MEMOIR OF JAMES D. DANA. 463 



logical time. The idea of study of "causes now in operation" as the 

 basis of induction in geology had been indeed introduced before Lyell, 

 especially by Hutton and Playfair, but Lyell first thoroughly and sys- 

 tematically used it and constructed a geological science upon it. So also 

 the idea of development of the earth was conceived before Dana, but 

 Dana first reconstructed geological science on this basis. As long as the 

 Lyellian idea of geology prevailed, the philosophic classifiers of the 

 sciences were justified in regarding it as a mere field for the application 

 of physics, chemistry and biology. Geology became one of the great de- 

 partments of abstract science with its own characteristic idea and its own 

 distinctive method under Dana. This I know is putting Dana on a very 

 high pedestal, but I am quite sure he deserves that position. 



The history of his life has already been presented by one far more 

 competent to do so than I — his own distinguished son. It is therefore 

 wholly unnecessary to give any extended account. Nevertheless, for the 

 sake of completeness and for the information of those who have not seen 

 the memoir referred to, I take from it the main points of his life. 



He was born at Utica, New York, February 12, 1813, of intelligent 

 New England parents, and died in New Haven, Connecticut, April 14, 

 1895, having therefore reached the great age of eighty- two years and two 

 months. His early taste for science was fostered, and the right method 

 in its pursuit — that is, by direct contact with nature — was taught him by 

 the example of his early teachers. In 1830 he entered Yale College, 

 where his scientific activity was still farther stimulated by intimate asso- 

 ciation with the elder Silliman, then in the zenith of his reputation. 

 Immediately on completing his college course in August, 1833, he entered 

 on a voyage of fifteen months as instructor in mathematics of the mid- 

 shipmen of tlie United States navy. In this capacit.y he visited many 

 points in and about the Mediterranean and took advantage of this op- 

 portunity to study the phenomena of volcanoes, and his first paper, pub- 

 lished in Silliman's journal in 1835, was on Vesuvius. Thus early were 

 his thoughts turned on interior earth forces. On returning he became 

 an assistant in chemistry to Silliman. la 1838 the United States Govern- 

 ment sent out an exploring expedition to circumnavigate the earth. On 

 this Dana was appointed naturalist. The fleet of five ships sailed in 

 August, 1838, and returned to New York in June, 1842, after an absence 

 of nearly four years. The scientific fruits of this famous expedition will 

 be discussed later. 



With the exception of these two voyages, Dana's life, like those of most 

 scientific men, was uneventful in the ordinary sense. His activity and 

 his achievements were almost wholly in the field of thought: but there 



