George Hadley
Encyclopedia
George Hadley was an English
lawyer
and amateur meteorologist who proposed the atmospheric mechanism by which the Trade Wind
s are sustained. As a key factor in ensuring that European sailing vessels reached North American shores, understanding the Trade Winds was becoming a matter of great importance at the time. Hadley was intrigued by the fact that winds which should by all rights have blown straight north had a pronounced westerly flow, and it was this mystery he set out to solve.
, England to Katherine FitzJames and George Hadley. He had an unremarkable childhood, and was eclipsed in his early years by his older brother John Hadley
(1682–1744), the inventor of the octant
(a precursor to the sextant
). With John and his brother, Henry, George had constructed effective Newtonian telescope
s.
George Hadley entered Pembroke College, Oxford
, on 30 May 1700, and on 13 August 1701 became a member of Lincoln's Inn
, where his father purchased chambers
for him. He was called to the bar
on 1 July 1709. He remained more interested in mechanical and physical studies than in legal work.
In 1686, Edmond Halley
proposed his theory attempting to explain the Trade Winds. Halley's theory remained the most widely known internationally almost to the beginning of the 19th century.
Hadley was elected a fellow of the Royal Society
on 20 February 1735, and on 22 May that year published a short paper in Philosophical Transactions (vol. 39, 1735, 58–62) giving his own explanation of the Trade Winds. His theory, remained unknown, but it was independently created several times. Among the later creators was John Dalton
, who later eventually became aware of Hadley's priority. During the second half of the 19th century the theory gradually became known as "Hadley's principle".
In retrospect the crucial step forward was the recognition that the Earth's rotation plays a role in the direction taken by air mass that moves relative to the Earth. That element had been missing in Halley's proposal.
Later, in the second half of the 19th century, Hadley's theory was shown to be deficient in several respects. Hadley's theory is based on an assumption that when air mass travels from one latitude to another its linear momentum
is conserved. However, since the air mass is at all times in a state of circumnavigating the Earth axis, it is in fact the angular momentum that is conserved. When using the correct angular momentum conservation in calculations the predicted effect is twice as large as when the erroneous conservation of linear momentum is used. The fact that Hadley's principle is a deficient theory is not known to all people who should know; it can still be found in popular books and popular websites.
Hadley succeeded William Derham
in the post of interpreter of the meteorological diaries sent to the Royal Society from observers around the world, mainly in Britain and Scandinavia. He tried to correlate the data in the different temperature and pressure scales then in use.
He attempted to deduce general patterns that emerged over time and twice he published an account of the results in Philosophical Transactions.
Hadley never married. In later life he left London and lived for a while at East Barnet
with a nephew, most likely his brother John Hadley's son John. Most of his later years were spent at Flitton, Bedfordshire
, where another nephew, Hadley Cox (d. 1782), son of his sister Elizabeth, was vicar.
Hadley died at Flitton on 28 June 1768 aged 83 years, and was buried in the chancel of Flitton church.
, within the UK Met Office
, was named in his honour and subsequently re-named due to the unfortunate acronym. A crater
on Mars
was also named after him.
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
lawyer
Lawyer
A lawyer, according to Black's Law Dictionary, is "a person learned in the law; as an attorney, counsel or solicitor; a person who is practicing law." Law is the system of rules of conduct established by the sovereign government of a society to correct wrongs, maintain the stability of political...
and amateur meteorologist who proposed the atmospheric mechanism by which the Trade Wind
Trade wind
The trade winds are the prevailing pattern of easterly surface winds found in the tropics, within the lower portion of the Earth's atmosphere, in the lower section of the troposphere near the Earth's equator...
s are sustained. As a key factor in ensuring that European sailing vessels reached North American shores, understanding the Trade Winds was becoming a matter of great importance at the time. Hadley was intrigued by the fact that winds which should by all rights have blown straight north had a pronounced westerly flow, and it was this mystery he set out to solve.
Life
Hadley was born in LondonLondon
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
, England to Katherine FitzJames and George Hadley. He had an unremarkable childhood, and was eclipsed in his early years by his older brother John Hadley
John Hadley
John Hadley was an English mathematician, inventor of the octant, a precursor to the sextant, around 1730.He was born in Bloomsbury, London, to Katherine FitzJames and George Hadley....
(1682–1744), the inventor of the octant
Octant (instrument)
The octant, also called reflecting quadrant, is a measuring instrument used primarily in navigation. It is a type of reflecting instrument.-Etymology:...
(a precursor to the sextant
Sextant
A sextant is an instrument used to measure the angle between any two visible objects. Its primary use is to determine the angle between a celestial object and the horizon which is known as the altitude. Making this measurement is known as sighting the object, shooting the object, or taking a sight...
). With John and his brother, Henry, George had constructed effective Newtonian telescope
Newtonian telescope
The Newtonian telescope is a type of reflecting telescope invented by the British scientist Sir Isaac Newton , using a concave primary mirror and a flat diagonal secondary mirror. Newton’s first reflecting telescope was completed in 1668 and is the earliest known functional reflecting telescope...
s.
George Hadley entered Pembroke College, Oxford
Pembroke College, Oxford
Pembroke College is one of the constituent colleges of the University of Oxford in England, located in Pembroke Square. As of 2009, Pembroke had an estimated financial endowment of £44.9 million.-History:...
, on 30 May 1700, and on 13 August 1701 became a member of Lincoln's Inn
Lincoln's Inn
The Honourable Society of Lincoln's Inn is one of four Inns of Court in London to which barristers of England and Wales belong and where they are called to the Bar. The other three are Middle Temple, Inner Temple and Gray's Inn. Although Lincoln's Inn is able to trace its official records beyond...
, where his father purchased chambers
Chambers (law)
A judge's chambers, often just called his or her chambers, is the office of a judge.Chambers may also refer to the type of courtroom where motions related to matter of procedure are heard.- United Kingdom and Commonwealth :...
for him. He was called to the bar
Bar association
A bar association is a professional body of lawyers. Some bar associations are responsible for the regulation of the legal profession in their jurisdiction; others are professional organizations dedicated to serving their members; in many cases, they are both...
on 1 July 1709. He remained more interested in mechanical and physical studies than in legal work.
In 1686, Edmond Halley
Edmond Halley
Edmond Halley FRS was an English astronomer, geophysicist, mathematician, meteorologist, and physicist who is best known for computing the orbit of the eponymous Halley's Comet. He was the second Astronomer Royal in Britain, following in the footsteps of John Flamsteed.-Biography and career:Halley...
proposed his theory attempting to explain the Trade Winds. Halley's theory remained the most widely known internationally almost to the beginning of the 19th century.
Hadley was elected a fellow of 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"...
on 20 February 1735, and on 22 May that year published a short paper in Philosophical Transactions (vol. 39, 1735, 58–62) giving his own explanation of the Trade Winds. His theory, remained unknown, but it was independently created several times. Among the later creators was John Dalton
John Dalton
John Dalton FRS was an English chemist, meteorologist and physicist. He is best known for his pioneering work in the development of modern atomic theory, and his research into colour blindness .-Early life:John Dalton was born into a Quaker family at Eaglesfield, near Cockermouth, Cumberland,...
, who later eventually became aware of Hadley's priority. During the second half of the 19th century the theory gradually became known as "Hadley's principle".
In retrospect the crucial step forward was the recognition that the Earth's rotation plays a role in the direction taken by air mass that moves relative to the Earth. That element had been missing in Halley's proposal.
Later, in the second half of the 19th century, Hadley's theory was shown to be deficient in several respects. Hadley's theory is based on an assumption that when air mass travels from one latitude to another its linear momentum
Momentum
In classical mechanics, linear momentum or translational momentum is the product of the mass and velocity of an object...
is conserved. However, since the air mass is at all times in a state of circumnavigating the Earth axis, it is in fact the angular momentum that is conserved. When using the correct angular momentum conservation in calculations the predicted effect is twice as large as when the erroneous conservation of linear momentum is used. The fact that Hadley's principle is a deficient theory is not known to all people who should know; it can still be found in popular books and popular websites.
Hadley succeeded William Derham
William Derham
William Derham was an English clergyman and natural philosopher. He produced the earliest, reasonably accurate estimate of the speed of sound.-Life:...
in the post of interpreter of the meteorological diaries sent to the Royal Society from observers around the world, mainly in Britain and Scandinavia. He tried to correlate the data in the different temperature and pressure scales then in use.
He attempted to deduce general patterns that emerged over time and twice he published an account of the results in Philosophical Transactions.
Hadley never married. In later life he left London and lived for a while at East Barnet
East Barnet
East Barnet is an area of North London within the London Borough of Barnet bordered by New Barnet, Cockfosters and Southgate. It is a largely residential suburb whose central area, known locally as the Village, contains a variety of shops, public houses, restaurants and services. East Barnet is...
with a nephew, most likely his brother John Hadley's son John. Most of his later years were spent at Flitton, Bedfordshire
Flitton, Bedfordshire
Flitton is a small village in Bedfordshire, England which forms part of the parish of Flitton and Greenfield. The village derives its name from river Flit which flows close by it. It is notable primarily as the home of the De Grey Mausoleum adjacent to St John the Baptist church. Richard Milward,...
, where another nephew, Hadley Cox (d. 1782), son of his sister Elizabeth, was vicar.
Hadley died at Flitton on 28 June 1768 aged 83 years, and was buried in the chancel of Flitton church.
Commemorations
The Hadley Centre for Climate Research and PredictionHadley Centre for Climate Prediction and Research
The Met Office Hadley Centre for Climate Change — named in honour of George Hadley — is part of, and based at the headquarters of the Met Office in Exeter...
, within the UK Met Office
Met Office
The Met Office , is the United Kingdom's national weather service, and a trading fund of the Department for Business, Innovation and Skills...
, was named in his honour and subsequently re-named due to the unfortunate acronym. A crater
Impact crater
In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...
on Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
was also named after him.