Unlike most of the earlier books in this series, this is not so much about the acquisition of knowledge as about the increasing role of oil in human affairs. But it's instructive nonetheless to approach today's varied uses of oil via an explanation of the formation of oil--and thereby to understand the difference between petroleum products with different-size hydrocarbon molecules. Otherwise the text describes early uses of oil (pitch to make ships watertight, and later to burn in lamps); the widespread burning of "coal gas," of kerosene derived from "oil shale," and finally of kerosene "refined" from petroleum; the new importance of oil as a fuel; and the present supply situation and impending shortage. Topic by topic, the text packs a great deal of information into a few pages; the illustrations, however, are grim. Uninviting but useful for its large view.