Fonds consists of original documents and printed materials concerning King’s research, but there is also some general correspondence, student materials, and personal papers.

Research materials comprise manuscripts, addresses, and research notes. The manuscripts and addresses (1901-1933) contain essays on fog-signals and the transmission of sound, radiation, the physics of viscous fluids, the hot-wire anemometer, astronomy, and theoretical problems. The research notes (1904-1935) comprise approximately 50 files. Eight of these concern fog-signal research (1915 1926) and include some correspondence. Other topics include radiation, physics of gases and liquids, acoustics, astronomy, electromagnetism and mathematical problems.

General correspondence covering the years 1908-1936 contains letters from his fellow physicists, including Rutherford, A.N. Shaw, E.S. Bieler and H.T. Barnes, on research and personal matters. There are also letters of introduction (1905), correspondence regarding his appointment at McGill, letters to the editor of Nature (1926), the National Research Council (1933-1934), and the Central Computing Bureau (1918). As well, files concerning ice research (1920), tests at Prescott, including his diary of the expedition (1920), and the St. Lawrence waterway (1931-1932) can be found here.

King's private papers comprise a diary for 1902, reading notes and reviews of Maria Chapdelaine (1919-1921), his pension papers, and an inventory of periodicals in his library. There are also two formal photographs and a number of snapshots of school groups, Cambridge scenes, and laboratory equipment.