Description: Papers of William N. Espy (1893-1975), M.S. '26, professor of mechanical engineering (1930-1961), including undergraduate notes, graduate notes, teaching notes, research results, newspaper and magazine clippings on thermodynamics, heat transfer, and mechanics, correspondence (1926-63), materials and letter concerning Tau Beta Pi (1922-50), materials on Pi Tau Sigma (1932, 1939, 1948) and books on mechanical engineering.