If you went into the average library as you motored across America in 1932, 1945, or 1953 you would have found: No Edgar Rice Burroughs. No L. Frank Baum and no Oz. In 1958 or 1962 you would have found no Asimov, no Heinlein, no Van Vogt, and, er, no Bradbury. Here and there, perhaps one book or two by the above. For the rest: a desert.
