William Arthur Douglas Rudge (or William Arthur Douglas-Rudge), physicist, was the son of Henry Rudge and Sarah Peters. He studied at St John's College, University of Cambridge, where he qualified as Bachelor of Arts (BA, 1899) and Master of Arts (MA, 1903). He then became science master at Woodbridge School, in Suffolk, from 1903 to 1907. In the latter year he was appointed as the first professor of physics at Grey University College (later the University of the Free State), Bloemfontein, in November 1907. That same year he became a member of the Philosophical Society of the Orange River Colony. By the next year he was a member also of the South African Association for the Advancement of Science and was elected president of its Section A (which included physics) for 1908/9. At the association's annual congress held in Bloemfontein in 1909 he delivered two papers. The first, of which only a summary was published in the association's Repoprt for that year (p. 312), dealt with "Liesegang's lines" (the stratification of precipitates formed in gels when one reactant diffuses into the other). The second paper (pp. 441-446) was on "Osmotic pressure and the theory of solution". At the 1910 meeting he delivered an "Abstract of physical observations taken during the proximity of Halley's Comet to the earth" (Report, 1910, pp. 87-91).
Around this time Rudge entered upon a field of study that would retain his interest for several years, namely atmospheric electricity, a topic briefly studied by Professor J.C. Beattie* of Cape Town and Mr James Lyle* of Bloemfontein around 1905. At the 1911 meeting of the South African Association for the Advancement of Science Rudge delivered two papers on this topic, "Some observations on atmospheric electricity taken in South Africa" (Report, 1911, pp. 232-238) and "Observations of atmospheric electricity at Bloemfontein" (pp. 262-269). He was elected a Fellow of the Royal Society of South Africa this year and subsequently published his papers in this society's Transactions: "On the variation in the value of the atmospheric electrical potential with the altitude" (1910-1912, Vol. 2, pp. 395-404) and "On the daily range of the atmospheric potential at Bloemfontein, and the influence of dust storms" (1914-1915, Vol. 4, pp. 75-88). He determined the electrical potential gradient under different conditions such as mist, rain, dust and smoke and found that dust in particular can lower and even reverse the normal positive gradient, while raindrops that reached the ground were invariably negatively charged. The potential gradient appeared to depend, among others, on the altitude of the observing station, and varied with the time of day.
In 1909 Rudge was admitted to the MA degree by the University of the Cape of Good Hope on the basis of his degree from the University of Cambridge. From 1908 to 1912 he was an examiner in applied mathematics, physics and chemistry for the university. He was elected a member of the Management Committee of the National Museum of the Orange Free State in June 1910, and served on the museum's building committee the next year. He had a good background in geology and attended to the museum's collection of rocks and minerals. The meteorites in the collection were of particular interest to him. He eventually received permission to cut a large meteorite in half for analysis and in September 1911 delivered a lecture on the results in the Town Hall. "A preliminary note on the meteorites in Bloemfontein Museum" appeared in the Transactions of the Royal Society of South Africa (1910-1912, Vol. 2, pp. 211-221) around the same time. Some of his other scientific interests are reflected in further papers that he contributed to the Transactions, namely "Action of radium salt on glass" (1910-1912) and "On variation in the magnetic declination at Bloemfontein" (1913). Several papers by him were published also in the Transactions of the Cambridge Philosophical Society.
Rudge returned to the United Kingdom in 1916 to become science master at Rugby School, a post he held until his retirement at the end of 1930. He was succeeded in Bloemfontein by Professor W.H. Logeman*.
