This is a collection of Cope's articles, papers, notes, lectures, notebooks, and some correspondence. There is much on his research pertaining to Charles Mason and Jeremiah Dixon, and other topics in the history of science on which he wrote. The collection includes lecture notes and three bound notebook volumes on mechanics from his study at the University of Berlin under Max Planck from 1912 to 1913. There are 11 additional bound volumes, all relating to physics, including: Minutes of meetings of the Department of Physics, University of Pennsylvania (1910-1919), two volumes on the history of physics, and a volume of data on the radiometer as a measurer of electric current. The collection also contains notes on electric circuit theory lectures (1924-1925) by J.R. Carson, notes on lectures on relativity (1921) by Albert Einstein, lectures by W.F.G. Swann (1928), and information about the Pennsylvania Academy of Science, and on radiation (1909). There is significant correspondence from Lionel G. Dixon and Victor Englehardt.

After receiving his doctorate from Harvard in 1923, the physicist John Clarke Slater did postgraduate work at Cambridge University and on the continent working n quantum theory with both Niels Bohr and Werner Heisenberg. Slater was appointed to the head of the department of physics at MIT in 1930, which he and Karl Compton worked effectively to transform into one of international stature. His own work on the electromagnetic theory of microwaves was fundamental to the development of radar systems. During the Second World War, he was affiliated with the radiation laboratory and after he helped found the solid state and molecular theory group, the interdisciplinary Center for Materials Science and Engineering, the Research Laboratory of Electronics, and the Laboratory for Nuclear Science. After his retirement from MIT in 1966, Slater moved to the University of Florida, remaining active until his death in 1976. The Slater Papers contains a wealth of information on the development of physics at MIT, as well as Slater's post-1966 work at the University of Florida. There are about 133 (7 linear ft.) research notebooks, 1944-1976, and a long series (30 linear ft.) of folders, containing lectures, scientific notes, drafts of manuscripts and papers, correspondence during his collaboration with the Los Alamos Labs, 1966-1970, and extensive correspondence relating to the National Academy of Science. Information about American-Swedish exchange in quantum science is located in the correspondence with Per-Olov Löwdin.