Fonds consists of records (originals, printed materials, photographs and motion pictures) that are almost entirely of a professional and research nature, covering Barnes’ general scientific and university work during World War I, a number of special research problems, and his involvement in scientific and social organizations.

His general scientific and university files (1914-1915) contain correspondence, including copies of some of Barnes' outgoing letters on departmental adminstration, Barnes' lectures, publications, scientific apparatus, research problems and the exchange of information. Correspondents include colleagues in other institutions (including Ernest Rutherford), learned societies, and private industry. This series also contains a file on purchases for the University Library, and inventories of Barnes' library.

Far more extensive are the materials on special research problems. These comprise notes, essays and correspondence on the detection of submarines (1915-1917) and on the development of anti-freezing devices for fire extinguisher and sprinkler systems (1917). A report by Barnes on the effect of ice conditions on St. Lawrence navigaton is supplemented by printed background materials and copies, or extracts from other reports. Barnes' work on icebergs is documented by five binders of clippings, photographs, maps and diary notes on research expeditions to Newfoundland (1924-1929). Practical experiments in ice clearance are illustrated by bound notebooks of clippings and photographs, as well as a number of loose photographs showing ice and flooding damage, use of thermite and calcium chloride, apparatus and ice-crushers (ca 1921- 1929). Finally, two reels of 35 mm motion picture film (ca 1930) show Barnes experimenting with a new mercury microthermometer.

Barnes' work as Hon. Secretary of the Canadian Committee of the British Science Guild is documented by correspondence from 1907 to 1919, largely concerning the recruitment of members and officers, but also touching on a survey of science teaching in schools and the Panama-Pacific Exposition of 1917. Less extensive files cover Barnes' involvement in the International Council for the Exploration of the Sea (1912-1914), the Rotary Club (1917) and the McGill Graduates' Society (1919)

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.