The Book of the Week is Universe by Robert A. Heinlein, one of the most important authors of the "Golden Age" of science fiction. Universe tells of a group of people inhabiting a strange enclosed environment -- they do not realize they are living in a spaceship sent off on a generations-long journey to another star system. Heinlein later expanded the story into the novel Orphans of the Sky. The cover art for Universe is by Robert Stanley, best known for his covers of mystery and western novels, few of which gave him a chance to draw characters with two heads.
Universe was #36 in Dell's series of dime novels published in 1951. It was the last Dell Dimer to be published and was the only science fiction title in the series. Similarly, few if any of the original Nineteenth Century dime novels could fairly be called science fiction, although many involved hot-air balloons, steam engines, and other high-tech (for the time) devices. In contrast, science fiction played an important role in the pulp magazines, which is why pulps are generally of more interest to SF collectors like me than dime novels. Next week we will begin to take a look at early science fiction in the pulps.