DANA CENTENARY 67 



On Taconic rocks and stratigraphy, with a geological map of the Ta- 

 conic region. 1885' and 1887. 



On the origin of the deep troughs of the oceanic depression. Are any 

 of volcanic origin? 1889. 



In this last paper he showed that these troughs could not be due to under- 

 mining by extraction of volcanic material nor to erosion by oceanic currents, 

 nor, again, to the ordinary laws of isostacy as we now understand them. He 

 felt that we must look to deeper lying causes for their solution. This paper 

 well illustrates a characteristic voiced by the speaker who has preceded me : 

 "I have found it best to be always afloat in regard to opinions in geology." 



As editor of the American Journal of Science, a position which he occupied 

 from 1846 until almost the day of his death, Dana naturally had occasion to 

 review either himself or through assistants nearly every publication on geo- 

 logical matters which appeared in America, with incidental reference to much 

 that was foreign, and the manner in which these papers were handled is a 

 striking illustration of his mastery of detail and breadth of view. In his 

 original papers — original as distinguished from reviews — he covered a range 

 of subjects that would seem almost absurd in one of the present day, as I 

 have already indicated— dynamic, structural, paleontologic, petrographic — pa- 

 pers dealing with the minutest structural details to those in which world 

 history is involved. The only branch which he let alone, even ignoring it 

 largely in reviews, was that relating to the origin of ore deposits, and this, I 

 think, may be accepted as another illustration of the breadth and acumen of 

 the man! 



In reading his papers, however, one must bear in mind the condition of 

 knowledge at the time they were written. Those on the geologic results of 

 the earth's contraction and the grand outline features of the earth were dan- 

 gerously theoretical and the subject one to delight the heart of the old-time 

 cosmogonist. Yet though he wrote, as Huxley would say, "with one eye on 

 fact and the other on Genesis," his vision never became confused nor his reason 

 confounded. He saw processes and effects, conceived certain possibilities, and 

 reasoned to conclusions. These conclusions, in the light of today, may not in 

 all cases be correct, but in their time they appeared justifiable. Other men 

 may have made more striking observations, perhaps more brilliant discoveries, 

 but they had not his breadth and staying power. 



Dana's early experience was undoubtedly of a kind best suited to bringing 

 out the latent qualities of a broad mind. It will be remembered that in 1833, 

 when little more than twenty years of age, he became :»n instructor in mathe- 

 matics in the navy, and in this capacity visited the Mediterranean region and 

 made the condition of Vesuvius the subject of his first geological paper. Again. 

 from 1838 to 1842, he was geologist and mineralogist to (lie Wilkes Exploring 

 Expedition, and as such made the long trip around Cape Horn to the Islands 

 of the South Pacific and back across the continent. That he utilized to ad 

 vantage the opportunities thus afforded there can be no question. 



Passing today the window of the room formerly occupied by bini as ;i study, 

 I looked up half expectant of seeing that thin, keen, Intellectual face, sur- 

 mounted by its halo of snow-white hair; but it is gone for all time. The 

 memory of it shall remain so long as memory itself remains. The work be 

 accomplished shall remain so long as a study of the fundamental problems of 



