Astronomers of the Royal Observatory Cape of Good Hope

Fearon Fallows (1820-1831) David Gill (1879-1907) Notable Assistants and Visitors

David Gill was the Willem de Sitter spent time Fallows was the first most brilliant of the with Gill to learn practical director of the Royal Royal Astronomers. astronomy. Later he became Observatory. He supervised He is specially noted famous for suggesting that the construction of the for his pioneering Einstein’s field equations for buildings, aligned the work in General Relativity have a instruments and made the astronomical solution implying an first observations in spite photography and for expanding universe. of facing enormous difficulties. having made the first ever photographic sky survey, the Cape Photographic Durchmusterung . Frank McClean was an He was the leading expert on the Astronomical amateur astronomer who spent Unfortunately, conditions at the Observatory Unit , the distance between the earth and the Sun, time with Gill a the Royal were very primitive and unsanitary and he died at and his value was accepted as the best-determined Observatory. He discovered an early age. He was buried on the grounds where for many decades. He was a major contributor to the first evidence for oxygen his grave can still be seen. This silhouette is the the Astrophotographic Congresses , the in stars . He was the donor of only image we have of him . forerunners of today’s International Astronomical the McClean telescope. Union.. In addition, he was an excellent instrumentalist who strongly influenced telescope Thomas Henderson (1831-1833) design in the later nineteenth century. He attracted many persons of international standing to visit the Robert Thorburn Ayton Innes was the discoverer of Henderson in spite of his short period at the Cape Cape or collaborate with him. The Royal the current nearest star, was responsible for a remarkable achievement: Observatory looks today much as he left it. Proxima Centauri . He worked the first observations that led to the distance to a with Gill at the Cape and later star . He was unfortunately slow to publish and was the first director of the lost priority to the German astronomer F.W. Sydney Samuel Hough (1907-1923) Union Observatory in Bessel, even though the latter made his Johannesburg observations several years later. Hough carried on the programmes of Gill, bringing The star that Henderson measured was Alpha them to a conclusion. His John Franklin-Adams was an Centauri, one of the brightest in the sky and still term saw the introduction of the second nearest known, at 4.4 light years. amateur astronomer who radio signalling, bringing in a produced the first all-sky Unfortunately, there is no surviving picture of new era in time- photographic atlas . The him. He resigned his post in protest at the poor determination. He also southern part of this was encouraged the growing band conditions under which the Cape observers had to started at the Royal live and returned to his home in Scotland, where of amateur astronomers in the Observatory at the invitation he became Astronomer Royal. Cape . of Gill.

Harold Spencer Jones (1933-1950) Joan George Erardus Thomas Maclear (1833-1870) Gijsbertus Voûte was a Dutch Spencer Jones continued the volunteer astronomer who Maclear during his long position-measuring tradition worked at the Cape at the time term of office of the Cape Observatory. He of Hough’s directorate. He concentrated mainly on started a parallax programme obtained the first reasonably the measurement of star on the McClean telescope He accurate distance for Proxima positions. In addition he also took a leading part in Centauri , the nearest star. carried out an elaborate the Eros project of 1930-31 survey to check whether to measure the Astronomical the earth was really Unit. Jakob Karl Ernst Halm pear-shaped as had been (middle of back row) held the suggested by the French position of First Assistant astronomer N.-L. de under Hough and was a John Jackson (1933-1950) pioneer of stellar kinematic Lacaille in the previous century (it wasn’t!). In studies . His work attracted the 1855 he replaced the by then obsolete transit and Jackson carried on the attention of Eddington (front mural circle with a transit circle that did the work routine programmes of his row, right), seen here on a of both instruments. predecessor. The most visit in 1914. He became in effect the chief advisor to the exciting work he did David Stanley Evans was colonial government on scientific matters such as concerned the solar eclipse First Assistant under Stoy meteorology, standard weights and measures, in Calvinia in 1940. lighthouses etc. and made early measurements of stellar diameters using high-speed Edward James Stone (1870-1879) photometry of lunar occultations. He is well- Stone was a Richard Hugh Stoy (1950-1968) known also for the Barnes- mathematician who was Stoy was the last Evans relation. He was not an active observer Royal Astronomer. largely responsible for the himself but concentrated The 18-inch and 1m selection of Sutherland for a on the reduction of reflectors were new observatory. previous observations, installed during his which had got time. The Royal Alan William James behindhand in Maclear’s Observatory also Cousins was a photometrist later years. He succeeded obtained the right to interested in precise in reducing the backlog 1/3 of the observing observations of bright stars. of publications. time at the Radcliffe His work is of fundamental 1.9m telescope in Pretoria. significance to many parts of The photoheliograph (which still exists) was the The search for a better observing site away from astronomy. Some of his best only new instrument to be installed during his the city lights began (later leading to the SAAO work was done while in retirement. tenure. Sutherland site).