1020 GEOLOGY OF OHIO. 
fire-clay floor. West of Wellston the roof shale is replaced by a mas- 
sive bed of sandstone over a considerable area; and at the Murphin 
mine the sandrock has cut down into the coal, forming a horseback. 
With the exception of this fault, which is merely local, no other mining 
trouble has yet been encountered in the region. 
This coal, like the Jackson Shaft coal, belongs to the family of 
open-burning or furnace coals. It is, however, of a rather tender 
nature, and is not fitted to bear a heavy burden in the furnace. In the 
process of mining, fully two-fifths of the coal is converted into nut and 
slack. This large per cent. of nut and slack, however, is not all made 
by reason of the tender nature of the coal, part of it being the result of 
the unskillful manner in which the seam is mined. The operators of 
the region exercise no concern in regard to the practical skill of their 
miners, in employing them, as the nut coal, for which the miner is paid 
nothing, is of nearly equal value in market to the lump coal. It is to 
the miner’s interest to make as much round or lump coal as possible, as 
he is paid for lump only, but unskillful workmen never succeed in turn- 
ing out as large round coal as the trained miner, accustomed to under- 
ground life from early boyhood. Of late years the art of digging coal 
has degenerated in Ohio, more reliance being placed upon blasting- 
powder than formerly. Coal is often blasted out of the solid and shat- 
tered into small, in a reckless and shameless manner, without any cause 
save that of the carelessness of the miner. 
The aggregate annual capacity of the mines of the county is 
1,200,000 tons; the product of the mines for 1883 has been estimated 
at a little over 400,000 tons. During the summer months there is a 
great falling off ia the trade. 
This coal has been rapidly finding a market in competition with 
our best Ohio and Pennsylvania coals in all the great coalless regions, 
west and north. Last year it was successfully introduced on the lake 
(Erie) as a steam coal, 30,000 tons being used for this purpose; during 
the present year the lake trade will double that of 1883. 
At several of the mines three grades of coal are made, viz., lump, nut 
and pea. The size of the screens is: for lump coal, 13 inches space 
between screen bars; for nut coal, } inch between screen bars; the pea 
coal is made by screening the refuse or slack, which is raised into a 
revolving circular screen by a self-loading elevator and sifted of fine or 
dust coal, the fine coal falling back to the ground, whence it is hauled 
away as refuse. 3 
