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Edward John Dent
Edward John Dent (1790–1853) was a famous English watchmaker noted for his highly accurate clocks and marine chronometers. He founded the Dent company. Early years Edward John Dent, son of John and Elizabeth Dent, was born in London on 19 August 1790. He was baptised on 18 October 1790, at St. Clement Danes Church in the Strand. Edward had a younger brother, William (born 11 February 1792). The boys' mother, Elizabeth, died while they were still young – she was buried on 16 May 1793. Interest in watchmaking At the age of 14, Dent became apprenticed to his grandfather, John Wright Dent, a tallow chandler. Under the terms of the indenture – dated 20 August 1804 – John Wright Dent was expected to find suitable lodgings for his apprentice. Fortunately, Edward John Dent's cousin, Richard Rippon, was willing to have him. Rippon was an expert watchmaker and Dent became fascinated by watchmaking and less interested in the business of making and selling candles. Indeed, Dent ...
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Clock
A clock or a timepiece is a device used to measure and indicate time. The clock is one of the oldest human inventions, meeting the need to measure intervals of time shorter than the natural units such as the day, the lunar month and the year. Devices operating on several physical processes have been used over the millennia. Some predecessors to the modern clock may be considered as "clocks" that are based on movement in nature: A sundial shows the time by displaying the position of a shadow on a flat surface. There is a range of duration timers, a well-known example being the hourglass. Water clocks, along with the sundials, are possibly the oldest time-measuring instruments. A major advance occurred with the invention of the verge escapement, which made possible the first mechanical clocks around 1300 in Europe, which kept time with oscillating timekeepers like balance wheels., pp. 103–104., p. 31. Traditionally, in horology, the term ''clock'' was used for a stri ...
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Local Mean Time
Local mean time (LMT) is a form of solar time that corrects the variations of Solar time#Apparent solar time, local apparent time, forming a uniform time scale at a specific longitude. This measurement of time was used for everyday use during the 19th century before time zones were introduced beginning in the late 19th century; it still has some uses in astronomy and navigation. Past use Local mean time was used from the early 19th century, when local solar time or sundial time was last used until standard time was adopted on various dates in the several countries. Each town or city kept its own Meridian (geography), meridian. This led to a situation where locations one degree of longitude apart had times four minutes apart. This became a problem in the mid 19th century when railways needed clocks that were synchronized between stations, at the same time as people needed to match their clock (or the church clock) to the time tables. Standard time means that the same time is used ...
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Big Ben
Big Ben is the nickname for the Great Bell of the Great Clock of Westminster, at the north end of the Palace of Westminster in London, England, and the name is frequently extended to refer also to the clock and the clock tower. The official name of the tower in which Big Ben is located was originally the Clock Tower, but it was renamed Elizabeth Tower in 2012 to mark the Diamond Jubilee of Elizabeth II. The tower was designed by Augustus Pugin in a neo-Gothic style. When completed in 1859, its clock was the largest and most accurate four-faced striking and chiming clock in the world. The tower stands tall, and the climb from ground level to the belfry is 334 steps. Its base is square, measuring on each side. Dials of the clock are in diameter. All four nations of the UK are represented on the tower on shields featuring a rose for England, thistle for Scotland, shamrock for Ireland, and leek for Wales. On 31 May 2009, celebrations were held to mark the tower's 150th a ...
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George Airy
Sir George Biddell Airy (; 27 July 18012 January 1892) was an English mathematician and astronomer, and the seventh Astronomer Royal from 1835 to 1881. His many achievements include work on planetary orbits, measuring the mean density of the Earth, a method of solution of two-dimensional problems in solid mechanics and, in his role as Astronomer Royal, establishing Greenwich as the location of the prime meridian. Biography Airy was born at Alnwick, one of a long line of Airys who traced their descent back to a family of the same name residing at Kentmere, in Westmorland, in the 14th century. The branch to which he belonged, having suffered in the English Civil War, moved to Lincolnshire and became farmers. Airy was educated first at elementary schools in Hereford, and afterwards at Colchester Royal Grammar School. An introverted child, Airy gained popularity with his schoolmates through his great skill in the construction of peashooters. From the age of 13, Airy stayed frequen ...
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Dipleidoscope
Dipleidoscope A dipleidoscope is an instrument used to determine true noon; its name comes from the Greek for ''double image viewer''. It consists of a small telescope and a prism that creates a double image of the sun. When the two images overlap, it is local true noon. The instrument is capable of determining true noon to within ten seconds. The dipleidoscope was invented by Giovanni Battista Amici in the first half of the 19th century. Edward John Dent Edward John Dent (1790–1853) was a famous English watchmaker noted for his highly accurate clocks and marine chronometers. He founded the Dent company. Early years Edward John Dent, son of John and Elizabeth Dent, was born in London on 1 ..., a chronometer and clockmaker in London, was working in the 1830s on a simple contrivance that would allow the public to set clocks correctly based on the transit of the sun (more complex and expensive transit telescopes had been developed by Ole Rømer in 1690). By 1840 he felt ...
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Remontoire
In mechanical horology, a remontoire (from the French ''remonter'', meaning 'to wind') is a small secondary source of power, a weight or spring, which runs the timekeeping mechanism and is itself periodically rewound by the timepiece's main power source, such as a mainspring. It was used in a few precision clocks and watches to place the source of power closer to the escapement, thereby increasing the accuracy by evening out variations in drive force caused by unevenness of the friction in the geartrain. In spring-driven precision clocks, a gravity remontoire is sometimes used to replace the uneven force delivered by the mainspring running down by the more constant force of gravity acting on a weight. In turret clocks, it serves to separate the large forces needed to drive the hands from the modest forces needed to drive the escapement which keeps the pendulum swinging. A remontoire should not be confused with a ''maintaining power spring'', which is used only to keep the timepiec ...
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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), or in the modern world its successor Coordinated Universal Time (UTC), 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 and enabling the Age of Discovery and Colonialism to accelerate. The term ''chronometer'' was coined from the Greek words '' χρόνος (chronos)'' (meaning time) and ''meter'' (meaning measure) in 1713 by ...
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On The Origin Of Species
''On the Origin of Species'' (or, more completely, ''On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life''),The book's full original title was ''On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life''. In the 1872 sixth edition, "On" was omitted, so the full title is ''The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life.'' This edition is usually known as ''The Origin of Species.'' The 6th is Darwin's final edition; there were minor modifications in the text of certain subsequent issues. See Freeman, R. B. In Van Wyhe, John, ed. ''Darwin Online: On the Origin of Species'', 2002. published on 24 November 1859, is a work of scientific literature by Charles Darwin that is considered to be the foundation of evolutionary biology. Darwin's book introduced the scientific theory that populatio ...
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Charles Darwin
Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all species of life have descended from a common ancestor is now generally accepted and considered a fundamental concept in science. In a joint publication with Alfred Russel Wallace, he introduced his scientific theory that this branching pattern of evolution resulted from a process he called natural selection, in which the struggle for existence has a similar effect to the artificial selection involved in selective breeding. Darwin has been described as one of the most influential figures in human history and was honoured by burial in Westminster Abbey. Darwin's early interest in nature led him to neglect his medical education at the University of Edinburgh; instead, he helped to investigate marine invertebrates. His studies at the University of Cambridge's Christ's Col ...
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Second Voyage Of HMS Beagle
The second voyage of HMS ''Beagle'', from 27 December 1831 to 2 October 1836, was the second survey expedition of HMS ''Beagle'', under captain Robert FitzRoy who had taken over command of the ship on its first voyage after the previous captain, Pringle Stokes, committed suicide. FitzRoy had thought of the advantages of having someone onboard who could investigate geology, and sought a naturalist to accompany them as a supernumerary. At the age of 22, the graduate Charles Darwin hoped to see the tropics before becoming a parson and accepted the opportunity. He was greatly influenced by reading Charles Lyell's ''Principles of Geology'' during the voyage. By the end of the expedition, Darwin had made his name as a geologist and fossil collector and the publication of his journal (later known as ''The Voyage of the Beagle'') gave him wide renown as a writer. ''Beagle'' sailed across the Atlantic Ocean, and then carried out detailed hydrographic surveys around the coasts of south ...
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Phillip Parker King
Rear Admiral Phillip Parker King, FRS, RN (13 December 1791 – 26 February 1856) was an early explorer of the Australian and Patagonian coasts. Early life and education King was born on Norfolk Island, to Philip Gidley King and Anna Josepha King ''née'' Coombe, and named after his father's mentor, Admiral Arthur Phillip (1738–1814), (first governor of New South Wales and founder of the British penal colony which later became the city of Sydney in Australia), which explains the difference in spelling of his and his father's first names. King was sent to England for education in 1796, and he joined the Royal Naval Academy, at Portsmouth, in county Hampshire, England in 1802. King entered the Royal Navy in 1807, where he was commissioned lieutenant in 1814. Expeditions in Australia King was assigned to survey the parts of the Australian coast not already examined by Royal Navy officer, Matthew Flinders, (who had already made three earlier exploratory voyages between 17 ...
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Robert FitzRoy
Vice-Admiral Robert FitzRoy (5 July 1805 – 30 April 1865) was an English officer of the Royal Navy and a scientist. He achieved lasting fame as the captain of during Charles Darwin's famous voyage, FitzRoy's second expedition to Tierra del Fuego and the Southern Cone. FitzRoy was a pioneering meteorologist who made accurate daily weather predictions, which he called by a new name of his own invention: "forecasts". In 1854 he established what would later be called the Met Office, and created systems to get weather information to sailors and fishermen for their safety. He was an able surveyor and hydrographer. As Governor of New Zealand, serving from 1843 to 1845, he tried to protect the Māori from illegal land sales claimed by British settlers. Early life and career Robert FitzRoy was born at Ampton Hall, Ampton, Suffolk, England, into the upper echelons of the British aristocracy and a tradition of public service. Through his father, General Lord Charles FitzRoy, Robe ...
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