Edmund Gunter (1581 - December 10, 1626), English mathematician, of Welsh extraction, was born in Hertfordshire in 1581. Events January 16 - English Parliament outlaws Roman Catholicism April 4 - Francis Drake completes a circumnavigation of the world and is knighted by Elizabeth I. July 26 - The Northern Netherlands proclaim their independence from Spain in the Oath of Abjuration. ... December 10 is the 344th day (345th in leap years) of the year in the Gregorian calendar. ... Events September 30 - Nurhaci, chieftain of the Jurchens and founder of the Qing Dynasty dies and is succeeded by his son Hong Taiji. ... Motto: (French for God and my right) Anthem: Multiple unofficial anthems Capital London Largest city London Official language(s) English (de facto) Government Constitutional monarchy  - Queen Queen Elizabeth II  - Prime Minister Tony Blair MP Unification    - by Athelstan AD 927  Area    - Total 130,395 km² (1st in UK)   50,346 sq... To meet Wikipedias quality standards, this article or section may require cleanup. ... Motto: (Welsh for Wales for ever) Anthem: Hen Wlad Fy Nhadau Capital Cardiff Largest city Cardiff Official language(s) English, Welsh Government Constitutional monarchy  - Queen Queen Elizabeth II  - Prime Minister Tony Blair MP  - First Minister Rhodri Morgan AM Unification    - by Gruffudd ap Llywelyn 1056  Area    - Total 20,779 km² (3rd...

He was educated at Westminster School, and in 1599 was elected a student of Christ Church, Oxford. He took orders, became a preacher in 1614, and in 1615 proceeded to the degree of bachelor in divinity. Mathematics, however, which had been his favorite study in youth, continued to engross his attention, and on the 6th of March 1619 he was appointed professor of astronomy in Gresham College, London. This post he held till his death. The Royal College of St. ... College name Christ Church Named after Jesus Christ Established 1546 Sister College Trinity College Dean The Very Revd Christopher Andrew Lewis JCR President William Dorsey Undergraduates 426 MCR or GCR President {{{MCR President}}} Graduates 154 Home page Boat Club Christ Church (Latin: Ædes Christi, the temple or house of Christ... A giant Hubble mosaic of the Crab Nebula. ... Gresham College is an unusual institution of higher learning in London which enrolls no students and grants no degrees. ...

With Gunter's name are associated several useful inventions, descriptions of which are given in his treatises on the Sector, Cross-staff, Bow, Quadrant and other Instruments. He contrived his sector about the year 1606, and wrote a description of it in Latin, but it was more than sixteen years afterwards before he allowed the book to appear in English. In 1620 he published his Canon triangulorum.

There is reason to believe that Gunter was the first to discover (in 1622 or 1625) that the magnetic needle does not retain the same declination in the same place at all times. By desire of James I he published in 1624 The Description and Use of His Majesties Dials in Whitehall Garden, the only one of his works which has not been reprinted. He introduced the words cosine and cotangent, and he suggested to Henry Briggs, his friend and colleague, the use of the arithmetical complement (see Briggs Arithmetica Logarithmica, cap. xv.). His practical inventions are briefly noticed below: In astronomy, declination (dec) is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. ... James VI of Scotland/James I of England and Ireland (Charles James Stuart) (June 19, 1566 – March 27, 1625) was King of England, King of Scots, and King of Ireland and was the first to style himself King of Great Britain. ... Henry Briggs (February 1556 - January 26, 1630) was an English mathematician notable for changing Napiers logarithms into common/Briggesian logarithms He was born at Warley Wood, near Halifax, in Yorkshire Enland. ...

Gunter's chain

The chain that was in common use for surveying, was 22 yards long and is divided into 100 links, each 7.92 inches in length. An acre was defined by 10 chains (or one furlong) by one chain; 100 links by 1000 links - 100,000 square links; 220 yards by 22 yards - 4840 square yards.. As a unit of measurement within the Imperial system, the chain (surveyors chain, Gunters chain) is defined as 22 yards, 66 feet, or four rods. ...

Gunter's line

Table of Trigonometry, from the 1728 Cyclopaedia, Volume 2 featuring a Gunter's scale

A logarithmic line, usually laid down upon scales, sectors, etc. It is also called the line of lines and the line of numbers, being only the logarithms graduated upon a ruler, which therefore serves to solve problems instrumentally in the same manner as logarithms do arithmetically. Image File history File linksMetadata Download high resolution version (850x2607, 683 KB) This article incorporates content from the 1728 Cyclopaedia, a publication in the public domain. ... Image File history File linksMetadata Download high resolution version (850x2607, 683 KB) This article incorporates content from the 1728 Cyclopaedia, a publication in the public domain. ... Events Astronomical aberration discovered by the astronomer James Bradley Swedish academy of sciences founded at Uppsala The founding of the University of Havana (Universidad de la Habana), Cubas most well-established university. ... 1913 advertisement for Encyclopædia Britannica. ... Logarithms to various bases: is to base e, is to base 10, and is to base 1. ...

Gunter's quadrant

An instrument made of wood, brass or other substance, containing a kind of stereographic projection of the sphere on the plane of the equinoctial, the eye being supposed to be placed in one of the poles, so that the tropic, ecliptic, and horizon form the arcs of circles, but the hour circles are other curves, drawn by means of several altitudes of the sun for some particular latitude every year. This instrument is used to find the hour of the day, the sun's azimuth, etc., and other common problems of the sphere or globe, and also to take the altitude of an object in degrees. Azimuth is the horizontal component of a direction (compass direction), measured around the horizon toward the East, i. ...

Gunter's scale

Generally called by seamen, the "Gunter," this is a large plane scale, usually 2 feet long by about 1 1/2 inches broad (600 mm by 40 mm), and engraved with various lines of numbers. On one side are placed the natural lines (as the line of chords, the line of sines, tangents, rhumbs, etc), and on the other side the corresponding artificial or logarithmic ones. By means of this instrument questions in navigation, trigonometry, etc., are solved with the aid of a pair of compasses. In mathematics, the trigonometric functions are functions of an angle, important when studying triangles and modeling periodic phenomena. ... In mathematics, the word tangent has two distinct, but etymologically-related meanings: one in geometry, and one in trigonometry. ... Table of geography, hydrography, and navigation, from the 1728 Cyclopaedia. ... Wikibooks has a book on the topic of Trigonometry Trigonometry (from the Greek trigonon = three angles and metro = measure [1]) is a branch of mathematics dealing with the purely arithmetic relations between specific geometric characteristics of right angled triangles. ...

See also

• Gresham Professor of Astronomy

The Professor of Astronomy at Gresham College is appointed by the City of London Corporation. ...

External links

• O'Connor, John J., and Edmund F. Robertson. "Edmund Gunter". MacTutor History of Mathematics archive.

This article incorporates text from the Encyclopædia Britannica Eleventh Edition, a publication now in the public domain. Encyclopædia Britannica, the 11th edition The Encyclopædia Britannica Eleventh Edition (1910–1911) is perhaps the most famous edition of the Encyclopædia Britannica. ... The public domain comprises the body of all creative works and other knowledge—writing, artwork, music, science, inventions, and others—in which no person or organization has any proprietary interest. ...