Concern over natural resources not only persists in the contemporary world but may be intensifying. World war, cold war, the race in space, and the almost universal push toward economic development have individually and collectively, constructively and destructively, renewed public and private interest in natural resource requirements and availabilities. Planners in various countries, capitalist or socialist, require fairly comprehensive resource information before they can hope to succeed in preparing lines of economic policy. Answers have to be found for a wide range of questions. Is the domestic resource base sufficient to meet present and anticipated claims on it? If not, can technology be relied upon to produce substitutes or more economical processes? Failing or supplementing this, are foreign supplies realistic alternatives? And finally, how accurate are estimates of resource capabilities and needs?