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Chester Moore Hall
Chester Moore Hall (9 December 1703, Leigh, Essex, England – 17 March 1771, Sutton) was a British lawyer and inventor who produced the first achromatic lenses in 1729 or 1733 (accounts differ). He used the achromatic lens to build the first achromatic telescope, a refracting telescope free from chromatic aberration (colour distortion). He lived at New Hall, Sutton. His name was also spelled ''Chester Moor Hall'' and ''Chester More Hall''. The design had two elements, a crown and flint glass, that brought two wavelengths of light to a focus. Chester is noted as having made the first twin color corrected lens in 1730. See also * List of largest optical telescopes in the 18th century *John Dollond John Dollond FRS (10 June O.S. (21 June N.S.) 170630 November 1761) was an English optician, known for his successful optics business and his patenting and commercialization of achromatic doublets. Biography Dollond was the son of a Hugue ... (also developed achromats in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leigh-on-Sea
Leigh-on-Sea (), commonly referred to simply as Leigh, is a town and civil parish in the City of Southend-on-Sea, in the ceremonial county of Essex, England. In 2011, it had a population of 22,509. Geography Leigh-on-Sea is on the northern side of the Thames Estuary, a few miles from the open waters of the North Sea to the east, and a similar distance from the Kent coast to the south. The coastal environs of the town feature a nature reserve at Two Tree Island and a centrally located beach adjacent to Bell Wharf. At low tide Leigh's foreshore has a wide expanse of mud flats and creeks, extending offshore towards the deep water channel of the Thames (Yantlet Channel). Leigh is from central London via road and rail networks and is part of the London commuter belt. History Origins Archaeological finds of pottery and coins from Romano-British era in the locality suggest early settlement. From at least the Saxon period a hilltop clearing amidst the woodland that covered much o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sutton, Essex
Sutton is a village and civil parish in the District of Rochford in Essex, England. It is located between the River Roach and the adjoining Borough of Southend-on-Sea, and includes the hamlet of Shopland. It has a population of 127, increasing at the 2011 Census to 135, the smallest in the District, although at the time of the Domesday Book it had a flourishing village with its own market and fair. The place-name 'Sutton' is first recorded in the Domesday Book of 1086, where it appears as ''Suttuna''. The name means 'southern town or settlement'. The place-name 'Shopland' is first attested in a list of c. 1000 AD of the manors of St Paul's Cathedral in Corpus Christi College, Cambridge (MS. 383), where it appears as ''Scopingland''. It appears as ''Scopelanda'' in the Domesday Book of 1086, and as ''Scopiland'' in the Feet of Fines in 1208. The name means 'island with a shed', the first element being the Old English ''sceoppa'', or the Middle English ''schoppe'', meaning 'sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Achromatic Lens
An achromatic lens or achromat is a lens that is designed to limit the effects of chromatic and spherical aberration. Achromatic lenses are corrected to bring two wavelengths (typically red and blue) into focus on the same plane. The most common type of achromat is the achromatic doublet, which is composed of two individual lenses made from glasses with different amounts of dispersion. Typically, one element is a negative (concave) element made out of flint glass such as F2, which has relatively high dispersion, and the other is a positive (convex) element made of crown glass such as BK7, which has lower dispersion. The lens elements are mounted next to each other, often cemented together, and shaped so that the chromatic aberration of one is counterbalanced by that of the other. In the most common type (shown), the positive power of the crown lens element is not quite equalled by the negative power of the flint lens element. Together they form a weak positive lens that will b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromatic Aberration
In optics, chromatic aberration (CA), also called chromatic distortion and spherochromatism, is a failure of a lens to focus all colors to the same point. It is caused by dispersion: the refractive index of the lens elements varies with the wavelength of light. The refractive index of most transparent materials decreases with increasing wavelength. Since the focal length of a lens depends on the refractive index, this variation in refractive index affects focusing. Chromatic aberration manifests itself as "fringes" of color along boundaries that separate dark and bright parts of the image. Types There are two types of chromatic aberration: ''axial'' (''longitudinal''), and ''transverse'' (''lateral''). Axial aberration occurs when different wavelengths of light are focused at different distances from the lens (focus ''shift''). Longitudinal aberration is typical at long focal lengths. Transverse aberration occurs when different wavelengths are focused at different positions i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Encyclopædia Britannica
The (Latin for "British Encyclopædia") is a general knowledge English-language encyclopaedia. It is published by Encyclopædia Britannica, Inc.; the company has existed since the 18th century, although it has changed ownership various times through the centuries. The encyclopaedia is maintained by about 100 full-time editors and more than 4,000 contributors. The 2010 version of the 15th edition, which spans 32 volumes and 32,640 pages, was the last printed edition. Since 2016, it has been published exclusively as an online encyclopaedia. Printed for 244 years, the ''Britannica'' was the longest running in-print encyclopaedia in the English language. It was first published between 1768 and 1771 in the Scottish capital of Edinburgh, as three volumes. The encyclopaedia grew in size: the second edition was 10 volumes, and by its fourth edition (1801–1810) it had expanded to 20 volumes. Its rising stature as a scholarly work helped recruit eminent con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Largest Optical Telescopes In The 18th Century
List of largest optical telescopes in the 18th century, are listings of what were, for the time period of the 18th century, large optical telescopes. The list includes various refractor and reflector that were active some time between about 1699 to 1801. It is oriented towards astronomy, not terrestrial telescopes (e.g. spyglass). Many of the largest were metal mirror reflectors, some of which had substational apertures even for the 20th century. One problems was that many instrument makers including Herschel did not pass on their mirror making craft, and by the next century reflectors had largely been passed over in favour of small achromats (2 lens refractors). It was not until the 20th century that really large reflectors would predominate once again. Some of the achievements in astronomy of the 19th century telescopes include the discovery of the planet Uranus, the Messier catalog, and overall increased detections of comets, stars, star catalogs, and other charting. The majo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Dollond
John Dollond FRS (10 June O.S. (21 June N.S.) 170630 November 1761) was an English optician, known for his successful optics business and his patenting and commercialization of achromatic doublets. Biography Dollond was the son of a Huguenot refugee, a silk-weaver at Spitalfields, London, where he was born. He followed his father's trade, but found time to acquire a knowledge of Latin, Greek, mathematics, physics, anatomy and other subjects. In 1752 he abandoned silk-weaving and joined his eldest son, Peter Dollond (1730–1820), who in 1750 had started in business as a maker of optical instruments; this business went on to become Dollond & Aitchison. His reputation grew rapidly, and in 1761 he was appointed optician to the king. In 1758 he published an "Account of some experiments concerning the different refrangibility of light" ('' Phil. Trans.'', 1758), describing the experiments that led him to the achievement with which his name is specially associated, the discovery ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1703 Births
Seventeen or 17 may refer to: *17 (number), the natural number following 16 and preceding 18 * one of the years 17 BC, AD 17, 1917, 2017 Literature Magazines * ''Seventeen'' (American magazine), an American magazine * ''Seventeen'' (Japanese magazine), a Japanese magazine Novels * ''Seventeen'' (Tarkington novel), a 1916 novel by Booth Tarkington *''Seventeen'' (''Sebuntiin''), a 1961 novel by Kenzaburō Ōe * ''Seventeen'' (Serafin novel), a 2004 novel by Shan Serafin Stage and screen Film * ''Seventeen'' (1916 film), an American silent comedy film *''Number Seventeen'', a 1932 film directed by Alfred Hitchcock * ''Seventeen'' (1940 film), an American comedy film *''Eric Soya's '17''' (Danish: ''Sytten''), a 1965 Danish comedy film * ''Seventeen'' (1985 film), a documentary film * ''17 Again'' (film), a 2009 film whose working title was ''17'' * ''Seventeen'' (2019 film), a Spanish drama film Television * ''Seventeen'' (TV drama), a 1994 UK dramatic short starring Christ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1771 Deaths
Events January– March * January 5 – The Great Kalmyk (Torghut) Migration is led by Ubashi Khan, from the east bank of the Lower Volga River back to the homeland of Dzungaria, at this time under Qing Dynasty rule. * January 9 – Emperor Go-Momozono accedes to the throne of Japan, following his aunt's abdication. * February 12 – Upon the death of Adolf Frederick, he is succeeded as King of Sweden by his son Gustav III. At the time, however, Gustav is unaware of this, since he is abroad in Paris. The news of his father's death reaches him about a month later. * March – War of the Regulation: North Carolina Governor William Tryon raises a militia, to put down the long-running uprising of backcountry militias against North Carolina's colonial government. * March 12 – The North Carolina General Assembly establishes Wake County (named for Margaret Wake, the wife of North Carolina Royal Governor William Tryon) from portions of Cumberland, Joh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Members Of The Inner Temple
Member may refer to: * Military jury, referred to as "Members" in military jargon * Element (mathematics), an object that belongs to a mathematical set * In object-oriented programming, a member of a class ** Field (computer science), entries in a database ** Member variable, a variable that is associated with a specific object * Limb (anatomy), an appendage of the human or animal body ** Euphemism for penis * Structural component of a truss, connected by nodes * User (computing), a person making use of a computing service, especially on the Internet * Member (geology), a component of a geological formation * Member of parliament * The Members, a British punk rock band * Meronymy, a semantic relationship in linguistics * Church membership, belonging to a local Christian congregation, a Christian denomination and the universal Church * Member, a participant in a club or learned society A learned society (; also learned academy, scholarly society, or academic association) is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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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