Samuel Molyneux FRS (16 July 1689 – 13 April 1728) was an amateur astronomer and politician who sat in the British House of Commons between 1715 and 1728 and in the

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. The membership of the House of Commons was directly elected, but on a highly restrictive fran ...

from 1727 to 1728. His work with

James Bradley James Bradley (1692–1762) was an English astronomer and priest who served as the third Astronomer Royal from 1742. He is best known for two fundamental discoveries in astronomy, the aberration of light (1725–1728), and the nutation of th ...

attempting to measure stellar parallax led to the discovery of the

aberration of light In astronomy, aberration (also referred to as astronomical aberration, stellar aberration, or velocity aberration) is a phenomenon which produces an apparent motion of celestial objects about their true positions, dependent on the velocity of t ...

. The aberration was the first definite evidence that the earth moved and that

Copernicus Nicolaus Copernicus (; pl, Mikołaj Kopernik; gml, Niklas Koppernigk, german: Nikolaus Kopernikus; 19 February 1473 – 24 May 1543) was a Renaissance polymath, active as a mathematician, astronomer, and Catholic canon, who formulated ...

and

Kepler Johannes Kepler (; ; 27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best known for his laws o ...

were correct.Science and Its Times via In addition to his astronomical works, Molyneux wrote about the natural history and other features of

Ireland Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...

. He died in suspicious circumstances.

Early life

Molyneux was born in

Chester, England Chester is a cathedral city and the county town of Cheshire, England. It is located on the River Dee, close to the English–Welsh border. With a population of 79,645 in 2011,"2011 Census results: People and Population Profile: Chester Loca ...

in 1689 and was the second son of

William Molyneux William Molyneux FRS (; 17 April 1656 – 11 October 1698) was an Irish writer on science, politics and natural philosophy. He is noted as a close friend of fellow philosopher John Locke, and for proposing Molyneux's Problem, a thought exp ...

, who was known for his work related to optics. His mother was Lucy Domville, daughter of Sir

William Domville William Domville (or Domvile) (1609–1689) was a leading Irish politician, barrister and Constitutional writer of the Restoration (1660), Restoration era. Due to the great trust which the English Crown had in him, he served as Attorney General ...

, the

Attorney General for Ireland The Attorney-General for Ireland was an Irish and then (from the Act of Union 1800) United Kingdom government office-holder. He was senior in rank to the Solicitor-General for Ireland: both advised the Crown on Irish legal matters. With the ...

. Molyneux studied at Trinity College, Dublin, where he earned a

Bachelor of Arts Bachelor of arts (BA or AB; from the Latin ', ', or ') is a bachelor's degree awarded for an undergraduate program in the arts, or, in some cases, other disciplines. A Bachelor of Arts degree course is generally completed in three or four year ...

(BA) in 1708 and a

Master of Arts A Master of Arts ( la, Magister Artium or ''Artium Magister''; abbreviated MA, M.A., AM, or A.M.) is the holder of a master's degree awarded by universities in many countries. The degree is usually contrasted with that of Master of Science. Th ...

(MA) in 1710. He was elected a Fellow of the Royal Society in 1712.

Astronomical work

Molyneux is best known for his work with Bradley in attempting to measure the parallax of

Gamma Draconis Gamma Draconis (γ Draconis, abbreviated Gamma Dra, γ Dra), formally named Eltanin , is a star in the northern constellation of Draco. Contrary to its gamma-designation (historically third-ranked), it is the brightest star in Draco at ...

leading to the discovery of the

. Molyneux was interested in detecting parallax that others such as 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

being a star that passes directly overhead in London, minimizing the effects of atmospheric refraction on its apparent position when it does so. Molyneux commissioned a larger set of telescopes and employed

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 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.

Political career

Molyneux was

Member of Parliament A member of parliament (MP) is the representative in parliament of the people who live in their electoral district. In many countries with bicameral parliaments, this term refers only to members of the lower house since upper house members o ...

(MP) for Bossiney in Cornwall from 1715 to 1722, for St Mawes from 1726 to 1727, and for Exeter from 1727 to 1728. He served as Secretary to the Prince of Wales from 1715 to 1727 and as

Lord of the Admiralty This is a list of Lords Commissioners of the Admiralty (incomplete before the Restoration, 1660). The Lords Commissioners of the Admiralty were the members of The Board of Admiralty, which exercised the office of Lord High Admiral when it was ...

from 1727 to 1728. Between 1727 and 1728 he represented

Dublin University The University of Dublin ( ga, Ollscoil Átha Cliath), corporately designated the Chancellor, Doctors and Masters of the University of Dublin, is a university located in Dublin, Ireland. It is the degree-awarding body for Trinity College Dubl ...

in the

Death and legacy

Molyneux married Lady Elizabeth Capel, daughter of

Algernon Capell, 2nd Earl of Essex Algernon Capell, 2nd Earl of Essex PC (28 December 1670 – 10 January 1710, Watford) of Cassiobury House, Watford, Hertfordshire, was an English nobleman, a soldier and courtier. Origins He was the son of Arthur Capell, 1st Earl of Essex ...

, on 5 April 1717. In 1728, he suffered a fit while in the House of Commons. He was treated by court anatomist

Nathaniel St André Nathaniel St André (c.1680–March 1776) was a Swiss physician who practised in England. Life Born in Switzerland, St André moved to England in his youth, as a page to a Jewish family. On arrival, he made his living teaching French, Ger ...

, but the treatment did not prove successful, and Molyneux died in Kew in April. On the night of the death, St André eloped with Molyneux's wife, Elizabeth, the two marrying in 1730.

Samuel Madden Samuel Madden (23 December 1686 – 31 December 1765) was an Irish author. His works include ''Themistocles; The Lover of His Country'', ''Reflections and Resolutions Proper for the Gentlemen of Ireland'', and ''Memoirs of the Twentieth Century' ...

, a relative of Molyneux's, claimed that St André had poisoned the MP. Although St André won an action for defamation, he found himself unable to secure regular work.

Notes

External links

* {{DEFAULTSORT:Molyneux, Samuel 1689 births 1728 deaths Alumni of Trinity College Dublin 18th-century British astronomers British MPs 1715–1722 British MPs 1727–1734 Fellows of the Royal Society Irish MPs 1727–1760 Lords of the Admiralty Members of the Parliament of Great Britain for Exeter Members of the Parliament of Ireland (pre-1801) for Dublin University Members of the Parliament of Great Britain for constituencies in Cornwall People from Chester Members of the Privy Council of Ireland