Although there are some critics who admire Love's Pilgrimage and Sylvia, and though there is much in both books to show the diversity of Sinclair's talent, it seems to me that King Coal (1917) is the first book after The Jungle to indicate his full power as a novelist of the social scene. If the people of the upper class are sometimes stiff and inhuman, the workers have great vitality; and so has Hal, the aristocratic hero. What is most impressive in King Coal, however, is the evidence that Sinclair had learned how to assimilate the vast quantities of information his restless mind collects. There are no solid blocks of exposition in King Coal as there are in The Jungle; the documentation is there, but it is an essential part of the story.

Rather surprisingly, Sinclair did not continue the artistic advance made in King Coal. The fiction written...