Arthur Cyril Jennings, civil engineer and colonial administrator involved in water and land development in Southern Rhodesia (now Zimbabwe), was educated at the Simon Langton Schools in Canterbury, England. He started his career in southern Africa as assistant engineer of the Sand, Palmiet and Bulk Rivers New Water Scheme near Port Elizabeth. After a period as chief assistant engineer for the Telephone Company of Egypt, in Cairo, he became resident engineer at the Kougapoort and Reenen irrigation schemes on the Gamtoos River near Port Elizabeth. During World War I (1914-1918) he served with the rank of captain in the South African Water Supply Corps and during the last two years of the war was with the forces in the East Africa Campaign. By 1922 he was Irrigation Engineer in the Administration of Southern Rhodesia (now Namibia).
Jennings was an associate member of both the (British) Institution of Civil Engineers and the Institution of Electrical Engineers. He became a member of the Rhodesia Scientific Association in 1919 and served as its president for 1935/6. In 1923 he was appointed by the city council of Salisbury (now Harare), with F.E. Kanthack* (chairman) and W.B. Leane, as a committee of inquiry to investigate and report on the failure of Cleveland Dam near the town. Jennings published a report on the investigation and the resulting repairs in the journal Civil Engineering (1925, Vol. 23(1), pp. 75-81).
Other publications by Jennings included: "Rainfall statistics" in the Rhodesia Agricultural Journal (1918, Vol. 15, pp. 535-536) in which he provided information about the average air temperature and rainfall for various periods of observation for five stations; "Soil washing" (Southern Rhodesia, Department of Agriculture, Bulletin No. 400, 1921); "Erosion, especially surface washing in Southern Rhodesia" (South African Journal of Science, 1923, Vol. 20, pp. 204-207); "Water supply development in native reserves" (Nada, 1923); and "Land apportionment in Southern Rhodesia" (African Affairs, 1935). At the time the latter paper was published he was assistant director of native lands in Southern Rhodesia.
Jennings served on the council of the South African Association for the Advancement of Science for 1926/7, representing Southern Rhodesia. At the association's annual congress held in Salisbury (now Harare) in 1927 he was president of Section A and delivered a presidential address on "Irrigation and water supplies in Southern Rhodesia" (South African Journal of Science, 1927, Vol. 24, pp. 21-29). In 1943 he married Mary Gladys Lucas.