MEMORIAL OF C. W. HAYES 109 



trative duties. This was a period of enormous expansion of the non- 

 metalliferous economic investigations of the Federal Survey, especially 

 in the investigation of mineral fuels. The broad plan of making a de- 

 tailed survey of the coal and oil fields of the United States is essentially 

 that of Hayes. His immediate attention on assuming the new position 

 was directed to making available the existing information about the coal 

 fields. 



During the first dozen years of its existence the Federal Survey had 

 investigated many of the coal fields of tlie United States. A much 

 larger amount of work had been done by State geological surveys. By 

 these various agencies a large amount of data had been accumulated, but 

 this was scattered through many publications, for no summary had been 

 made since that contained in the Tenth Census, prepared under the direc- 

 tion of Clarence King. Meanwhile the coal-mining industry had grown 

 apace and the public had become deeply interested in the question of 

 mineral reserves. These conditions made a new summary of the data 

 relating to coal desirable, and to this end a plan was formulated, in co- 

 operation with E. W. Parker. It contemplated the enormous task of 

 summarizing not only the geology of the coal fields, but also the statistics 

 of production, together with a discussion of economic conditions. The 

 first of these tasks fell to Hayes. Within a year manuscripts describing 

 all the coal fields, prepared by ten authors, were submitted. These, when 

 printed, formed a volume of nearly six hundred pages. Hayes not only 

 supervised this work, but himself prepared two important chapters. 

 Summary reports on a number of other mineral deposits were also pre- 

 pared under Hayes's direction. 



Meanwhile, in 1902, Hayes first turned his attention to the geology of 

 petroleum. This was a field where his training in detailed structure w^as 

 to find its most important application. His personal investigations were 

 in Louisiana and Texas, but he also gave close attention to the California, 

 mid-continental, and Appalachian oil fields, Mdiere other geologists were 

 working under his direction. It was under his guidance that the refine- 

 ments of detailed stratigraphic and structural studies were first to be 

 applied in a large way. Mining engineers and geologists had, of course, 

 applied similar methods to small areas before Hayes introduced them 

 into the ]N"ational Survey. It remained for him, however, to show that 

 detailed structures could be worked out over large areas without an in- 

 ordinate expenditure of time and money. It was his success in the lo- 

 cating of oil pools that led to his being called later to the important 

 Mexican position. Hayes closed his career as an investigator by his 

 researches on oil. It is a great loss to the science of geology that con- 



