Edmund Gunter

Edmund Gunter was an English clergyman, mathematician, geometer and astronomer of Welsh descent, born in Hertfordshire in 1581 and died on 10 December 1626. He was educated at Westminster School and Christ Church, Oxford, took orders and became rector of St George's Church in Southwark. Mentored in mathematics by Henry Briggs, he became Gresham Professor of Astronomy in London in 1619 and held the post until his death. His inventions include Gunter's chain for land surveying, Gunter's quadrant and Gunter's scale, and in 1620 he built the first successful analogue device for calculating logarithmic tangents. His logarithmic scales are the basis of the slide rule, and he is credited with coining the terms cosine and cotangent.