STRATIGRAPHICAL ORDER. 109 
Reference will here be made to a few disputed points in this part 
of the field, and to the correction of such errors as have been noted. 
The account given in the report referred to, of the westward ex- 
tension of the Middle Kittanning coal seam (No. 6) from Nelsonville, 
has been called in question by Dr. T. S. Hunt, in his reports uy-on the 
Hocking Valley coal field, and also by others. The.question is of 
fundamental importance in its relations to the order of our coal meas- 
ures, for all of the identifications of the various elements of the Southern 
Ohio sections are connected with or dependent upon this. 
Andrews asserted in the report of 1870 the probable identity of 
the Carbondale and Mineral City coals with the Nelsonville seam 
(pp. 89-92). My report in vol. III (Hanging Rock district) confirmed 
his conclusion, but established this identity on other and distinct 
grounds. 
The Carbondale coal is easily traced down Hewitt’s Fork of Rac- 
coon Creek to Mineral City, the seam being opened on every quarter 
section of the interval. The Mineral City coal is as easily followed by 
continuous workings to Hope Station and Zaleski. The character of 
the coal as well as its relations demonstrates the identity here claimed, 
an identity undisputed and unquestioned so far as is known. 
At Hope Station the Carbondale coal comes into a section of which 
the Lower Mercer Limestone is the base and the Cambridge limestone 
is the summit, and that also holds the Ferriferous limestone with its 
ore in good development at the proper level. More could not be asked 
in a geological section of the Lower Coal Measures of Ohio, and con- 
clusions built upon a consistent interpretation of such a section cannot 
easily be set aside. 
_ The Carbondale coal proves to be the second seam above the Fer- 
riferous limestone. But the identity of the Baird ore and the Ferrifer- 
ous limestone ore has been already proved, and the Nelsonville seam is 
the second above the Baird ore. The two seams, therefore, hold the 
same position, and the Carbondale coal, like the Nelsonville seam, is 
the Middle Kittanning coal. This conclusion is supported by every 
line of facts that bears upon the question. 
The section obtained in the vicinity of Hope Furnace is so inter- 
esting and complete, that its main facts. and measurements are given 
below: . . 
