Interview in four sessions, February 1979 and April 1982, with Arthur L. ("Maj") Klein, who entered Throop College, the predecessor of the California Institute of Technology, in 1916. When R. A. Millikan arrived as the institute's head, Klein decided to change his major from mechanical engineering to physics in order to work with him, earning his bachelor's degree in 1921 and a PhD in 1925. He stayed on as a research fellow in physics and soon become involved in the activities of the new Guggenheim Aeronautical Laboratory at Caltech (GALCIT), along with Clark B. Millikan and the aircraft designer Arthur E. Raymond. He became an assistant professor of aeronautics in 1929. Klein designed much of GALCIT's 10-foot-diameter wind tunnel, which went into operation in 1929, and he later helped design the Southern California Cooperative Wind Tunnel (1945), which was financed by five Southern California aircraft companies and operated by Caltech. Klein was also responsible for many aspects of the design and testing of important aircraft, including Douglas Aircraft's DC series. He had begun consulting for Douglas Aircraft in 1932; by 1937, he was spending half his time there and half at Caltech, and this arrangement continued until his 1968 retirement from Caltech as a full professor in the Division of Engineering and Applied Science
