Thomas Maclear (17 March 1794 – 14 July 1879) was an Irish-born Cape Colony

astronomer An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galax ...

who became Her Majesty's astronomer at the

Cape of Good Hope The Cape of Good Hope ( ) is a rocky headland on the Atlantic Ocean, Atlantic coast of the Cape Peninsula in South Africa. A List of common misconceptions#Geography, common misconception is that the Cape of Good Hope is the southern tip of Afri ...

Early life

Born on 17 March 1794, 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 the ...

, 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 ...

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, This figur ...

Bedfordshire Bedfordshire (; abbreviated ''Beds'') is a Ceremonial County, ceremonial county in the East of England. It is bordered by Northamptonshire to the north, Cambridgeshire to the north-east, Hertfordshire to the south and the south-east, and Buckin ...

. In 1825, he was married to Mary Pearse, the daughter of Theed Pearse, Clerk of the Peace for the county of Bedford.

Career

Maclear had a keen interest in amateur astronomy, and would begin a long association with the

Royal Astronomical Society The Royal Astronomical Society (RAS) is a learned society and charitable organisation, charity that encourages and promotes the study of astronomy, planetary science, solar-system science, geophysics and closely related branches of science. Its ...

, 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

, 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 and experimental photographer who invented the blueprint and did botanical work. ...

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 survey for the purpose of recalculating the

figure of the Earth In geodesy, the figure of the Earth is the size and shape used to model planet Earth. The kind of figure depends on application, including the precision needed for the model. A spherical Earth is a well-known historical approximation that is ...

(its dimensions and shape) via an

arc measurement Arc measurement, sometimes called degree measurement (), is the astrogeodetic technique of determining the radius of Earth and, by Circumference#Circle, extension, Earth's circumference, its circumference. More specifically, it seeks to determine ...

. 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 (; ) 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 Table Mountain Aerial Cableway, cableway or hik ...

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 m ...

station for the checking of de Lacaille's arc measurement. He became close friends with

David Livingstone David Livingstone (; 19 March 1813 – 1 May 1873) was a Scottish physician, Congregationalist, pioneer Christian missionary with the London Missionary Society, and an explorer in Africa. Livingstone was married to Mary Moffat Livings ...

, and they shared a common interest in the exploration of Africa. He performed many other useful scientific activities, including collecting meteorological, magnetic and tide data.

Later life and death

In 1861, his wife died. In 1863, 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 died on 14 July 1878, aged 85, in

Cape Town Cape Town is the legislature, legislative capital city, capital of South Africa. It is the country's oldest city and the seat of the Parliament of South Africa. Cape Town is the country's List of municipalities in South Africa, second-largest ...

. He is buried next to his wife in the grounds of the Royal Observatory, Cape of Good Hope.

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 1801 ...

(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 are given for "the mo ...

of the Royal Society (1869), for his measurement of an arc of the meridian in the 1840s. * The crater Maclear on the

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

is named after him; as is Maclear's Beacon on

; the South African town, Maclear, Eastern Cape; and Cape Maclear in Malawi, so named by his friend

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 19th-century Irish astronomers Knights Bachelor People from Newtownstewart Royal Medal winners Cape Colony scientists Astronomers Ulster Scots people Recipients of the Lalande Prize Scientists from County Tyrone