Born: 1581 in Hertfordshire, England
Died: 10 Dec 1626 in London, England.
Edmund Gunter attended Westminster School, then entered Christ Church, Oxford in 1599. He graduated in 1603 but he remained at Oxford until 1615 when he received a divinity degree. Gunter was ordained and became Rector of St George's Church in Southwark in 1615. He held this Church position until his death.
In addition to being Rector of St George's Church, Gunter became professor of astronomy at Gresham College London in 1619, also holding this post until his death.
A colleague and friend of Briggs, Gunter published seven figure tables of logarithms of sines and tangents in 1620 in Canon Triangulorum, or Table of Artificial Sines and Tangents. The words cosine and cotangent are due to him.
He made a mechanical device, Gunter's Scale, to multiply numbers based on the logs using a single scale and a pair of dividers. It was called the gunter by seamen and was an important step in the development of the slide rule. Gunter published his description in 1624 in Description and Use of the Sector, the Crosse-staffe and other Instruments. It is worth noting that in this work Gunter uses the contractions sin for sine and tan for tangent in his drawing of his scale although not in the text of the book.
He also invented Gunter's chain which was 22 yards long with 100 links. It was used for surveying and the unit of area called an acre is ten square chains.
Gunter also did important work on navigation, publishing New Projection of the Sphere in 1623. He also studied magnetic declination and was the first to observe the secular variation.
By J. J. O'Connor and E. F. Robertson