GOVERNMENT GEOLOGICAL SURVEYS 215 



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 sur- 

 veys 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 con- 

 clusion to this review of a century of Government sur- 

 veys. 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 gov- 

 ernments, in cooperating 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 Depart- 

 ment with similar technical data. A special contribution 

 has been the application to aerial surveys of photogram- 

 metric 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 post- 

 ponement of current work for the Geological Survey 

 itself. Throughout the organization the records, the 

 methods, and the personnel which represent the product 



