John C.S. Beynon, civil engineer, was a foundation member of the South African Association of Engineers and Architects (Johannesburg) in 1892 and an associate member of the (British) Institution of Civil Engineers. He practiced as a civil and sanitary engineer in Johannesburg until at least 1911. In 1903 he joined the South African Association for the Advancement of Science and the next year read a paper at its second annual meeting in Johannesburg on "The septic tank treatment of sewage". The paper was published in the association's Report for 1904 (pp. 434-440). At this time he had just completed such a sewage installation for 3000 people in Pretoria. The technique had only recently been developed and was being adopted on a large scale in Britain. His work on the topic continued, for in 1906 he delivered a second paper, on "Further experience in the bacteriological treatment of sewage", at the association's annual meeting in Kimberley (Report, 1906, pp. 380-385). This paper provided further details of the techniques being investigated.
Beynon was married twice, first to Alice C.F.E. Brodrick, who died in 1911, then to Clara Ada Bower, who died in 1937. He was survived by four children from his first marriage. He should not be confused with John Beynon, born in 1875, who came to South Africa in 1900 and was manager of the Transvaal Land and Trust Company, Ltd.