154 C. SCHUCHERT THE NORTH AMERICAN GEOSYXCLIXES 



came into being, besides the path-finding Federal ones of Foster and 

 AMiitney in the Lake Superior country, and the railway- sun^eys across 

 the Eock}' Mountains of Emory, Marcy, Pope, Ives, l^ewberry, and 

 Macombe. The stratigraphic results of these many and widely spread 

 geologic and geographic efforts stand recorded chiefly in the ^yQvk of 

 Hall, Yanuxem, and Emmons in Xew York and elsewhere, of Hitchcock 

 in New England, of the brothers Rogers in Pennsylvania and Virginia, 

 of Safford in Tennessee, of Owen in the Mississippi Valle}^, and of Daw- 

 son and Logan in Canada. 



In the matter of mountain origins, the path was blazed first by the 

 Rogers brothers and later by James Hall, followed by James D. Dana 

 and Joseph Le Conte. The area of their generalizations was chiefly the 

 Appalachian Mountains, extending from Tennessee through the Vir- 

 ginias, Pennsylvania, New York, Vermont; thence northeast through 

 Quebec to Gaspe. As early as 1842 the Rogers brothers offered an ex- 

 jDlanation, not only for the structure of the Appalachians, but for their 

 causes as well, though H. D. Rogers did not see his epochal ''Final Reports 

 on Pennsylvania'^ published until 1858. 



The pioneer theory of mountain-making which is of most interest to 

 us at present, however, was that of James Hall, first formulated in his 

 presidential address on the "Geological history of the North American 

 Continent," before the American Association, at Montreal, in 1857 — ac- 

 cording to J. M. Clarke, Hall's ''most notable performance in philosoph- 

 ical geology,'' having "all the exciting interest of novelty." This address 

 had to do with the procedure of mountain-making and continental uplift. 

 "It was a carefully thought out course of argument,^' continues Clarke ; 

 "but obviously Hall presented it with tentative caution and some degree 

 of timidity — at all events, with entire absence of finality — for he would 

 not permit its publication in the usual way in the next year's volume of 

 the Association's proceedings." ^ 



In the meantime Hall hinted at his ideas in the "Geology of Iowa" 

 (1859), and set them forth more in detail in the third volume of the 

 "Paleontology of New York," published in 1861. Even after reading 

 this more extended account, however, one gets no such clear mental pic- 

 ture of HalFs theory as in the original statement of 185T, first published 

 in 1883.-^ Hall's views are not yet altogether clear, and it is therefore 

 no wonder that "the geologists went away from Montreal shaking their 

 heads," and that shortly afterward Hall was told by Dana that he had 



3 J. M. Clarke : James Plall, of Albany, geologist and paljpontologlst, 1021. p. 325. 

 * James Hall : Contributions to the geological history of the American continent. 

 Troc. Amer. Assoc. Adv. Sci., vol. .31, pp. 29-69. 



