14 THE U. S. GEOLOGICAL SURVEY 



with the Isthmian Canal Commission and the Smithsonian 

 Institution for geologic studies in the Canal Zone. 



Development of Survey's Functions. The broad pur- 

 poses of the Survey's work have remained constant through- 

 out its history, but its functions and the manner of their per- 

 formance have undergone many changes from time to time. 

 These will here be briefly outlined, detailed discussion of the 

 development of particular activities being reserved for the 

 following chapter. 



The organic act of 1879, together with the amending act of 

 1882, specified four distinct functions to be performed by the 

 Survey — the geological survey of the public lands, the classifi- 

 cation of the public lands, the examination of the geological 

 structure and the mineral resources and products of the na- 

 tional domain, and the preparation of the geologic map of the 

 United States. 



At first the Survey took the position that by the term "classi- 

 fication of the public lands," Congress did not intend to imply 

 a detailed survey of the individual tracts of land in the public 

 domain, with respect to their inclusion under the provisions of 

 one or another of the public land laws, but merely a general 

 survey of the soil and mineral characteristics of the lands. 

 In effect, therefore, this portion of the law was regarded as 

 adding little if anything to the clauses calling for the geologi- 

 cal survey of the public lands and for the examination of the 

 mineral resources and products of the national domain, and 

 in this interpretation Congress apparently acquiesced, as it was 

 followed by the Survey for many years without evoking any 

 change in the phraseology of the successive appropriation acts. 



The authority to prepare a geologic map of the country 

 was construed by the Survey as giving authority to prepare 

 also a topographic map ; the position being taken that a geo- 

 logic map could properly be prepared only if a topographic 

 map were available as a base. 



In accordance with the interpretation of the statutes the early 



