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SUPPLEMENTAL REPORT—HANGING ROCK DISTRICT. 917 
height of twenty to forty-five feet above Coal No. V. This former measure is 
observed in the northern part of the district; the latter in the southern. 
A better known horizon with which to associate it is found, however, in 
the Gray Limestone and the ore that accompanies it. Coal No. VI lies 
from thirty to fifty feet above the Baird ore in Hocking county. The 
single measure that will best represent thé facts is forty-two feet. This 
measure is held almost, without wavering, through Hocking, Vinton, 
and northern Jackson counties. The interval begins to expand in Mil- 
ton township, Jackson county, at Keystone Furnace. In Bloomfield 
township it has become fifty-five feet. In the next ten miles another 
gain of ten feet is made, and from this point on the best measure of the 
interval is sixty-five feet. South of Keystone Furnace the seam is known 
as the Sheridan Coal, while to the northward any one of a half dozen 
names can be used to designate it. The most common designations are 
derived from the great mining centers, Nelsonville and Straitsville. 
Along the line of the Marietta and Cincinnati Railroad it is styled the 
Carbondale Coal or the Mineral City Coal. 
It is not necessary at this point to go into any detailed description of 
Coal No. VI. Full accounts of its quantity and quality in the Hocking 
Valley, have been already given in the present volume. West of the 
Hocking River, it is gradually reduced in volume. A few mines are 
opened in Starr and York townships which hold six or even seven feet 
-of coal, but the common measure of three and cne-half to five feet is 
soon reached, and that is held through the townships of Brown, 
Swan, Madison and a part of Elk, in Vinton county. In all of these 
townships the coal everywhere holds its place and its quality is, in the 
main, excellent. 
It will be remembered that the seam, in the region of its greatest 
development, occurs in not lessthan three benches: In following it south- 
ward, the lower one of these divisions, shrinks rapidly, being found 
but six inches thick along the line of the Marietta road, (Carbondale and 
‘Mineral City Coals). In Clinton township, Vinton county, the lower 
bench is altogether lost and the upper division is also much reduced, the 
main thickness of the seam (three feet) being found in the middle bench, . 
A mark here comes in by which the seam can be followed without the 
slightest difficulty or uncertainty to the southward. The uppermost 
bench is separated from the middle beneh by four to six inches of hard 
fire-clay. The seam holds this peculiarity until it comes te be known 
by a new name, viz., the Sheridan Coal, of Gallia county, In Jackson 
county, the upper bench is found only as soft coal and is not mined, the 
middle bench being all that remains of the great vein of the Hocking ' 
