CLAY DEPOSITS. | 665 
The deposits heretofore described are all quite local developments of the 
clays of the various horizons. The growth of the next coal vein was 
accompanied with the deposition of the best marked clay beds of the 
whole series. The whole horizon for twenty feet above and below the 
coal is filled with clays. The horizon is not only marked as the level 
on which clay occurs in large amounts, but it is of more economic im- 
portance than any other in the value of its deposits. It produces very 
fine flint clay, yellow-ware clays, stone-ware clays, admirable pipe-clays 
and good second class brick, and terra cotta-ware clays. 
The first district of Kittanning clays met on entering the State 
from the east, is the yellow-ware beds of Liverpool and Wellsville. 
The vein, here well up in the hills, through a low arch in the series, 1s 
plastic and easily mined, and it is reached mainly through drifts. It 
underlies the Kittanning coal directly. The clay, after washing, is 
singularly free from specks and granules of iron, which are the great 
trouble in yellow-ware clays. The next district is the Jefferson county 
pipe works, which line the Ohio river for twenty miles, from Wellsville 
nearly to Steubenville. The Kittanning clay is here called the clay 
vein; it is regularly excellent in quality ; easily found and at convenient 
levels for mining, in all the upper works, but gets a little below the 
railroad level in the Southern Works. It is rather sandy or silicious, 
quite hard at first, but quickly slacking on exposure; is plastic and 
readily moulded after grinding, and makes a superior pipe, and a very 
fair brick for boiler settings, forges and all second class work. The 
clay extends up Yellow creek, beyond Irondale, where it is still of 
good quality, and is in constant use. ‘There are no exposures of clays 
on this level in Carroll or Stark counties or north of Columbiana, but 
in the northern part of Tuscarawas county, at Mineral Point, the 
Kittanning clay appears in a new and valuable phase. It.is found as a 
very hard and fine flint clay, suitable for making any refractory material. 
It is used for retorts, glass pots, brick of finest special grades, ete. It 
is found about three feet below the Kittanning coal, separated from it 
by worthless clay. There can scarcely be a more beautiful or faultless 
stratum of clay than the hard clay of this place. It lies in a band 33 
feet thick, showing faces smoother than the most regular coal; it is so 
hard that chips from a pick blow will cut the hands of the miner; it is 
of a light-drab tint burning to a light-cream color; it shows the blue 
concentric venation of organic matter noticed in the flint clay at Scioto- 
