List of sources:
Cape of Good Hope. Report of the Meteorological Commission, 1895-1897, 1899.
Cape of Good Hope. Report of the Surveyor-General, 1903.
FamilySearch: Harry D'Arcy Fortescue Harrison. https://www.familysearch.org/ark:/61903/3:1:3Q9M-CS7R-KHX1-R?view=index&personArk=/ark:/61903/1:1:QPC7-YTN4&action=view&cc=2573604
General Directory of South Africa..., 1903.
Journal of the Institute of Land Surveyors of the Transvaal, 1905, Vol. 1(1), list of members.
National Automated Archival Information Retrieval System (NAAIRS).http://www.national.archives.gov.za/naairs.htm Documents relating to Harrison, Harry D'Arcy Fortesque.
Ritchie, W. The history of the South African College, 1829-1918. Cape Town: T. Maskew Miller, 1918.
Transvaal Civil Service List, 1906, pp. 147-148: Government Land Surveyors.
University of the Cape of Good Hope. Calendar, 1904/5.