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Adits
An adit (from Latin ''aditus'', entrance) is an entrance to an underground mine which is horizontal or nearly horizontal, by which the mine can be entered, drained of water, ventilated, and minerals extracted at the lowest convenient level. Adits are also used to explore for mineral veins. Construction Adits are driven into the side of a hill or mountain, and are often used when an ore body is located inside the mountain but above the adjacent valley floor or coastal plain. In cases where the mineral vein outcrops at the surface, the adit may follow the lode or vein until it is worked out, in which case the adit is rarely straight. The use of adits for the extraction of ore is generally called drift mining. Adits can only be driven into a mine where the local topography permits. There will be no opportunity to drive an adit to a mine situated on a large flat plain, for instance. Also if the ground is weak, the cost of shoring up a long adit may outweigh its possible advantage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adit
An adit (from Latin ''aditus'', entrance) is an entrance to an underground mine which is horizontal or nearly horizontal, by which the mine can be entered, drained of water, ventilated, and minerals extracted at the lowest convenient level. Adits are also used to explore for mineral veins. Construction Adits are driven into the side of a hill or mountain, and are often used when an ore body is located inside the mountain but above the adjacent valley floor or coastal plain. In cases where the mineral vein outcrops at the surface, the adit may follow the lode or vein until it is worked out, in which case the adit is rarely straight. The use of adits for the extraction of ore is generally called drift mining. Adits can only be driven into a mine where the local topography permits. There will be no opportunity to drive an adit to a mine situated on a large flat plain, for instance. Also if the ground is weak, the cost of shoring up a long adit may outweigh its possible advant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great County Adit
The Great County Adit, sometimes called the County Adit, or the Great Adit was a system of interconnected adits that helped drain water from the tin and copper mines in the Gwennap area of Cornwall, in the United Kingdom. Construction started in 1748 and it eventually reached a length of over of a tunnel, providing drainage to over 100 mines at an average depth of . The adit was the brainchild of John Williams (born 1714) of Scorrier who was the manager of Poldice mine. Although work was started in 1748, it did not reach Poldice mine until the late 1760s. By 1778 the adit had been extended past Wheal Busy to Wheal Peevor, and another branch, known as the Consols Adit was driven west in the 1770s and 80s to drain the Consolidated Mines and United Mines. By 1792 a branch from Poldice extended to Wheal Unity. The portal of the adit is in the Carnon Valley below the hamlet of Twelveheads. In 1839, probably at its peak, it discharged over 14.5 million gallons (66 million litres) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gwennap
Gwennap ( kw, Lannwenep (village), Pluw Wenep (parish)) is a village and civil parish in Cornwall, England. It is about five miles (8 km) southeast of Redruth. Hamlets of Burncoose, Comford, Coombe, Crofthandy, Cusgarne, Fernsplatt, Frogpool, Hick's Mill, Tresamble and United Downs lie in the parish, as does Little Beside country house. In the 18th and early 19th centuries Gwennap parish was the richest copper mining district in Cornwall, and was called the "richest square mile in the Old World". It is near the course of the Great County Adit which was constructed to drain mines in the area including several of the local once-famous mines such as Consolidated Mines, Poldice mine and Wheal Busy. Today it forms part of area A6i (the Gwennap Mining District) of the Cornwall and West Devon Mining Landscape World Heritage Site. It lends its name to Gwennap Pit, where John Wesley preached eighteen times between 1762 and 1789, although Gwennap Pit is about to the nort ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drift Mining
Drift mining is either the mining of an ore deposit by underground methods, or the working of coal seams accessed by adits driven into the surface outcrop of the coal bed. A drift mine is an underground mine in which the entry or access is above water level and generally on the slope of a hill, driven horizontally into the ore seam. Random House dictionary says the origin of the term "drift mine" is an Americanism, circa 1885–1890. Drift is a more general mining term, meaning a near-horizontal passageway in a mine, following the bed (of coal, for instance) or vein of ore. A drift may or may not intersect the ground surface. A drift follows the vein, as distinguished from a crosscut that intersects it, or a level or gallery, which may do either. All horizontal or subhorizontal development openings made in a mine have the generic name of drift. These are simply tunnels made in the rock, with a size and shape depending on their use—for example, haulage, ventilation, or e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mining In Cornwall And Devon
Mining in Cornwall and Devon, in the southwest of England, began in the early Bronze Age, around 2150 BC. Tin, and later copper, were the most commonly extracted metals. Some tin mining continued long after the mining of other metals had become unprofitable, but ended in the late 20th century. In 2021, it was announced that a new mine was extracting battery-grade lithium carbonate, more than 20 years after the closure of the last South Crofty tin mine in Cornwall in 1998. Historically, tin and copper as well as a few other metals (e.g. arsenic, silver, and zinc) have been mined in Cornwall and Devon. Tin deposits still exist in Cornwall, and there has been talk of reopening the South Crofty tin mine. In addition, work has begun on re-opening the Hemerdon tungsten and tin mine in south-west Devon. In view of the economic importance of mines and quarries, geological studies have been conducted; about forty distinct minerals have been identified from type localities in Cor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sutro Tunnel
The Sutro Tunnel is a drainage tunnel (adit) connected to the Comstock Lode in Northern Nevada. It begins at Dayton, Nevada and connects Northwest to the Savage mine in Virginia City, Nevada. The tunnel was proposed by Adolph Sutro, a Prussian Jewish mining entrepreneur, in 1860. He promoted the drainage tunnel to allow access to deeper mineral exploration in the Comstock. Flooding and inadequate pumps had inhibited some exploration until that time. By 1865, Sutro's idea had gained the approval of state and federal governments. The mining interests of the Comstock initially supported the project, but later opposed the idea. They feared that an alternate access point to the Comstock minerals would threaten their monopoly on the mining and milling of gold and silver in the Comstock. Nonetheless, Sutro formed the Sutro Tunnel Company, selling stock certificates to raise funds for its construction, which began in 1869. Financing also came from local miners motivated by the prospect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comstock Lode
The Comstock Lode is a lode of silver ore located under the eastern slope of Mount Davidson, a peak in the Virginia Range in Virginia City, Nevada (then western Utah Territory), which was the first major discovery of silver ore in the United States and named after American miner Henry Comstock. After the discovery was made public in 1859, it sparked a silver rush of prospectors to the area, scrambling to stake their claims. The discovery caused considerable excitement in California and throughout the United States, the greatest since the California Gold Rush in 1849. Mining camps soon thrived in the vicinity, which became bustling commercial centers, including Virginia City and Gold Hill. The Comstock Lode is notable not just for the immense fortunes it generated and the large role those fortunes had in the growth of Nevada and San Francisco, but also for the advances in mining technology that it spurred, such as square set timbering and the Washoe process for extractin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virginia City
Virginia City is a census-designated place (CDP) that is the county seat of Storey County, Nevada, and the largest community in the county. The city is a part of the Reno– Sparks Metropolitan Statistical Area. Virginia City developed as a boomtown with the 1859 discovery of the Comstock Lode, the first major silver deposit discovery in the United States, with numerous mines opening. The population peaked in the mid-1870s, with an estimated 25,000 residents. The mines' output declined after 1878, and the population declined as a result. As of the 2020 Census, the population of Virginia City was 787. History Peter O'Riley and Patrick McLaughlin are credited with the discovery of the Comstock Lode. Henry T. P. Comstock's name was associated with the discovery through his own machinations. According to folklore, James Fennimore, nicknamed Old Virginny Finney, christened the town when he tripped and broke a bottle of whiskey at a saloon entrance in the northern section of Go ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nevada
Nevada ( ; ) is a state in the Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the 7th-most extensive, the 32nd-most populous, and the 9th-least densely populated of the U.S. states. Nearly three-quarters of Nevada's people live in Clark County, which contains the Las Vegas–Paradise metropolitan area, including three of the state's four largest incorporated cities. Nevada's capital is Carson City. Las Vegas is the largest city in the state. Nevada is officially known as the "Silver State" because of the importance of silver to its history and economy. It is also known as the "Battle Born State" because it achieved statehood during the Civil War (the words "Battle Born" also appear on its state flag); as the " Sagebrush State", for the native plant of the same name; and as the " Sage-hen State". The name means "snowy" in Spanish, re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Advanced Diploma In International Taxation
ADIT (the Advanced Diploma in International Taxation) is a professional qualification and credential, offered globally by the UK-based Chartered Institute of Taxation (CIOT) to international tax professionals. As of August 2021, there were more than 5,000 ADIT students, graduates and International Tax Affiliates in approximately 120 countries. The biggest employers of ADIT professionals are the “ Big Four”, major international law firms, industry and commerce, and revenue authorities. A candidate who successfully completes ADIT is awarded the ADIT credential. Candidates who wish to adhere to professional requirements by retaining an ongoing link with the CIOT can apply to become an International Tax Affiliate of the Chartered Institute of Taxation. This subscription package entitles the Affiliate to a number of benefits and resources, including the right to use the letters 'ADIT' after their name, discounts and priority access for online CIOT events, and access to the CIOT ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cornwall
Cornwall (; kw, Kernow ) is a historic county and ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people. Cornwall is bordered to the north and west by the Atlantic Ocean, to the south by the English Channel, and to the east by the county of Devon, with the River Tamar forming the border between them. Cornwall forms the westernmost part of the South West Peninsula of the island of Great Britain. The southwesternmost point is Land's End and the southernmost Lizard Point. Cornwall has a population of and an area of . The county has been administered since 2009 by the unitary authority, Cornwall Council. The ceremonial county of Cornwall also includes the Isles of Scilly, which are administered separately. The administrative centre of Cornwall is Truro, its only city. Cornwall was formerly a Brythonic kingdom and subsequently a royal duchy. It is the cultural and ethnic origin of the Cornish diaspora ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canal
Canals or artificial waterways are waterways or engineered channels built for drainage management (e.g. flood control and irrigation) or for conveyancing water transport vehicles (e.g. water taxi). They carry free, calm surface flow under atmospheric pressure, and can be thought of as artificial rivers. In most cases, a canal has a series of dams and locks that create reservoirs of low speed current flow. These reservoirs are referred to as ''slack water levels'', often just called ''levels''. A canal can be called a ''navigation canal'' when it parallels a natural river and shares part of the latter's discharges and drainage basin, and leverages its resources by building dams and locks to increase and lengthen its stretches of slack water levels while staying in its valley. A canal can cut across a drainage divide atop a ridge, generally requiring an external water source above the highest elevation. The best-known example of such a canal is the Panama Can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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