282 GEOLOGY OF OHIO. 
Middle Kittanning seam in Perry county. The Diamond seam at Lin- 
ton may also be looked upon as a twin or double seam, as will be seen 
by reference to the account given of that interesting and anomalous de- 
posit. 
In the present instance, facts have not been accumulated in suffi- 
cient quantity to warrant an attempt at explanation. The suggestion is 
offered that the lower seam may replace the Upper Freeport limestone, 
at the apparent horizon of which it is found. A wider examination of 
the field may show this suggestion to be inadmissible. 
The Lower Freeport coal (No. 6a) is found at but a single locality 
of a single township in the county, so far as is known. The section re- 
ferred to is shown in Fig. XX, A. It was taken on the tract made 
famous by the expensive plant and disastrous failure of the Glasgow- 
Port Washington Furnace Company. After locating in haste, the com- 
pany proceeded to explore at leisure, and among the deposits investi- 
gated was an abnormal coal seam, that lies 40 feet below the blackband 
coal. The seam was exceedingly unsteady, ranging from 2 to 9 feet in 
thickness.. Its appearance, when freshly mined, recommended it, but 
its quality was so sulphurous and impure that nothing could be done 
with it as a furnace fuel. Experiments were made in coking the seam 
and also in purifying the coke by washing the coal, but the quality was 
too poor to admit of any successful amelioration. This seam has 
strangely enough been confounded with Coal No. 6, or the Middle Kit- 
tanning seam, but there is nothing in common in the characteristics of 
this irregular and impure bed with the steady and serviceable coal seam 
that bears the latter name and number. Moreover, this latter seam is 
found in its own place, with all its normal qualities, 70 feet below the 
Lower Freeport coal, now under discussion, as shown in Fig. XX. 
The Lower Freeport seam will, no doubt, be found at many points 
within the county, in the course of subsequent explorations. Its blossom 
is not linfrequent in the hills, and it is known to be of fairly workable 
proportions on the eastern margin of the county. 
VIIl. COAL MINES OF GUERNSEY COUNTY. 
The range of the Lower Coal Measures in Guernsey county is from 
the Putnam Hill limestone to the summit of the series, viz., the 
Mahoning sandstone. The Barren Measures are well developed through 
