THE review of the petroleum industry in the United States by Hale B. Soyster and members of the U.S. Geological Survey, Bureau of Mines and Petroleum Administrative Board, recently published by the U.S. Department of the Interior (Circular 11), gives an authoritative, unbiased survey of the American petroleum industry to-day, besides supplying up-to-date statistics of production, stocks, imports and exports. A vital fact is that petroleum reserves, both proved and unproved, are limited and irreplaceable. Wastage, whether physical or economic, is to be deplored and must be combatted with carefully planned and controlled development of all supplies. Latterly, knowledge of methods of preventing waste of both oil and gas and conserving natural energy necessary for recovery of these substances, has rapidly increased, but there are still varied forms of economic waste, to some of which it is difficult to find a solution. Competitive development and premature extraction of petroleum still characterise a majority of new fields and will continue to do so as long as the theory of ‘capture and reduction to possession’ holds sway.