1034 GEOLOGY OF OHIO. 
have been opened in this field, and it is at the present pretty well 
occupied. < oteih 
A single mine has been opened in each of the remaining seams, 
but one is dormant and the other has not a very vigorous life. It is, 
however, certain that the limestone coal, by reason of its good volume, 
fair quality, and unbroken persistency, must at no distant day become 
the basis of a considerable mining industry in the county. 
