Sir Thomas Maclear (1794–1879) was an Irish-born South African astronomer who became Astronomer Royal at the Cape of Good Hope. Maclear would later became a good friend of David Livingstone.
Maclear arrived in Cape Town in 1834 with his wife and 5 daughters. He worked there with John Herschel (1792-1871) until 1838. Herschel and his wife arrived in late 1833.
Herschel built an observatory at a place known as The Grove which Herschel named "Feldhausen", at Claremont, close to Table Mountain, near Cape Town.
Also in 1834, arriving at around the same time as Herschel and Maclear, the young Charles Piazzi Smyth (1819-1900), arrived in Cape Town aged 16 to join the Royal Observatory as an assistant to Sir Thomas Maclear, where he observed Halley's comet and the Great Comet of 1843.
Smyth made a calotype of the Royal Observatory, Cape of Good Hope, in 1842. He made the camera himself. It is most likely that it was Herschel who taught Smyth the calotype process by correspondence after Herschel had returned to Britain in 1838.
Smyth was Astronomer Royal for Scotland from 1846 to 1888 based at the Calton Hill Observatory in Edinburgh, and through his interest in photography most probably met Hill & Adamson in Edinburgh and would surely have been acquainted with the circle of Sir David Brewster in St Andrews. In 1865 Smyth would to travel to Egypt and made collodion plates of the pyramids, one of his major research interests.
Kirk met Maclear at Cape Town in 1858 on his way out to Livingstone's Zambesi Expedition (1858-64), when Maclear would have been 64 years old. On April 29th Kirk wrote in his journal, "At the observatory with Mr. Maclear, examined the various instruments, Magnetic etc".
The following day Kirk wrote "Arranged the packing up and transportation of the collection of live plants to SImon's Bay. Went down in the mail cart afterwards and joined the ship. Mr. Maclear came with us and amused us on the way with discussions of the course of projectiles and other things."
So we have this link between Kirk through Maclear to Herschel himself and to Smyth, who made what was probably the first calotype in southern Africa.
In 1861 Livingstone named Cape Maclear on Lake Malawi after Maclear.