64 GEOLOGY OF OHIO. 
limestones almost always carries some iron ore; generally in flattened 
concretions or nodules, sumetimes forming continuous sheets of plate or 
block ore. It is not now known that either of these ore-beds is of suffi- 
cient richness anywhere in Tuscarawas county to pay for drifting, but in 
many places on the slopes of the hills one or the other may be profitably 
stripped. It is possible, also, that in some localities the bedded ore may 
be of sufficient thickness to warrant systematic mining. As a guide to 
the judgment of those who may be hereafter interested in this question, 
it may be said that one foot of solid ore of average richness (83 per cent. 
metallic iron) will repay the expense of working by drift. 
Fire-clay.In Summit, Portage, and Columbiana counties the fire-clay 
which underlies Coal No. 3.is usually thick and of excellent quality, so 
that it forms the basis of a great industry in pottery, fire-brick, etc. 
Little is known of the character of this bed of clay in Tuscarawas county, 
since it is almost universally below drainage, and has been but rarely 
exposed to view. In the Uhrichsville boring, however, a remarkably 
thick bed of fire-clay 1s reported to have been passed through beneath 
Coal No. 8. It is, however, difficult to distinguish between fire-clays and 
shales in boring, and thus the thickness of the stratum at Unrichsville 
may have been over-estimated. Its quality also needs to be determined 
before it can be said to have any positive value. It would be well, how- 
ever, for the inhabitants of the county to remember that a valuable 
deposit of fire-clay occurs locally under Coal No. 3, and should be looked 
for wherever an opportunity is offered for its examination. _ 
Coau No. 5. | 
From fifty to eighty feet above the Putnam Hill limestone, we find, in 
most parts of Tuscazawas county, a coal seam which is of very consider- 
able importance. This is extensively worked in the northern part of 
the county, especially at Mineral Point and at the tunnel of the Tusca- 
rawas Branch Railroad. Its maximum thickness here is four feet, though 
more generally it is somewhat thinner. The quality of the coal is usu- 
ally good; it is hard and bright, partially open-burning, contains a 
moderate quantity of sulphur, and about five per cent. of ash, kindles 
readily, and holds fire to a somewhat remarkable degree. Its normal 
composition is shown in the analysis given at the end of this chapter. 
Some varieties of this coal make an excellent coke, hard, bright, and 
silvery, containing ten per cent. of ash, and a little over one per cent, of 
sulphur. More generally, however, the quantity of sulphur is greater, 
and to make a first-class coke the coal should be washed. In some trials 
made at the Cleveland Gas Works of the coal from the south side of 
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