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Thomas Mercer Chronometers
Thomas Mercer Chronometers is a British company specialising in the design and production of bespoke marine chronometer, chronometers. History The story begins with John Harrison, as documented in Dava Sobel's book ''Longitude (book), Longitude'' and its Longitude (TV series), British television adaptation. Until then, ships had been navigating with accuracy only as regards the ship’s north-south position, using the North Star and/or the Southern Cross. Determining the east-west position of a ship and its destination was vital to the British Admiralty, Admiralty’s, (and the Government’s), plans for further expansion and empire. It was also necessary to avoid the massive losses in time, money and human life that inaccurate navigation and shipwreck caused. Lack of solutions led to the government making an Act of Parliament in 1714 offering a prize of £20,000 (£3M today). There was a whole spectrum of ideas suggested, ranging from serious (Whitton and Diston’s light-houses) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richmond Upon Thames
The London Borough of Richmond upon Thames () in south-west Greater London, London, England, forms part of Outer London and is the only London boroughs, London borough on both sides of the River Thames. It was created in 1965 when three smaller council areas amalgamated under the London Government Act 1963. It is governed by Richmond upon Thames London Borough Council. The population is 198,019 and the major communities are Barnes, London, Barnes, East Sheen, Mortlake, Kew, Richmond, London, Richmond, Twickenham, Teddington and Hampton, London, Hampton. The borough is home to Richmond Park, the largest park in London, along with the National Physical Laboratory (United Kingdom), National Physical Laboratory and The National Archives (United Kingdom), The National Archives. Kew Gardens, Hampton Court Palace, Twickenham Stadium and the WWT London Wetlands Centre are within its boundaries and draw domestic and international tourism. In 2023, the borough was ranked first in Rightmo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detent
A detent is a mechanical or magnetic means to resist or arrest the movement of a mechanical device. Such a device can be anything ranging from a simple metal pin to a machine. The term is also used for the method involved. Magnetic detents are most often used to divide a shaft rotation into discrete increments. Magnetic detents are inherent in some types of electric motors, most often stepper motors. Mechanics Arresting movement Ratchet and pawl The ratchet-and- pawl design arrests movements by employing a small gravity- or spring-actuated lever paired with a notched wheel. The lever is mounted on a pivot point in proximity to the wheel. The vertical angle of the sides of the notches that face the direction of rotation desired is generally very acute (45 degrees or less), so that as the wheel rotates in that direction, the end of the lever is easily lifted or pushed out and over the top of a notch. Following this, the lever drops into the next notch and the next et cetera ... [...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 (Greenwich), Prime Meridian passed 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 Charles II of England, 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 for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frank Watson Dyson
Sir Frank Watson Dyson, KBE, FRS, FRSE (8 January 1868 – 25 May 1939) was an English astronomer and the ninth Astronomer Royal who is remembered today largely for introducing time signals ("pips") from Greenwich, England, and for the role he played in proving Einstein's theory of general relativity. Biography Dyson was born in Measham, near Ashby-de-la-Zouch, Leicestershire, the son of the Rev Watson Dyson, a Baptist minister, and his wife, Frances Dodwell. The family lived on St John Street in Wirksworth while Frank was one- to three-years-old. They moved to Yorkshire in his youth. There he attended Heath Grammar School, Halifax, and subsequently won scholarships to Bradford Grammar School and Trinity College, Cambridge, where he studied mathematics and astronomy, being placed Second Wrangler in 1889. In 1894 he joined the Royal Astronomical Society, the British Astronomical Association and was given the post of Senior Assistant at Greenwich Observatory and worked ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomer Royal
Astronomer Royal is a senior post in the Royal Households of the United Kingdom. There are two officers, the senior being the astronomer royal dating from 22 June 1675; the junior is the astronomer royal for Scotland dating from 1834. The Astronomer Royal works to make observations to improve navigation, cartography, instrument design, and applications of geomagnetism. The position was created with the overall goal of discovering a way to determine longitude at sea when out of sight of land. History The post was created by Charles II in 1675, at the same time as he founded the Royal Observatory, Greenwich. He appointed John Flamsteed, instructing him "." The first six Astronomer Royals dedicated themselves primarily to this task and focused on astronomical observations that would benefit navigation. The astronomer royal was director of the Royal Observatory, Greenwich from the establishment of the post in 1675 until 1972. The astronomer royal became an honorary title in 197 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenwich
Greenwich ( , , ) is an List of areas of London, area in south-east London, England, within the Ceremonial counties of England, ceremonial county of Greater London, east-south-east of Charing Cross. Greenwich is notable for its maritime history and for giving its name to the Prime meridian (Greenwich), Greenwich Meridian (0° longitude) and Greenwich Mean Time. The town became the site of a royal palace, the Palace of Placentia, from the 15th century and was the birthplace of many House of Tudor, Tudors, including Henry VIII of England, Henry VIII and Elizabeth I. The palace fell into disrepair during the English Civil War and was demolished, eventually being replaced by the Greenwich Hospital (London), Royal Naval Hospital for Sailors, designed by Sir Christopher Wren and his assistant Nicholas Hawksmoor. These buildings became the Old Royal Naval College, Royal Naval College in 1873, and they remained a military education establishment until 1998, when they passed into the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Chronometer
A marine chronometer is a precision timepiece that is carried on a ship and employed in the determination of the ship's position by celestial navigation. It is used to determine longitude by comparing Greenwich Mean Time (GMT), and the time at the current location found from observations of celestial bodies. When first developed in the 18th century, it was a major technical achievement, as accurate knowledge of the time over a long sea voyage was vital for effective navigation, lacking electronic or communications aids. The first true chronometer was the life work of one man, John Harrison, spanning 31 years of persistent experimentation and testing that revolutionized naval (and later aerial) navigation. The term ''wikt:chronometer, chronometer'' was coined from the Greek words () (meaning time) and (meaning measure). The 1713 book ''Physico-Theology'' by the English cleric and scientist William Derham includes one of the earliest theoretical descriptions of a marine chronome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Treasurer
A treasurer is a person responsible for the financial operations of a government, business, or other organization. Government The treasury of a country is the department responsible for the country's economy, finance and revenue. The treasurer is generally the head of the treasury, although, in some countries (such as the United Kingdom or the United States) the treasury reports to a Secretary of the Treasury or Chancellor of the Exchequer. In Australia, the Treasurer is a senior minister and usually the second or third most important member of the government after the Prime Minister and Deputy Prime Minister. Each Australian state and self-governing territory also has its own treasurer. From 1867 to 1993, Ontario's Minister of Finance was called the Treasurer of Ontario. Originally the word referred to the person in charge of the treasure of a noble; however, it has now moved into wider use. In England during the 17th century, a position of Lord High Treasurer was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clerkenwell
Clerkenwell ( ) is an area of central London, England. Clerkenwell was an Civil Parish#Ancient parishes, ancient parish from the medieval period onwards, and now forms the south-western part of the London Borough of Islington. The St James's Church, Clerkenwell, church of St James in Clerkenwell Close and nearby Clerkenwell Green sit at the centre of Clerkenwell. Located on the edge of the City of London, it was the home of the Clerkenwell Priory, Priory of St John and the site of a number of wells and spas, including Sadlers Wells and Spa Green. The well after which the area was named was rediscovered in 1924. The Marquess of Northampton owned much of the land in Clerkenwell, reflected in placenames such as Northampton Square, Spencer Street and Compton Street. The watchmaking and watch repairing trades were once of great importance, particularly in the area around Northampton Square. In the 20th century, Clerkenwell became known as a centre for architecture and design. Cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Horological Institute
The British Horological Institute (BHI) is the representative body of the horology, horological industry in the United Kingdom. It was founded by a group of clockmakers in 1858, and has its current premises at Upton Hall, Nottinghamshire, Upton Hall in Nottinghamshire, which includes a museum of clock history. History The BHI was founded in 1858 by a small group of clockmakers, one of whom was Edward Daniel Johnson. Their aim was to unify the British horological industry and trades in the face of large numbers of imports of clocks and watches from abroad. The institute was an immediate success and within a year it had founded its own museum and library; it also began to offer evening classes in clock- and watch-making. The journal of the institute is the ''Horological Journal'', which has been published monthly since September 1858. It is claimed to be the oldest continuously published technical journal in the world. Upton Hall The current premises of the BHI are at Upton Hal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercer Chronometer Used By Shackleton
Mercer may refer to: Business * Mercer (automobile), a defunct American automobile manufacturer (1909–1925) * Mercer (consulting firm), a human resources consulting firm headquartered in New York City, US * Mercer (occupation), a merchant or trader, more specifically a merchant who deals in textiles (mercery) ** Mercer, a member of the London guild of the Worshipful Company of Mercers * Mercer Pottery Company, a defunct American company * Mercer Union, an artist-run centre in downtown Toronto, Ontario, Canada People and fictional characters * Mercer (surname), a list of people and fictional characters with the surname * Mercer (given name), a list of people and fictional characters so named Places United States * Fort Mercer, American Revolution fort along the Delaware River in New Jersey * Mercer Township, Adams County, Iowa, an unincorporated community * Mercer, Maine, a town * Mercer, Missouri, a city * Mercer, North Carolina, an unincorporated community * Mercer, N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Merseyside
Merseyside ( ) is a ceremonial counties of England, ceremonial and metropolitan county in North West England. It borders Lancashire to the north, Greater Manchester to the east, Cheshire to the south, the Wales, Welsh county of Flintshire across the Dee Estuary to the southwest, and the Irish Sea to the west. The largest settlement is the city of Liverpool. The county is highly urbanised, with an area of and a population of 1.42 million in 2007. After Liverpool (552,267), the largest settlements are Birkenhead (143,968), St Helens, Merseyside, St Helens (102,629), and Southport (94,421). For Local government in England, local government purposes the county comprises five metropolitan boroughs: Metropolitan Borough of Knowsley, Knowsley, Metropolitan Borough of St Helens, St Helens, Metropolitan Borough of Sefton, Sefton, Metropolitan Borough of Wirral, Wirral, and Liverpool. The borough councils, together with that of Borough of Halton, Halton in Cheshire, collaborate through th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
