Notes: Information on this book from The Whole Science Fiction Data Base No. 4, ABE and WorldCat. Worldcat gives date as 1931, which is date of original edition, and gives page count incorrectly as 188 pages. "Possibly 1948 When Hillman Reportedly First Published Softcover Books, But Some Reports Indicate This Series Published 1943; There Is A Full Page Ad On Inside Rear Cover"For Defense Buy United States Savings Bonds And Stamps"." [info on date from seller on Biblio.com]