The hot discussion that was waged for years on the question of military versus scientific administration of topographic surveys is in striking contrast with the present concentration of all the topographic mapping under the Geological Survey in those areas where it may best serve the needs of the Army. In 1916 Congress specifically recognized the possibility of greater cooperation of this kind, both in the appropriation made to the Geological Survey and in a special appropriation made to the War Department. For a number of years indeed special military information had been contributed to the Army by the Survey topographers, but since March 26, 1917, every Geological Survey topographer has worked exclusively on the program of military surveys laid down by the General Staff of the Army, and the places of some of the 44 Survey topographers now in France as engineer officers are filled by 34 other reserve engineer officers detailed by order of the Secretary of War to the Director of the Geological Survey to assist in this military mapping and to receive instruction fitting them in turn for topographic service in France. The contribution of this civilian service to the military operations in the present emergency forms a fitting conclusion to this review of a century of Government surveys. At present 215 members of the Geological Survey are in uniform, 107 as engineer officers, two of whom are on the staff of the American Commanding General in France. In the war work carried on in the United States the Survey’s contribution is by no means limited to military mapping: the geologists are also mobilized for meeting war needs, assisting in developing new sources of the essential war minerals, in speeding up production of mineral products, in collecting information for the purchasing officers both of our own and of the Allied governments, in coöperating with the constructing quarter-masters in the location of gravel and sand for structural use and in both general and special examinations of underground water supply and of drainage possibilities at cantonment sites, and in supplying the Navy Department with similar technical data. A special contribution has been the application to aërial surveys of photogrammetric methods developed in the Alaskan topographic work and the perfection of a camera specially adapted to airplane use. The utilization of the Survey’s map engraving and printing plant for confidential and urgent work for both the Army and Navy has necessitated postponement of current work for the Geological Survey itself. Throughout the organization the records, the methods, and the personnel which represent the product of many years of scientific activity are all being utilized; thus is the experience of the past translated into special service in the present crisis. _Notes._ Footnote 96: Hess, R. H., Foundations of National Prosperity, p. 100. Footnote 97: Report Nat’l Museum, 1904, pp. 189–733.