62 GEOLOGY OF OHIO. 
of quality. The average of the Roger coal is not as good as the best of 
the Shaft coal, but there is no other seam that would fare better in such 
a comparison. It is also true that as poor a quality is found in some of 
the shaft seam mines as in any of the mines of the Roger coal, outside 
the limits of the shaft seam field. 
It may be objected that the coals reported below the Steubenville 
coal in shafts and well records cannot be as satisfactorily accounted for 
on this identification as on that previously given. The objection has 
but little weight. Ifall the facts of the series that lie open to-day can 
be harmoniously adjusted, we need not allow the obscure and often dis- 
torted sections of well records to perplex us overmuch. But there are 
no serious difficulties to be reconciled. ‘The first coal seam found below 
the shaft coal comes in very well, as far as interval is concerned, for the 
Upper Kittanning or 18-inch seam. The intervals as recorded are 28 
feet in the Alicanna shaft, 44 feet in the Rolling Mill shaft, 45 feet in 
the McElroy well, 54 feet in the Market Street test well, and 52 feet in 
the Mingo well. The reported thickness does not agree as well. This 
is given as 4 feet, cannel coal, in the McElroy well, and as 2% feet at : 
several other points. It is reported “thin” in the Mingo well. The 
Upper Kittanning seam nowhere shows 2% feet in its outcrops. 
The second seam below the Shaft coal is reported at 80, 92 and 98 
feet, respectively, in three wells. If these figures stand for the same 
seam, it could be either the Middle or Lower Kittanning, without doing 
violence to the sections obtained elsewhere. | 
As to the coal seam, 3 ft. 9 in. thick, reported 139 feet below the 
Shaft coal in the Mingo boring, it is scarcely worth while to essay an 
identification. There are setims enough to compete for the place. A 
fairly probable determination would make the 80 to 100 feet coal the 
Middle Kittanning or Strip Vein, and 139 feet seam, the Lower Kit- 
tanning or Clay Vein. In any case, there are more coal seams shown 
in vertical section at Steubenville than at any other point in Ohio, as 
far as is now known. 
In view of the facts that have now been presented, the place of the 
Steubenville Shaft seam in the series is counted definitely settled. It 
is the Lower Freeport coal of the general section, and the Roger seam 
of the Ohio and Yellow Creek valley. 
The credit for working out the essential facts in this demonstration 
belongs to F. W. Sperr, M.E., an assistant on the survey. 
