Sir Thomas Maclear (17 March 1794 – 14 July 1879) was an
Irish
Irish may refer to:
Common meanings
* Someone or something of, from, or related to:
** Ireland, an island situated off the north-western coast of continental Europe
***Éire, Irish language name for the isle
** Northern Ireland, a constituent unit ...
-born
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...
n
astronomer
An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, natural satellite, moons, comets and galaxy, g ...
who became Her Majesty's astronomer at the
Cape of Good Hope
The Cape of Good Hope ( af, Kaap die Goeie Hoop ) ;''Kaap'' in isolation: pt, Cabo da Boa Esperança is a rocky headland on the Atlantic coast of the Cape Peninsula in South Africa.
A common misconception is that the Cape of Good Hope is t ...
.
Life
He was born in
Newtownstewart
Newtownstewart is a village and townland of in County Tyrone, Northern Ireland. It is overlooked by hills called Bessy Bell and Mary Gray and lies on the River Strule below the confluence with its tributary the Owenkillew. It is situated in th ...
,
County Tyrone
County Tyrone (; ) is one of the six Counties of Northern Ireland, counties of Northern Ireland, one of the nine counties of Ulster and one of the thirty-two traditional Counties of Ireland, counties of Ireland. It is no longer used as an admini ...
,
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 ...
, the eldest son of Rev James Maclear and Mary Magrath.
In 1808 he was sent to England to be educated in the medical profession. After passing his examinations, in 1815 he was accepted into the
Royal College of Surgeons
The Royal College of Surgeons is an ancient college (a form of corporation) established in England to regulate the activity of surgeons. Derivative organisations survive in many present and former members of the Commonwealth. These organisations a ...
of England. He then worked as house-surgeon in the Bedford Infirmary.
In 1823 he went into partnership with his uncle at
Biggleswade
Biggleswade ( ) is a market town and civil parish in Central Bedfordshire in Bedfordshire, England. It lies on the River Ivel, 11 miles (18 km) south-east of Bedford. Its population was 16,551 in the 2011 United Kingdom census, and its e ...
,
Bedfordshire
Bedfordshire (; abbreviated Beds) is a ceremonial county in the East of England. The county has been administered by three unitary authorities, Borough of Bedford, Central Bedfordshire and Borough of Luton, since Bedfordshire County Council wa ...
. Two years later in 1825 he was married to Mary Pearse, the daughter of Theed Pearse, Clerk of the Peace for the county of Bedford.
Maclear had a keen interest in amateur astronomy, and would begin a long association with the
Royal Astronomical Society
(Whatever shines should be observed)
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, to which he would be named a Fellow. In 1833, when the post became vacant, he was named as Her Majesty's Astronomer at the
Cape of Good Hope
The Cape of Good Hope ( af, Kaap die Goeie Hoop ) ;''Kaap'' in isolation: pt, Cabo da Boa Esperança is a rocky headland on the Atlantic coast of the Cape Peninsula in South Africa.
A common misconception is that the Cape of Good Hope is t ...
, and arrived there aboard the ''Tam O'Shanter'' with his wife and five daughters, to take up his new duties in 1834. He worked with
John Herschel
Sir John Frederick William Herschel, 1st Baronet (; 7 March 1792 – 11 May 1871) was an English polymath active as a mathematician, astronomer, chemist, inventor, experimental photographer who invented the blueprint and did botanical wor ...
until 1838, performing a survey of the southern sky, and continued to perform important astronomical observations over several more decades. The Maclears and Herschels formed a close friendship, the wives drawn together by the unusual occupations of their husbands and the raising of their large families. Mary Maclear, like Margaret Herschel, was a noted beauty and intelligent, though suffering from extreme deafness.
Between 1841 and 1848, Maclear would be occupied in performing a
geodetic
Geodesy ( ) is the Earth science of accurately measuring and understanding Earth's figure (geometric shape and size), orientation in space, and gravity. The field also incorporates studies of how these properties change over time and equivale ...
survey for the purpose of recalculating the
figure of the Earth
Figure of the Earth is a Jargon, term of art in geodesy that refers to the size and shape used to model Earth. The size and shape it refers to depend on context, including the precision needed for the model. A Spherical Earth, sphere is a well-k ...
(its dimensions and shape) via an
arc measurement
Arc measurement, sometimes degree measurement (german: Gradmessung), is the astrogeodetic technique of determining of the radius of Earth – more specifically, the local Earth radius of curvature of the figure of the Earth – by relating the la ...
. He caused a
beacon
A beacon is an intentionally conspicuous device designed to attract attention to a specific location. A common example is the lighthouse, which draws attention to a fixed point that can be used to navigate around obstacles or into port. More mode ...
to be erected on top of
Table Mountain
Table Mountain ( naq, Huriǂoaxa, lit= sea-emerging; af, Tafelberg) is a flat-topped mountain forming a prominent landmark overlooking the city of Cape Town in South Africa. It is a significant tourist attraction, with many visitors using the ...
which was used as a
triangulation
In trigonometry and geometry, triangulation is the process of determining the location of a point by forming triangles to the point from known points.
Applications
In surveying
Specifically in surveying, triangulation involves only angle me ...
station for the checking of
de Lacaille's arc measurement
Abbé Nicolas-Louis de Lacaille (; 15 March 171321 March 1762), formerly sometimes spelled de la Caille, was a French astronomer and geodesist who named 14 out of the 88 constellations. From 1750 to 1754, he studied the sky at the Cape of Goo ...
.
He became close friends with
David Livingstone
David Livingstone (; 19 March 1813 – 1 May 1873) was a Scottish physician, Congregationalist, and pioneer Christian missionary with the London Missionary Society, an explorer in Africa, and one of the most popular British heroes of t ...
, and they shared a common interest in the exploration of
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
. He performed many other useful scientific activities, including collecting meteorological, magnetic and tide data.
In 1861 his wife died.
Two years later he was granted a pension, but did not retire from the observatory until 1870. He lived thereafter at Grey Villa, Mowbray.
By 1876, he had lost his sight, and he died three years later in Cape Town, South Africa. He is buried next to his wife in the grounds of the
Royal Observatory, Cape of Good Hope
The Royal Observatory, Cape of Good Hope, is the oldest continuously existing scientific institution in South Africa. Founded by the British Board of Longitude in 1820, it now forms the headquarters building of the South African Astronomical Obs ...
.
Awards and honors
* Knighted in 1860 for his achievements as an astronomer.
*
Lalande Prize
The Lalande Prize (French: ''Prix Lalande'' also known as Lalande Medal) was an award for scientific advances in astronomy, given from 1802 until 1970 by the French Academy of Sciences.
The prize was endowed by astronomer Jérôme Lalande in 180 ...
(1866)
*
Royal Medal
The Royal Medal, also known as The Queen's Medal and The King's Medal (depending on the gender of the monarch at the time of the award), is a silver-gilt medal, of which three are awarded each year by the Royal Society, two for "the most important ...
of the Royal Society (1869), for his measurement of an
arc of the meridian
In geodesy and navigation, a meridian arc is the curve between two points on the Earth's surface having the same longitude. The term may refer either to a segment of the meridian, or to its length.
The purpose of measuring meridian arcs is to ...
in the 1840s.
* The crater
Maclear on the
Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...
is named after him; as is
Maclear's Beacon
Maclear's Beacon is a triangulation station used in Maclear's arc measurement for Earth's circumference determination.
The beacon is on top of Table Mountain in Cape Town, South Africa. It is situated on the Eastern end on the plateau of the mou ...
on
Table Mountain
Table Mountain ( naq, Huriǂoaxa, lit= sea-emerging; af, Tafelberg) is a flat-topped mountain forming a prominent landmark overlooking the city of Cape Town in South Africa. It is a significant tourist attraction, with many visitors using the ...
; the South African town,
Maclear, Eastern Cape;
and
Cape Maclear
Cape Maclear or Chembe is a town in the Mangochi District of Malawi's Southern Region. The town, on the Nankumba Peninsula, is on the southern shore of Lake Malawi and is the busiest resort on Lake Malawi. Cape Maclear is close to the island ...
in Malawi, so named by his friend
David Livingstone
David Livingstone (; 19 March 1813 – 1 May 1873) was a Scottish physician, Congregationalist, and pioneer Christian missionary with the London Missionary Society, an explorer in Africa, and one of the most popular British heroes of t ...
.
See also
*
John Maclear
John Fiot Lee Pearse Maclear (27 June 1838 in Cape Town – 17 July 1907 in Niagara) was an admiral in the Royal Navy, known for his leadership in hydrography.
He is best known for being commander of during the ''Challenger'' Expedition (1 ...
, his son, was an admiral in the Royal Navy, and commander of the 1873–1876 expedition
*
Charles Piazzi Smyth
Charles Piazzi Smyth (3 January 1819 – 21 February 1900) was an Italian-born British astronomer who was Astronomer Royal for Scotland from 1846 to 1888; he is known for many innovations in astronomy and, along with his wife Jessica Duncan P ...
*
Edward James Stone
Notes
References
*
*
External links
*
Thomas Maclear 1794–1879– SA History
South African Astronomical Observatory History
{{DEFAULTSORT:Maclear, Thomas
1794 births
1879 deaths
Fellows of the Royal Astronomical Society
Fellows of the Royal Society
Irish astronomers
Knights Bachelor
People from Newtownstewart
Royal Medal winners
South African astronomers
Ulster Scots people
Recipients of the Lalande Prize