The authors, who are prominent on the faculty at California Tech, have summarized here their mutual conclusions after a series of fact-finding discussions held with industrial leaders on questions of long-range economic forecast. Primarily, what are the potential fuel and food resources of the earth, and how are these resources apt to be utilized by man? All of the speculations stem from accredited knowledge and statistics, and also from reasonable projections of the role of newly emerging fuel supplies-that is nuclear and solar energy. The intervention of some unforeseeable force or discovery or social change into this airtight scheme of things is serenely overlooked. And with this necessary omission, the destiny of the industrial world which the authors conjure up seems persuasive enough. Solar energy is likely to prove expensive for general consumption, there may be a real lack of science teachers unless teaching is made more attractive financially, and it is to be hoped that the papulation will level off at about the 7,000,000,000 mark. These and other problems and possibilities form a discussion piece of interest and concern to industry and science alike. That will be the market to approach.