Francis Baily
Encyclopedia
Francis Baily was an English
astronomer
, most famous for his observations of 'Baily's beads
' during an eclipse
of the Sun.
in Berkshire
in 1774. After a tour in the unsettled parts of North America
in 1796–1797, his journal of which was edited by Augustus de Morgan
in 1856, Baily entered the London Stock Exchange
in 1799. The successive publication of Tables for the Purchasing and Renewing of Leases (1802), of The Doctrine of Interest and Annuities (1808), and The Doctrine of Life-Annuities and Assurances (1810), earned him a high reputation as a writer on life-contingencies; he amassed a fortune through diligence and integrity and retired from business in 1825, to devote himself wholly to astronomy.
, and its Gold Medal
was awarded him, in 1827, for his preparation of the Society's Catalogue of 2881 stars (Memoirs R. Astr. Soc. ii.). Later, in 1843, he would win the Gold Medal again. He was elected as president of the society for four consecutive two-year terms prior to his death.
The reform of the Nautical Almanac
in 1829 was set on foot by his protests. He was elected a Foreign Honorary Member of the American Academy of Arts and Sciences
in 1832. He recommended to the British Association in 1837, and in great part executed, the reduction of Joseph de Lalande's and Nicolas de Lacaille's catalogues containing about 57,000 stars; he superintended the compilation of the British Association's Catalogue of 8377 stars (published 1845); and revised the catalogues of Tobias Mayer
, Ptolemy
, Ulugh Beg
, Tycho Brahe
, Edmund Halley and Hevelius (Memoirs R. Astr. Soc. iv,, xiii.).
His observations of "Baily's Beads
", during an annular eclipse of the sun on 15 May 1836, at Inch Bonney in Roxburghshire
, started the modern series of eclipse expeditions. The phenomenon, which depends upon the irregular shape of the moon's limb, was so vividly described by him as to attract an unprecedented amount of attention to the total eclipse of 8 July 1842, observed by Baily himself at Pavia
.
In other work, he completed and discussed H. Foster
's pendulum experiments, deducing from them an ellipticity for the earth of 1/289.48 (Memoirs R. Astr. Soc. vii.). This value was corrected for the length of the seconds-pendulum by introducing a neglected element of reduction, and was used, in 1843, in the reconstruction of the standards of length. His laborious operations for determining the mean density of the earth, carried out by Henry Cavendish
's method (1838–1842), yielded the authoritative value of 5.66.
Baily died in London on 30 August 1844 and was buried in the family vault in St Mary's Church
in Thatcham
. His Account of the Rev. John Flamsteed
(1835) is of fundamental importance to the scientific history of that time. It included a republication of the British Catalogue.
The lunar crater Baily
was named in his honour.
Attribution
English people
The English are a nation and ethnic group native to England, who speak English. The English identity is of early mediaeval origin, when they were known in Old English as the Anglecynn. England is now a country of the United Kingdom, and the majority of English people in England are British Citizens...
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...
, most famous for his observations of 'Baily's beads
Baily's beads
As the moon "grazes" by the Sun during a solar eclipse, the rugged lunar limb topography allows beads of sunlight to shine through in some places, and not in others. This effect is called Baily's beads in honor of Francis Baily who first provided an exact explanation of the phenomenon in 1836...
' during an eclipse
Eclipse
An eclipse is an astronomical event that occurs when an astronomical object is temporarily obscured, either by passing into the shadow of another body or by having another body pass between it and the viewer...
of the Sun.
Life
Baily was born at NewburyNewbury, Berkshire
Newbury is a civil parish and the principal town in the west of the county of Berkshire in England. It is situated on the River Kennet and the Kennet and Avon Canal, and has a town centre containing many 17th century buildings. Newbury is best known for its racecourse and the adjoining former USAF...
in Berkshire
Berkshire
Berkshire is a historic county in the South of England. It is also often referred to as the Royal County of Berkshire because of the presence of the royal residence of Windsor Castle in the county; this usage, which dates to the 19th century at least, was recognised by the Queen in 1957, and...
in 1774. After a tour in the unsettled parts of North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
in 1796–1797, his journal of which was edited by Augustus de Morgan
Augustus De Morgan
Augustus De Morgan was a British mathematician and logician. He formulated De Morgan's laws and introduced the term mathematical induction, making its idea rigorous. The crater De Morgan on the Moon is named after him....
in 1856, Baily entered the London Stock Exchange
London Stock Exchange
The London Stock Exchange is a stock exchange located in the City of London within the United Kingdom. , the Exchange had a market capitalisation of US$3.7495 trillion, making it the fourth-largest stock exchange in the world by this measurement...
in 1799. The successive publication of Tables for the Purchasing and Renewing of Leases (1802), of The Doctrine of Interest and Annuities (1808), and The Doctrine of Life-Annuities and Assurances (1810), earned him a high reputation as a writer on life-contingencies; he amassed a fortune through diligence and integrity and retired from business in 1825, to devote himself wholly to astronomy.
Astronomical work
By 1820, Baily had already taken a leading part in the foundation of the Royal Astronomical SocietyRoyal Astronomical Society
The Royal Astronomical Society is a learned society that began as the Astronomical Society of London in 1820 to support astronomical research . It became the Royal Astronomical Society in 1831 on receiving its Royal Charter from William IV...
, and its Gold Medal
Gold Medal of the Royal Astronomical Society
-History:In the early years, more than one medal was often awarded in a year, but by 1833 only one medal was being awarded per year. This caused a problem when Neptune was discovered in 1846, because many felt an award should jointly be made to John Couch Adams and Urbain Le Verrier...
was awarded him, in 1827, for his preparation of the Society's Catalogue of 2881 stars (Memoirs R. Astr. Soc. ii.). Later, in 1843, he would win the Gold Medal again. He was elected as president of the society for four consecutive two-year terms prior to his death.
The reform of the Nautical Almanac
Nautical Almanac
Nautical Almanac can refer to:* Nautical almanac - a publication describing the positions and movements of celestial bodies* American Ephemeris and Nautical Almanac - first published in 1852* U.S...
in 1829 was set on foot by his protests. He was elected a Foreign Honorary Member of the American Academy of Arts and Sciences
American Academy of Arts and Sciences
The American Academy of Arts and Sciences is an independent policy research center that conducts multidisciplinary studies of complex and emerging problems. The Academy’s elected members are leaders in the academic disciplines, the arts, business, and public affairs.James Bowdoin, John Adams, and...
in 1832. He recommended to the British Association in 1837, and in great part executed, the reduction of Joseph de Lalande's and Nicolas de Lacaille's catalogues containing about 57,000 stars; he superintended the compilation of the British Association's Catalogue of 8377 stars (published 1845); and revised the catalogues of Tobias Mayer
Tobias Mayer
Tobias Mayer was a German astronomer famous for his studies of the Moon.He was born at Marbach, in Württemberg, and brought up at Esslingen in poor circumstances. A self-taught mathematician, he had already published two original geometrical works when, in 1746, he entered J.B. Homann's...
, Ptolemy
Ptolemy
Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...
, Ulugh Beg
Ulugh Beg
Ulugh Bek was a Timurid ruler as well as an astronomer, mathematician and sultan. His commonly-known name is not truly a personal name, but rather a moniker, which can be loosely translated as "Great Ruler" or "Patriarch Ruler" and was the Turkic equivalent of Timur's Perso-Arabic title Amīr-e...
, Tycho Brahe
Tycho Brahe
Tycho Brahe , born Tyge Ottesen Brahe, was a Danish nobleman known for his accurate and comprehensive astronomical and planetary observations...
, Edmund Halley and Hevelius (Memoirs R. Astr. Soc. iv,, xiii.).
His observations of "Baily's Beads
Baily's beads
As the moon "grazes" by the Sun during a solar eclipse, the rugged lunar limb topography allows beads of sunlight to shine through in some places, and not in others. This effect is called Baily's beads in honor of Francis Baily who first provided an exact explanation of the phenomenon in 1836...
", during an annular eclipse of the sun on 15 May 1836, at Inch Bonney in Roxburghshire
Roxburghshire
Roxburghshire or the County of Roxburgh is a registration county of Scotland. It borders Dumfries to the west, Selkirk to the north-west, and Berwick to the north. To the south-east it borders Cumbria and Northumberland in England.It was named after the Royal Burgh of Roxburgh...
, started the modern series of eclipse expeditions. The phenomenon, which depends upon the irregular shape of the moon's limb, was so vividly described by him as to attract an unprecedented amount of attention to the total eclipse of 8 July 1842, observed by Baily himself at Pavia
Pavia
Pavia , the ancient Ticinum, is a town and comune of south-western Lombardy, northern Italy, 35 km south of Milan on the lower Ticino river near its confluence with the Po. It is the capital of the province of Pavia. It has a population of c. 71,000...
.
Henry Foster (scientist)
Henry Foster was a British naval officer who took part in expeditions to the Arctic and Antarctic and made various notable scientific observations....
's pendulum experiments, deducing from them an ellipticity for the earth of 1/289.48 (Memoirs R. Astr. Soc. vii.). This value was corrected for the length of the seconds-pendulum by introducing a neglected element of reduction, and was used, in 1843, in the reconstruction of the standards of length. His laborious operations for determining the mean density of the earth, carried out by Henry Cavendish
Henry Cavendish
Henry Cavendish FRS was a British scientist noted for his discovery of hydrogen or what he called "inflammable air". He described the density of inflammable air, which formed water on combustion, in a 1766 paper "On Factitious Airs". Antoine Lavoisier later reproduced Cavendish's experiment and...
's method (1838–1842), yielded the authoritative value of 5.66.
Baily died in London on 30 August 1844 and was buried in the family vault in St Mary's Church
St Mary's Church, Thatcham
The St Mary's Church is a Church of England parish church at Thatcham in the English county of Berkshire. The church, is dedicated to the Virgin Mary.- History :...
in Thatcham
Thatcham
Thatcham is a town in Berkshire, England 3 miles east of Newbury and 15 miles west of Reading. It covers about and has a population of 23,000 people . This number has grown rapidly over the last few decades from 5,000 in 1951 and 7,500 in 1961.It lies on the River Kennet, the Kennet and Avon...
. His Account of the Rev. 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...
(1835) is of fundamental importance to the scientific history of that time. It included a republication of the British Catalogue.
The lunar crater Baily
Baily (crater)
Baily is the remnant of a lunar crater on the boundary between Mare Frigoris to the north and Lacus Mortis to the south. The crater interior has been flooded by lava in the past, and only the northern half of the crater rim remains relatively intact. There is an outward bulge in the northeastern...
was named in his honour.
Further reading
Obituary by John HerschelExternal links
- Map of Etoiles fixes
- Awarding of RAS gold medal, 1827: MNRAS 1 (1827) 14
- Awarding of RAS gold medal, 1843: MNRAS 5 (1843) 248
Attribution