The land-classification idea is of course the basis of the National forest and irrigation movements. The laws of 1888 and 1896, which mark the beginning of active endorsement by Congress of these conservation movements, placed upon the Survey the duties of examining reservoir sites and forest reserves respectively. The earlier of these laws began the investigation of the water resources of the country, which is still an important phase of the Survey’s activity, and led to the creation of an independent organization—the Reclamation Service. It is easy to trace the beginnings of Federal reclamation of arid lands in the pioneer work of Powell, whose report in 1878 on the arid region of the United States was the first adequate statement of the problem of largest use of these lands in terms broader than those of individualistic endeavor. For years, however, Powell’s appeal for Congressional consideration of this National task was like the “voice of one crying in the wilderness.” In a somewhat similar way the forestry surveys under the Geological Survey helped in the organization of a separate bureau—now the Forest Service. The other important Federal bureau tracing direct relationship to the Survey is the Bureau of Mines, established in 1910, which continued the investigations in mining technology specifically provided for by Congress for six years under the Geological Survey but in some degree begun in the early days of the Survey under Directors King and Powell. Another equally important organization of a public nature, though not a Federal bureau, traces its beginnings to the Geological Survey: the Geophysical Laboratory of the Carnegie Institution, which now exercises so potent an influence over geologic investigation, had its origin in the official work of the Geological Survey’s Division of Chemical and Physical Research, and its personnel was at first largely recruited from the Survey. The highly original experimental work of this laboratory has extended far beyond the scope of the Survey’s work—at least far beyond the scope possible with the Federal funds available—yet most of the results of these investigations may eventually come under even a strict construction of the language used in the Survey’s appropriation “for chemical and physical researches relating to the geology of the United States.” The topographic work of the present Survey continues with constant refinement of standards and economy of methods the work of the earlier organizations. The primary purpose of these topographic surveys is to provide the bases for geologic maps, yet these topographic maps, which cover 40 per cent of the area of the United States, are used in every type of civil engineering as well as by the public generally. The annual distribution by sale of half a million of these maps is an index of their value to the people.