The Age of Petroleum began with sudden and dramatic power on August 27, 1859, when the first commercial oil well was completed near Titusville, Pennsylvania. The story of oil and of the industrial and social transformations it brought about in the century following the Titusville discovery is a rewarding one in itself. But J. Stanley Clark has provided extra insight into this great development by tracing also the course of production techniques from rank waste to conservation. Here is a story of the quick grab for mineral riches; of unpredictable results in times when geology had as yet few or no applications; of wild-flowing wells and insufficient storage and pipeline facilities; of consolidations and mergers and small and large facilities; of attempts, fumbling at first, precise and effective later, to exploit the hugh subterranean storehouse of oil and natural gas. In short, it is the record of the greatest bonanza of them all. For a country grown accustomed to high-speed individual transportation, Mr. Clark's reconstruction of certain events will seem almost incredible. As late as 1920, the oil industry and its twin, the automobile industry, literally had no place to go. Public roads were deplorably inadequate - so much so that oil-field trucks had to give way to mules in moving equipment to well locations. But the slow triumph of road construction and the fast accelerating development of other fields have given the country what it may keep as long as it has access to a well-managed petroleum resource, at home and abroad.