666 GEOLOGY OF OHIO. 
ville. The mining of this clay is carried along with the mining of the 
coal, both being taken out of the same pit-mouth. The coal is usually 
worked first and then the clay ; the latter being at a lower level, gives 
the best of ventilation and drainage. There is enough plastic clay 
occurring with the flint to allow its perfect working. This bed of hard 
clay marks the Kittanning horizon from Magnolia, Carroll county, to 
below Dover, Tuscarawas county, where it disappears. The whole 
formation is absent in nearly all Coshocton county. In Muskingum it 
reappears at Zanesville and Roseville, carrying the clay from which the. 
stone-ware of that district is made. The coal is usually absent, leaving 
the clay, hence some question can be raised as to whether the clay lies 
under or over the coal. From its distance to the Middle Kittanning 
coal, it seems probable that it is above the coal. This deposit extends 
from north of Zanesville to below McLuney, in Perry county, and to- 
wards Deavertown, Morgan county. ‘The next developments are found 
in Gore, Hocking county, where clay of a plastic grade from this horizon 
is mined and shipped to Columbus for pipe-clay, ete. This is merely a 
local use of this horizon. In Vinton county no clay is mined at any 
horizon; in Jackson county the Kittanning clay is again found in the 
Oak Hill mines. The clay here lies on a three-foot stratum of hard and 
soft clays just over the coal. The most remarkable mixing of hard and 
soft clay to be found in the State is seen in this case ; no two volumes 
of clay run alike in proportion. The clays are not used in any other 
place in the county. In Lawrence county, the Kittanning horizon is 
well developed. It gives both hard and soft clays above and below the 
coal; it furnishes clay of much the same grade as the clay above the 
Ferriferous limestone, and which is applied to the same uses. It is 
mined extensively at Newcastle and along the river for shipment to 
Cincinnati. The importance of this horizon can now be estimated since 
it is seen to figure in workings in every county on the line of its out- 
crop in which clay is handled at all; and also from the varied forms it 
presents and the varied uses to which it is applied. 
The Middle Kittanning clay is also worked in a few cases, though 
its developments have none of the characteristics that attach to the 
lower coal. The clay is used at Zanesville in small extent in the fire- 
brick works; it is a hard clay of inferior quality. Also clay is shipped 
from Clay Bank Station, three miles north of Moxahala, which is 
mined just under this coal ; it is soft and of fair quality. 
