His introduction says that he set out to prove that you can have science fiction mysteries with Caves of Steel and these are his short story science fiction mysteries. I enjoyed reading them again. They're not great prose but the mysteries are still interesting, as is Dr. Urth, the Mary Sue of the stories. The latest of the stories is 41 years old, so they are a bit dated. There are forewords with the stories that explain why he wrote them and so forth.
I had some trouble finding a copy and this one smells of dust so I think that may be why my nose keeps running. It needs a new home and if you would like it for the cost of postage, let me know. If you've never read the stories, you might enjoy them, and if you have, maybe you'd like to read them again! LJ gets first go, then ML, then it goes to the Friends of the Library, so it won't be homeless.