AMERICAN GEOLOGY SURVEYS UNDER HAYDEN. 605 



Hayden's scientific career, so promisingly begun, was, however, inter- 

 rupted by the outbreak of the civil war, when he promptly volunteered, 

 entering the Union army as an assistant surgeon and gradually rising 

 to become post-surgeon and surgeon in chief to the Twenty-second 

 Division of Cavalry. In June, 1865, he resigned from the army, but 

 was subsequently breveted lieutenant-colonel for meritorious conduct. 

 In the same year he was elected professor of geology and mineralogy 

 in the University of Pennsylvania, holding this chair until 1872, when 

 he was forced to resign, owing to his rapidly increasing duties in con- 

 nection with the Geological Survey. 



In 1879, after the consolidation of the various surveys. Doctor Hay- 

 den was appointed one of the geologists on the new organization. Dur- 

 ing the next four years his time was devoted mainly to the completion 

 of the business and final publication of the reports of the Geological 

 and Geographical Survey of the Territories. His health began failing 

 soon after his acceptance of this position, and in .June. lss w J. at his own 

 request, he was relieved from the work of supervision of printing the 

 reports and assigned to duty in the held, spending the summers of 

 1883-ISsh in Montana. His disease {locomotor ataxia), however, grew 

 steadily upon him, and in 1886 he resigned on account of complete 

 incapacity for duty, thus closing a career of nearly thirty years of 

 actual service as naturalist, surgeon, and geologist in connection with 

 the Government. 



The apparent diffidence which impressed Doctor Hayden's fellow- 

 students at Oberlin, and led them to be doubtful as to his future course 

 in life, characterized his maturer years, and to those not well acquainted 

 with him made it difficult to account for his success. However, enthu- 

 siasm, perseverance, and energy were qualities equally characteristic 

 of him all his life, and what seemed to be diffidence was largel}" the 

 result of his nervous temperament. The secret of his success is to be 

 found in his enthusiastic frankness and his energetic determination to 

 carry through whatever he undertook. He was absorbed in the work 

 of the Geological Survey and bent all his energies to its success. 

 Excitable in temperament and frequently impulsive in action, he was 

 generous to a fault, and, although ever ready to defend what he believed 

 to be right, he was willing upon the presentation of evidence to modify 

 his views. 



He was always careful to give due credit to all who had worked in 

 the fields he afterwards explored. In one of his reports, speaking of 

 those who had preceded him, he says: 



Any man who regards the permanency or endurance of his own reputation witl not 

 ignore any of those frontiersmen who made their early explorations under circum- 

 stances of great danger and hardship. 



The same spirit actuated him in his treatment of his subordinates 

 and co-workers. His honesty and integrity were undoubted and his 

 work for the Government and for science was a labor of love. 



