List of sources:
Addresses and papers read at the joint meeting of the British and South African Associations for the Advancement of Science, South Africa, 1905 (Vol. 2). Johannesburg: SAAAS, 1906.
FamilySearch: Harold Scott Harger. https://ancestors.familysearch.org/en/9JJ1-XLV/harold-scott-harger-1870-1947 AND https://www.familysearch.org/ark:/61903/3:1:3Q9M-CS27-536X-N?view=index&personArk=/ark:/61903/1:1:6ZCM-FZW2&action=view&cc=2821281
Geological Society of South Africa. Proceedings, 1915, Vol. 18, p. xiii-xix and 1920, Vol. 23, p. xii-xvi: Past presidents, and Lists of members; Transactions, 1897, Vol. 2.
Hall, A.L. A bibliography of South African geology.... Pretoria: Geological Survey, Memoirs No. 18 (1922), No. 25 (1927), No. 27 (1931), and No. 30 (1937).
Harger, H.S. Historical notes on the Geological Society of South Africa. Proceedings of the Geological Society of South Africa, 1939, Vol. 42, pp. lxvii-lxxiv.
Harger, H.S. Historical notes on the Geological Museum of Johannesburg. Southern African Museums Association Bulletin, 1942, Vol. 2, pp. 293-298.
National Archives Repository (TAB), Source MHG, Vol. 0, Ref. 4736/47: death notice, Harold Scott Harger.
Pask, T.P. An historical note of 1897. Transactions of the South African Institute of Electrical Engineers, 1930, Vol. 2(11), pp. 240-243.
Royal Society of South Africa. Transactions, 1908-1910, Vol. 1 and 1917, Vol. 6: Lists of Fellows and members.
South African Association for the Advancement of Science. Report, 1905/6, 1910: Lists of members.
South African Committee for Stratigraphy (SACS). Stratigraphy of South Africa. Part 1. Lithostratigraphy... (p.335). Pretoria: Geological Survey of South Africa, Handbook 8, 1980.
South African Philosophical Society. Transactions, 1906-1907, Vol. 16-17: Lists of members.
South African who's who, 1908.