Archimedes' screw

The origins of the water screw are unknown. Archimedes of Syracuse is traditionally credited with inventing the water screw, but other academics argue Archimedes found the Egyptians already using the screw. The earliest mention of the screw is from between 250 and 220 BC, and archaeological remains of water screws in Europe and Asia suggested that it was diffused across the territories of the Roman Empire, though the screw largely fell out of use in Europe in the third century AD. However, it resurfaced during Renaissance, with the screw introduced to other regions such as China and Japan. In 1991, a patent for the Archimedes screw turbine was filed, and the testing was done between 1993 and 1995.

As a machine used for lifting water from a low-lying body of water into irrigation ditches, it lifts water by turning a screw-shaped surface inside a pipe. In the modern world, Archimedes' screw pumps are widely used in wastewater treatment plants and for dewatering low-lying regions. Run in reverse, Archimedes screw turbines act as a small hydroelectric powerplant that can be applied even in low head sites. Such generators operate in a wide range of flows (0.01 m³/s to 14.5 m³/s) and heads (0.1 m to 10 m), including low heads and moderate flow rates that are not ideal for traditional turbines and not occupied by high performance technologies.

History

Origins

The origins of the water screw are unknown; Archimedes is credited with inventing the water screw, but this point is controversial amongst historians. According to Posidonius, Archimedes invented the water screw when he visited Egypt, possibly between 283 and 246 BC, with academics arguing that he invented the water screw based on a water wheel he saw in operation. Other academics posit that Archimedes possibly found Egyptians already using the screw, though Canadian archaeologist John Peter Oleson notes that "no explanation is ever provided for the subsequent identification of the device with Archimedes or for the total lack of any literary or archaeological evidence for the existence of the water-screw before ca. 250 BC", and argues that there may have been confusion over terms used by Posidonius. Scholars also argue that Archimedes's investigations into spirals and the quadrature of a circle led to the development of Archimedes' screw.

Assyrianologist Stephanie Dalley argued in several of her publications that according to an inscription from Assyrian king Sennacherib, bronze water screws were used to irrigate the Hanging Gardens of Babylon; she also interpreted Strabo's Geography and Philo of Byzantium's On the Seven Wonders of the World to imply that water screws were used in the Hanging Gardens of Babylon. An Archimedes' screw, under Dalley's supervision, was constructed from Sennacherib's inscription as part of a BBC documentary to determine if the screw was known in Assyria, with Oleson supervising the construction of a screw using Vitruvius's description in De Architectura. Academic Yaman Boluk proposed that if Dalley's theory was true, then the screws would have had an opening on its outer cylinder, and its blades would have been separated from the outer cylinder unlike the screw constructed in the BBC documentary, which had the screw's blades joined to the outer cylinder.

Antiquity and decline

Moschion reported in Treatise on the Great Ship of Hieron of Syracuse, written between 250 and 220 BC, that the screw was used as a bilge pump in a ship built for Hiero II of Syracuse, and Posidonius also recorded water screws in Spanish mines used for drainage. Oleson notes that archaeological remains of the water screw were found in the territory of the Roman Empire such as Egypt, Spain, France, and Italy, whilst literary texts and inscriptions describe the screw to be present in Mesopotamia, Egypt, Syria, and Spain, though the lack of screws in Rome and northern Europe suggests that the screw was not utilised much there as irrigation and mining were less prioritised in those regions.

By the late 1st century BC or 1st century AD, there were not many records mentioning the screw, according to Oleson's investigation in Fayum; he posits that they were either uncommon in the city or were not taxed, and hence were not recorded. Diodorus describes the Archimedes' screw usage for irrigation in the Nile Delta for nearby military camps and cities in his Bibliotheca Historica, and Vitruvius details a wooden Archimedes' screw with eight blades in his De Architectura, written between 27–22 BC. The earliest depiction of the water screw is a fresco at the villa Casa di P. Cornelius Teges in Pompeii dating earlier than 79 AD. Archimedes' screw continued to be used in Europe until it fell out of use in the end of the third century. Historian Lynn White Jr. posits that the screw continued to be used in Visigothic and Islamic Spain, with Oleson theorising that the Arabs may have reintroduced the screw to Europe following the conquest of Spain in the 8th century.

Revival and development

The first illustration of the Archimedes' screw after antiquity was from German engineer Konrad Kyeser in his 1405 manuscript Bellifortis. During the Renaissance, scientists such as Leonardo da Vinci and Agostino Ramelli depicted on the Archimedes' screw in several of their "theatre of machine" books, which catalogued machines, and Galileo Galilei explained the function of the Archimedes' screw in his Mecchanice. Polder mills, consisting of windmill-powered Archimedes' screws, were used during the Dutch Golden Age for land drainage as it could move large quantities of water in low heads. In 1612, Italian Jesuit Sabatino de Ursis along with Chinese official Xu Guangqi published Hydraulic Methods of the Far West, a book describing the Archimedes' screw's usage in agriculture and its construction; although other books were published, there was limited use of the screw in China and Korea, despite praises from scholars. Albert Koenig suggests that the screw was not widely used there as imperial scholars preferred works on philosophy, among other factors such as high production costs for an Archimedean screw and the impracticality of Virtuvius's design. Portuguese traders ostensibly introduced the Archimedes' screw to Japan in 1637, with scrolls dating between the 1730s to the 1850s suggesting that miners in Sado used the Archimedes' screw for mining gold.

In 1738, Daniel Bernoulli investigated the size of a pocket of water carried by a water screw; Leonhard Euler would later develop a question regarding the theory of the screw as part of his Quaestiones Mathematicae, 14 mathematical questions that were read to the Petersburg Academy in 1757. However, Archimedes' screws were not commonly used as water pumps when public water systems were first established in the early 19th century because of its low delivery head. Dutch engineer Joan Muysken investigated the efficiency and discharge capacity of the Archimedes' screw in 1932, and developed the formula for the rotational speed of the screw. In 1991, Karl-August Radlik filed a patent for the Archimedes screw turbine (AST), in which mechanical power would be generated by pouring water from the top. Academics note that the Archimedes' screw was proposed as a generator for mechanical power since 1862, with the screw being used to generate power since the early 1900s in places such as Japan. Klaus Brada experimented with the Archimedes' screw as a turbine between 1993–1995 at the University of Prague, and found that most of the hydraulic energy collected by a screw can be converted to mechanical energy.