Alexander Ross Clarke (1828–1914) was a British geodesist, primarily remembered for his work defining different
reference ellipsoidIn geodesy, a reference ellipsoid is a mathematically-defined surface that approximates the geoid, the truer figure of the Earth, or other planetary body....
s approximating the shape of the
geoidThe geoid is that equipotential surface which would coincide exactly with the mean ocean surface of the Earth, if the oceans were in equilibrium, at rest , and extended through the continents . According to C.F...
.
Clarke was born on December 16, 1828 in
Reading, BerkshireReading is a large town and unitary authority area in England. It is located in the Thames Valley at the confluence of the River Thames and River Kennet, and on both the Great Western Main Line railway and the M4 motorway, some west of London....
,
EnglandEngland 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...
. He spent his childhood in the British colony of
JamaicaJamaica is an island nation of the Greater Antilles, in length, up to in width and 10,990 square kilometres in area. It is situated in the Caribbean Sea, about south of Cuba, and west of Hispaniola, the island harbouring the nation-states Haiti and the Dominican Republic...
, until his family returned to England.
On October 1, 1847 he joined the British army and was assigned to the Royal Engineers. He got his training at
ChathamChatham is one of the Medway towns located within the Medway unitary authority, in North Kent, in South East England.Although the dockyard has long been closed and is now being redeveloped into a business and residential community as well as a museum featuring the famous submarine, HMS Ocelot,...
in
KentKent is a county in southeast England, and is one of the home counties. It borders East Sussex, Surrey and Greater London and has a defined boundary with Essex in the middle of the Thames Estuary. The ceremonial county boundaries of Kent include the shire county of Kent and the unitary borough of...
, at the School of Military Engineering. In 1850 he was transferred to the
Ordnance SurveyOrdnance Survey , an executive agency and non-ministerial government department of the Government of the United Kingdom, is the national mapping agency for Great Britain, producing maps of Great Britain , and one of the world's largest producers of maps.The name reflects its creation together with...
in
SouthamptonSouthampton is the largest city in the county of Hampshire on the south coast of England, and is situated south-west of London and north-west of Portsmouth. Southampton is a major port and the closest city to the New Forest...
.
From 1851 to 1854 Clarke served in Canada, where he married Frances Dixon in 1853. The couple had four sons and nine daughters.
On his return to England he served again with the Ordnance Survey in Southampton, where in 1856 he became director of the measurement department. In 1858 he published his first article on the history of land surveying in Great Britain. On June 5, 1862 he was elected to the
Royal SocietyThe 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"...
.
In 1866 he described a new
reference ellipsoidIn geodesy, a reference ellipsoid is a mathematically-defined surface that approximates the geoid, the truer figure of the Earth, or other planetary body....
, known as
Clarke 1866The expression figure of the Earth has various meanings in geodesy according to the way it is used and the precision with which the Earth's size and shape is to be defined. The actual topographic surface is most apparent with its variety of land forms and water areas. This is, in fact, the surface...
and still used today, particularly in English-language countries and areas. In his 1880 book
Geodesy he described a different ellipsoid, known as
Clarke 1880The expression figure of the Earth has various meanings in geodesy according to the way it is used and the precision with which the Earth's size and shape is to be defined. The actual topographic surface is most apparent with its variety of land forms and water areas. This is, in fact, the surface...
, which is used mainly in Africa.
After he had served 27 years in England, he was formally obliged to serve overseas. Upon receiving notice of transfer, Clarke submitted his resignation. Soon after, he withdrew from the
Royal SocietyThe 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"...
for financial reasons.
In October 1883 Clarke was the British delegate at the geodetic conference in Rome, and in 1884 he represented Britain at the International Geodetic Conference.
From the Royal Society he received the gold medal, and was re-elected to membership and his dues were waived.
Alexander Ross Clarke died on 11 February 1914 in
StrathmoreStrathmore, from the Scottish Gaelic for large valley , can refer to a number of people, places in Scotland, or places named by Scottish emigrants:-Buildings:...
,
ReigateReigate is a historic market town in Surrey, England, at the foot of the North Downs, and in the London commuter belt. It is one of the main constituents of the Borough of Reigate and Banstead...
,
SurreySurrey is a county in the South East of England and is one of the Home Counties. The county borders Greater London, Kent, East Sussex, West Sussex, Hampshire and Berkshire. The historic county town is Guildford. Surrey County Council sits at Kingston upon Thames, although this has been part of...
.
External links
- http://www.reubique.com/clarke.htm