Water power was an important source of energy in ancient China civilization. One of the most intriguing applications was for iron. Water power was also applied at an early date to grinding grain. Large rotary mills appeared in China about the same time as in Europe (2nd century BC). But while for centuries Europe relied heavily on slave- and donkey-powered mills, in China the waterwheel was a critical power supply.
Chinese waterwheels were typically horizontal (illustration left). The vertical wheel, however, was known. It was used to operate trip hammers for hulling rice and crushing ore. The edge-runner mill was another commonly used crushing device. With the latter a circular stone on edge running around a lower millstone was used to pulverize. The edge runner appeared in China in the 5th century AD. Both the trip hammer and edge runner were not used in Europe until eight centuries later.
Throughout the first 13 centuries AD, technological innovations filtered slowly but steadily from the advanced East to the somewhat more backward West. Carried at first through central Asia over the 4,000-mile Silk Route and later by sea, some innovations were exported swiftly, while others (like waterwheel paraphernalia) took centuries.
The first description of a water wheel that can be definitely identified as vertical is from Vitruvius, an engineer of the Augustan Age (31 BC – 14 AD), who composed a 10 volume treatise on all aspects of Roman engineering. One of the most remarkable Roman applications of a waterwheel was at Barbegal (illustration right) near Arles in southern France. Dating from the 4th Century AD, the factory was an immense flour mill which employed 16 overshot water wheels.
Some water wheels are fed by water from a mill pond, which is formed when a flowing stream is dammed. A channel for the water flowing to or from a water wheel is called a mill race or simply a “race”, and is customarily divided into sections. The race bringing water from the mill pond to the water wheel is a headrace; the one carrying water after it has left the wheel is commonly referred to as a tailrace.
Now you know. Of course, we at AquAid don’t make use of water wheels to bring your water to you, nor do we employ water wheels to dispense your cool, fresh drinking water, but rather a range of water coolers, all designed to best suit your requirements.