38 PROCEEDINGS OF THE BALTIMORE MEETING 



entered on his graduate study in the antnmn. During the vacation of 

 1897 he was a member of Dr. Whitman Cross's party in the San Juan 

 region of Colorado, and in the open season of the next year took up the 

 field-work for his doctorate in the northern Black Hills of South Dakota. 

 In June, 1899, he received his Ph. D., and having passed with high credit 

 the civil-service examinations for the United States Geological Survey, 

 he received an appointment and was sent back to the Black Hills, where 

 he studied the ore deposits under the general oversight of Dr. S. F. 

 Emmons. The appended bibliography will show the printed results ; but 

 the association began at this time with Doctor Emmons later developed 

 into much work together, and ultimately made of the younger man the 

 chief assistant, and finally the literary and scientific executor of the older. 

 Years afterward, when Doctor Emmons passed away, leaving in frag- 

 mentary and uncompleted state the great new monograph on Leadville, 

 John Irving finished the manuscript and forwarded it to the Survey 

 ready for the printer. 



The- field experience which Irving had gained in one Eastern and three 

 Western States before he had been three years out of college was later 

 amplified by work in many parts of the country. He assisted F. L. 

 Eansome in the Globe district of Arizona; worked with J. M. Boutwell 

 in the Park City district of Utah; prepared with W. H. Emmons the 

 economic geology of the Needle Mountains quadrangle, Colorado; with 

 Whitman Cross and Ernest Howe the description of the Ouray quad- 

 rangle; with S. F. Emmons the Bulletin on the Downtown District of 

 Leadville, and with Howland Bancroft the Bulletin on the Geology and 

 Ore Deposits near Lake City. He also did mapping of coal-bearing quad- 

 rangles in Indiana with M. L. Fuller and in southwestern Pennsylvania 

 with M. E. Campbell. 



These field experiences with parties of the United States Geological 

 Survey lasted long after he had taken up teaching and were chiefly per- 

 formed during the summer vacations. The desire to teach and to come 

 in close personal and formative relations with younger men grew stronger 

 and stronger in Doctor Irving and led him, in 1903, to begin his teaching 

 career as substitute for Prof. Wilbur C. Knight in the University of 

 Wyoming, when the latter was granted a year's leave of absence. The 

 following year a call to be Assistant Professor at Lehigh University took 

 him to South Bethlehem, and two years later he was promoted to the full 

 chair. In 1907 he was called to be Professor of Economic Geology in the 

 Sheffield Scientific School of Yale and shared in developing the mining 

 courses made possible by the gift of the Hammond Laboratory. In this 



