Thank you for wasting my time ;-). That story was in "Los Alamos from Below," which may not have been part of "Surely You're Joking." Feynman was a fascinating guy and an excellent writer, even if he was a bit too young to be a serious player in the Manhattan Project. By the way, if you're interested in physics, these are about as good as it gets: http://www.feynmanlectures.caltech.edu/