FOR assistance in the prosecution of this study, the basic material of which was presented for the degree of Doctor of Philosophy at Yale University, the author has many debts of gratitude. To the members of the staff of the Yale, Congressional, and U. S. Department of Commerce libraries, thanks are due for their aid in the search for references. Acknowledgments are likewise extended to the personnel of the Bureau of Foreign and Domestic Commerce (particularly the Minerals Division), the Department of Agriculture, the U. S. Bureau of Mines, and the War Department for their kindness in making available information which could not otherwise have been procured. Special recognition is due Mr. J. Edward Ely for his indispensable assistance in the compilation of statistics and in the arrangement of the charts and maps, Miss Ethel Peterson for the drafting of the latter, and Miss Phyllis Parker for her stenographic aid. Finally the author is particularly obligated to Prof. N. J. Spykman of Yale University, Prof. W. Y. Elliott of Harvard University, Lt. Colonel C. T. Harris of the Office of the Assistant Secretary of War, Dr. William P. Rawles, Secretary of the Planning Committee for Mineral Policy, and Mr. Frank H. Simonds for their reading and criticism of the manuscript, and to the Bureau of International Research of Harvard University and Radcliffe College under whose auspices this book has been published.
B. E. Washington, D. C. June, 1934