The records relate chiefly to the erection and administration of the laboratory buildings and their contents. Indeed, the earliest records are vouchers for equipment purchased by James Clerk Maxwell, first Professor, in 1876-9. There are also smaller quantities of records relating to laboratory clubs, 1902-72, the celebration of the Clerk Maxwell centenary, 1931, research programmes, 1960-92, including the Cambridge Energy Research Group, and applications to work and study at the laboratory, 1944-78. Much of the administrative correspondence, 1930s, is written by J.D. Cockcroft (1897-1967), then departmental lecturer.