206 TRANSACTIONS OF THE 



I know, however, that the western beds dip towards 

 the centre at Blossburg, and that it is wholly uncon- 

 nected with any other coal district, along at least five 

 sixths of its external margin. The northern edge of this 

 basin rises to the summit of the Armenia mountain, and 

 the southern margin caps the Elk mountain ; and so in- 

 sulated in fact is the geological arrangement prevailing 

 throughout, that convenience suggests the adoption of 

 the term I have thought proper to apply to it. 



Northward of this mineral district it would be in vain 

 to search for these coal strata; for independent of the 

 geological character of that country being dissimilar, 

 consisting almost wholly of the old red sandstone, there 

 is no ground lofty enough to contain them in that di- 

 rection, unless in the case of another insulated basin, 

 which the structure of the whole region negatives. 

 Sufficient data are also at hand, wherewith to form a 

 decisive estimate of the relative position of the coal 

 measures of Blossburg and the northern rock formations ; 

 and to show that as the dip of stratification is, almost 

 without exception, towards the south, there must be an 

 enormous elevation of land indeed in the north, ere it 

 could be capped with the carboniferous deposits. 



A rapid recital of some of these data, in a sectional 

 line from the south to the north, will render this position 

 more intelligible. 



Beginning at Blossburg, the upper coal series of Bear 

 creek is found to be about 130 feet lower than the same 

 beds in East creek, to the north ; the rise in that direc- 

 tion is here therefore 80 per mile. 



Three miles below Blossburg, the Tioga running north, 

 there is a regular dip, at the rate of 260 feet to the mile 

 to the southward, which increases until, at 17 miles dis- 

 tance, it is about 500 feet in a mile, and then decreases 

 to 200 feet per mile, to the distance of 26 miles at the 

 state line between Pennsylvania and New York. Con- 



