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Henry Gregory (instrument Maker)
Henry Gregory (1744–1782) was an English mathematical and optical instrument maker. Gregory was apprenticed to John Fowler in 1732 and was himself in business from c. 1750–1792 from premises in Francis Court, Clerkenwell, London and an establishment known as "The Azimuth Compass" in Leadenhall Street, London. His company later became known as Gregory and Son. Gregory manufactured navigational instruments, including quadrants of the type invented by John Hadley and compasses. One of his azimuth compasses traveled with the explorer James Cook on his second voyage to the southern Pacific Ocean in 1772–1775. An azimuth compass is a compass fitted with vertical sights, used to take the magnetic azimuth of a star or planet. Surviving examples of the azimuth compass exist in the collections of the National Maritime Museum, Greenwich and the Smithsonian National Museum of American History The National Museum of American History: Kenneth E. Behring Center is a histori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mathematical Instrument
A mathematical instrument is a tool or device used in the study or practice of mathematics. In geometry, construction of various proofs was done using only a compass and straightedge; arguments in these proofs relied only on idealized properties of these instruments and literal construction was regarded as only an approximation. In applied mathematics, mathematical instruments were used for measuring angles and distances, in astronomy, navigation, surveying and in the measurement of time.Gerard L'Estrange Turner ''Scientific Instruments, 1500-1900: An Introduction'' ( University of California Press, 1998) page 8 Overview Instruments such as the astrolabe, the quadrant, and others were used to measure and accurately record the relative positions and movements of planets and other celestial objects. The sextant and other related instruments were essential for navigation at sea. Most instruments are used within the field of geometry, including the ruler, dividers, protracto ... [...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] |
Leadenhall Street
__NOTOC__ Leadenhall Street () is a street in the City of London. It is about and links Cornhill, London, Cornhill in the west to Aldgate in the east. It was formerly the start of the A11 road (England), A11 road from London to Norwich, but that route now starts further east at Aldgate. Leadenhall Street has always been a centre of commerce. It connected the medieval market of Leaden Hall with Aldgate, the eastern gate in the Roman city wall. The East India Company had its headquarters there, as later did P&O. By the mid 20th century, grand stone-faced offices lined the street. Today it is closely associated with the insurance industry and particularly the Lloyd’s of London, Lloyd's insurance market, with its dramatic building in the adjacent Lime Street. It forms part of a cluster of tall buildings including the 48-storey 122 Leadenhall Street and the 38-storey The Scalpel, Scalpel. Other buildings planned for the street include the 57-storey 100 Leadenhall, the 50-storey Pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadrant (instrument)
A quadrant is an instrument used to measure angles up to 90°. Different versions of this instrument could be used to calculate various readings, such as longitude, latitude, and time of day. It was first proposed by Ptolemy as a better kind of astrolabe. Several different variations of the instrument were later produced by medieval Muslim astronomers. Mural quadrants were important astronomical instruments in 18th-century European observatories, establishing a use for positional astronomy. Etymology The term ''quadrant'', meaning one fourth, refers to the fact that early versions of the instrument were derived from astrolabes. The quadrant condensed the workings of the astrolabe into an area one fourth the size of the astrolabe face; it was essentially a quarter of an astrolabe. History During Rigvedic times in ancient India, quadrants called 'Tureeyam's were used to measure the extent of a great solar eclipse. The use of a Tureeyam for observing a solar eclipse by Ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Hadley
John Hadley (16 April 1682 – 14 February 1744) was an England, English mathematician, and laid claim to the invention of the octant (instrument), octant, two years after Thomas Godfrey (inventor), Thomas Godfrey claimed the same. Biography He was born in Bloomsbury, London the eldest son of George Hadley of Osidge, East Barnet, Hertfordshire and his wife Katherine FitzJames. His younger brother George Hadley became a noted meteorologist. In 1717 John became a member (and later vice-president) of the Royal Society of London. In 1729 he inherited his father's East Barnet estate. He died in East Barnet in 1744 and is buried in the local churchyard with other members of his family. He had married Elizabeth, daughter of Thomas Hodges, FRS (former Attorney General of Barbados) and had one child, a son and heir John, born in 1738. Work In 1730 Hadley invented the reflecting octant, which could be used to measure the altitude of the sun or other celestial sphere, celestial obje ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compass
A compass is a device that shows the cardinal directions used for navigation and geographic orientation. It commonly consists of a magnetized needle or other element, such as a compass card or compass rose, which can pivot to align itself with North magnetic pole, magnetic north. Other methods may be used, including gyroscopes, magnetometers, and GPS receivers. Compasses often show angles in degrees: north corresponds to 0°, and the angles increase clockwise, so east is 90°, south is 180°, and west is 270°. These numbers allow the compass to show azimuths or bearing (angle), bearings which are commonly stated in degrees. If local magnetic declination, variation between magnetic north and true north is known, then direction of magnetic north also gives direction of true north. Among the Four Great Inventions, the magnetic compass was first invented as a device for divination as early as the history of science and technology in China, Chinese Han dynasty (since c. 206 BC),#Li, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azimuth Compass
An azimuth compass (or azimuthal compass) is a nautical instrument used to measure the magnetic azimuth, the angle of the arc on the horizon between the direction of the Sun or some other celestial object and the magnetic north. This can be compared to the true azimuth obtained by astronomical observation to determine the magnetic declination, the amount by which the reading of a ship's compass must be adjusted to obtain an accurate reading. Azimuth compasses were important in the period before development of the reliable chronometers needed to determine a vessel's exact position from astronomical observations. Theory In navigation, the true azimuth of a heavenly body is the arc of the horizon between the point where a vertical plane containing the observer and the heavenly body intersects the horizon and the direction of true north. The magnetic azimuth is the arc between the point on the horizon below the heavenly body and the direction of magnetic north. When the latitude and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Cook
Captain (Royal Navy), Captain James Cook (7 November 1728 – 14 February 1779) was a British Royal Navy officer, explorer, and cartographer famous for his three voyages of exploration to the Pacific and Southern Oceans, conducted between 1768 and 1779. He completed the first recorded circumnavigation of the main islands of New Zealand and was the first known European to visit the eastern coastline of Australia and the Hawaiian Islands. Cook joined the British merchant navy as a teenager before enlisting in the Royal Navy in 1755. He served during the Seven Years' War, and subsequently surveyed and mapped much of the entrance to the St. Lawrence River during the Battle of the Plains of Abraham, siege of Quebec. In the 1760s, he mapped the coastline of Newfoundland (island), Newfoundland and made important astronomical observations which brought him to the attention of the Admiralty (United Kingdom), Admiralty and the Royal Society. This acclaim came at a crucial moment in Brit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific Ocean
The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is bounded by the continents of Asia and Australia in the west and the Americas in the east. At in area (as defined with a southern Antarctic border), the Pacific Ocean is the largest division of the World Ocean and the hydrosphere and covers approximately 46% of Earth's water surface and about 32% of the planet's total surface area, larger than its entire land area ().Pacific Ocean . ''Encyclopædia Britannica, Britannica Concise.'' 2008: Encyclopædia Britannica, Inc. The centers of both the Land and water hemispheres, water hemisphere and the Western Hemisphere, as well as the Pole of inaccessi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Maritime Museum
The National Maritime Museum (NMM) is a maritime museum in Greenwich, London. It is part of Royal Museums Greenwich, a network of museums in the Maritime Greenwich World Heritage Site. Like other publicly funded national museums in the United Kingdom, it has no general admission charge; there are admission charges for most side-gallery temporary exhibitions, usually supplemented by many loaned works from other museums. Creation and official opening The museum was created by the National Maritime Museum Act 1934 under a Board of Trustees, appointed by HM Treasury. It is based on the generous donations of Sir James Caird (1864–1954). King George VI formally opened the museum on 27 April 1937 when his daughter Princess Elizabeth accompanied him for the journey along the Thames from London. The first director was Sir Geoffrey Callender. Collection Since the earliest times Greenwich has had associations with the sea and navigation. It was a landing place for the Romans, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Museum Of American History
The National Museum of American History: Kenneth E. Behring Center is a historical museum in Washington, D.C. It collects, preserves, and displays the heritage of the United States in the areas of social, political, cultural, scientific, and military history. Among the items on display is the original Star-Spangled Banner (flag), Star-Spangled Banner. The museum is part of the Smithsonian Institution and located on the National Mall at 14th Street (Washington, D.C.), 14th Street and Constitution Avenue NW in Washington, D.C. In 2023, the museum received 2.1 million visitors, ranking the List of most-visited museums in the United States, eighth-most visited museum in the U.S. History The museum opened in 1964 as the Museum of History and Technology. It was one of the last structures designed by the renowned architectural firm McKim Mead & White. In 1980, the museum was renamed the National Museum of American History to represent its mission of the collection, care, study, and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1744 Births
Events January–March * January 6 – The Royal Navy ship ''Bacchus'' engages the Spanish Navy privateer ''Begona'', and sinks it; 90 of the 120 Spanish sailors die, but 30 of the crew are rescued. * January 24 – The Dagohoy rebellion in the Philippines begins, with the killing of Father Giuseppe Lamberti. * February 22–February 23, 23 – Battle of Toulon (1744), Battle of Toulon: The British fleet is defeated by a joint Franco-Spanish fleet. * February 27 – Violent storms frustrate a Planned French invasion of Britain (1744), planned French invasion of Britain. * March 1 (approximately) – The Great Comet of 1744, one of the brightest ever seen, reaches perihelion. * March 13 – The British ship ''Betty'' capsizes and sinks off of the Gold Coast (modern-day Ghana) near Anomabu. More than 200 people on board die, although there are a few survivors. * March 15 – France declares war on Great Britain. April–June * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
