List of sources:
Chemical and Metallurgical Society of South Africa. Proceedings, 1899, Vol. 2, list of members.
Chemical, Metallurgical and Mining Society of South Africa. Proceedings, 1903, Vol. 3, list of members.
De Villiers, R. & Brooke-Norris, S. The story of the Rand Club (p. 175). Johannesburg: Rand Club,1976.
Google Patents. https://www.google.com/patents/US766165
Men of the times: Pioneers of the Transvaal and glimpses of South Africa. Johannesburg: Transvaal Publishing Company, 1905.
National Archives Repository, Pretoria (TAB). Source MHG, Reference 16674. Estate documents, Thomas Johnson Britten.
South African Association of Engineers and Architects. Proceedings, 1897-1898, Vol. 4, lists of members and office bearers.
South African Who's Who, 1908, 1909.