308 



NOTES ON A MAP INTENDED TO ILLUSTRATE 



pressing interest, for they showed to the Government at Washington what a herculean 

 task it would be to operate with large armies upon the Central Valley of Virginia and East 

 Tennessee, from the Ohio as a base. A glance at this map will explain the long continu- 

 ance of the Rebellion, — the shifting fortunes of the fight, — the repeated losses of the 

 national arms in Western Virginia, — the necessity for that favorite project of Mr. Lin- 

 coln's, a railroad from Louisville to Knoxville, which he was induced to abandon only by 

 the threats of Kentucky, — the peculiarly anti-secession posture of North Carolina, the State 

 of the Smoky Mountains, — and some other points of the history of the last four years, — 

 better than the most elaborate written descriptions alone could do it. 



I should be glad to offer the whole map to the Society for publication ; but it would not 

 bear reduction to a scale small enough for these Transactions, without losing many of 

 its most interesting features. I have been content, therefore, to select an area which 

 would show the above five specified kinds of topography, and at the same time some of 

 the variations to which two of them are subject, viz.: 1. The broadening of the Blue 

 Ridge belt near its southern end, and its double structure as it runs north into Pennsyl- 

 vania ; and 2. The difference between the looped structure of the Appalachians, about 

 Winchester, and their duplicated straight outcrops, cut off by oblique faults, in the neigh- 

 borhood of Knoxville. 



I have selected this area for other reasons also : the principal one being a hope that it 

 may pique the scientific zeal of some of our younger geologists to study this almost un- 

 trodden ground. There are not more than one or two reliable topographical maps of all 

 the area exhibited here, and these are very local. It is a grand field for study, and will 

 bear splendid delineation. 



But there is one remarkable feature of this particular area, which holds in reserve, as I 

 believe, the future explanation of one of the largest of our American structural pro- 

 blems — the cause of the rectangular opposition of the southwest- and northeast-outcrop 

 and fault system of the Appalachians to the southeast- and northwest-outcrop and fault 

 system of the lower Ohio, upper Mississippi and lower Missouri region. In the centre 

 of the map it will be seen, that the New River (or Kanawha) heads not, like all the other 

 affluents of the Ohio, on the inside edge or at the brow of the great backbone-escarpment 

 of the Alleghanies, but starts from the recesses of the Blue Ridge, and among the heads 

 of the Atlantic seaboard rivers; that it penetrates the Appalachian belt; and that it finally 

 enters and passes through the Cumberland or Alleghany Plateau, to the Ohio River, by 

 which, in fact, it is continued, almost in the same straight line, to Cincinnati. Now I 

 have no doubt, that with this strangely exceptional thorough-cut, is dynamically connected 

 the 350 fathom fault, which runs parallel to and just north of the New River, and the 

 south side of which carries up the floor of the great Silurian Valley almost to the height of 



