Dictionary of National Biography, 1885-1900/Ridley, Mark
RIDLEY, MARK, M.D. (1560–1624), physician, second son of Lancelot Ridley [q. v.], was born in 1560 at Stretham, Cambridgeshire, of which place his father was rector. He graduated B.A. from Clare Hall, Cambridge, in 1580, and M.A. in 1584. He was admitted a licentiate of the College of Physicians of London on 25 Sept. 1590, and was elected a fellow on 28 May 1594. He went to Russia as physician to the English merchants resident there, was recommended to the czar by Lord Burghley, and appointed his chief physician. In 1598, on the death of the czar, Boris Gudonoff, he returned to England, with many compliments from the new czar, and settled in practice in London. He was elected censor of the College of Physicians in 1607, again from 1609 to 1613, and in 1615 and in 1618, and was treasurer in 1610 and 1620. He was fond of mathematics, and in 1613 published ‘A Short Treatise of Magneticall Bodies and Motions,’ a small quarto printed by Nicholas Okes, at the Hand, near Holborn Bridge. He claims acquaintance with William Gilbert [q. v.], whom he commends as the greatest discoverer in magnetical science. After twenty-four chapters on the properties and description of the magnet, he discusses the variation of the compass and methods of estimating it in eight chapters, the inclinatory needle in eight others, and concludes with a chapter on finding the longitude, and one ‘of the matter of the Magneticall globe of the earth by the needle.’ He writes in a clear, scientific style, and in his preface gives a succinct account of the history of the subject. In 1617 he published ‘Animadversions on a late Work entitled Magnetical Advertisement.’ He died early in 1624, leaving no issue. His portrait, at the age of thirty-four, is engraved in his short treatise after the table of contents, and represents him as a man of middle height with a square-cut beard and curling hair. His coat-of-arms is blazoned within the frame.
[Munk's Coll. of Phys. i. 106; Ridlon's Ancient Ryedales, p. 425 (with portrait).]