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Reverse Overshot Water-wheel
Frequently used in mines and probably elsewhere (such as agricultural drainage), the reverse overshot water wheel was a Roman innovation to help remove water from the lowest levels of underground workings. It is described by Vitruvius in his work ''De architectura'' published circa 25 BC. The remains of such systems found in Roman mines by later mining operations show that they were used in sequences so as to lift water a considerable height. Vitruvius The Roman author Vitruvius gives explicit instructions on the construction of dewatering devices, and describes three variants of the "tympanum" in Chapter X of ''De architectura''. It is a large wheel fitted with boxes, which in the first design, encompass the whole diameter of the wheel. Holes are bored in the boxes to allow water into them, so that as a box dips into the water, it enters and is raised as the wheel turns. When it reaches to the top of the turn, the water runs out into a channel. He then describes a second variant w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Wheel
A water wheel is a machine for converting the kinetic energy of flowing or falling water into useful forms of power, often in a watermill. A water wheel consists of a large wheel (usually constructed from wood or metal), with numerous blades or buckets attached to the outer rim forming the drive mechanism. Water wheels were still in commercial use well into the 20th century, although they are no longer in common use today. Water wheels are used for milling flour in gristmills, grinding wood into pulp for papermaking, hammering wrought iron, machining, ore crushing and pounding fibre for use in the manufacture of cloth. 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. 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. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hunedoara County
Hunedoara County () is a county (''județ'') of Romania, in Transylvania, with its capital city at Deva, Romania, Deva. The county is part of the Danube–Criș–Mureș–Tisa Euroregion. Name In Hungarian language, Hungarian, it is known as , in German language, German as , and in Slovak language, Slovak as . The county got its name from the city of Hunedoara (), which is the Romanian language, Romanian transliteration of the Hungarian language, Hungarian (, archaic: ), old name of the municipality. That most likely originated from the Hungarian language, Hungarian verb meaning 'to close' or 'to die', but may also come from wear the name of the Huns, who were headquartered near for a time and were the first to establish solid rule over the land since the Dacians. Geography This county has a total area of 7,063 km2. Mainly, the relief is made up of mountains, divided by the Mureș River valley which crosses the county from East to West. To the North side there are the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
France
France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlantic, North Atlantic, the French West Indies, and List of islands of France, many islands in Oceania and the Indian Ocean, giving it Exclusive economic zone of France, one of the largest discontiguous exclusive economic zones in the world. Metropolitan France shares borders with Belgium and Luxembourg to the north; Germany to the northeast; Switzerland to the east; Italy and Monaco to the southeast; Andorra and Spain to the south; and a maritime border with the United Kingdom to the northwest. Its metropolitan area extends from the Rhine to the Atlantic Ocean and from the Mediterranean Sea to the English Channel and the North Sea. Its Regions of France, eighteen integral regions—five of which are overseas—span a combined area of and hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barbegal Aqueduct And Mill
The Barbegal aqueduct and mills was a Roman watermill complex in the commune of Fontvieille, Bouches-du-Rhône, near the town of Arles, in southern France. The complex has been referred to as "the greatest known concentration of mechanical power in the ancient world" and the 16 overshot wheels are considered to be the largest ancient mill complex. Another similar mill complex existed on the Janiculum in Rome, and there are suggestions that further such complexes existed at other major Roman sites, such as Amida (Mesopotamia). Description The Barbegal site is located 12 kilometres east northeast of Arles near Fontvieille, where the Arles aqueduct passed near a steep escarpment. The mills consisted of 16 water wheels in two parallel sets of eight descending a steep hillside. There are substantial masonry remains of the water channels and foundations of the individual mills, together with a staircase rising up the hill upon which the mills were built. The mills operated from t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roman Empire
The Roman Empire ruled the Mediterranean and much of Europe, Western Asia and North Africa. The Roman people, Romans conquered most of this during the Roman Republic, Republic, and it was ruled by emperors following Octavian's assumption of effective sole rule in 27 BC. The Western Roman Empire, western empire collapsed in 476 AD, but the Byzantine Empire, eastern empire lasted until the fall of Constantinople in 1453. By 100 BC, the city of Rome had expanded its rule from the Italian peninsula to most of the Mediterranean Sea, Mediterranean and beyond. However, it was severely destabilised by List of Roman civil wars and revolts, civil wars and political conflicts, which culminated in the Wars of Augustus, victory of Octavian over Mark Antony and Cleopatra at the Battle of Actium in 31 BC, and the subsequent conquest of the Ptolemaic Kingdom in Egypt. In 27 BC, the Roman Senate granted Octavian overarching military power () and the new title of ''Augustus (title), Augustus'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axle
An axle or axletree is a central shaft for a rotation, rotating wheel and axle, wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In the former case, bearing (mechanical), bearings or Bushing (bearing), bushings are provided at the mounting points where the axle is supported. In the latter case, a bearing or bushing sits inside a central hole in the wheel to allow the wheel or gear to rotate around the axle. Sometimes, especially on bicycles, the latter type of axle is referred to as a ''spindle (tool), spindle''. Terminology On cars and trucks, several senses of the word ''axle'' occur in casual usage, referring to the shaft itself, its housing, or simply any transverse pair of wheels. Strictly speaking, a shaft that rotates with the wheel, being either Bolt (fastener), bolted or rotating spline, splined in fixed relation to it, is called an ''axle'' or ''axle shaft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crank (mechanism)
A crank is an arm attached at a right angle to a rotating shaft by which circular motion is imparted to or received from the shaft. When combined with a connecting rod, it can be used to convert circular motion into reciprocating motion, or vice versa. The arm may be a bent portion of the shaft, or a separate arm or disk attached to it. Attached to the end of the crank by a pivot is a rod, usually called a connecting rod (conrod). The term often refers to a human-powered crank which is used to manually turn an axle, as in a bicycle crankset or a brace and bit drill. In this case a person's arm or leg serves as the connecting rod, applying reciprocating force to the crank. There is usually a bar perpendicular to the other end of the arm, often with a freely rotatable handle or pedal attached. Examples Familiar examples include: Hand-powered cranks * Spinning wheel * Mechanical pencil sharpener * Fishing reel and other reels for cables, wires, ropes, etc. *Starti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archimedean Screw
The Archimedes' screw, also known as the Archimedean screw, hydrodynamic screw, water screw or Egyptian screw, is one of the earliest documented hydraulic machines. It was so-named after the Greek mathematician Archimedes who first described it around 234 BC, although the device had been developed in Egypt earlier in the century. It is a reversible hydraulic machine that can be operated both as a pump or a power generator. As a machine used for lifting water from a low-lying body of water into irrigation ditches, water is lifted 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 new form of small hydroelectric powerplant that can be applied even in low head sites. Such generators operate in a wide range of flows (0.01 m^3/s to 14.5 m^3/s) and heads (0.1 m to 10 m), including low heads and moderate flow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Dated
Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was developed in the late 1940s at the University of Chicago by Willard Libby. It is based on the fact that radiocarbon () is constantly being created in the Earth's atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting combines with atmospheric oxygen to form radioactive carbon dioxide, which is incorporated into plants by photosynthesis; animals then acquire by eating the plants. When the animal or plant dies, it stops exchanging carbon with its environment, and thereafter the amount of it contains begins to decrease as the undergoes radioactive decay. Measuring the amount of in a sample from a dead plant or animal, such as a piece of wood or a fragment of bone, provides information that can be used to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiff
Cardiff (; ) is the capital city, capital and List of urban areas in the United Kingdom, largest city of Wales. Cardiff had a population of in and forms a Principal areas of Wales, principal area officially known as the City and County of Cardiff (). The city is the List of cities in the United Kingdom, eleventh largest in the United Kingdom. Located in the South East Wales, southeast of Wales and in the Cardiff Capital Region, Cardiff is the county town of the Historic counties of Wales, historic county of Glamorgan and in 1974–1996 of South Glamorgan. It belongs to the Eurocities network of the largest European cities. A small town until the early 19th century, its prominence as a port for coal when mining began in the region helped its expansion. In 1905, it was ranked as a city and in 1955 proclaimed capital of Wales. The Cardiff urban area covers a larger area outside the county boundary, including the towns of Dinas Powys and Penarth. Cardiff is the main commercial ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Museum Of Wales
National may refer to: Common uses * Nation or country ** Nationality – a ''national'' is a person who is subject to a nation, regardless of whether the person has full rights as a citizen Places in the United States * National, Maryland, census-designated place * National, Nevada, ghost town * National, Utah, ghost town * National, West Virginia, unincorporated community Commerce * National (brand), a brand name of electronic goods from Panasonic * National Benzole (or simply known as National), former petrol station chain in the UK, merged with BP * National Book Store, a bookstore and office supplies chain in the Philippines * National Car Rental, an American rental car company * National Energy Systems, a former name of Eco Marine Power * National Entertainment Commission, a former name of the Media Rating Council * National Motor Vehicle Company, Indianapolis, Indiana, USA 1900–1924 * National Radio Company, Malden, Massachusetts, USA 1914–1991 * National ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
