146 Prof. Rogers's Address before the 



Hall, Mather and Vanuxem ; through Ohio by Briggs, Lawrence, Locke 

 and Owen ; through Upper Canada, north of Lake Erie, by my brother 

 and myself; through Michigan by Houghton and his corps ; through In- 

 diana, Illinois and part of Wisconsin by Owen and Locke ; through 

 Kentucky and Middle Tennessee by Owen and Troost, and southward 

 along the broad Appalachian chain and the coal fields west of it in 

 New Jersey and Pennsylvania, by myself and corps ; in Maryland by 

 Prof. Ducatel, my brother and myself; in Virginia by my brother and 

 his corps, and in East Tennessee to Alabama, by my brother and my- 

 self. From Lake Champlain therefore, westward to the mouth of the 

 Wisconsin river, a distance of at least eleven hundred miles, and south- 

 ward to Alabama over a still larger and very complicated tract, and 

 throughout the entire triangular area included between these limits, the 

 boundaries of each of our Palaeozoic Appalachian formations have been 

 determined, and with very considerable precision. To a result so prac- 

 tically useful, so fraught with scientific benefit, so creditable to our 

 young country, the numerous geological surveys by state authority, 

 either completed or begun, have principally contributed. 



Although but seven or eight years have elapsed since most of the 

 surveys of the wide region before us were instituted, so diligent have 

 those engaged upon them been, that we are now almost ready to unite 

 the whole of our lines, into one comprehensive and huge map of the 

 entire Appalachian basin. If there were a general map of the United 

 States, or a series of state maps based on a common scale, it might even 

 now be practicable, combining the published data with the yet unpub- 

 lished materials for Pennsylvania, Maryland, Virginia and East Ten- 

 nessee, in the possession of my brother and myself, to produce a geo- 

 logical picture of the wide surface mentioned, upon which should ap- 

 pear each special formation in all its separate belts or outcrops. The 

 real condition of topographical geology, is indeed already such, that our 

 treasures are beyond the size of the caskets which should contain them ; 

 and much that has been deciphered, the most beautiful structural fea- 

 tures, it is feared must go unwritten, not for want of scribes certainly, 

 but because of the narrowness of our tablets, because of the insurmount- 

 able impediments from bad geographical maps. A tolerably correct 

 and clear delineation of the limits of the strata is practicable enough, 

 with imperfect maps, where the rocks are nearly horizontal, and their 

 outcrops are wide and not tortuous, and, therefore, from the Mohawk 

 westward, the formations are depicted with sufficient precision in the 

 geological map of New York, and in the unpublished one of the states 



