820 THE POPULAR SCIENCE MONTHLY. 



with a series of rocks which, up to that time, had received no full 

 elucidation in any country ; hence the necessity of comparing obser- 

 vations and views, with the purpose of agreeing upon some common 

 terms of designation became apparent, and very soon, imperative. 

 The comparison of observations and interchange of views led to the 

 opening of correspondence, by a formal resolution of the New York 

 Board, with other geologists, especially with those engaged in State 

 surveys, of which several were then in progress. This correspondence 

 led to an agreement for a meeting of geologists in Philadelphia in the 

 spring of 1840, and this assemblage of less than a score of persons led 

 to the organization of the American Association of Geologists, which, 

 at a later period, on the occasion of its third meeting, added the term 

 Naturalists ; and finally, by expanding its title, it became the Ameri- 

 can Association for the Advancement of Science. It is due to the 

 State of New York that these facts appear in this connection, and it 

 is but fair to state that her geologists have contributed largely to the 

 subjects of discussion and to the array of new facts which have been 

 brought before the scientific world through the agency of this organi- 

 zation. 



During the few years of field work, the New York geologists had 

 harmonized the conflicting views before entertained regarding the rela- 

 tions of the geology of the eastern and western parts of the State ; 

 they had traced the boundaries of the successive geological forma- 

 tions ; had shown the extent and limits of the iron-bearing strata, and 

 had rectified the erroneous views which had been held till some time 

 after the commencement of the survey, regarding the boundaries and 

 distribution of the salt-bearing formation of the State. They had, 

 also, shown the limits of the granitic formations, and their associated 

 mineral products ; the thickness and extent of all the limestone, sand- 

 stone, and shale formations of the State, and had definitely settled the 

 relations of the rocks of New York to the coal-measures of Pennsyl- 

 vania and the geological formations of the Western States. 



Their labors had in a great degree quieted the feverish anxiety 

 regarding the discovery of coal within the limits of New York, for 

 which frequent explorations had been made in the black slates of the 

 Hudson River Valley and elsewhere, involving the expenditure of 

 much money and loss of time.* A rational idea of the general geo- 

 logical structure, and the relations of the geological formations of the 

 State, had been acquired by the intelligent population, through the 

 annual reports of the survey, which presented the results of each sea- 

 son's work in the field. 



* Professor Mather has estimated, from what he regarded as reliable data, that the 

 fruitless coal-mining enterprises which had been undertaken in the Hudson Valley alone, 

 during the fifty years preceding 1840, had cost more than a quarter of a million of dollars. 

 The sums thus expended in other parts of the State, though doubtless much less, must, 

 nevertheless, have been very large. 



