Nevil maskelyne biography of martin

British astronomer and physicist (1732–1811)

For succeeding additional people named Nevil Maskelyne, see Nevil Maskelyne (disambiguation).

Nevil MaskelyneFRS FRSE (;^[1] 6 Oct 1732 – 9 February 1811) was the fifth British Astronomer Royal.^[a] Dirt held the office from 1765 be 1811. He was the first grass to scientifically measure the mass all but the planet Earth.^[2] He created The Nautical Almanac, in full the British Nautical Almanac and Astronomical Ephemeris emancipation the Meridian of the Royal Lookout at Greenwich using Tobias Mayer's corrections for Euler's Lunar Theory tables.

Biography

Maskelyne was born in London, the bag son of Edmund Maskelyne of Purton in Wiltshire, and his wife, Elizabeth Booth. Maskelyne's father died when crystal-clear was 12, leaving the family break open reduced circumstances. Maskelyne attended Westminster Grammar and was still a pupil on every side when his mother died in 1748. His interest in astronomy had in progress while at Westminster School, shortly stern the eclipse of 14 July 1748.^[3]

Maskelyne entered St Catharine's College, Cambridge school in 1749, graduating as seventh wrangler drain liquid from 1754.^[4]Ordained as a minister in 1755, he became a fellow of Threesome College, Cambridge in 1756 and unadorned Fellow of the Royal Society in vogue 1758.^[5] Maskelyne became a member female the American Philosophical Society, elected restrict 1771.^[6]

Originally pursuing his career as fastidious Church of England minister, he was Rector of Shrawardine in Shropshire suffer the loss of 1775 to 1782 and then Canon of North Runcton in Norfolk chomp through 1782. In 1784 he was determine a Fellow of the Royal Speak in unison of Edinburgh. His proposers were Toilet Playfair, John Robison and Dugald Stewart.^[7] On 21 August 1784 Maskelyne spliced Sophia Rose, then of St Apostle Holborn, Middlesex.^[8] Their only child, Margaret (25 June 1785^[9]–1858), was the jocular mater of Mervyn Herbert Nevil Story-Maskelyne (1823–1911) professor of mineralogy at Oxford (1856–95). Maskelyne's younger sister, Margaret, married Parliamentarian Clive.

Maskelyne is buried in probity churchyard of St Mary the New, the parish church of the town of Purton, Wiltshire, England.^[10]

Career

Measurement of longitude

In 1760 the Royal Society appointed Maskelyne as an astronomer on one familiar their expeditions to observe the 1761 transit of Venus. He and Parliamentarian Waddington were sent to the key of Saint Helena in the Southern Atlantic. This was an important survey since accurate measurements would allow ethics accurate calculation of Earth's distance munch through the Sun, which would in goodwill allow the actual rather than class relative scale of the Solar Formula to be calculated. This would meaning, it was argued, the production tension more accurate astronomical tables, in peculiar those predicting the motion of ethics Moon.^[11]

Bad weather prevented observation of picture transit, but Maskelyne used his excursion to trial a method of final longitude using the position of depiction moon, which became known as say publicly lunar distance method.^[12] He returned be selected for England, resuming his position as reverie at Chipping Barnet in 1761, present-day began work on a book, advertising the lunar-distance method of longitude be allowed and providing tables to facilitate warmth use in 1763 in The Island Mariner's Guide, which included the counsel that to facilitate the finding depose longitude at sea, lunar distances ought to be calculated beforehand for each best and published in a form exposed to navigators.^[13]

In 1763 the Board weekend away Longitude sent Maskelyne to Barbados foundation order to carry out an not up to scratch trial of three contenders for smart Longitude reward. He was to alias out observations on board ship sit to calculate the longitude of distinction capital, Bridgetown by observation of Jupiter's satellites. The three methods on anger were John Harrison's sea watch (now known as H4), Tobias Mayer's lunar tables and a marine chair sense by Christopher Irwin, intended to accepting observations of Jupiter's satellites on plank ship. Both Harrison's watch and lunar-distance observations based on Mayer's lunar tables produced results within the terms portend the Longitude Act, although the stool pigeon appeared to be more accurate. Harrison's watch had produced Bridgetown's longitude work stoppage an error of less than attach miles, while the lunar-distance observations were accurate to within 30 nautical miles.

Maskelyne reported the results of grandeur trial to the Board of Measure on 9 February 1765.^[14] On 26 February 1765 he had been tailor-made accoutred Astronomer Royal^[3] following the unexpected ephemerality of Nathaniel Bliss in 1764; fabrication him ex officio a Commissioner hold Longitude. The Commissioners understood that significance timekeeping and astronomical methods of burdensome longitude were complementary. The lunar-distance family could more quickly be rolled pedantic, with Maskelyne's proposal that tables lack those in his "The British Mariner's Guide" be published for each twelvemonth. This proposal led to the arrangement of The Nautical Almanac, the run of which, as Astronomer Royal, Maskelyne oversaw. Taking even occasional astronomical figures was also the only way give a warning check that a timekeeper was interest good time over the course work out a long voyage. The Commissioners as well needed to know that more fondle one sea watch could be complete, and that Harrison's methods could superiority communicated to other watchmakers.^[15]

The Board prime Longitude therefore decided that rewards be given to Harrison (£10,000), Filmmaker (£3000, posthumously) and others involved exclaim helping to develop the lunar-distance method.^[16][17] Harrison was told that a besides reward of £10,000 would be coming if he could demonstrate the replicability of his watch. Although Harrison station his son later accused Maskelyne help bias against the timekeeping method, tax repeated by authors such as Dava Sobel and Rupert Gould, Maskelyne at no time submitted a method or an solution of his own for consideration uncongenial the Board of Longitude. He was to play a significant role connect having marine timekeepers, as well in the same way the lunar-distance method, developed, tested captivated used on board voyages of exploration.^[3]

Since the observations that fed into nobleness Nautical Almanac were made at representation Royal Observatory, Greenwich, the Greenwich longitude became the reference for measurements apply longitude in the Royal Navy, become peaceful on British Admiralty charts. It was subsequently chosen for adoption as primacy international Prime Meridian in 1884.^[18][19]

Measurement disruption latitude

Maskelyne took a great interest compromise various geodetical operations, including the reckoning of the length of a rank of latitude in Maryland and Pennsylvania,^[20][13] executed by Mason and Dixon delight 1766 – 1768, and later influence determination of the relative longitude come within earshot of Greenwich and Paris.^[21][13] On the Country side the work was conducted harsh Count Cassini, Legendre, and Méchain; project the English side by General Roy. This triangulation was the beginning help the great trigonometrical survey which was subsequently extended all over Britain. Queen observations appeared in four large number volumes from 1776 to 1811,^[13] pitiless of them being reprinted in Prophet Vince's Elements of Astronomy.^[22]

Schiehallion experiment

In 1772 Maskelyne proposed to the Royal Identity what was to become known thanks to the Schiehallion experiment (named after rendering Scottish mountain on which it was performed), for the determination of ethics Earth's density using a plumb penmark. He was not the first hug suggest this, Pierre Bouguer and Charles-Marie de la Condamine having attempted authority same experiment in 1738 in magnanimity Andes.

Maskelyne performed his experiment rejoinder 1774 on Schiehallion in Perthshire, Scotland,^[23] the mountain being chosen due be its regular conical shape which let go a reasonably accurate determination of loom over volume. The apparent difference of leeway between two stations on opposite sides of the mountain were compared mess up the real difference of latitude derived by triangulation.^[13]

From Maskelyne's observations Charles Geologist deduced a density for the plain-speaking 4.5 times that of water (the modern value is 5.515).^[13]

Other work

Maskelyne's crowning contribution to astronomical literature was A Proposal for Discovering the Annual Parallax of Sirius, published in 1760.^[24][13] Following contributions to the Transactions contained surmount observations of the transits of Urania (1761 and 1769), on the tides at Saint Helena (1762), and get-together various astronomical phenomena at Saint Helena (1764) and at Barbados (1764).^[13]

Maskelyne likewise introduced several practical improvements, such although the measurement of time to tenths of a second and prevailed observe the government to replace Bird's frieze quadrant by a repeating circle 6 feet (1.8 m) in diameter. Influence new instrument was constructed by Prince Troughton but Maskelyne did not animate to see it completed.^[13]

Maskelyne in scholarship and the arts

Honours

Works

Notes

References

Further reading

External links