Pierre Charles Le Monnier
Encyclopedia
Pierre Charles Le Monnier (23 November 1715 – 31 May 1799) was a French
astronomer
. His name is sometimes given as Lemonnier.
(1675–1757), also an astronomer, was professor of philosophy
at the college d'Harcourt.
His first recorded astronomical observation was made before he was sixteen, and the presentation of an elaborate lunar map resulted in his admission to the French Academy of Sciences
, on 21 April 1736, aged only 20. He was chosen in the same year to accompany Pierre Louis Maupertuis
and Alexis Clairaut on their geodetical expedition for measuring a meridian arc
of approximately one degree
's length to Torne Valley
in Lapland. In 1738, shortly after his return, he explained, in a memoir read before the Academy, the advantages of John Flamsteed
's mode of determining right ascension
s.
His persistent recommendation of British methods and instruments contributed effectively to the reform of French practical astronomy, and constituted the most eminent of his services to science. He corresponded with James Bradley
, was the first to represent the effects of nutation
in the solar tables, and introduced, in 1741, the use of the transit-instrument at the Paris Observatory
. He visited England in 1748, and, in company with the Earl of Morton
and James Shore the optician, continued his journey to Scotland
, where he observed the annular eclipse of 25 July.
The liberality of King Louis XV of France
, in whose favour Le Monnier stood high, furnished him with the means of procuring the best instruments, many made in Britain. Amongst the fruits of his industry may be mentioned a laborious investigation of the disturbances of Jupiter
by Saturn
, the results of which were employed and confirmed by Euler
in his prize essay of 1748; a series of lunar observations extending over fifty years; some interesting researches in terrestrial magnetism and atmospheric electricity, in the latter of which he detected a regular diurnal period; and the determination of the places of a great number of stars, including at least twelve separate observations of Uranus
, between 1750 and its discovery as a planet. In his lectures at the Collège de France
he first publicly expounded the analytical theory of gravitation
, and his timely patronage secured the services of J. J. Lalande for astronomy.
Le Monnier's temper and hasty speech resulted in many arguments and grudges. He fell out with Lalande "during an entire revolution of the moon's nodes". His career was ended by paralysis
late in 1791, and a repetition of the stroke
terminated his life. He died at Héril near Bayeux
. By his marriage with Mademoiselle de Cussy he left three daughters, one of whom became the wife of J. L. Lagrange
.
Le Monnier was admitted on April 5, 1739 to the Royal Society
, and was one of the 144 original members of the Institute
. On January 29, 1745, he also became a member of the Prussian Academy of Sciences
.
The crater Le Monnier
on the Moon
is named after him.
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
astronomer
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
. His name is sometimes given as Lemonnier.
Biography
Le Monnier was born in Paris, where his father PierrePierre Lemonnier
Pierre Lemonnier was a French astronomer, a Professor of Physics and Philosophy at the Collège d'Harcourt , and a member of the French Academy of Sciences....
(1675–1757), also an astronomer, was professor of philosophy
Philosophy
Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...
at the college d'Harcourt.
His first recorded astronomical observation was made before he was sixteen, and the presentation of an elaborate lunar map resulted in his admission to the French Academy of Sciences
French Academy of Sciences
The French Academy of Sciences is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French scientific research...
, on 21 April 1736, aged only 20. He was chosen in the same year to accompany Pierre Louis Maupertuis
Pierre Louis Maupertuis
Pierre-Louis Moreau de Maupertuis was a French mathematician, philosopher and man of letters. He became the Director of the Académie des Sciences, and the first President of the Berlin Academy of Science, at the invitation of Frederick the Great....
and Alexis Clairaut on their geodetical expedition for measuring a meridian arc
Meridian arc
In geodesy, a meridian arc measurement is a highly accurate determination of the distance between two points with the same longitude. Two or more such determinations at different locations then specify the shape of the reference ellipsoid which best approximates the shape of the geoid. This...
of approximately one degree
Degree (angle)
A degree , usually denoted by ° , is a measurement of plane angle, representing 1⁄360 of a full rotation; one degree is equivalent to π/180 radians...
's length to Torne Valley
Torne Valley
The Torne Valley or Torne River Valley lies at the border of Sweden and Finland. In 2009 it became one of the Sub-regions of Finland. It is named after the Torne River flowing through the valley and into the Gulf of Bothnia...
in Lapland. In 1738, shortly after his return, he explained, in a memoir read before the Academy, the advantages of John Flamsteed
John Flamsteed
Sir John Flamsteed FRS was an English astronomer and the first Astronomer Royal. He catalogued over 3000 stars.- Life :Flamsteed was born in Denby, Derbyshire, England, the only son of Stephen Flamsteed...
's mode of determining right ascension
Right ascension
Right ascension is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. The other coordinate is the declination.-Explanation:...
s.
His persistent recommendation of British methods and instruments contributed effectively to the reform of French practical astronomy, and constituted the most eminent of his services to science. He corresponded with James Bradley
James Bradley
James Bradley FRS was an English astronomer and served as Astronomer Royal from 1742, succeeding Edmund Halley. He is best known for two fundamental discoveries in astronomy, the aberration of light , and the nutation of the Earth's axis...
, was the first to represent the effects of nutation
Nutation
Nutation is a rocking, swaying, or nodding motion in the axis of rotation of a largely axially symmetric object, such as a gyroscope, planet, or bullet in flight, or as an intended behavior of a mechanism...
in the solar tables, and introduced, in 1741, the use of the transit-instrument at the Paris Observatory
Paris Observatory
The Paris Observatory is the foremost astronomical observatory of France, and one of the largest astronomical centres in the world...
. He visited England in 1748, and, in company with the Earl of Morton
James Douglas, 14th Earl of Morton
James Douglas, 14th Earl of Morton KT FRS was a Scottish astronomer and representative peer who was President of the Philosophical Society of Edinburgh from its foundation in 1737 until his death...
and James Shore the optician, continued his journey to Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
, where he observed the annular eclipse of 25 July.
The liberality of King Louis XV of France
Louis XV of France
Louis XV was a Bourbon monarch who ruled as King of France and of Navarre from 1 September 1715 until his death. He succeeded his great-grandfather at the age of five, his first cousin Philippe II, Duke of Orléans, served as Regent of the kingdom until Louis's majority in 1723...
, in whose favour Le Monnier stood high, furnished him with the means of procuring the best instruments, many made in Britain. Amongst the fruits of his industry may be mentioned a laborious investigation of the disturbances of Jupiter
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...
by Saturn
Saturn
Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Saturn is named after the Roman god Saturn, equated to the Greek Cronus , the Babylonian Ninurta and the Hindu Shani. Saturn's astronomical symbol represents the Roman god's sickle.Saturn,...
, the results of which were employed and confirmed by Euler
Leonhard Euler
Leonhard Euler was a pioneering Swiss mathematician and physicist. He made important discoveries in fields as diverse as infinitesimal calculus and graph theory. He also introduced much of the modern mathematical terminology and notation, particularly for mathematical analysis, such as the notion...
in his prize essay of 1748; a series of lunar observations extending over fifty years; some interesting researches in terrestrial magnetism and atmospheric electricity, in the latter of which he detected a regular diurnal period; and the determination of the places of a great number of stars, including at least twelve separate observations of Uranus
Uranus
Uranus is the seventh planet from the Sun. It has the third-largest planetary radius and fourth-largest planetary mass in the Solar System. It is named after the ancient Greek deity of the sky Uranus , the father of Cronus and grandfather of Zeus...
, between 1750 and its discovery as a planet. In his lectures at the Collège de France
Collège de France
The Collège de France is a higher education and research establishment located in Paris, France, in the 5th arrondissement, or Latin Quarter, across the street from the historical campus of La Sorbonne at the intersection of Rue Saint-Jacques and Rue des Écoles...
he first publicly expounded the analytical theory of gravitation
Gravitation
Gravitation, or gravity, is a natural phenomenon by which physical bodies attract with a force proportional to their mass. Gravitation is most familiar as the agent that gives weight to objects with mass and causes them to fall to the ground when dropped...
, and his timely patronage secured the services of J. J. Lalande for astronomy.
Le Monnier's temper and hasty speech resulted in many arguments and grudges. He fell out with Lalande "during an entire revolution of the moon's nodes". His career was ended by paralysis
Paralysis
Paralysis is loss of muscle function for one or more muscles. Paralysis can be accompanied by a loss of feeling in the affected area if there is sensory damage as well as motor. A study conducted by the Christopher & Dana Reeve Foundation, suggests that about 1 in 50 people have been diagnosed...
late in 1791, and a repetition of the stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...
terminated his life. He died at Héril near Bayeux
Bayeux
Bayeux is a commune in the Calvados department in Normandy in northwestern France.Bayeux is the home of the Bayeux Tapestry, which depicts the events leading up to the Norman conquest of England.-Administration:Bayeux is a sub-prefecture of Calvados...
. By his marriage with Mademoiselle de Cussy he left three daughters, one of whom became the wife of J. L. Lagrange
Joseph Louis Lagrange
Joseph-Louis Lagrange , born Giuseppe Lodovico Lagrangia, was a mathematician and astronomer, who was born in Turin, Piedmont, lived part of his life in Prussia and part in France, making significant contributions to all fields of analysis, to number theory, and to classical and celestial mechanics...
.
Le Monnier was admitted on April 5, 1739 to the Royal Society
Royal Society
The Royal Society of London for Improving Natural Knowledge, known simply as the Royal Society, is a learned society for science, and is possibly the oldest such society in existence. Founded in November 1660, it was granted a Royal Charter by King Charles II as the "Royal Society of London"...
, and was one of the 144 original members of the Institute
Institute
An institute is a permanent organizational body created for a certain purpose. Often it is a research organization created to do research on specific topics...
. On January 29, 1745, he also became a member of the Prussian Academy of Sciences
Prussian Academy of Sciences
The Prussian Academy of Sciences was an academy established in Berlin on 11 July 1700, four years after the Akademie der Künste or "Arts Academy", to which "Berlin Academy" may also refer.-Origins:...
.
The crater Le Monnier
Le Monnier (crater)
Le Monnier is the remnant of a lunar crater that has been partly inundated by lava flows. It is located on the eastern edge of Mare Serenitatis, and the western part of the rim is missing so that it now forms a large bay. To the north is the crater Chacornac....
on the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
is named after him.
Works
- Histoire céleste (1741)
- Théorie des comètes (1743, a translation, with additions of Halley's Synopsis)
- Institutions astronomiques (1746, an improved translation of John KeillJohn KeillJohn Keill was born in Edinburgh, Scotland, and was primarilya mathematician and important disciple of Isaac Newton. He studied at Edinburgh University, under David Gregory, and obtained his bachelors degree in 1692 with a distinction in physics and mathematics...
's text-book) - Nouveau zodiaque (1755)
- Observations de la lune, du soleil, et des étoiles fixes (1751–1775)
- Lois du magnétisme (1776–1778)