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PIONEERS OF SCIENCE IN AMERICA. 



adds : " Prof. Eaton was among the first in this country to 

 study Nature in the field with his classes. In pursuance of this 

 idea, he used to make an annual excursion with Rensselaer 

 School, sometimes leading these expeditions in person, at others 

 deputing some competent teacher to take the lead. The cause 

 of natural history in Williams College owes, undoubtedly, a 

 good deal to Prof. Eaton. I think his zeal in the department 

 of botany led Prof. Dewey to direct his discriminating mind 

 to the study of plants, a study which he pursued further than 

 Prof. Eaton had done in certain lines. ... At this time, also, 

 Dr. Emmons took the field. In fact, natural history came on 

 with the spring tide, and has never lost the impulse since." 

 While at Albany, in 1818, on the invitation of Governor Clin- 

 ton, delivering a course of lectures before the members of the 

 Legislature of New York, Prof. Eaton became acquainted with 

 many leading men of the State, and interested them in geology 

 and its application by means of surveys to agriculture. Here 

 was planted the idea which eventually fructified in that great 

 work, The Natural History of New York. In the same year 

 Prof. Eaton published his Index to the Geology of the North- 

 ern States, which has been pronounced " the first attempt at a 

 general arrangement of geological strata in North America." 

 Although under the undeveloped condition of geology at the 

 time, with the defective knowledge even among its advanced 

 students, this book could not fail to contain many state- 

 ments now known to be errors, it must be recognised as a 

 creditable and valuable effort. An interesting view of the 

 conditions of geology at the time and of the method of study 

 is given in a letter which Prof. Eaton wrote to Mr. Henry R. 

 Schoolcraft, in 1820, while preparing a second volume of his 

 Index. In it he said : " I have written the whole over anew, 

 and extended it to about two hundred and fifty pages, i2mo. 

 I have taken great pains to collect facts in this district dur- 

 ing the two years since my first edition was published, but I 

 am rather deficient in my knowledge of secondary and alluvial 

 formations. I wish to trouble you with a few inquiries on that 

 subject. From what knowledge I have been able to obtain 

 in that department, I am inclined to arrange the secondary 

 class thus : Breccia, compact, or shell limestone ; gypsum, sec- 

 ondary sandstone. I leave much, also, for peculiar local for- 

 mations. A gentleman presented specimens to the Troy Ly- 



