July 28, 1916] 



SCIENCE 



125 



placement of several miles, and proved that 

 they are characteristic and essential features 

 of Appalachian structure where the thrust was 

 concentrated on a single fold. The discovery 

 of these faults, the importance of which was 

 first recognized by Hayes, and their coincident 

 mapping in another area by Keith, with sub- 

 sequent fuller elaboration by Keith, Willis and 

 Campbell, established what may, in. effect, be 

 regarded as a geologic principle that has influ- 

 enced the interpretation of geologic structures 

 in many other parts of North America. 



Meanwhile modern physiography, largely an 

 American product, which was then being or- 

 ganized and made a science by Powell, Gilbert, 

 Russell and Davis, found an enthusiastic dis- 

 ciple in Hayes, who, with Campbell, began to 

 apply the principles of the new science in the 

 interpretation of the surface features of the 

 field in which he was at work. Their first 

 paper, " Geomorphology of the Southern Ap- 

 palachians," published in the National Geo- 

 graphic Magazine, is regarded generally as 

 the standard work on the physiography of the 

 region covered, and as having laid a broader 

 foundation for physiographic investigation in 



In 1891, Hayes participated as geologist in 

 an Alaska expedition by Lieut. Frederick 

 Schwatka, during which a region between the 

 Yukon and Copper Rivers, not previously seen 

 by white men, was traversed with topographic 

 sketching and observations on the geology, 

 geography and mineral resources. Some re- 

 sults of this, at that time very difficult explora- 

 tion, including data on the northern limit of 

 Pleistocene glaciation in Alaska, on recent 

 volcanic activity, and on the distribution of 

 gold and copper in the region, were contrib- 

 uted in the National Geographic Magazine for 

 that year. To the insight then gained by 

 Hayes of the possibilities of mineral wealth in 

 Alaska which then was little known, was due, 

 in no small part, the organization, later, by the 

 Geological Survey of the systematic investiga- 

 tion of the geology and mineral resources of 

 Alaska. 



As Hayes became more strongly identified 

 in the economic work of the Geological Survey, 



more attention was given by it to the syste- 

 matic investigation of the non-metalliferous 

 and the fuel mineral resources of the country. 

 As a result of his special interest and personal 

 accomplishments in this department of the 

 survey activities, he was, in 1899, placed in 

 charge of the newly established Section of 

 Non-metalliferous Resources. In 1902, he was 

 made chief geologist of the survey, in which 

 position he continued until his resignation in 

 1911. 



At the request of the military governor of 

 Cuba, Hayes was, in March of 1900, detailed 

 to make a reconnaissance of the economic geol- 

 ogy of that island. The principal results of 

 his observations on the island, supplemented 

 by those of his assistants, T. Wayland Vaughan 

 and A. C. Spencer, were contributed in a re- 

 port to General Wood. 



In response to a request from the State De- 

 partment, Hayes was, in 1907, detailed to make 

 a geological investigation in Nicaragua and 

 Costa Rica, primarily for the advice of the 

 Nicaragua Canal Commission. Some accounts 

 of this work, which occupied also a part of the 

 following year, were embodied in several 

 papers, chief among which is his report to 

 Admiral Walker, president of the commission, 

 on the " Geology and physiography of a region 

 adjacent to the proposed Nicaragua canal." 

 This is a principal source of information as to 

 the geology of that part of Central America. 



On account of the interest taken by citizens 

 of the United States in the important dis- 

 coveries of oil in Mexico, and of the apprehen- 

 sion as to the effects of these discoveries upon 

 the oil industry of this country, Hayes, in com- 

 pany with David T. Day, was, in 1909, selected 

 to visit the new developments in the southern 

 republic. Following his return to this coun- 

 try, a report was transmitted to the President, 

 a summary of which appeared as a Senate 

 Document (No. 79), stating that the Mexican 

 oils were of fuel grade, being inferior to most 

 of the American oils, and that their principal 

 markets were likely to be found in Mexico 

 itself and in other foreign countries. 



In 1910, Hayes was, by request of the War 

 Department, sent to Panama to procure data 



