- Michell , John
- (1724–1793) English geologist and astronomerMichell studied at Cambridge University and became a fellow. In 1762 he was appointed Woodward Professor of Geology but left academic life to take up a post as rector at Thornhill, Yorkshire, in 1764.Before his departure from Cambridge he published, in 1760, a fundamental paper, Conjectures Concerning the Cause, and Observations upon the Phenomena of Earthquakes. After the great Lisbon earthquake (1755) this was a fashionable subject. Michell assigned the cause of earthquakes to the force generated by high-pressure steam, produced when water suddenly met subterranean fires. He appreciated that such a force would generate waves in the Earth's crust and tried to estimate the velocity of these, giving a not unreasonable figure of 1200 miles per hour. Finally, Michell showed various means to determine the point of origin of the earthquake.In 1790 he constructed a torsion balance to measure gravitational attraction and thus the mean density of the Earth. Michell was unable to use this before his death, but Henry Cavendish carried on his work, deriving a value for the density of the Earth in 1798.Michell also made contributions to astronomy. In 1767 he published a paper on double stars, pointing out with originality and insight that there are far too many of them to result from a random scattering and therefore they must in many cases constitute a genuine binary system. He also devised a method for calculating the distance of the stars.
Scientists. Academic. 2011.
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Michell, John — ▪ British geologist and astronomer born 1724, Nottinghamshire, England died April 21, 1793, Thornhill, Yorkshire British geologist and astronomer who is considered one of the fathers of seismology, the science of earthquakes (earthquake).… … Universalium
MICHELL, John Henry (1863-1940) — mathematician son of John and Grace Michell, was born at Maldon, Victoria, on 26 October 1863. Educated at first at Maldon, he went to Wesley College, Melbourne, in 1877, where he won the Draper and Walter Powell scholarships. In 1881 he began… … Dictionary of Australian Biography
Michell — John … Scientists
John Henry Michell — (26 October 1863 – 3 February 1940) was an Australian mathematician, Professor of Mathematics at the University of Melbourne.Early lifeMichell was the son of John Michell (pronounced Mitchell), a miner, and his wife Grace, née Rowse and was born… … Wikipedia
John Michell (writer) — For other people named John Michell, see John Michell (disambiguation). John Michell In repose … Wikipedia
John Michell — Pour les articles homonymes, voir Michell. John Michell (ou Mitchell, 1724 – 29 avril 1793) est un physicien, astronome et géologue britannique. Certains de ses travaux n ont été redécouverts par les astronomes que dans les années 1970 … Wikipédia en Français
John Michell — (December 25, 1724 – April 29, 1793) was an English natural philosopher and geologist, whose work spanned a wide range of subjects, from astronomy to geology, optics, and gravitation. He was both a theorist and an experimenter.Michell was… … Wikipedia
Michell — may refer to: Person Anthony Michell (21 June 1870 17 February 1959), an Australian mechanical engineer Bradley Michell (born 14 January 1991), an Australian professional footballer Charles Collier Michell (29 March 1793 –28 March 1851), a… … Wikipedia
John Michell (disambiguation) — John Michell (1724–1793) was an English scientist.John Michell may also refer to:*John Henry Michell (1863–1940), Australian mathematician *John Michell (writer) (b. 1933), English contemporary writer on esotericismee also*John Michels (born… … Wikipedia
John Michell — (25 de diciembre de 1724 29 de abril de 1793) fue un filósofo inglés naturales y geólogo, cuya labor abarcó una amplia gama de temas, desde la astronomía a la geología, la óptica y la gravitación. Era a la vez un teórico y un experimentador.… … Wikipedia Español