The sun clock lost its function when it was cloudy, rainy, or at night. Hence the water clock that could keep time at both day and night came into being. It is called clepsydra. Also called water glass, the clepsydra is an ancient device that measured time by marking the regulated flow of water through a small opening. As a time-measuring device, the clepsydra was more commonly used than the sundial.
Lou (water clock) is an idiom used by ancient Chinese equivalent to today's "clock". Zhonghu Dilou is also called clepsydra or water clock...
It was quite inconvenient to measure the time through the regulated flow of water, so the ancient Chinese gradually invented the time-measuring apparatus which used water as motive power to drive the mechanic device. In 117 B.C., Zhang Heng in the Eastern Han Dynasty created a large scale astronomical time measuring apparatus – water-driven armillary sphere, which generally had the function of mechanic time keeping. The later generations successively created devices with time measuring function, among which the water-driven astronomical clock tower (shuiyun yixiangtai) invented by Su Song of the Song Dynasty was a new peak of the development of mechanic timing. There was a puppet in the device which could tell the time by either hitting the drum or shaking the bell.
As the water in the clepsydra would be frozen in winter, a device driven by sand was invented. The “Astronomical Treatise” in The History of Ming Dynasty records the creation of “five-wheel sandglass” by Zhan Xiyuan in the early Ming Dynasty.
For over hundreds of years, the ancient Chinese used some primitive tools to measure the time. Apart from the above-mentioned methods, some used the burning incense to count the time, thus came the phrases “yizhuxiang” and “liangzhuxiang” (the time period when an incense or two is burnt out). However, these concepts of time are not quite precise in a large sense.
The water-driven astronomical clock tower (water clock) invented by Su Song of the Song Dynasty in 1088 is considered as the first real-sense mechanic clock in the world. It was a comprehensive observation apparatus integrating the functions of observing and demonstrating astronomical phenomena as well as measuring and reporting time. It was virtually a small astronomical observatory.