Personal records of Robert William McKay, Professor of Physics, University of Toronto. Contains high school prize essay; physics course notes from University of Toronto; Treatise on Thermodynamics; copy of his doctoral thesis; drafts of papers; offprints and notes relating to research, including that carried out for the Department of Defence during World War II on Japanese paper 'fire' balloon bombs, 'Fu-Go' and mechanical parts and wooden circuit board from a Fu-Go; high school textbook written by McKay and Donald Ivey.