John Orr, engineer and educationist, entered Glasgow University in 1887 and qualified as Bachelor of Science (BSc) in mechanical and electrical engineering. He also received technical training at Glasgow Technical College and Coatbridge Mining College (just east of Glasgow) and in 1893 won the Whitworth exhibition and medal. After serving an apprenticeship in mechanical engineering he gained further practical experience with various engineering and shipbuilding firms in Scotland and England. In 1897 he emigrated to the Cape Colony, where he was appointed as iron and woodwork master in the Physics Department of the South African College, Cape Town. The next year, at the age of 28, he became the first professor of mechanical and electrical engineering at the Kimberley branch of the South African School of Mines, established in 1896 with Professor J.G. Lawn* as principal. Orr's tuition there was interrupted by the siege of Kimberley (14 October 1899 to 15 February 1900) during the Anglo-Boer War (1899-1902), when he served with the British forces and was awarded the Queen's medal.
At the end of 1903 the South African School of Mines moved to Johannesburg to become the Transvaal Technical Institute, where Orr continued to teach from early in 1904 as professor of mechanical and electrical engineering. The institute successively became the Transvaal University College (1906), the South African School of Mines and Technology (1910), the University College of Johannesburg (1920), and finally the University of the Witwatersrand (1922). Orr's career continued as head of the university's Department of Mechanical and Electrical Engineering. During the early part of his career he published several papers, including "Notes on the development of the rotary engine" (Journal of the Mechanical Engineers' Association of the Witwatersrand, 1903-1904, Vol. 2(11), pp. 298-307); and three papers in the Journal of the Transvaal Institute of Mechanical Engineers: "Tests of pumping engine No. 5 at the Zwartkopjes pumping station of the Rand Water Board" (1907/8, Vol. 6), "Education and training of artesans and mechanical engineers, with special reference to South Africa" (1909/10, Vol. 8) and "The measurement of compressed air" (1909/10, Vol. 8). He was a popular lecturer and led many excursions to mines and power stations. Though not regarded as a great engineer and not particularly theoretically minded, he was an excellent organiser and enormously industrious, a colourful figure, inclined to be overbearing, and informally known as "Jock".
All through his life Orr strove for the improvement of educational facilities and was interested in benevolent institutions of all kinds. For example, he delivered a paper on "Trade schools as aids to industry" before the South African Association for the Advancement of Science (Report, 1916, pp. 576-597). In December 1925, at the age of 55, he made a major career change by resigning his professorship to become director of the Witwatersrand Technical Institute (later the Witwatersrand Technical College), which took over the technical evening classes for artisans from the university. With his customary energy and indomitable will he worked tirelessly to establish branches of the college in every nearby town with mines or industries, namely Benoni, Boksburg, Brakpan, Germiston, Klerksdorp, Krugersdorp, Maraisburg, Nigel, Randfontein, Roodepoort, Springs, Vanderbijlpark, Venterspos, Vereeniging, and Witbank. This system of branches was eventually completed to Orr's satisfaction by the time he retired in April 1945. It constituted a major contribution to the development of technical education in South Africa, as reflected by the growth of the college's enrolment from 1 600 in 1925 to over 21 000 in 1945. His later publications included a brochure on Technical education and training (Johannesburg, 1932).
Orr played an active role in many scientific and technical societies and served on various bodies. From 1903 to 1909 he was an examiner for the University of the Cape of Good Hope, setting papers on drawing and graphics for its mining students. He was a foundation member of the South African Association for the Advancement of Science (in 1902), served as president of Section A in 1916, and as president of the association the next year. In his presidential address (published in the association's Report for 1917, Vol. 14, pp. 1-32) he dealt comprehensively with the development and work of the association. That same year he presided over a conference of more that 30 local scientific and technical societies, which adopted unanimously recommendation to government that the metric system be made compulsory in South Africa - to no avail. He was president of the Transvaal Institution of Mechanical Engineers (1908-1909) and later an honorary life member of its successor, the South African Institution of Mechanical Engineers; also a member of the South African Institute of Electrical Engineers; the Chemical, Metallurgical and Mining Society of South Africa; the (British) Institutions of Mechanical Engineers, Civil Engineers and Electrical Engineers; several American engineering societies; the Geological Society of South Africa; and the South African Geographical Society. Among others he served on the South African Engineering Standards Committee and its successor, the South African Standards Institute, forerunner of the South African Bureau of Standards, from 1909 to 1945, and as chairman from 1934 for a number of years; served on the Technical Education Board from its inception in 1912, and as its chairman from 1924; during World War II (1939-1945) commanded the Witwatersrand centre of the Central Organisation for Technical Training (COTT), which provided basic training for the army and war industries; was chairman of the Transvaal Mechanical and Electrical Apprenticeship Committee from its origin in 1925 until 1940; a member of the Government Assize Board from its inception in 1923 to 1948; a member of the Scientific and Technical Committee on Industrial Research (1917-1918); and a foundation member of the executive committee of the Associated Scientific and Technical Societies of South Africa, and president in 1937/8. His presidential address before the latter institution (Orr, 1938) was a comprehensive historical review of many scientific and technical societies in South Africa since 1892, and the cooperation between them. He was also honorary secretary to the Johannesburg Museum Committee for many years, served on the first Board of Management of the McGregor Museum, Kimberley, and on the governing bodies of two high schools in Johannesburg, belonged to several cultural orginisations, and rose to provincial grand master in the Freemasons.
In 1919 Orr was decorated as an Officer of the Order of the British Empire (OBE), mainly for his services as chairman of the Disabled Soldiers' Board after World War I (1914-1918). He received the King's Silver Jubilee medal in 1935, and two years later the King's Coronation medal. An honorary Doctor of Laws (LLD) degree was conferred upon him by the University of the Witwatersrand in 1936. The John Orr Technical High School in Johannesburg was named after him.