Excellent collection of short stories -- perhaps not too surprising given that the editors selected eight stories from ten extremely prolific years! You might get the impression that 1940s SF was rather depressing...
The surprise in Eric Frank Russell's "Hobbyist" was rather spoiled by Terry Pratchett having used the same story in "The Last Continent" (as the APF notes). But "Hobbyist" also deserves note for describing nanotech 3D printing, twelve years before Feynman's lecture.
ISBN 0330250337.