I got many invitations to speak at various universities and I found that in every place people were very receptive to my very simple nuclear theory based very largely on beta piles and a little bit more. And so I thought it would be useful to put it all down on paper. And sure enough one of my invitations was to Minnesota, which was the home of [John] Tate, the editor of the Physical Review, and Tate said 'Why, that's a wonderful idea. Why don't you write something for Reviews of Modern Physics?' So I began writing that. The first part was just about Static Problems, by myself... no, the first part was with... with Bacher. Bacher knew a lot about hyperfine structure, and its interpretation in terms of nuclear spin. And so he wrote the last chapter of this first part, and then the second part was about experiment, together with Livingston. And I expanded my calculations on stopping power for this purpose, and we put in together interpretation of a number of nuclear reactions. And while I was writing the first part Niels Bohr came out with his theory of the compound nucleus; and Fermi came out with his experiments together with four or five other Italian physicists on the action of neutrons on every nucleus in the periodic table, and he found radioactivities of many types.