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Thomas Maclear

South African astronomer (1794-1879)

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Thomas Maclear (17 March 1794, 14 July 1879) was an Irish-born Cape Colony astronomer who became Her Majesty's astronomer at the Cape of Good Hope.

01Early life

Born on 17 March 1794, in Newtownstewart, 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 of England. He then worked as house-surgeon in the Bedford Infirmary.

In 1823, he went into partnership with his uncle at Biggleswade, Bedfordshire. In 1825, he was married to Mary Pearse, the daughter of Theed Pearse, Clerk of the Peace for the county of Bedford.

Mary Maclear
Mary Maclear

02Career

Maclear had a keen interest in amateur astronomy, and would begin a long association with the Royal Astronomical Society, 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, 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 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 (its dimensions and shape) via an arc measurement. He caused a beacon to be erected on top of Table Mountain which was used as a triangulation station for the checking of de Lacaille's arc measurement.

He became close friends with David Livingstone, 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.

A memorial to Nicolas-Louis de Lacaille and Thomas Maclear, at Aurora, Western Cape, South Africa. The English portion of the inscription reads: "This is the site of the Maclear Beacon positioned in 1838 near the original North Terminal of the Arc of Meridian positioned by Abbé de la Caille, the first surveyor to introduce Geodetic Surveying into South Africa."
A memorial to Nicolas-Louis de Lacaille and Thomas Maclear, at Aurora, Western Cape, South Africa. The English portion of the inscription reads: "This is the site of the Maclear Beacon positioned in 1838 near the original North Terminal of the Arc of Meridian positioned by Abbé de la Caille, the first surveyor to introduce Geodetic Surveying into South Africa."

03Later 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. He is buried next to his wife in the grounds of the Royal Observatory, Cape of Good Hope.

Maclear's Beacon, Table Mountain, Cape Town, 2023
Maclear's Beacon, Table Mountain, Cape Town, 2023

04Awards and honors

Sir Thomas, on the receipt of his knighthood, 1860
Sir Thomas, on the receipt of his knighthood, 1860
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Sources and credits

This article is adapted from the Wikipedia article Thomas Maclear, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.

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