In this series Asimov found his metier. These books, are clear, fascinating, and quite simple. No details to get lost in, but plenty to satisfy the curious adult reader who knows nothing about the subject, like me!

This one is especially good, covering the nature and origins of petroleum, the use of its products in ancient and more contemporary times, the innovation of actually drilling for it, the dependence on foreign oil of many populous nations, and the question of where to go from here as petroleum reserves are depleted. I believe that "fracking" is also forecasted, although not under that name. As in a prior book "How Did We Find out about Nuclear Power?" Asimov anticipates nuclear fusion power, optimistically.

David Wool had become the regular illustrator on this series. He did his usual excellent work, with diagrams of molecules, portraits of significant individuals, a diagram of a nuclear refinery, and several tableaux, as for example a picture of a whale hunt. ( )