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SCIENCE 



[N. S. Vol. XXXIII. No. 851 



introduced the plan of presenting outlines of 

 the geological relations of the ore bodies in 

 connection with the statistical data. 



The monograph and atlas on the " Geology 

 and Mining Industry of Leadville " were pub- 

 lished in 1888, although an abstract of results 

 had appeared as early as 1882. This great 

 work established the reputation of its author, 

 not only with men of science, who recognized 

 the care and thoroughness of the basal ob- 

 servations, the essential soundness of the de- 

 ductions and generalizations, the breadth of 

 view displayed, and the masterly treatment 

 and presentation of the material, but also 

 with the miners, who found that they could 

 sink shafts with the certainty of finding con- 

 tacts and faults substantially as Emmons had 

 drawn them in his remarkably accurate sec- 

 tions. The passing years, while they have 

 necessitated some modifications of the theoret- 

 ical conclusions advanced in this monograph, 

 have brought out more and more clearly the 

 sound basis of honest ability and conscientious 

 workmanship upon which lasting fame must 

 rest. The Leadville report was preceded in 

 publication by Becker's monograph on the 

 ■" Geology of the Comstock Lode and Washoe 

 District " and by Curtis's less extensive report 

 on the " Silver-lead Deposits of Eureka, Ne- 

 vada," but with these, and probably more 

 decisively than these, it marked the beginning 

 of a new era in economic geology and became 

 the model for the numerous monographic re- 

 ports on western mining districts that have 

 since been published by the United States 

 Geological Survey. 



Up to a few years ago Mr. Emmons con- 

 tinued in general charge of the investigations 

 on western ore deposits carried on by the U. S. 

 Geological Survey and many studies were 

 planned and completed under his supervision 

 and with his suggestive advice. In some 

 reports he appeared as collaborator — notably 

 in those on the " Economic Geology of the 

 Mercur Mining District " (U. S. Geol. Survey 

 Ann. Eept., 1895) ; " Economic Eesources of 

 the Northern Black Hills " (Professional 

 Paper No. 26), and the "Economic Geology 

 of the Bingham Mining District, Utah " (Pro- 



fessional Paper No. 38) ; in others his share 

 was less patent, although perhaps scarcely less 

 important. In the series of folios of the 

 Geologic Atlas of the United States he wrote 

 part of No. 9, " Anthracite-crested Butte, 

 Colo.," parts of No. 38, " Butte Special, 

 Mont.," and No. 65, " Tintic Special, Utah," 

 and the whole of No. 48, " Ten-mile Special, 

 Colo." During this period of administrative 

 and directive work he collaborated also as 

 senior author in the monograph (No. 27) on 

 the " Geology of the Denver Basin, Colo." 

 (1896) and published a paper on the " Mines 

 of Custer County, Colo." (1896). 



Among the many important contributions 

 made by Mr. Emmons to scientific journals 

 and to the proceedings of societies may be 

 mentioned " The Genesis of Certain Ore De- 

 posits " (1887) ; " Notes on the Geology of 

 Butte " (1887) ; " Structural Relations of Ore 

 Deposits " (1888) ; " On the Origin of Fissure 

 Veins " (1888) ; " Orographic Movements in 

 the Eocky Mountains " (1890) ; " Geological 

 Distribution of the Useful Metals in the 

 United States " (1894) ,• " The Secondary En- 

 richment of Ore Deposits " (1901) ; " Theories 

 of Ore Deposition Historically Considered " 

 (presidential address. Geological Society of 

 America, 1904) ; " Los Pilares Mine, Naco- 

 zari, Mexico" (1906), and "Biographical 

 Memoir of Clarence King " (read before the 

 National Academy of Sciences in 1903, pub- 

 lished in 1907). 



The paper on the secondary enrichment of 

 ores was the outcome of observations and 

 study extending over many years and it is 

 characteristic of Mr. Emmons's largeness of 

 mind that he discussed this principle freely 

 with his assistants and showed no haste to 

 secure to himself priority in announcing re- 

 sults whose great scientific and practical im- 

 portance he fully realized. 



At the fifth session of the International 

 Geological Congress, held in Washington in 

 1891, Mr. Emmons served as general secretary 

 and was the author of a large part of the 

 geological guide prepared for the excursion 

 by members of this congress to the Eocky 

 Mountains. He was also vice-president at 



