The collection includes two series of lectures given at the informally organized Los Alamos University and attended by employees of the Los Alamos Laboratory. The first series, entitled 'LA Report 24: Lecture Series on Nuclear Physics', is comprised of typewritten, mimeographed notes on lectures given in 1943-1944 by: Felix Bloch, Robert F. Christy, C.L. Critchfield, Edwin M. McMillan, Emilio Segr,̈ Edward Teller, Victor F. Weisskopf, and John H. Williams. Topics include: diffusion theory, neutron physics, the statistical theory of nuclear reactions, terminology, the two body problem, and radioactivity. The second series of handwritten, mimeographed notes on advanced topics in physics is in two volumes. Volume One (1945-1946) contains notes from lectures given by: Hans A. Bethe (assisted by Robert E. Marshak), Lyman G. Parratt (assisted by Bruno Rossi and John W. Trischa), Rudolf Peierls (assisted by Robert F. Christy and Klaus Fuchs), John Manley and Victor F. Weisskopf (assisted by Bernard T. Feld and Julian Schwinger). Volume Two (1945-1946) comprises notes from lectures by: Joseph Keller (assisted by Julius Askin and Chaim Richman), George B. Kistiakowsky, Leonard Schiff (assisted by Eugene M. Baroody), and Edward Teller (assisted by Robert F. Christy and Emil J. Konopinski). Topics include: electromagnetic theory, hydrodynamics, modern physics and nuclear physics (vol. 1); quantum mechanics, statistical mechanics, theoretical mechanics, and thermodynamics (vol. 2). The collection comprises notes taken by attendees of the lectures, and also some compiled by the lecturers. The notes were collected by Jack H. Smith during his employment at Los Alamos.