STRATIGRAPHICAL ORDER. 61 
These figures show the steadiness of the sections as a whole. There 
is more play in some of the intervals than is usual, but in the large 
way the surprising regularity that characterizes the rest of the Ohio 
coal field, appears here also. 
The facts are represented to the eye in the accompanying plate, 
Fig. XIV A. 
The place thus given to the Steubenville shaft seam in the Ohio 
series of coals differs from that previously assigned to it. Newberry 
strongly inclines to the view that the Steubenville seam is the Upper 
Freeport, though he does not consider the question demonstrated. He 
seems to count the Groff or Brush Creek seam as the only competitor of 
the Upper Freeport for this place, but why the claims of the Roger or 
Lower Freeport seam should have been overlooked until now, it is not 
easy to see. The Roger seam corresponds better in every way in the 
matter of intervals, as all can see, but undue stress need not be laid on 
this point, because of the fact that the interval between the Upper and 
Lower Freeport horizons in this region does not exceed the play of the 
sections reported. 
The Roger coal is a persistent seam through the district, across 
which our sections have carried us. Mines are opened in it for almost 
every mile of the interval between Yellow Creek and Island Creek, 
where it falls to the drainage level. On the other hand, the Upper 
Freeport coal does not appear as a mineable seam at a single point in 
this interval. | 
The interval between the Roger and the Groff coals is shorter at 
the end of this line of sections than it was at the beginning, it is true, 
but the change is progressively accomplished. At Hammondsville, the 
measurement is 125 feet. At McCoy’s it is 85 feet, at Toronto 80 feet, 
at Island Creek 77 feet, and at Wills Creek 65 feet. The principal 
change has been accomplished in a part of the field where there is no 
- dispute in regard to the elements. 
It cannot be objected that the Roger coal is not a seam of sufficient 
thickness to represent the Steubenville coal, for it rises to 5 feet on 
King’s Creek, while the Steubenville shaft coal falls to 28 inches at 
Mingo. In any case the Roger coal is the thickest as well as the 
steadiest seam that is to be found in all the region to the north of Steu- 
benville. 
No argument can be raised against the identification on the score 
