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Principal Triangulation Of Britain
The Principal Triangulation of Britain was the first high-precision triangulation survey of the whole of Great Britain (including Ireland), carried out between 1791 and 1853 under the auspices of the Board of Ordnance. The aim of the survey was to establish precise geographical coordinates of almost 300 significant landmarks which could be used as the fixed points of local topographic surveys from which maps could be drawn. In addition there was a purely scientific aim in providing precise data for geodetic calculations such as the determination of the length of meridian arcs and the figure of the Earth. Such a survey had been proposed by William Roy (1726–1790) on his completion of the Anglo-French Survey but it was only after his death that the Board of Ordnance initiated the trigonometric survey, motivated by military considerations in a time of a threatened French invasion. Most of the work was carried out under the direction of Isaac Dalby, William Mudge and Thomas F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clarke Principal Triangulation Of Britain 1860
Clarke is a surname which means "clerk". The surname is of English and Irish origin and comes from the Latin . Variants include Clerk and Clark. Clarke is also uncommonly chosen as a given name. Irish surname origin Clarke is a popular surname in Ireland. The Irish version of the surname is believed to have come from County Galway and County Antrim and spread to County Donegal and County Dublin. The name is derived from the Irish Gaelic sept , meaning "clerk". English surname origin Clarke, as well as Clark, is also a widespread surname in England. The English version is of Anglo-Saxon origin and was used in the Middle Ages for the name of a scribe or secretary. The word "clerc", which came from the pre-7th century Old English (meaning priest), originally denoted a member of a religious order, but later became widespread. In the Middle Ages, virtually the only people who could read and write were members of religious orders, linking the word with literacy. Thus the surname be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Observatory, Greenwich
The Royal Observatory, Greenwich (ROG; known as the Old Royal Observatory from 1957 to 1998, when the working Royal Greenwich Observatory, RGO, temporarily moved south from Greenwich to Herstmonceux) is an observatory situated on a hill in Greenwich Park in south east London, overlooking the River Thames to the north. It played a major role in the history of astronomy and navigation, and because the Prime Meridian passes through it, it gave its name to Greenwich Mean Time, the precursor to today's Coordinated Universal Time (UTC). The ROG has the IAU observatory code of 000, the first in the list. ROG, the National Maritime Museum, the Queen's House and the clipper ship ''Cutty Sark'' are collectively designated Royal Museums Greenwich. The observatory was commissioned in 1675 by King Charles II, with the foundation stone being laid on 10 August. The old hilltop site of Greenwich Castle was chosen by Sir Christopher Wren, a former Savilian Professor of Astronomy; as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Roys Baseline
A general officer is an officer of high rank in the armies, and in some nations' air forces, space forces, and marines or naval infantry. In some usages the term "general officer" refers to a rank above colonel."general, adj. and n.". OED Online. March 2021. Oxford University Press. https://www.oed.com/view/Entry/77489?rskey=dCKrg4&result=1 (accessed May 11, 2021) The term ''general'' is used in two ways: as the generic title for all grades of general officer and as a specific rank. It originates in the 16th century, as a shortening of ''captain general'', which rank was taken from Middle French ''capitaine général''. The adjective ''general'' had been affixed to officer designations since the late medieval period to indicate relative superiority or an extended jurisdiction. Today, the title of ''general'' is known in some countries as a four-star rank. However, different countries use different systems of stars or other insignia for senior ranks. It has a NATO rank sc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordnance Survey
Ordnance Survey (OS) is the national mapping agency for Great Britain. The agency's name indicates its original military purpose (see ordnance and surveying), which was to map Scotland in the wake of the Jacobite rising of 1745. There was also a more general and nationwide need in light of the potential threat of invasion during the Napoleonic Wars. Since 1 April 2015 Ordnance Survey has operated as Ordnance Survey Ltd, a government-owned company, 100% in public ownership. The Ordnance Survey Board remains accountable to the Secretary of State for Business, Energy and Industrial Strategy. It was also a member of the Public Data Group. Paper maps for walkers represent only 5% of the company's annual revenue. It produces digital map data, online route planning and sharing services and mobile apps, plus many other location-based products for business, government and consumers. Ordnance Survey mapping is usually classified as either " large-scale" (in other words, more detaile ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
East India Company
The East India Company (EIC) was an English, and later British, joint-stock company founded in 1600 and dissolved in 1874. It was formed to trade in the Indian Ocean region, initially with the East Indies (the Indian subcontinent and Southeast Asia), and later with East Asia. The company seized control of large parts of the Indian subcontinent, colonised parts of Southeast Asia and Hong Kong. At its peak, the company was the largest corporation in the world. The EIC had its own armed forces in the form of the company's three Presidency armies, totalling about 260,000 soldiers, twice the size of the British army at the time. The operations of the company had a profound effect on the global balance of trade, almost single-handedly reversing the trend of eastward drain of Western bullion, seen since Roman times. Originally chartered as the "Governor and Company of Merchants of London Trading into the East-Indies", the company rose to account for half of the world's trade du ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spherical Trigonometry
Spherical trigonometry is the branch of spherical geometry that deals with the metrical relationships between the sides and angles of spherical triangles, traditionally expressed using trigonometric functions. On the sphere, geodesics are great circles. Spherical trigonometry is of great importance for calculations in astronomy, geodesy, and navigation. The origins of spherical trigonometry in Greek mathematics and the major developments in Islamic mathematics are discussed fully in History of trigonometry and Mathematics in medieval Islam. The subject came to fruition in Early Modern times with important developments by John Napier, Delambre and others, and attained an essentially complete form by the end of the nineteenth century with the publication of Todhunter's textbook ''Spherical trigonometry for the use of colleges and Schools''. Since then, significant developments have been the application of vector methods, quaternion methods, and the use of numerical methods. P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arcsecond
A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The nautical mile (nmi) was originally defined as the arc length of a minute of latitude on a spherical Earth, so the actual Earth circumference is very near . A minute of arc is of a radian. A second of arc, arcsecond (arcsec), or arc second, denoted by the symbol , is of an arcminute, of a degree, of a turn, and (about ) of a radian. These units originated in Babylonian astronomy as sexagesimal subdivisions of the degree; they are used in fields that involve very small angles, such as astronomy, optometry, ophthalmology, optics, navigation, land surveying, and marksmanship. To express even smaller angles, standard SI prefixes can be employed; the milliarcsecond (mas) and microarcsecond (μas), for instance, are commonly used in as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ramsden Theodolite
The Ramsden surveying instruments are those constructed by Jesse Ramsden and used in high precision geodetic surveys carried out in the period 1784 to 1853. This includes the five great theodolites—great in name, great in size and great in accuracy—used in surveys of Britain and other parts of the world. Ramsden also provided the equipment used in the measurement of the many base lines of these surveys and also the zenith telescope used in latitude determinations. The great theodolites A total of eight such instruments were manufactured by Ramsden and others for use in Britain, India and Switzerland. The Great Theodolites Ramsden himself constructed three theodolites and a further two were completed to his design by Mathew Berge, his son-in-law and business successor, after Ramsden's death in 1805. Of the other instruments one was constructed by William Cary and the other two by the firm of Troughton and Simms. The Royal Society theodolite In 1783 the Royal Society of Lon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jesse Ramsden
Jesse Ramsden FRS FRSE (6 October 1735 – 5 November 1800) was a British mathematician, astronomical and scientific instrument maker. His reputation was built on the engraving and design of dividing engines which allowed high accuracy measurements of angles and lengths in instruments. He produced instruments for astronomy that were especially well known for maritime use where they were needed for the measurement of latitudes and for his surveying instruments which were widely used for cartography and land survey both across the British Empire and outside. An achromatic eyepiece that he invented for telescopes and microscopes continues to be known as the Ramsden eyepiece. Life Ramsden was born at Salterhebble, Halifax, West Riding of Yorkshire, England the son of Thomas Ramsden, an innkeeper and his wife Abigail née Flather. Having attended the free school at Halifax from 1744 to 1747, he was sent at the age of twelve to his maternal uncle, Mr Craven, in the North Riding, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theodolite
A theodolite () is a precision optical instrument for measuring angles between designated visible points in the horizontal and vertical planes. The traditional use has been for land surveying, but it is also used extensively for building and infrastructure construction, and some specialized applications such as meteorology and rocket launching. It consists of a moveable telescope mounted so it can rotate around horizontal and vertical axes and provide angular readouts. These indicate the orientation of the telescope, and are used to relate the first point sighted through the telescope to subsequent sightings of other points from the same theodolite position. These angles can be measured with accuracies down to microradians or seconds of arc. From these readings a plan can be drawn, or objects can be positioned in accordance with an existing plan. The modern theodolite has evolved into what is known as a total station where angles and distances are measured electronically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hounslow Heath
Hounslow Heath is a local nature reserve in the London Borough of Hounslow and at a point borders Richmond upon Thames. The public open space, which covers , is all that remains of the historic Hounslow Heath which covered more than . The present day area is bounded by A315 Staines Road, A3063 Wellington Road South, A314 Hanworth Road, and the River Crane. History The heathland of Hounslow Heath originally covered an area underlain by Taplow gravel that now includes parts of Bedfont, Brentford, Cranford, Feltham, Hampton, Fulwell, Hanworth, Harlington, Harmondsworth, Heston, Hounslow, Isleworth, Stanwell, Teddington, Twickenham, and Heathrow. Hounslow Heath has had major historical importance, originally crossed by main routes from London to the west and southwest of Britain. Staines Road, the northern boundary of the present heath, was the Roman Road, Via Trinobantes. There are several historic references to Roman camps on or close to the heath. Continuous recorded hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
