As in all machinery, rotary motion is more efficient in water-raising devices than oscillating motion. In terms of power source, water wheels can be turned by either human respectively animal force or by the water current itself. water wheels come in two basic designs, either equipped with a vertical or a horizontal axle. The latter type can be subdivided, depending on where the water hits the wheel paddles, into overshot, breastshot and undershot wheels. The two main functions of water wheels were historically water-lifting for irrigation purposes and milling, particularly of grain. In case of horizontal-axle mills, a system of gears is required for power transmission, which vertical-axle mills do not need.
Ancient Near East The water wheel first appeared in the
ancient Near East, prior to the 3rd century BC. The water wheel was used in the Near East by the 3rd century BC for use in moving
millstones and small-scale
grain grinding. Water wheels were used in the Near East during the
Hellenistic period between the 3rd and 1st centuries BC,
Water-lifting in Egypt The compartmented water wheel comes in two basic forms, the wheel with compartmented body (
Latin tympanum) and the wheel with compartmented rim or a rim with separate, attached containers. While the tympanum had a large discharge capacity, it could lift the water only to less than the height of its own radius and required a large torque for rotating. Paddle-driven water-lifting wheels had appeared in
ancient Egypt by the 4th century BC. The
Egyptians are credited with inventing the water wheel with attached pots, a water wheel with water compartments and a bucket chain, which ran over a pulley with buckets attached to it. The invention of the compartmentalized water wheel occurred in
ancient Egypt around the 4th century BC, in a rural context, away from the metropolis of
Hellenistic Alexandria, and then spread to other parts of
North Africa. According to
John Peter Oleson, both the compartmented wheel and the hydraulic
noria appeared in
Egypt by the 4th century BC, with the
Sakia being invented there a century later. This is supported by archeological finds at
Faiyum, where the oldest archeological evidence of a water-wheel has been found, in the form of a Sakia dating back to the 3rd century BC. A
papyrus dating to the 2nd century BC also found in Faiyum mentions a water wheel used for irrigation, a 2nd-century BC
fresco found at Alexandria depicts a compartmented Sakia, and the writings of
Callixenus of Rhodes mention the use of a Sakia in
Ptolemaic Egypt during the reign of
Ptolemy IV in the late 3rd century BC. The earliest literary reference to a water-driven, compartmented wheel appears in a medieval Arabic translation of
Pneumatica (chap. 61) by
Philo of Byzantium (), describing its use in Egyptian irrigation. In his
Parasceuastica (91.43−44), Philo advises the use of such wheels for submerging siege mines as a defensive measure against enemy sapping. Unlike other water-lifting devices and pumps of the period, the invention of the compartmented wheel cannot be traced to any particular
Hellenistic engineer and may have been made in the late 4th century BC in a rural Egyptian context away from the Hellenistic metropolis of Alexandria. The origins of water power is attributed to the reality of rural Egyptian life along the
Nile, rather than the intellectual capital of Alexandria which had no stream suitable for driving a paddle wheel. The sakia gear system is already shown fully developed to the point that "modern Egyptian devices are virtually identical". An episode from the
Alexandrian War in 48 BC tells of how Caesar's enemies employed geared water wheels to pour sea water from elevated places on the position of the trapped Romans.
Watermills The invention of the
watermill is a question open to scholarly discussion. According to historian
Helaine Selin, there is evidence indicating that the watermill originated from the
Persian Empire before 350 BC, likely in what are today
Iran or
Iraq, originally for the purpose of
grinding grain. There were
quarries known for their
millstones in Iran and on the upper
Tigris in what is today
Turkey. The mills invented at this date had horizontal, propeller-like water wheels that drove the millstones directly. However, there is a lack of literary evidence of water wheels being used in
Mesopotamia at the time. However,
Örjan Wikander notes the hypothesis is open to scholarly discussion.
China -powered
chain pumps from the
Tiangong Kaiwu of 1637, written by the
Ming Dynasty encyclopedist,
Song Yingxing (1587–1666). According to
Joseph Needham and other historians, the text known as the
Xin Lun written by
Huan Tan about 20 AD (during the usurpation of
Wang Mang) infers that water wheels had been used for pounding machinery in grain mills. Around 300 AD, the
noria was introduced when the wooden compartments were replaced with inexpensive ceramic pots that were tied to the outside of an open-framed wheel. Vitruvius's account is particularly valuable in that it shows how the watermill came about, namely by the combination of the separate Greek inventions of the toothed gear and the water wheel into one effective mechanical system for harnessing water power. Vitruvius' water wheel is described as being immersed with its lower end in the watercourse so that its paddles could be driven by the velocity of the running water (X, 5.2). ,
Asia Minor, powered by a breastshot wheel About the same time, the overshot wheel appears for the first time in a poem by
Antipater of Thessalonica, which praises it as a labour-saving device (IX, 418.4–6). The motif is also taken up by
Lucretius (ca. 99–55 BC) who likens the rotation of the water wheel to the motion of the stars on the firmament (V 516). The third horizontal-axled type, the breastshot water wheel, comes into archaeological evidence by the late 2nd century AD context in
central Gaul. Most excavated Roman watermills were equipped with one of these wheels which, although more complex to construct, were much more efficient than the vertical-axle water wheel. In the 2nd century AD
Barbegal watermill complex a series of sixteen overshot wheels was fed by an artificial aqueduct, a proto-industrial grain factory which has been referred to as "the greatest known concentration of mechanical power in the ancient world". In
Roman North Africa, several installations from around 300 AD were found where vertical-axle waterwheels fitted with angled blades were installed at the bottom of a water-filled, circular shaft. The water from the mill-race which entered tangentially the pit created a swirling water column that made the fully submerged wheel act like true
water turbines, the earliest known to date.
Navigation '' Apart from its use in milling and water-raising, ancient engineers applied the paddled water wheel for
automatons and in navigation. Vitruvius (X 9.5–7) describes multi-geared paddle wheels working as a ship
odometer, the earliest of its kind. The first mention of paddle wheels as a means of propulsion comes from the 4th–5th century military treatise
De Rebus Bellicis (chapter XVII), where the anonymous Roman author describes an ox-driven paddle-wheel warship.
Islamic world on the
Orontes River After the spread of Islam, engineers of the Islamic world continued the water technologies of the ancient Near East; as evident in the excavation of a canal in the Basra region with remains of a water wheel dating from the 7th century.
Hama in
Syria still preserves
some of its large wheels, on the river
Orontes, although they are no longer in use. One of the largest had a diameter of about and its rim was divided into 120 compartments. Another wheel that is still in operation is found at
Murcia in
Spain, La Nora, and although the original wheel has been replaced by a steel one, the
Moorish system during
al-Andalus is otherwise virtually unchanged. Some medieval Islamic compartmented water wheels could lift water as high as .
Muhammad ibn Zakariya al-Razi's
Kitab al-Hawi in the 10th century described a
noria in Iraq that could lift as much as , or . This is comparable to the output of modern norias in
East Asia, which can lift up to , or . ,
Sumatra, c. 1918 The industrial uses of watermills in the Islamic world date back to the 7th century, while horizontal-wheeled and vertical-wheeled water mills were both in widespread use by the 9th century. A variety of industrial watermills were used in the Islamic world, including
gristmills,
hullers,
sawmills, shipmills,
stamp mills,
steel mills,
sugar mills, and
tide mills. By the 11th century, every province throughout the Islamic world had these industrial watermills in operation, from
al-Andalus and
North Africa to the
Middle East and
Central Asia. Muslim engineers also used
crankshafts and
water turbines,
gears in watermills and water-raising
machines, and
dams as a source of water, used to provide additional power to watermills and water-raising machines. Fulling mills and steel mills may have spread from Islamic Spain to Christian Spain in the 12th century. Industrial water mills were also employed in large
factory complexes built in
al-Andalus between the 11th and 13th centuries. The engineers of the Islamic world developed several solutions to achieve the maximum output from a water wheel. One solution was to mount them to
piers of
bridges to take advantage of the increased flow. Another solution was the shipmill, a type of
water mill powered by water wheels mounted on the sides of
ships
moored in midstream. This technique was employed along the
Tigris and
Euphrates rivers in 10th-century
Iraq, where large shipmills made of
teak and
iron could produce 10
tons of
flour from grain every day for the
granary in
Baghdad. The
flywheel mechanism, which is used to smooth out the delivery of power from a driving device to a driven machine, was invented by Ibn Bassal (
fl. 1038–1075) of
Al-Andalus; he pioneered the use of the flywheel in the
saqiya (
chain pump) and noria. The engineers
Al-Jazari in the 13th century and
Taqi al-Din in the 16th century described many inventive water-raising machines in their technological treatises. They also employed water wheels to power a variety of devices, including various
water clocks and
automata.
Indian subcontinent The early history of the watermill in the
Indian subcontinent is obscure.
Ancient Indian texts dating back to the 4th century BC refer to the term
cakkavattaka (turning wheel), which commentaries explain as
arahatta-ghati-yanta (machine with wheel-pots attached). On this basis,
Joseph Needham suggested that the machine was a
noria. Terry S. Reynolds, however, argues that the "term used in Indian texts is ambiguous and does not clearly indicate a water-powered device." Thorkild Schiøler argued that it is "more likely that these passages refer to some type of tread- or hand-operated water-lifting device, instead of a water-powered water-lifting wheel." According to Greek historical tradition, India received water-mills from the Roman Empire in the early 4th century AD when a certain Metrodoros introduced "water-mills and baths, unknown among them [the Brahmans] till then". Irrigation water for crops was provided by using water raising wheels, some driven by the force of the current in the river from which the water was being raised. This kind of water raising device was used in
ancient India, predating, according to Pacey, its use in the later Roman Empire or China, though earlier literary, archaeological and pictorial evidence of the water wheel appeared in the Hellenistic world. Around 1150, the astronomer
Bhaskara Achārya observed water-raising wheels and imagined such a wheel lifting enough water to replenish the stream driving it, effectively, a
perpetual motion machine. The construction of water works and aspects of water technology in India is described in
Arabic and
Persian works. During medieval times, the diffusion of Indian and Persian irrigation technologies gave rise to an advanced irrigation system which bought about economic growth and also helped in the growth of material culture.
Ismail al-Jazari's
Book of Knowledge of Ingenious Mechanical Devices (1206) uses the term "
Sindhi wheel" to describe a
sāqiya. This indicates it may have originated in the northwestern Indian subcontinent (modern
Pakistan).
Medieval Europe Early medieval Europe Ancient water-wheel technology continued unabated in the early medieval period where the appearance of new documentary genres such as
legal codes,
monastic charters, but also
hagiography was accompanied with a sharp increase in references to watermills and wheels. The earliest vertical-wheel in a
tide mill is from 6th-century Killoteran near
Waterford,
Ireland, while the first known horizontal-wheel in such a type of mill is from the Irish
Little Island (c. 630). As for the use in a common Norse or Greek mill, the oldest known horizontal-wheels were excavated in the Irish Ballykilleen, dating to c. 636. An early example of a very large water wheel is the still extant wheel at the early 13th century
Real Monasterio de Nuestra Senora de Rueda, a Cistercian monastery in the
Aragon region of
Spain. Grist mills (for grain) were undoubtedly the most common, but there were also sawmills, fulling mills and mills to fulfil many other labour-intensive tasks. The water wheel remained competitive with the
steam engine well into the
Industrial Revolution. At around the 8th to 10th century, a number of irrigation technologies were brought into Spain and thus introduced to Europe. One of those technologies is the Noria, which is basically a wheel fitted with buckets on the peripherals for lifting water. It is similar to the undershot water wheel mentioned later in this article. It allowed peasants to power watermills more efficiently. According to Thomas Glick's book,
Irrigation and Society in Medieval Valencia, the Noria probably originated from somewhere in
Persia. It has been used for centuries before the technology was brought into Spain by Arabs who had adopted it from the Romans. Thus the distribution of the Noria in the Iberian peninsula "conforms to the area of stabilized Islamic settlement".
Late medieval Europe The assembly convened by
William of Normandy, commonly referred to as the "
Domesday" or Doomsday survey, took an inventory of all potentially taxable property in England, which included over six thousand mills spread across three thousand different locations, up from less than a hundred in the previous century. For large volumes of water with small waterfalls the undershot wheel would have been used, since it was more adapted to such conditions and cheaper to construct. So long as these water supplies were abundant the question of efficiency remained irrelevant. By the 18th century, with increased demand for power coupled with limited water locales, an emphasis was made on efficiency scheme. water wheels influenced the construction of cities, more specifically canals. The techniques that developed during this early period such as stream jamming and the building of
canals, put Europe on a
hydraulically focused path, for instance water supply and irrigation technology was combined to modify supply power of the wheel. 's
De re metallica (1556) The water mill was used for grinding grain, producing flour for bread, malt for beer, or coarse meal for porridge.
Early modern Western world Early modern Europe Millwrights distinguished between the two forces, impulse and weight, at work in water wheels long before 18th-century Europe. Fitzherbert, a 16th-century agricultural writer, wrote "druieth the wheel as well as with the weight of the water as with strengthe [impulse]".
Leonardo da Vinci also discussed water power, noting "the blow [of the water] is not weight, but excites a power of weight, almost equal to its own power". However, even realisation of the two forces, weight and impulse, confusion remained over the advantages and disadvantages of the two, and there was no clear understanding of the superior efficiency of weight. Prior to 1750 it was unsure as to which force was dominant and was widely understood that both forces were operating with equal inspiration amongst one another. The waterwheel sparked questions of the laws of nature, specifically the
laws of force.
Evangelista Torricelli's work on water wheels used an analysis of Galileo's work on falling bodies, that the velocity of a water sprouting from an orifice under its
head was exactly equivalent to the velocity a drop of water acquired in falling freely from the same height.
Industrial Europe , Laxey, Isle of Man, used to drive mine pumps The water wheel was a driving force behind the earliest stages of industrialization in Britain. Water-powered reciprocating devices were used in trip hammers and blast furnace bellows.
Richard Arkwright's water frame was powered by a water wheel.
North America Water wheels were used to power sawmills, grist mills and for other purposes during development of the United States. The diameter
water wheel at McCoy, Colorado, built in 1922, is a surviving one out of many which lifted water for irrigation out of the
Colorado River. Two early improvements were
suspension wheels and rim gearing. Suspension wheels are constructed in the same manner as a bicycle wheel, the rim being supported under tension from the hub- this led to larger lighter wheels than the former design where the heavy spokes were under compression. Rim-gearing entailed adding a notched wheel to the rim or shroud of the wheel. A stub gear engaged the rim-gear and took the power into the mill using an independent line shaft. This removed the rotative stress from the axle which could thus be lighter, and also allowed more flexibility in the location of the power train. The shaft rotation was geared up from that of the wheel which led to less power loss. An example of this design pioneered by Thomas Hewes and refined by
William Armstrong Fairburn can be seen at the 1849 restored wheel at the
Portland Basin Canal Warehouse.
Australia (built 1887) Australia has a relatively dry climate, nonetheless, where suitable water resources were available, water wheels were constructed in 19th-century Australia. These were used to power sawmills, flour mills, and
stamper batteries used to crush gold-bearing ore. Notable examples of water wheels used in gold recovery operations were the large
Garfield water wheel near
Chewton—one of at least seven water wheels in the surrounding area—and the two water wheels at
Adelong Falls; some remnants exist at both sites. The mining area at
Walhalla once had at least two water wheels, one of which was rolled to its site from
Port Albert, on its rim using a novel trolley arrangement, taking nearly 90 days. A
water wheel at Jindabyne, constructed in 1847, was the first machine used to extract energy—for flour milling—from the
Snowy River. Compact water wheels, known as
Dethridge wheels, were used not as sources of power but to measure water flows to irrigated land.
New Zealand Water wheels were used extensively in New Zealand. The well-preserved remains of the Young Australian mine's overshot water wheel exist near the ghost town of
Carricktown, and those of the Phoenix flour mill's water wheel are near
Oamaru.
Modern developments A recent development of the breastshot wheel is a hydraulic wheel which effectively incorporates automatic regulation systems. The Aqualienne is one example. It generates between 37 kW and 200 kW of electricity from a waterflow with a head of . It is designed to produce electricity at the sites of former watermills. == Efficiency ==