This collection contains considerable material relating to aviation history, particularly in western and northern Canada, including material on: the Keng Wah Aviation School for Nationalist Chinese pilots; the RCAF; illustrations of the technology of flight; reference material; and microfilms of the Hudson Strait Expedition fonds (1927-1928) and "The Bulletin" (Western Canada Airways, 1929-1937). Additionally, there is material on Tweddell's other research interests, notably aerial mapping and surveying.

This fonds contains information concerning various professional associations, including the American, Canadian, and Saskatchewan Psychological Associations; Government departments and agencies, such as the Defense Research Board, the Women's Bureau, and the National Research Council; and the Royal Commission on Health Services. There are also several files of lecture and research notes (including work done with Dr. Jaques), personal correspondence, and departmental material, including reports, curriculum, recruitment, and promotion; as well as two of Dr. McMurray's abstracts: "Theories of Pain and Congenital Universal Insensitivity to Pain" and "The Background of Thought and Language."