40 PROCEEDINGS OF THE BALTIMORE MEETING 



the conceptions of replacement, leads him to seek criteria whereby re- 

 placement bodies may be identified. 



And then, while in the active exercise of his many nsefnl activities, 

 came the war of German aggression. As its early months passed, and 

 every thinking American realized that his country could not maintain 

 much longer its supine attitude, while common decency as well as civilized 

 life hung in the balance, I know from intimate talks with John Irving 

 that he became convinced that he should respond in person to the call. 

 Being unmarried, he felt it his duty to go to Plattsburg, although he was 

 beyond forty years of age. He entered the ofiicers" training camp in the 

 summer of 1916 and took up its routine earnestly and seriously. He 

 passed through the grades of non-commissioned officer, and when the 

 camp closed entered his name as one available for service if conditions 

 called for him. The following spring the anticipated conditions ma- 

 terialized. He was commissioned captain, was assigned to the Eleventh 

 Eegiment of Engineers, and was granted leave of absence by the authori- 

 ties of Yale. He sailed for France in July, 1917. We are permitted by 

 the censor to know that he was early engaged in railway construction and 

 worked at top speed to maintain these arteries of supply for the army in 

 full activity. His duties brought him under shell-fire, and he learned to 

 keep his nerve under these trying conditions. Later, when dug-outs, tun- 

 neling, and the exploding of mines beneath the enemy's works achieved 

 such importance, he was transferred to the Engineers' school at head- 

 quarters, and was busy with a seemingly endless procession of classes to 

 be instructed in the rudiments of mining engineering. His letters show 

 that the calls were hard, exacting, and exhausting. He returned again 

 to the front, met a class or two of engineers there, was stricken with the 

 Spanish influenza, and developed pneumonia, against which he had not 

 the strength to rally, although every resource of modern medicine was 

 used to aid him. July 20 his name was added to the honor roll. 



John Duer Irving was a man of the highest ideals of service, whether 

 the service was rendered to his students, his university, or his country. 

 His duties were discharged faithfully and with a deep sense of responsi- 

 bility. The magazine Economic Geology was a labor of love. The time 

 of Professor Irving was never so valuable but that a student could com- 

 mand advice and guidance. The full strength and more of Captain 

 Irving was given to his country. As a geologist his work is marked by 

 painstaking care and a conscientious ambition for accuracy. He was 

 given to thinking out his problems to a carefully grounded solution. In 

 literary expression he is clear and easily understood, and in these respects 



