[on filming 'San Francisco'] The big-theater-nightclub set for this picture, in which Miss McDonald warbled her lovely lyric soprano, occupied all of Stage 12 at MGM. There had been some argument about the destructive movement of an earthquake. I supported the 'horizontal' theory, while others insisted that it was the vertical 'rolling-ups-and-downs' which caused the damage. An expert from California Polytechinc College in Pasadena was contacted, and I won. In fact, he commented that our 'schematic' for the set actually represented the very kind of an 'earthquake table' upon which, in small scale, Cal Tech experiments were conducted.