the four sheets before him the geologist, mining engineer, Landowner, or other inquirer has in view in graphic form all that the geologist can tell him of the area. A general text accompanies the folio; and, when considered necessary, a full, detailed description will be published in the form of a bulletin. This is as far as the director of the survey considers that he is legally authorized to go in the preparation of a geologic map. On the scale now used this map will require many years for its completion. Its value depends upon its thoroughness, and it is thought that quality, up to the scale adopted, is to be considered before the question of area. The standard adopted is to do the field work up to and beyond the scale of the map, and to represent on the map all that the scale will permit. The result thus far is shown in the folios published, and the folios of the future will prove the quality of the work now being done. Cost and practical working methods limit the ideal perfection of field work and of the resulting maps; but in all cases the ideal standard will be aimed at, and the attempt made to present the best results obtainable under the conditions surrounding the work.
Economic Work.—Some one has said that utility is the bane of science, and a greater man has written that Philosophy is never more exalted than when she stoops to minister to humanity. Geology is essentially practical in many of its branches, and thus commends itself to those interested in the material welfare of individuals, communities, and nations; and, at the same time, its great problems concerning the history of the evolution of the earth and of life, including man, command the attention of intelligent mankind. In its economic aspect the Geological Survey touches the interests of the people in many and varied ways. Human endeavor is limited to the surface of the earth and its immediate underground resources, and whatever is of assistance here is an aid in the development of the higher material civilization.
In the first place, good topographic maps are essential. They are needed in the construction of roads of all kinds, and in problems of water supply and drainage. In all future military operations such maps will be of service. As a basis for representing the distribution of mineral resources they can not be dispensed with, and in all investigations relating to the surface of the earth they are of great value.
Mineral Resources. The organic law of the survey provides that the director shall have charge of the examination of the mineral resources and products of the national domain. This has been interpreted to mean a statistical examination of the products from the mineral resources, and a geologic examination of their occurrence and character. The former has led to the compilation
