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. 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." 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. == Later life and death ==