1856.] Pomeroy, Ohio. 511 



Here, after a short interval of open road, we again enter the earth, 

 upon the same level where the operation of mining is now carried on, 

 the first hill through which we had passed being considered as ex- 

 hausted. The speed with which we traveled in this mine forbade our 

 observations of the character of the rocks. 



AN EXHAUSTED 3HINE. 



Our next excursion was made in company with Mr. Staa-r, Super- 

 intendent, as our intelligent guide into an old shaft in the eastern 

 part of the town. AVe entered on foot, each carrying a lamp. Here, 

 as generally, the passage was too low to admit even the shortest of 

 us to stand erect, being scarcely five feet high. Occasionally we met 

 a depression in the rock above, reducing the passage to three feet! 

 Then, immediately beyond, the ceiling would arise to seven feet for 

 a short distance, affording us an opportunity for straightening our 

 weary backs — a privilege highly appreciated. These depressions are 

 called horse-hacks^ whether from their resemblance to the inverted 

 back of that animal in a fossil state, or because the backs of the 

 recent animals get a hard rubbing in these places, we did not learn. 

 In every instance we observed, at the sides of these horse-backs, frac- 

 tures in the rock whos<3 sides were glazed, polished, and scarified with 

 parallel striae as if subjected to friction under immense pressure; in- 

 dicating that these depressions in the rock overlaying the coal are 

 the result of a movement subsequent to the deposition of the strata. 

 The coal-bed, being less solid in these places than elsewhere, yielded 

 to the enormous pressure of the superincumbent rock, which thus 

 subsided, causing the friction of mass against mass, as mentioned 

 above. 



THE EOSSIL FLORA. 



In these passages and deserted chambers, which we traversed for 

 nearly a mile, we often found our way obstructed by heaps of rocks 

 fallen and falling from the ceiling. The shales above were every- 

 where cleaving and crumbling, and occasionally a slab was heard to 

 fall, remote or near, so near in one instance as to give us a broad hint 

 of the propriety of making good our retreat from the jaws of the 

 mountain, while yet we might. But our guide, Mr. Starr, was too 

 well acquainted with these scenes to regard the danger of crumbling 

 shales; and laughing at our apprehensions he led us forward, and 



