264 GEOLOGY OF OHIO. 
It is impossible to trace the top coals into West Virginia and Pennsy - 
vania so as to determine the exact equivalence at distant localities. 
They are found over a large area, but only in small and widely separated 
patches, so that we are forced to rely only upon relative position, which, 
owing to the rapid variations in interval between beds, is at best an ex- 
ceedingly unsafe basis on which to reason. The other beds, from 8 to 11 
inclusive, those of the Upper Coal Group, are traceable without difficulty, 
and the identifications are certain. 
- Owing to the extensive operations of erosive forces in this county, Coal 
No. 18 is seen at but few localities. It is well exposed at the summit 
cut of the Central Ohio Railroad, being there one foot thick, and imbed- 
ed in dark shale. It occurs also about a mile north from this cut, but, as 
is ordinarily the case, it is exposed at the road-side. Near Morristown it 
should occur, but there its place is covered by débris. At no point is it 
of any economical value. 
Coal No. 12, lying at a lower elevation and protected by the overlying 
sandstone, is visible at a much greater number of localities than the last. 
Along the Central Ohio Railroad it is exposed in cuts east and west from 
Burr’s Mills, and in the tunnel at Barnesville. The exposures are quite 
numerous in Goshen, Warren, Union, and Richland townships, and in 
the latter it has been worked to a slight extent. The thickness rarely 
exceeds eighteen inches. 
Coal No. 11 is worthy of note, chiefly because of the suddenness and 
extent of its changes, which seem to be as characteristic of it here as in 
its eastern extension, the “ Waynesburg” of Pennsylvania and West Vir- 
ginia. In the second cut west from Barnesville, on the Central Ohio 
Railroad, it varies from six inches to nearly six feet within one hundred 
yards. In this portion of the county it is known as the “Jumping six- 
foot seam. It is readily traceable through Warren, Goshen, Kirkwood, 
Flushing, Richland, and Pease townships. It is rarely of any economical 
value, and at no locality does it yield good coal. 
Coal No. 10 is second in importance only to the Pittsburgh (No. 8), and 
is mined extensively to supply local demand in Warren, Goshen, Union, 
and Flushing townships. At the west it is rarely less than four feet 
thick, but steadily diminishes until at the Ohio it has entirely disap- 
peared. In the western townships it is very much like the Pittsburgh 
structure, being a double bed, and, sometimes, still farther divided. The 
coal is variable in quality, and, as a whole, is inferior to that of the Pitts- 
burgh. 
Coal No. 9 is a very persistent bed, seldom less than thirty inches 
thick, though at one locality it is only eighteen. It is every where 
