Bygrave Slide Rule
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Bygrave Slide Rule
The Bygrave slide rule is a slide rule named for its inventor, Captain Leonard Charles Bygrave of the RAF. It was used in celestial navigation, primarily in aviation. Officially, it was called the A. M. L. Position Line Slide Rule (A.M.L. for Air Ministry Laboratories). It was developed in 1920 at the Air Ministry Laboratories at Kensington in London and was produced by Henry Hughes & Son Ltd of London until the mid-1930s. It solved the so-called celestial triangle accurately to about one minute of arc and quickly enough for aerial navigation. The solution of the celestial triangle used the John Napier rules for solution of square-angled spherical triangles. The slide rule was constructed as two coaxial tubes with spiral scales, like the Fuller's cylindrical slide rules, with yet another tube on the outside carrying the cursors. During the Second World War, a closely related version was produced in Germany by Dennert & Pape as the HR1, MHR1 and HR2. Famous users Sir Franci ...
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Bygrave Slide Rule
The Bygrave slide rule is a slide rule named for its inventor, Captain Leonard Charles Bygrave of the RAF. It was used in celestial navigation, primarily in aviation. Officially, it was called the A. M. L. Position Line Slide Rule (A.M.L. for Air Ministry Laboratories). It was developed in 1920 at the Air Ministry Laboratories at Kensington in London and was produced by Henry Hughes & Son Ltd of London until the mid-1930s. It solved the so-called celestial triangle accurately to about one minute of arc and quickly enough for aerial navigation. The solution of the celestial triangle used the John Napier rules for solution of square-angled spherical triangles. The slide rule was constructed as two coaxial tubes with spiral scales, like the Fuller's cylindrical slide rules, with yet another tube on the outside carrying the cursors. During the Second World War, a closely related version was produced in Germany by Dennert & Pape as the HR1, MHR1 and HR2. Famous users Sir Franci ...
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Slide Rule
The slide rule is a mechanical analog computer which is used primarily for multiplication and division, and for functions such as exponents, roots, logarithms, and trigonometry. It is not typically designed for addition or subtraction, which is usually performed using other methods. Maximum accuracy for standard linear slide rules is about three decimal significant digits, while scientific notation is used to keep track of the order of magnitude of results. Slide rules exist in a diverse range of styles and generally appear in a linear, circular or cylindrical form, with slide rule scales inscribed with standardized graduated markings. Slide rules manufactured for specialized fields such as aviation or finance typically feature additional scales that aid in specialized calculations particular to those fields. The slide rule is closely related to nomograms used for application-specific computations. Though similar in name and appearance to a standard ruler, the slide rule is ...
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Celestial Navigation
Celestial navigation, also known as astronavigation, is the practice of position fixing using stars and other celestial bodies that enables a navigator to accurately determine their actual current physical position in space (or on the surface of the Earth) without having to rely solely on estimated positional calculations, commonly known as " dead reckoning", made in the absence of satellite navigation or other similar modern electronic or digital positioning means. Celestial navigation uses "sights", or timed angular measurements, taken typically between a celestial body (e.g. the Sun, the Moon, a planet, or a star) and the visible horizon. Celestial navigation can also take advantage of measurements between celestial bodies without reference to the Earth horizon, such as when the Moon and other selected bodies are used in the practice called "lunars" or lunar distance method, used for determining precise time when time is unknown. Celestial navigation by taking sights of th ...
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John Napier
John Napier of Merchiston (; 1 February 1550 – 4 April 1617), nicknamed Marvellous Merchiston, was a Scottish landowner known as a mathematician, physicist, and astronomer. He was the 8th Laird of Merchiston. His Latinized name was Ioannes Neper. John Napier is best known as the discoverer of logarithms. He also invented the so-called " Napier's bones" and made common the use of the decimal point in arithmetic and mathematics. Napier's birthplace, Merchiston Tower in Edinburgh, is now part of the facilities of Edinburgh Napier University. There is a memorial to him at St Cuthbert's at the west side of Edinburgh. Life Napier's father was Sir Archibald Napier of Merchiston Castle, and his mother was Janet Bothwell, daughter of the politician and judge Francis Bothwell, and a sister of Adam Bothwell who became the Bishop of Orkney. Archibald Napier was 16 years old when John Napier was born. There are no records of Napier's early education, but many believe that he w ...
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Fuller's Cylindrical Slide Rule
The Fuller calculator, sometimes called Fuller's cylindrical slide rule, is a cylindrical slide rule with a helical main scale taking 50 turns around the cylinder. This creates an instrument of considerable precision – it is equivalent to a traditional slide rule long. It was invented in 1878 by George Fuller, professor of engineering at Queen's University Belfast, and despite its size and price it remained on the market for nearly a century because it outperformed nearly all other slide rules. As with other slide rules, the Fuller is limited to calculations based on multiplication and division with additional scales allowing for trigonometical and exponential functions. The mechanical calculators produced in the same era were generally restricted to addition and subtraction with only advanced versions, like the Arithmometer, able to multiply and divide. Even these advanced machines could not perform trigonometry or exponentiation and they were bigger, heavier and much mo ...
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Sir Francis Chichester
Sir Francis Charles Chichester KBE (17 September 1901 – 26 August 1972) was a British businessman, pioneering aviator and solo sailor. He was knighted by Queen Elizabeth II for becoming the first person to sail single-handed around the world by the clipper route and the fastest circumnavigator, in nine months and one day overall in 1966–67. Biography Early life Chichester was born in the rectory at Shirwell near Barnstaple in Devon, England, the son of a Church of England clergyman, Charles Chichester, himself the seventh son of Sir Arthur Chichester, 8th Baronet. His mother was Emily Annie, daughter of Samuel Page. At the age of six he was sent as a boarder to The Old Ride Preparatory School for boys, then attended Marlborough College during World War I. At the age of eighteen Chichester emigrated to New Zealand where in ten years he built up a prosperous business in forestry, mining and property development, only to suffer severe losses in the Great Depression. A ...
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Gipsy Moth
The de Havilland DH.60 Moth is a 1920s British two-seat touring and training aircraft that was developed into a series of aircraft by the de Havilland Aircraft Company. Development The DH.60 was developed from the larger DH.51 biplane. The first flight of the ADC Cirrus powered prototype DH.60 Moth (registration ''G-EBKT'') was carried out by Geoffrey de Havilland at the works airfield at Stag Lane on 22 February 1925. The Moth was a two-seat biplane of wooden construction, it had a plywood covered fuselage and fabric covered surfaces, a standard tailplane with a single tailplane and fin. A useful feature of the design was its folding wings which allowed owners to hangar the aircraft in much smaller spaces. The then Secretary of State for Air Sir Samuel Hoare became interested in the aircraft and the Air Ministry subsidised five flying clubs and equipped them with Moths. The prototype was modified with a horn-balanced rudder, as used on the production aircraft, and ...
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Gipsy Moth IV
''Gipsy Moth IV'' is a ketch that Sir Francis Chichester commissioned specifically to sail single-handed around the globe, racing against the times set by the clipper ships of the 19th century. Gipsy Moth IV was the first ever purpose built ocean racer and has over the years become the most famous of small sailing vessels. Gipsy Moth IV’s voyage was the inspiration for the Golden Globe Race (GGR)which continues today. The name, the fourth boat in Chichester’s series, all named ''Gipsy Moth,'' originated from the de Havilland Gipsy Moth aircraft in which Chichester completed pioneering work in aerial navigation techniques. Background and design After being nursed back to health from a suspected lung abscess by his wife, Chichester undertook two single-handed Transatlantic races from Plymouth to New York in 1960 and Plymouth to Newport in 1964 in ''Gipsy Moth III''. He won the '60 race and was runner-up in the '64 race. During the '64 race he became inspired to challenge ...
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Clipper Route
The clipper route was the traditional route derived from the Brouwer Route and sailed by clipper ships between Europe and the Far East, Australia and New Zealand. The route ran from west to east through the Southern Ocean, to make use of the strong westerly winds of the Roaring Forties. Many ships and sailors were lost in the heavy conditions along the route, particularly at Cape Horn, which the clippers had to round on their return to Europe. The clipper route fell into commercial disuse with the introduction of marine steam engines, and the opening of the Suez and Panama Canals. It remains the fastest sailing route around the world, and as such has been the route for several prominent yacht races, such as the Velux 5 Oceans Race and the Vendée Globe. Australia and New Zealand The clipper route from England to Australia and New Zealand, returning via Cape Horn, offered captains the fastest circumnavigation of the world, and hence potentially the greatest rewards; many gra ...
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Otis King's Patent Calculator
Otis Carter Formby King (1876–1944) was an electrical engineer in London who invented and produced a cylindrical slide rule with helical scales, primarily for business uses initially. The product was named Otis King's Patent Calculator, and was manufactured and sold by Carbic Ltd. in London from about 1922 to about 1972. With a log-scale decade length of 66 inches, the Otis King calculator should be about a full digit more accurate than a 6-inch pocket slide rule. But due to inaccuracies in tic-mark placement, some portions of its scales will read off by more than they should. For example, a reading of 4.630 might represent an answer of 4.632, or almost one part in 2000 error, when it should be accurate to one part in 6000 (66"/6000 = 0.011" estimated interpolation accuracy). The Geniac brand cylindrical slide rule sold by Oliver Garfield Company in New York was initially a relabelled Otis King; Garfield later made his own, probably unauthorized version of the Otis King ...
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Navigational Equipment
Navigation is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another.Bowditch, 2003:799. The field of navigation includes four general categories: land navigation, marine navigation, aeronautic navigation, and space navigation. It is also the term of art used for the specialized knowledge used by navigators to perform navigation tasks. All navigational techniques involve locating the navigator's position compared to known locations or patterns. Navigation, in a broader sense, can refer to any skill or study that involves the determination of position and direction. In this sense, navigation includes orienteering and pedestrian navigation. History In the European medieval period, navigation was considered part of the set of '' seven mechanical arts'', none of which were used for long voyages across open ocean. Polynesian navigation is probably the earliest form of open-ocean navigation; it wa ...
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Mechanical Calculators
Mechanical may refer to: Machine * Machine (mechanical), a system of mechanisms that shape the actuator input to achieve a specific application of output forces and movement * Mechanical calculator, a device used to perform the basic operations of arithmetic * Mechanical energy, the sum of potential energy and kinetic energy * Mechanical system, a system that manages the power of forces and movements to accomplish a task * Mechanism (engineering), a portion of a mechanical device Other * Mechanical (character), one of several characters in Shakespeare's ''A Midsummer Night's Dream'' * A kind of typeface in the VOX-ATypI classification See also * Machine, especially in opposition to an electronic item * ''Mechanical Animals'', the third full-length studio release by Marilyn Manson * Manufactured or artificial, especially in opposition to a biological or natural component * Automation, using machine decisions and processing instead of human * Mechanization, using machine labor inste ...
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