Thomas Maclear

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Sir Thomas Maclear (January 17, 1794–July 14, 1879) was an Irish-born South African astronomer.

He was born in Newton Stewart, Ireland, the eldest son of James Maclear. 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 partnered with his Uncle at Biggleswade, Bedfordshire. Two years later in 1825 he was married to Mary Pearse, the daughter of the county clerk of the pence.

Dr. 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 he was named as royal astronomer at the Cape of Good Hope, and arrived there to take up his new duties in 1834. He worked with John Herschel until 1834, performing a survey of the southern sky. He continued to perform important astronomical observations several decades.

In 1750 Abbe Nicolas Louis de Lacaille had measured a triangulation arc northwards from Cape Town, to determine the shape of the earth and found that the curvature of the earth was less in southern latitudes than at corresponding northern ones. Sir George Everest visited the Cape in 1820 and visited the site of LaCailles measurements. From his experience in the Himalayas he believed that the presence of considerable mountain masses in the Cape could have caused false measurements to be made by LaCaille. Between 1841 and 1848 Maclear would be occupied in performing a geodesic survey for the purpose of recalculating the dimensions and shape of the Earth. 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.

In 1861 his wife died. Two years later he was granted a pension, but he would only retire from the observatory in 1870, living thereafter at Grey Villa, Mowbray. By 1876 he had lost his sight, and he died three years later. He is buried next to his wife on the grounds of the Royal Observatory.

[edit] Awards and honors

Knighted in 1860 for his achievements as an astronomer.
Maclear crater on the Moon is named after him, as is Maclear's Beacon on Table Mountain and the town of Maclear.