As a country built on the basis of agriculture. China has made a great deal of admirable achievements in agronomy-related technologies. Irrigation. as a critical part of agriculture. has witnessed some of the most important inventions.
All dynasties in Chinese history spent a great deal of manpower. material resources. and money into various irrigation projects like channels or canals. However. most of these projects were built in the major agricultural regions. and could not cover the areas of high altitudes or those far from water. Subsequently. the Chinese devised the waterwheel with their wisdom to meet the need of irrigation in areas anywhere.
One of the ancient Chinese classic writings shows that the earliest sophisticated device for drawing water was the use of a beam on a wooden shelf. On one side of the beam was a bucket. and on the other side hung a heavy thing. The device saved great energy by applying the lever principle. The primary application of easy mechanics was the predecessor of the waterwheel invention.
According to official records. the waterwheel probably appeared in the Eastern Han Dynasty (25-220). when the emperor ordered the building of a ``running wheel.`` which boasted the basic parts of a waterwheel. like an axle and bucket-like devices. In any case. there are actual historical records showing that the waterwheels were built in the Three Kingdoms Period (220-280).
From the Tang Dynasty (618-907) to the Song Dynasty (960-1279). there were great achievements in using the axle. There were ``buckets wagons`` that used the waterpower itself to lift water. The device not only significantly improved efficiency. but also saved manpower.
By the Yuan (1271-1368) and Ming (1368-1644) dynasties. the axle experienced further improvement. The water wheel usually had a set of gears. with some even having three sets. Besides the waterwheels driven by waterpower and manpower. some also used cows or donkeys to supply power. Different types were used according to different local topographies. Nonetheless. there was no more distinct development of Chinese waterwheels after the Yuan and Ming dynasties.
The waterwheel has made significant contributions to the development of Chinese agriculture. greatly lifting the topographical limitations. and enabling the exploitation of hilly and sloped areas. In addition. the waterwheel can also be used for drainage purposes.