1969 marked the return of the Cryogenic Engineering Conference, now affiliated with the National Academy ofSciences through the Division ofEngineering, National Research Council, to the University of California at Los Angeles. As in 1962, the Cryogenic Engineering Conference gratefully acknowledges the assistance of UCLA, its Engineering and Physical Seien ces Extension Division, and in particular J. Dillon, S. Houston, H. L. Tallman, and their stafffor...