684. | GEOLOGY OF OHIO. 
feet thick, and of good quality. All the facts indicate that the coal is 
persistent over this whole area, and that it is of strictly first class qual- 
ity. It is quite natural that the coal should be first worked where it is 
well up in the hills, and can be mined by drifting ; but when its horizon 
is at a moderate depth below the bottom of the valleys, there is the 
marked advantage that no coal has been lost through the erosion of the 
valleys—there is no poor “crop coal.” Shafts may be sunk in immedi- 
ate proximity to the valley roads, the cost often being much less than 
that of the construction of the long trestles which are needed to connect. 
the mines on the hill sides with the roads in the valleys. These coals 
are not ordinarily the first to be developed, but the whole cost of mining 
‘is no more than the average of drift mining, and the area of workable 
coal may be regarded as equal to the surface area, so that the ultimate 
value of the land is much greater than where erosion has carried away 
a large percentage of the coal. : 
BAYLEY’S RUN COAL, OR COAL NUMBER SEVEN. 
At an average distance of about seventy or seventy-five feet above the 
Great Vein, there is here another important eoal, which has ordinarily 
been regarded as the equivalent of the Stallsmith coal of the upper 
Sunday Creek, although the interval between it and the Great Vein is 
considerably less. But the Stallsmith coal is clearly No. 7, and the 
thin coal above the Bayley’s Run, with its associated iron ores, is every- 
where suggestive of its identity with No.7. A revision of the sections 
at Millertown, and west of Buckingham, where are the openings which 
have given the local names to these coals on the upper Sunday Creek, 
shows clearly that the Bayley’s Run and the Norris coals are the same, al- 
though the interval between it and the Great Vein is on the average 
considerably greater on the lower Sunday Creek. The coal has also pe- 
culiarities quite different from the ordinary character of No. 7. 
It isa bright black, with a resinous lustre, burns with a long light 
flame, and shows little sulphur; in some of the openings forming a sin- 
gle bench, in others having a thin shale parting near the top. In thick- 
ness it ranges from four and one-half to five feet, and is generally a little 
