John Crosley
John Crosley (1762–1817) was an English astronomer and mathematician who was an assistant at the Royal Observatory, Greenwich, a computer of the '' Nautical Almanac'', an observer on maritime voyages of scientific exploration and a member and President of the Spitalfields Mathematical Society. Life John Crosley was born in Yorkshire, but little is known of his life before his employment as an assistant at the Royal Observatory, Greenwich to the Astronomer Royal, Nevil Maskelyne. He was the Observatory's assistant in 1789–1792 and again in 1798. He was an observer appointed by the Board of Longitude between 1793 and 1798 to George Vancouver's expedition to the north-west coast of America, replacing William Gooch, who was murdered in Hawaii. During this voyage his ship, , was wrecked on a reef near Okinawa, and he returned to England on another sloop. His salary was £400 per annum, but he spent some years seeking compensation from the Board of Longitude for the loss of his boo ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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John Crosley
John Crosley (1762–1817) was an English astronomer and mathematician who was an assistant at the Royal Observatory, Greenwich, a computer of the '' Nautical Almanac'', an observer on maritime voyages of scientific exploration and a member and President of the Spitalfields Mathematical Society. Life John Crosley was born in Yorkshire, but little is known of his life before his employment as an assistant at the Royal Observatory, Greenwich to the Astronomer Royal, Nevil Maskelyne. He was the Observatory's assistant in 1789–1792 and again in 1798. He was an observer appointed by the Board of Longitude between 1793 and 1798 to George Vancouver's expedition to the north-west coast of America, replacing William Gooch, who was murdered in Hawaii. During this voyage his ship, , was wrecked on a reef near Okinawa, and he returned to England on another sloop. His salary was £400 per annum, but he spent some years seeking compensation from the Board of Longitude for the loss of his boo ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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John Arnold (watchmaker)
John Arnold (1736 – 11 August 1799) was an English watchmaker and inventor. John Arnold was the first to design a watch that was both practical and accurate, and also brought the term "chronometer" into use in its modern sense, meaning a precision timekeeper. His technical advances enabled the quantity production of marine chronometers for use on board ships from around 1782. The basic design of these has remained, with a few modifications unchanged until the late twentieth century. His legacy includes, together with Abraham-Louis Breguet, as one of the inventors of the modern mechanical watch. One of his most important inventions, the overcoil balance spring is still used in most mechanical wristwatches. It was from around 1770 that Arnold developed the portable precision timekeeper, almost from the point where John Harrison ended his work in this field. But, compared to Harrison's complicated and expensive watch, Arnold's basic design was simple whilst consistently accurate ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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18th-century British Astronomers
The 18th century lasted from January 1, 1701 ( MDCCI) to December 31, 1800 ( MDCCC). During the 18th century, elements of Enlightenment thinking culminated in the American, French, and Haitian Revolutions. During the century, slave trading and human trafficking expanded across the shores of the Atlantic, while declining in Russia, China, and Korea. Revolutions began to challenge the legitimacy of monarchical and aristocratic power structures, including the structures and beliefs that supported slavery. The Industrial Revolution began during mid-century, leading to radical changes in human society and the environment. Western historians have occasionally defined the 18th century otherwise for the purposes of their work. For example, the "short" 18th century may be defined as 1715–1789, denoting the period of time between the death of Louis XIV of France and the start of the French Revolution, with an emphasis on directly interconnected events. To historians who expand ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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1817 Deaths
Events January–March * January 1 – Sailing through the Sandwich Islands, Otto von Kotzebue discovers New Year Island. * January 19 – An army of 5,423 soldiers, led by General José de San Martín, starts crossing the Andes from Argentina, to liberate Chile and then Peru. * January 20 – Ram Mohan Roy and David Hare found Hindu College, Calcutta, offering instructions in Western languages and subjects. * February 12 – Battle of Chacabuco: The Argentine–Chilean patriotic army defeats the Spanish. * March 3 ** President James Madison vetoes John C. Calhoun's Bonus Bill. ** The U.S. Congress passes a law to split the Mississippi Territory, after Mississippi drafts a constitution, creating the Alabama Territory, effective in August. * March 4 – James Monroe is sworn in as the fifth President of the United States. * March 21 – The flag of the Pernambucan Revolt is publicly blessed by the dean of Recife Cathedral, Brazil. ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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1762 Births
Year 176 ( CLXXVI) was a leap year starting on Sunday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Proculus and Aper (or, less frequently, year 929 ''Ab urbe condita''). The denomination 176 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * November 27 – Emperor Marcus Aurelius grants his son Commodus the rank of ''Imperator'', and makes him Supreme Commander of the Roman legions. * December 23 – Marcus Aurelius and Commodus enter Rome after a campaign north of the Alps, and receive a triumph for their victories over the Germanic tribes. * The Equestrian Statue of Marcus Aurelius is made. It is now kept at Museo Capitolini in Rome (approximate date). Births * Fa Zheng, Chinese nobleman and adviser (d. 220) * Liu Bian, Chinese emperor of the Han Dynasty ( ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Mary Croarken
Mary G. Croarken is a British independent scholar and author in the history of mathematics and the history of computing. Education and career Croarken earned a degree in computer science from the University of Warwick in 1982 and a doctorate in the history of science there in 1986, supervised by Martin Campbell-Kelly, who describes her as one of his two most successful students. After leaving academia to raise a family in Norwich, she became a health research manager in the National Health Service, while continuing to work in the history of science as an independent scholar. She has been a research fellow at the National Maritime Museum in Greenwich and in the computer science department at the University of Warwick. Books Croarken is the author of the book ''Early Scientific Computing in Britain'' (Clarendon Press, 1990). She is a co-editor of ''The History of Mathematical Tables, The History of Mathematical Tables: from Sumer to Spreadsheets'' (Oxford University Press, 2003) a ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Lunar Distance (navigation)
In celestial navigation, lunar distance is the angular distance between the Moon and another celestial body. The lunar distances method uses this angle, also called a lunar, and a nautical almanac to calculate Greenwich time if so desired, or by extension any other time. That calculated time can be used in solving a spherical triangle. The theory was first published by Johannes Werner in 1524, before the necessary almanacs had been published. A fuller method was published in 1763 and used until about 1850 when it was superseded by the marine chronometer. A similar method uses the positions of the Galilean moons of Jupiter. Purpose In celestial navigation, knowledge of the time at Greenwich (or another known place) and the measured positions of one or more celestial objects allows the navigator to calculate latitude and longitude. Reliable marine chronometers were unavailable until the late 18th century and not affordable until the 19th century. After the method was firs ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Cape Of Good Hope
The Cape of Good Hope ( af, Kaap die Goeie Hoop ) ;''Kaap'' in isolation: pt, Cabo da Boa Esperança is a rocky headland on the Atlantic coast of the Cape Peninsula in South Africa. A common misconception is that the Cape of Good Hope is the southern tip of Africa, based on the misbelief that the Cape was the dividing point between the Atlantic and Indian oceans, and have nothing to do with north or south. In fact, by looking at a map, the southernmost point of Africa is Cape Agulhas about to the east-southeast. The currents of the two oceans meet at the point where the warm-water Agulhas current meets the cold-water Benguela current and turns back on itself. That oceanic meeting point fluctuates between Cape Agulhas and Cape Point (about east of the Cape of Good Hope). When following the western side of the African coastline from the equator, however, the Cape of Good Hope marks the point where a ship begins to travel more eastward than southward. Thus, the first mode ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Matthew Flinders
Captain Matthew Flinders (16 March 1774 – 19 July 1814) was a British navigator and cartographer who led the first inshore circumnavigation of mainland Australia, then called New Holland. He is also credited as being the first person to utilise the name ''Australia'' to describe the entirety of that continent including Van Diemen's Land (now Tasmania), a title he regarded as being "more agreeable to the ear" than previous names such as ''Terra Australis''. Flinders was involved in several voyages of discovery between 1791 and 1803, the most famous of which are the circumnavigation of Australia and an earlier expedition when he and George Bass confirmed that Van Diemen's Land was an island. While returning to Britain in 1803, Flinders was arrested by the French governor at Isle de France (Mauritius). Although Britain and France were at war, Flinders thought the scientific nature of his work would ensure safe passage, but he remained under arrest for more than six years. In ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Thomas Earnshaw
Thomas Earnshaw (4 February 1749 in Ashton-under-Lyne – 1 March 1829 in London) was an English watchmaker who, following John Arnold's earlier work, further simplified the process of marine chronometer production, making them available to the general public. He is also known for his improvements to the transit clock at the Royal Greenwich Observatory in London and his invention of a chronometer escapement and a form of bimetallic compensation balance.Thomas Earnshaw at Encyclopædia Britannica Online. [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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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 Greenw ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Okinawa
is a prefecture of Japan. Okinawa Prefecture is the southernmost and westernmost prefecture of Japan, has a population of 1,457,162 (as of 2 February 2020) and a geographic area of 2,281 km2 (880 sq mi). Naha is the capital and largest city of Okinawa Prefecture, with other major cities including Okinawa, Uruma, and Urasoe. Okinawa Prefecture encompasses two thirds of the Ryukyu Islands, including the Okinawa, Daitō and Sakishima groups, extending southwest from the Satsunan Islands of Kagoshima Prefecture to Taiwan ( Hualien and Yilan Counties). Okinawa Prefecture's largest island, Okinawa Island, is the home to a majority of Okinawa's population. Okinawa Prefecture's indigenous ethnic group are the Ryukyuan people, who also live in the Amami Islands of Kagoshima Prefecture. Okinawa Prefecture was ruled by the Ryukyu Kingdom from 1429 and unofficially annexed by Japan after the Invasion of Ryukyu in 1609. Okinawa Prefecture was officially founded in 1879 by the Empi ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |