148 GEOLOGY OF OHIO. 
is called the Upper Freeport seam, and the limestone under it is called the 
Freeport limestone. 
Going southward from our starting point in Holmes county, we find 
that Coal No. 6, in Coshocton, exhibits an excellent development. It is 
mined in a great number of places, for the most part retaining the char- 
acters that have been alraady attributed to it. Here, as elsewhere, it 
usually lies in two benches, with a parting usually below the middle. 
At Coshocton, and in that vicinity, it is harder and purer than’ further 
north; is largely mined and shipped on the Pittsburgh, Cincinnati and 
St. Louis Railroad. Though not yet used for iron-making, if properly 
coked, the coal of this seam in Coshocton county would supply a very 
large amount of good furnace fuel. 
South of the National Road Coal No. 6 acquires such magnitude and 
excellence that it quite overshadows all the other coal seams of the State. 
In Muskingum county it has much the appearance it has further 
north, but is not so thick and pure as in Coshocton. In the adjoining 
county of Perry it expands to a maximum thickness of nearly thirteen 
feet, and is the “Great vein” of the Straitsville region. It is also of ex- 
cellent quality, is open-burning furnace coal, containing a small amount 
of sulphur, and is successfully used for the manufacture of gas. The 
identity of the Straitsville coal with No. 6 will hardly be questioned by 
any one who follows the seam down through its line of outcrops and 
mines by which it is connected with the No. 6 of Coshocton, Holmes, and 
Tuscarawas. It is almost always recognizable by its dimensions, its 
partings, and by its relation to the Putnam Hill limestone and Coal No. 
5, below, and to the Cambridge coal and the Crinoidal lLmestone (Ames 
limestone) of the Barren Measures, above. 
What the reach of Coal No. 6 toward the east and back from its line 
of outcrop in Perry and Athens may be, we do not know; but it has been 
struck in borings in numerous localities where it had passed 100 feet be- 
‘low the surface, here maintaining a thickness of from 8 to 12 feet. It is 
highly probable that it extends beneath a large tract of country east of 
where it is now mined, where it is, far below the surface, readily accessi- 
ble by shafts. It will be remembered that in passing southward on the 
‘Ohio, Coal No. 6 becomes thicker than further north, and we are thus en- 
couraged to hope that its greatest development is in this direction. 
The Straitsville coal has not been certainly recognized south of Athens 
‘county. If extending further in this direction, it is, on its western out- 
erop, much diminished in thickness and value. 
