Feather 'slonhaugWs Geological Report. 109 



an easterly dip, whilst on the west side the beds are truncated, 

 and the greater portion of the mountain on this side seems to 

 have been carried away. The origin i have here attributed 

 to these ridges seems the more probable, when it is considered 

 that they only commence where the shales come in, which 

 being easily removed, soon cause the ruin of the superincum- 

 bent strata. 



In the vicinity of Bedford, which is remarkable for its effi- 

 cacious mineral waters, the limestone and shale alternate. 

 The limestone, in strong strata, contains impressions of pro- 

 ducta, sphifers, and cardia,.and in a crumbling shale superin- 

 cumbent, I found great quantities both of bellerophon and 

 goniatites. 



From this place I pursued a northwesterly course again, 

 towards the bituminous coal field, passing over the usual beds 

 of limestone, shale, and sandstone. Fifteen miles from Bed- 

 ford I again came upon the great horizontal deposites of the 

 country, from whence the waters flow to the Ohio, called here 

 the Backbone mountain, in many places the great Alleghany 

 mountain, but which, from its being the constant limit, during 

 its long course, of the great Western bituminous coal field,, 

 should be known by a general characteristic name. Here, on 

 the Shellburg road, the mountain is twelve miles from base 

 to base, and has a table land at the summit of eight miles 

 broad. Advancing to the summit, a regular millstone grit 

 occurs, with beds of conglomerate, underlain by shale; and 

 at the top, about half a mile to the right of the road, there 

 is a coal vein, worked by a person named Stotler, about seven 

 feet wide, with two feet of bituminous shale in the centre. 

 This vein is perfectly horizontal, and conforms to the subjacent 

 strata. 



From hence to Pittsburg, about eighty miles, the coal con- 

 stantly crops out in all the ravines and in descending most of 

 the hills. Opposite to this prosperous town, at the junction 

 of the Monongahela with the Ohio, there is a fine section, 



