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Edmund Gunter
Edmund Gunter (158110 December 1626), was an English clergyman, mathematician, geometer and astronomer of Welsh descent. He is best remembered for his mathematical contributions which include the invention of the Gunter's chain, the Gunter's quadrant, and the Gunter's scale. In 1620, he invented the first successful analogue device which he developed to calculate logarithmic tangents. He was mentored in mathematics by Reverend Henry Briggs and eventually became a Gresham Professor of Astronomy, from 1619 until his death. Biography Gunter was born in Hertfordshire in 1581. He was educated at Westminster School, and in 1599 he matriculated at Christ Church, Oxford. He took orders, became a preacher in 1614, and in 1615 proceeded to the degree of bachelor in divinity. He became rector of St. George's Church in Southwark. Mathematics, particularly the relationship between mathematics and the real world, was the one overriding interest throughout his life. In 1619, Sir Henry Sav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geometer
A geometer is a mathematician whose area of study is geometry. Some notable geometers and their main fields of work, chronologically listed, are: 1000 BCE to 1 BCE * Baudhayana (fl. c. 800 BC) – Euclidean geometry, geometric algebra * Manava (c. 750 BC–690 BC) – Euclidean geometry * Thales of Miletus (c. 624 BC – c. 546 BC) – Euclidean geometry * Pythagoras (c. 570 BC – c. 495 BC) – Euclidean geometry, Pythagorean theorem * Zeno of Elea (c. 490 BC – c. 430 BC) – Euclidean geometry * Hippocrates of Chios (born c. 470 – 410 BC) – first systematically organized '' Stoicheia – Elements'' (geometry textbook) * Mozi (c. 468 BC – c. 391 BC) * Plato (427–347 BC) * Theaetetus (c. 417 BC – 369 BC) * Autolycus of Pitane (360–c. 290 BC) – astronomy, spherical geometry * Euclid (fl. 300 BC) – '' Elements'', Euclidean geometry (sometimes called the "father of geometry") * Apollonius of Perga (c. 262 BC – c. 190 BC) – Euclidean geometry, conic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Egerton, 1st Earl Of Bridgewater
John Egerton, 1st Earl of Bridgewater KB, PC (1579 – 4 December 1649) was an English peer and politician from the Egerton family. The son of Thomas Egerton, 1st Viscount Brackley and Elizabeth Ravenscroft, he matriculated at Brasenose College, Oxford in 1589 at the age of 10, and received a Bachelor of Arts in 1594. He was a Member of Parliament (MP) for Callington from 1597 to 1598, and for Shropshire in 1601. Knighted on 8 April 1599, he was Baron of the Exchequer of Chester from 1599 to 1605. In 1603, Egerton was appointed Knight of the Order of the Bath and in 1605, he received a Master of Arts from the University of Oxford. Having succeeded to his father's titles in March 1617, he was created Earl of Bridgewater on 27 May 1617. Egerton was sworn of the Privy Council in 1626. From 1605 to 1646, he was Custos Rotulorum of Shropshire and from 1628 to 1649 Custos Rotulorum of Buckinghamshire. Between 1631 and 1634, he was Lord President of Wales and Lord Lieu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tangent (trigonometric Function)
In mathematics, the trigonometric functions (also called circular functions, angle functions or goniometric functions) are real functions which relate an angle of a right-angled triangle to ratios of two side lengths. They are widely used in all sciences that are related to geometry, such as navigation, solid mechanics, celestial mechanics, geodesy, and many others. They are among the simplest periodic functions, and as such are also widely used for studying periodic phenomena through Fourier analysis. The trigonometric functions most widely used in modern mathematics are the sine, the cosine, and the tangent. Their multiplicative inverse, reciprocals are respectively the cosecant, the secant, and the cotangent, which are less used. Each of these six trigonometric functions has a corresponding Inverse trigonometric functions, inverse function, and an analog among the hyperbolic functions. The oldest definitions of trigonometric functions, related to right-angle triangles, define ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sine
In mathematics, sine and cosine are trigonometric functions of an angle. The sine and cosine of an acute angle are defined in the context of a right triangle: for the specified angle, its sine is the ratio of the length of the side that is opposite that angle to the length of the longest side of the triangle (the hypotenuse), and the cosine is the ratio of the length of the adjacent leg to that of the hypotenuse. For an angle \theta, the sine and cosine functions are denoted simply as \sin \theta and \cos \theta. More generally, the definitions of sine and cosine can be extended to any real value in terms of the lengths of certain line segments in a unit circle. More modern definitions express the sine and cosine as infinite series, or as the solutions of certain differential equations, allowing their extension to arbitrary positive and negative values and even to complex numbers. The sine and cosine functions are commonly used to model periodic phenomena such as sound and lig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azimuth
An azimuth (; from ar, اَلسُّمُوت, as-sumūt, the directions) is an angular measurement in a spherical coordinate system. More specifically, it is the horizontal angle from a cardinal direction, most commonly north. Mathematically, the relative position vector from an observer (origin) to a point of interest is projected perpendicularly onto a reference plane (the horizontal plane); the angle between the projected vector and a reference vector on the reference plane is called the azimuth. When used as a celestial coordinate, the azimuth is the horizontal direction of a star or other astronomical object in the sky. The star is the point of interest, the reference plane is the local area (e.g. a circular area with a 5 km radius at sea level) around an observer on Earth's surface, and the reference vector points to true north. The azimuth is the angle between the north vector and the star's vector on the horizontal plane. Azimuth is usually measured in d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Table Of Trigonometry, Cyclopaedia, Volume 2
Table may refer to: * Table (furniture), a piece of furniture with a flat surface and one or more legs * Table (landform), a flat area of land * Table (information), a data arrangement with rows and columns * Table (database), how the table data arrangement is used within databases * Calligra Tables, a spreadsheet application * Mathematical table * Table (parliamentary procedure) * Tables (board game) * Table, surface of the sound board (music) of a string instrument * ''Al-Ma'ida'', the fifth ''surah'' of the Qur'an, usually translated as “The Table” * Water table See also * Spreadsheet, a computer application * Table cut, a type of diamond cut * The Table (other) * Table Mountain (other) * Table Rock (other) * Tabler (other) * Tablet (other) Tablet may refer to: Medicine * Tablet (pharmacy), a mixture of pharmacological substances pressed into a small cake or bar, colloquially called a "pill" Computing * Tablet computer, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chain (unit)
The chain is a unit of length equal to 66 feet (22 yards). It is subdivided into 100 links (PDF) or 4 rods. There are 10 chains in a furlong, and 80 chains in one statute mile. In metric terms, it is 20.1168 m long. By extension, chainage (running distance) is the distance along a curved or straight survey line from a fixed commencing point, as given by an odometer. The chain has been used for several centuries in England and in some other countries influenced by English practice. In the United Kingdom, there were 80 chains to the mile, but until the early nineteenth century the Scottish and Irish customary miles were longer than the statute mile; consequently a Scots chain was about 74 (imperial) feet, an Irish chain 84 feet. These longer chains became obsolete following the adoption of the imperial system of units in 1824. Definition The UK statute chain is 22 yards, which is . This unit is a statute measure in the United Kingdom, defined in the Weights and Measures Act 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cotangent
In mathematics, the trigonometric functions (also called circular functions, angle functions or goniometric functions) are real functions which relate an angle of a right-angled triangle to ratios of two side lengths. They are widely used in all sciences that are related to geometry, such as navigation, solid mechanics, celestial mechanics, geodesy, and many others. They are among the simplest periodic functions, and as such are also widely used for studying periodic phenomena through Fourier analysis. The trigonometric functions most widely used in modern mathematics are the sine, the cosine, and the tangent. Their reciprocals are respectively the cosecant, the secant, and the cotangent, which are less used. Each of these six trigonometric functions has a corresponding inverse function, and an analog among the hyperbolic functions. The oldest definitions of trigonometric functions, related to right-angle triangles, define them only for acute angles. To extend the sine and cosi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James I Of England
James VI and I (James Charles Stuart; 19 June 1566 – 27 March 1625) was King of Scotland as James VI from 24 July 1567 and King of England and King of Ireland, Ireland as James I from the Union of the Crowns, union of the Scottish and English crowns on 24 March 1603 until his death in 1625. The kingdoms of Kingdom of Scotland, Scotland and Kingdom of England, England were individual sovereign states, with their own parliaments, judiciaries, and laws, though both were ruled by James in personal union. James was the son of Mary, Queen of Scots, and a great-great-grandson of Henry VII of England, Henry VII, King of England and Lord of Ireland, and thus a potential successor to all three thrones. He succeeded to the Scottish throne at the age of thirteen months, after his mother was compelled to abdicate in his favour. Four different regents governed during his minority, which ended officially in 1578, though he did not gain full control of his government until 1583. In 1603, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Declination
Magnetic declination, or magnetic variation, is the angle on the horizontal plane between magnetic north (the direction the north end of a magnetized compass needle points, corresponding to the direction of the Earth's magnetic field lines) and true north (the direction along a meridian towards the geographic North Pole). This angle varies depending on position on the Earth's surface and changes over time. Somewhat more formally, Bowditch defines variation as “the angle between the magnetic and geographic meridians at any place, expressed in degrees and minutes east or west to indicate the direction of magnetic north from true north. The angle between magnetic and grid meridians is called grid magnetic angle, grid variation, or grivation.” By convention, declination is positive when magnetic north is east of true north, and negative when it is to the west. ''Isogonic lines'' are lines on the Earth's surface along which the declination has the same constant value, and line ... [...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. Its earliest recorded usage was in ancient India in Rigvedic times by Rishi Atri to observe a solar eclipse. It was then 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
