John Wesley Powell told the Allison Commission in 1885 that "Sound geologic conclusions cannot be reached by following a few narrow lines of investigation, but all such lines of research must be followed that each may shed light upon the other. Unless this principle is fully recognized, a geologic survey might lead to conclusions of no value to the people at large, or conclusions might be reached so erroneous as to be misleading." The principle is sound, but Powell, like many others of his time, did not fully comprehend the magnitude of the task that he proposed of encompassing all knowledge of a given science before applying any part of it.

The same principle may be applied to history but would obviously produce the same impossible task, and therefore, it is customary to deal with limited portions of history or with a particular aspect. Nonetheless, as explained in Volume 1, it was decided not to treat Survey history from a thematic point of view, although it would have been possible to consider the Survey in that way, as a Government agency, as a research institution, in terms of its-contribution to the industrial development of the country, or to the conservation of its natural resources and preservation of its environment. All of these are only facets of the total Survey, and rather early in the study of Survey history it was discovered that focusing on a particular aspect could easily, and in fact has, led to conclusions far different from those drawn from consideration of the whole. In the traditional view of the Survey's first 25 years, which are the subject of much of this volume, John Wesley Powell, with his broad view of science and advanced ideas of land and water in the West, is the heroic figure. Clarence King is dismissed as brilliant but with a limited view of science as mining geology, and Charles D. Walcott is regarded primarily as a brilliant paleontologist chosen by Powell to succeed him. The Survey's first quarter century, however, spanned a watershed in American history that separated a primarily rural and agrarian nation and a primarily urban and industrial nation, a nation intent on conquering the continent and isolated from the Old World and a nation involved in world politics, a nation that believed in the virtues of competition and limited government and a nation that saw the virtue of cooperation and insisted on reform and regulation to ensure equal opportunities to all. Science itself changed during this period. The age of instruments was just beginning when the Survey was established; by the turn of the century, instruments had almost revolutionized science and the era of the lone investigator had to give way to an era of organized effort in the solution of problems.

When these facts are taken into consideration, it can be concluded that the importance the Geological Survey achieved in its first 25 years, in fact its longevity, should be attributed not to the broad view of science taken by John Wesley Powell, but to the foresight of Clarence King in organizing the Survey's research to aid in the industrial progress of the country while seeking ultimately the advancement of science and to the perspicacity, administrative skill, and seemingly limitless energy of Charles D. Walcott, who held that the Survey's field was geology and not all science, who directed its research toward the aid of not just the mineral industry, as envisioned by King, but of all industries and practical undertakings that would benefit from a knowledge of the Earth and its resources, and who insisted that basic research and applied science cannot be separated. The development of economic geology as a science and not just applied geology must be considered one of the achievements of this era, and to this development, the Geological Survey was a major contributor.

Economic geology, however, was not the sole achievement. There were advances in other fields, sometimes as part of economic geology, sometimes apart from it, to name but a few: the growth of petrography and petrology, the development of glacial geology, the definition of mapping units, stratigraphic classification, and geologic time divisions, the conservation of water, changing standards of topographic mapping, the emergence of geophysics and geochemistry. Each of these could fill a separate book. The detailed indexes will help those who wish to follow a particular development or to obtain a bird's-eye view of the variety.

Basic to all, however, is the idea that Federal science must respond to national needs as perceived at the time in order to remain healthy. And so the presentation must be chronological rather than thematic. In time-honored Survey fashion, the facts are presented and a conclusion drawn, but acceptance of the conclusion must rest of the facts, not on any special pleading.

I should like to acknowledge my indebtedness to many members of the Geological Survey for their help in preparation of this volume. In particular, I wish to thank Thomas B. Nolan, Director, 1956-1965, for his interest, encouragement, advice, and many useful discussions; Arthur A. Baker, former Associate Director, Vincent E. McKelvey, Director, 1971-1978, and Clifford M. Nelson, Associate Historian, 1976-1980, for thorough and detailed reviews of the manuscript; and other reviewers, including R. H. Lyddan, R. P. Southard, Morris Thompson, George H. Brett, G. D. Robinson, and E. Roy Hendricks for valuable suggestions.

vi