Mark Kac, Alan J. Perlis, John W. Carr. Notes on Lectures delivered by Professor Mark Kac, Cornell University. Applications of Statistical Methods to Differential and Integral Equations. MIT, November 1949.   1949/1950 (?) 11”x8.5”, 38 leaves, offset from typed sheets. Bound in a manila two-hole punch folder; homemade title label on cover. Very much an in-house production by two grad students producing the notes for the Kac class. Only ONE copy located by WorldCat/OCLC (Padua). Scarce $150

On Kac: “From 1939-61 he was at Cornell University, first as an instructor, then from 1943 as assistant professor and from 1947 as full professor. While there, he became a naturalized US citizen in 1943. In the academic year 1951–1952 Kac was on sabbatical at the Institute for Advanced Study. In 1952, Kac, with Theodore H. Berlin, introduced the spherical model of a ferromagnet (a variant of the Ising model) and, with J. C. Ward, found an exact solution of the Ising model using a combinatorial method. In 1961 he left Cornell and went to The Rockefeller University in New York City. In the early 1960s he worked with George Uhlenbeck and P. C. Hemmer on the mathematics of a van der Waals gas. After twenty years at Rockefeller, he moved to the University of Southern California where he spent the rest of his career.”–Wikipedia

Perlis (numerical analyst who would get his Ph.D. at MIT in the next year) and Carr are both prominent figures in the history of computing, Perlis especially so (particularly in the development of programming languages, ALGOL 58, ALGOL 60, etc., and  founder and first editor of ACM Computing Reviews).  and in the See JAN Lee’s Computer Pioneers.