John Michell (1724 – April 29, 1793) was an English natural philosopher and geologist, whose work was rediscovered in the 1970s. It appeared that John Michell was the first to consider a heavenly object massive enough to prevent light from escaping it (the concept of escape velocity was well known at the time). Such an object would thus be invisible, nowadays called a black hole. Michell therefore contemplated the idea of a black hole before the mathematician Pierre-Simon Laplace promoted the same idea in his book Exposition du Systeme du Monde in 1796. Events January 14 - King Philip V of Spain abdicates the throne February 20 - The premiere of Giulio Cesare, an Italian opera by George Frideric Handel, takes place in London June 23 - Treaty of Constantinople signed. ... April 29 is the 119th day of the year in the Gregorian calendar (120th in leap years). ... 1793 was a common year starting on Tuesday (see link for calendar). ... Royal motto: Dieu et mon droit (French: God and my right) Englands location within the UK Official language English de facto Capital London de facto Largest city London Area  - Total Ranked 1st UK 130,395 km² Population  - Total (2001)  - Density Ranked 1st UK 49,138,831 377/km² Ethnicity... A geologist is a contributor to the science of geology. ... This article provides extensive lists of events and significant personalities of the 1970s. ... In physics, for a given gravitational field and a given position, the escape velocity is the minimum speed an object without propulsion, at that position, needs to have to move away indefinitely from the source of the field, as opposed to falling back or staying in an orbit within a... A black hole is a concentration of mass great enough that the force of gravity prevents anything from escaping from it except through quantum tunneling behavior. ... Pierre-Simon Laplace Pierre-Simon, Marquis de Laplace (March 23, 1749 – March 5, 1827) was a French mathematician and astronomer who put the final capstone on mathematical astronomy by summarizing and extending the work of his predecessors in his five volume Mécanique Céleste (Celestial Mechanics) (1799-1825). ... 1796 was a leap year starting on Friday. ...

Michell was educated at Queens College, Cambridge. He earned his M.A. in 1752, and B.D. in 1761. He was a fellow of his college, and was appointed Woodwardian Professor of Geology in 1762, and in 1767 rector of Thornhill in Yorkshire, where he died. He was elected a fellow of the Royal Society in the same year as Henry Cavendish (1760). In 1750 he published at Cambridge a work of some eighty pages entitled A Treatise of Artificial Magnets, in which is shown an easy and expeditious method of making them superior to the best natural ones. Besides the description of the method of magnetization which still bears his name, this work contains a variety of accurate magnetic observations, and is distinguished by a lucid exposition of the nature of magnetic induction. He was the original inventor of the torsion balance, which afterwards became so famous in the hands of its second inventor Charles-Augustin de Coulomb. Michell described it in his proposal of a method for obtaining the mean density of the earth. He did not live to put his method into practice; but this was done by Henry Cavendish, who made, by means of Michell's apparatus, the celebrated determination that now goes by the name of Cavendish's experiment. His most important geological essay was that entitled "Conjectures concerning the Cause and Observations upon the Phaenomena of Earthquakes" (Philosophical Transactions, li. 1760), which showed a remarkable knowledge of the strata in various parts of England and abroad. Full name The Queens College of St Margaret and St Bernard Motto Floreat Domus May this House Flourish Named after - Previous names - Established 1448 Sister College Pembroke College President Lord Eatwell Location Silver Street Undergraduates 490 Graduates 270 Homepage Boatclub Queens College was first founded in 1448 by Margaret... 1752 was a leap year starting on Saturday (see link for calendar). ... 1761 was a common year starting on Thursday (see link for calendar). ... The Woodwardian Professor of Geology is a professorship at the University of Cambridge. ... 1762 was a common year starting on Friday (see link for calendar). ... 1767 was a common year starting on Thursday (see link for calendar). ... Yorkshire as a traditional county. ... The Royal Society of London for the Improvement of Natural Knowledge, known simply as the Royal Society, is claimed to be the oldest learned society still in existence. ... Henry Cavendish (October 10, 1731 - February 24, 1810) was a British scientist. ... 1760 was a leap year starting on Tuesday (see link for calendar). ... Events March 2 - Small earthquake in London April 4 - Small earthquake in Warrington, England August 23 - Small earthquake in Spalding, England September 30 - Small earthquake in Northampton, England November 16 – Westminster Bridge officially opened Jonas Hanway is the first Englishman to use an umbrella James Gray reveals her sex to... Portrait of Coulomb Charles Augustin Coulomb (June 14, 1736 – August 23, 1806) was a French physicist. ... The Philosophical Transactions of the Royal Society is the oldest scientific journal printed in the English-speaking world, and was only three months shy of being the oldest in the world. ... 1760 was a leap year starting on Tuesday (see link for calendar). ...

Some of his other contributions include:

• Observations On the Comet of January 1760 at Cambridge, Philosophical Transactions (1760)
• A Recommendation of Hadley's Quadrant for Surveying, ibid. (1765)
• Proposal of a Method for measuring Degrees of Longitude upon Parallels of the Equator, ibid. (1766)
• An Inquiry into the Probable Parallax and Magnitude of the Fixed Stars, ibid. (1767)
• On the Twinkling of the Fixed Stars, ibid. (1767)
• On the Means of Discovering the Distance, Magnitude, &c., of the Fixed Stars, ibid. (1784).

The Philosophical Transactions of the Royal Society is the oldest scientific journal printed in the English-speaking world, and was only three months shy of being the oldest in the world. ... 1760 was a leap year starting on Tuesday (see link for calendar). ... 1765 was a common year starting on Tuesday (see link for calendar). ... 1766 was a common year starting on Wednesday (see link for calendar). ... 1767 was a common year starting on Thursday (see link for calendar). ... 1767 was a common year starting on Thursday (see link for calendar). ... 1784 was a leap year starting on Thursday (see link for calendar). ...

External links

• Black Holes - Part 1 - History (description of Michell's theory of black holes)

This article incorporates text from the 1911 Encyclopædia Britannica, which is in the public domain. Supporters contend that the Eleventh Edition of the Encyclopædia Britannica (1911) represents, in many ways, the sum of knowledge at the beginning of the 20th century. ... 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. ...