THE LOWER COAL MEASURES. 239 
ping banks in time to come, but in any case, small mines, but of con- 
siderable aggregate importance, are sure to be maintained in these de- 
posits for a long period. 
THE CAMBRIDGE CoAL FIELD. 
We have now reached the confines of the great development of the 
seam in Guernsey county. In parts of Cambridge, Center, Jackson and 
Valley townships, the Upper Freeport coal scores its highest mark in 
Ohio. In quality the seam is nowhere else quite as good as here. In 
thickness the Cambridge coal has an advantage, at its best, of a foot 
above either of the other fields that are based upon this seam. In 
steadiness and persistency, though very much is to be desired, perhaps not 
quite as much is to be deplored as in the two eastern districts already de- 
scribed. There are several mines of large extent in which no interruption 
has yet been encountered, but in almost all, more or less serious “ horse- 
backs” and “ wants” are met. In a number of the mines, the interrup- 
tions of continuity have proved very unfortunate, but in no case have © 
they brought complete failure to the mining enterprises established on 
the coal. 
The Cambridge coal field does not extend to the limits of the 
village of Cambridge, but it occupies the southern tier of sections of 
the township. It goes under drainage not far from the eastern boundary 
of Cambridge, the Scott mine being the last that is level free. It 
extends, in its best volume and conditions, through the central portions 
of Jackson township, and through the northeastern sections of Valley 
township. In the main, the areas now described form portions of the 
valleys of Will’s Creek and of Leatherwood Creek, from which, and 
from the minor tributaries of which, the coal has been, in‘ all instances, 
attacked. The seam goes under drainage near Byesville, in the center 
of Jackson township, but some of its most important mines are located 
at and beyond this point. 
The Cambridge coal agrees with the product of the other fields of 
the same seam already described, in both physical and chemical prop- 
erties. Like the Big Vein of Salineville, and like the Dell Roy seam, 
it is a bright, well-jointed coal, mining in large, oblong blocks, but 
lacking strength to bear transportation well. The Cambridge coal is 
also, like the Upper Freeport ‘seam in the other fields that have been 
19 G. 
