286 ‘GEOLOGY OF OHIO. 
Valley. To it should be referred, apparently, a thin but very pure 
coal, mined in a very small way, and only for blacksmiths’ use, on the 
Oldham farm, two miles northeast of Cambridge. A thin seam found 
many years ago in the bed of Will’s Creek, in excavating for the foun- 
dation of a mill, in the village of Cambridge, testified to by Hon. Isaac 
Morton, belongs also at this level. Here, too, may perhaps be placed 
the seam that is reported by credible witnesses as lying about the level 
of Crooked Creek, west of Cambridge, and sometimes taken out of the 
bed of the creek. The seam has also been opened at Warden’s Salt 
Works, in Liberty township, but it was too thin to admit of being 
worked. It adds nothing of value to the coal resources of the county. 
THE LOWER FREEPORT COAL. 
This seam is but of the smallest account in Guernsey county, but 
its place can be seen in numberless sections. One opening to the seam 
has been already noted. On Robert R. Miller’s farm, in Liberty town- 
ship, an entry was driven in upon the seam for a number of yards, but 
the thickness of the coal, which was 18 inches, did not warrant further 
work. The seam was here covered with 4 feet of blue shales. In the 
Tunnel section, near Cambridge, the Lower Freeport coal is also shown 
(see page 86). The coal is 15 inches thick, and is about 55 feet below 
the place of the upper seam. 
THe Uprer FREEporT Coan. (Coat No. 7.) 
Not only is the Upper Freeport coal vastly more valuable in 
Guernsey county than all of the other seams combined, but the mining 
center to which it here gives rise, takes rank among the most important 
coal fields of the Stute. The coal of this seam is known in the markets 
as the Cambridge coal. 
The seam comes in from the northward as the blackband coal. An 
important field of the blackband ore is found on Bird’s Run in Oxford 
township, Tuscarawas county. It extends across the county line in 
some of its outliers. We find here the coal 15 inches thick, but very 
sulphurous and impure, so much so, in fact, that but little use is made 
of it. The noble deposit of ore, 6 feet in thickness, that overlies it, 
gives great value to the horizon, despite the worthlessness of the coal. 
The blackband is 143 feet above the Middle Kittanning coal. This 
horizon can be followed with ease and certainty through Wheeling and 
