Samuel Molyneux
Encyclopedia
Samuel Molyneux FRS (16 July 1689 – 13 April 1728), son of William Molyneux
, was an 18th-century member of the British parliament
from Kew
and an amateur astronomer whose work with James Bradley
attempting to measure stellar parallax led to the discovery of the aberration of light
. The aberration was the first definite evidence that the earth moved and that Copernicus and Kepler were correct. In addition to his astronomical works, Molyneux wrote about the natural history and other features of Ireland
.
, the Irish Attorney General. Molyneux studied at Trinity College, Dublin
, where he earned a Bachelor of Arts
(BA) in 1708 and a Master of Arts (MA) in 1710. He was elected a Fellow of the Royal Society in 1712. and served as a member of the Parliament in 1715, 1726, 1727 and Ireland 1727, and as Lord of the Admiralty
from 1727–1728.
. Molyneux was interested in detecting parallax
that others such Robert Hooke
had attempted but failed to detect. Unlike Hooke, Molyneux had large amounts of patience and had resources to expend. Like Hooke, Molyneux decided to take advantage of Gamma Draconis always being over London. Molyneux commissioned a larger set of telescopes and employed James Bradley
as an expert who had more astronomical and mathematical knowledge. Working together, Bradley and Molyneux performed over 80 observations to a precision of greater than 1 arcsecond from December of 1725 until late in 1727. Measurements of this precision had never before been performed with telescopes. Bradley and Molyneux were surprised to find that rather than detect a parallax they detected an unexplained wobble of the star. Moreover, similar wobbles were found by Bradley using another high-precision telescope for some 200 other stars. Molyneux died shortly before Bradley realized that the observed changes they were seeing was in fact due to the aberration of light.
(MP) for Bossiney
from 1715 to 1722, for St Mawes
from 1726 to 1727, and for Exeter
from 1727 to 1728. Between 1727 and 1728 he represented Dublin University
in the Irish House of Commons
.
William Molyneux
William Molyneux FRS was an Irish natural philosopher and writer on politics.He was born in Dublin to Samuel Molyneux , lawyer and landowner , and his wife, Anne, née Dowdall. The second of five children, William Molyneux came from a relatively prosperous Anglican background...
, was an 18th-century member of the British parliament
Parliament of Great Britain
The Parliament of Great Britain was formed in 1707 following the ratification of the Acts of Union by both the Parliament of England and Parliament of Scotland...
from Kew
Kew
Kew is a place in the London Borough of Richmond upon Thames in South West London. Kew is best known for being the location of the Royal Botanic Gardens, now a World Heritage Site, which includes Kew Palace...
and an amateur astronomer whose work 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...
attempting to measure stellar parallax led to the discovery of the aberration of light
Aberration of light
The aberration of light is an astronomical phenomenon which produces an apparent motion of celestial objects about their real locations...
. The aberration was the first definite evidence that the earth moved and that Copernicus and Kepler were correct. In addition to his astronomical works, Molyneux wrote about the natural history and other features of Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
.
Life
Molyneux was born in Chester, England in 1689 and died in Kew in 1728. He was the second son of William Molyneux, who was known for his work related to optics. His mother was Lucy Domville, daughter of Sir William DomvilleWilliam Domville
William Domville was a leading Irish politician and barrister of the Restoration era. Due to the great trust which the Crown had in his ability, he remained Attorney General for Ireland throughout the reign of Charles II, and it has been argued that it was in his term of office that the Attorney...
, the Irish Attorney General. Molyneux studied at Trinity College, Dublin
Trinity College, Dublin
Trinity College, Dublin , formally known as the College of the Holy and Undivided Trinity of Queen Elizabeth near Dublin, was founded in 1592 by letters patent from Queen Elizabeth I as the "mother of a university", Extracts from Letters Patent of Elizabeth I, 1592: "...we...found and...
, where he earned a Bachelor of Arts
Bachelor of Arts
A Bachelor of Arts , from the Latin artium baccalaureus, is a bachelor's degree awarded for an undergraduate course or program in either the liberal arts, the sciences, or both...
(BA) in 1708 and a Master of Arts (MA) in 1710. He was elected a Fellow of the Royal Society in 1712. and served as a member of the Parliament in 1715, 1726, 1727 and Ireland 1727, and as Lord of the Admiralty
Lord Commissioner of the Admiralty
The Lords Commissioners of the Admiralty were the members of the Board of Admiralty, which exercised command over the Royal Navy.Officially known as the Commissioners for Exercising the Office of Lord High Admiral of the United Kingdom of Great Britain and Northern Ireland &c. The Lords...
from 1727–1728.
Astronomical Work
Molyneux is best known for his work with Bradley in attempting to measure the parallax of Gamma Draconis leading to the discovery of the aberration of lightAberration of light
The aberration of light is an astronomical phenomenon which produces an apparent motion of celestial objects about their real locations...
. Molyneux was interested in detecting parallax
Parallax
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight, and is measured by the angle or semi-angle of inclination between those two lines. The term is derived from the Greek παράλλαξις , meaning "alteration"...
that others such Robert Hooke
Robert Hooke
Robert Hooke FRS was an English natural philosopher, architect and polymath.His adult life comprised three distinct periods: as a scientific inquirer lacking money; achieving great wealth and standing through his reputation for hard work and scrupulous honesty following the great fire of 1666, but...
had attempted but failed to detect. Unlike Hooke, Molyneux had large amounts of patience and had resources to expend. Like Hooke, Molyneux decided to take advantage of Gamma Draconis always being over London. Molyneux commissioned a larger set of telescopes and employed 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...
as an expert who had more astronomical and mathematical knowledge. Working together, Bradley and Molyneux performed over 80 observations to a precision of greater than 1 arcsecond from December of 1725 until late in 1727. Measurements of this precision had never before been performed with telescopes. Bradley and Molyneux were surprised to find that rather than detect a parallax they detected an unexplained wobble of the star. Moreover, similar wobbles were found by Bradley using another high-precision telescope for some 200 other stars. Molyneux died shortly before Bradley realized that the observed changes they were seeing was in fact due to the aberration of light.
Parliament
Molyneux was Member of ParliamentMember of Parliament
A Member of Parliament is a representative of the voters to a :parliament. In many countries with bicameral parliaments, the term applies specifically to members of the lower house, as upper houses often have a different title, such as senate, and thus also have different titles for its members,...
(MP) for Bossiney
Bossiney (UK Parliament constituency)
Bossiney was a parliamentary constituency in Cornwall, one of a number of Cornish rotten boroughs, and returned two Members of Parliament to the British House of Commons from 1552 until 1832, when it was abolished by the Great Reform Act.-History:...
from 1715 to 1722, for St Mawes
St Mawes (UK Parliament constituency)
St Mawes was a rotten borough in Cornwall. It returned two Members of Parliament ) to the House of Commons of England from 1562 to 1707, to the House of Commons of Great Britain from 1707 to 1800, and to the House of Commons of the United Kingdom until it was abolished by the Great Reform Act in...
from 1726 to 1727, and for Exeter
Exeter (UK Parliament constituency)
Exeter is a borough constituency represented in the House of Commons of the Parliament of the United Kingdom. It elects one Member of Parliament by the first past the post system of election....
from 1727 to 1728. Between 1727 and 1728 he represented Dublin University
Dublin University (Parliament of Ireland constituency)
Dublin University was a constituency represented in the Irish House of Commons from 1603 to 1801.-History:This university constituency was first enfranchised as a Parliamentary constituency in 1603...
in the Irish House of Commons
Irish House of Commons
The Irish House of Commons was the lower house of the Parliament of Ireland, that existed from 1297 until 1800. The upper house was the House of Lords...
.