bckel.] CLAYS OF TENNESSEE AND MISSISSIPPI. 383 
There seems to be no doubt about the order of this series, but 
from the examination of a large number of exposures it would seem 
probable that a very marked geologic break occurs between- the orange 
sands and the stoneware clays. The stoneware clays are normally 
accompanied by and interbedded with a series of fine white and light 
yellow sands, commonly ver} r thinly and evenly bedded. At a few pits 
the contact between the clays (and interbedded sands) and the orange 
sands of the Lafayette seemed regular and conformable, but in most 
places, notably near Grand Junction, very marked erosion appears to 
have taken place before the deposition of the orange sands. 
A few of the pits visited near Pinson and Paris seem to have pene- 
trated to a horizon lower than that of the stoneware clays. The pits 
in question produce a very dark, lignitic clay, used in places as a ball 
clay. It seems probable that these dark-colored ball clays are of Lig- 
nitic (Tertiary) age. 
The claj^s used in the stoneware industry are in general obtainable in 
clean masses, free from (extraneous) sand and gravel. So far as known 
no mechanical analyses of these clays have been made, so that it can 
not be ascertained just how much of their silica is really present as 
fine sand and chert. The fusing point of the clays is very high, and is 
proved by the fact that most of the potteries use, in addition to the 
usual Albany slip clay, slip clay from Seneca Falls, N. Y., or slips 
made up from feldspar and quartz. As both these latter fuse only at 
a high temperature, their use proves the relative inf usibility of the 
stoneware clays. 
Many improvements in the stoneware industry in this district are 
possible. First of all, the method — or lack of method — in excavat- 
ing is very wasteful and extravagant. By s} T stematic work all the 
clay in the banks could be extracted, and that at a lower cost per ton 
than now obtains. In some cases observed the selection of spots in 
which to work is left entirety to the caprice of the negroes who do the 
digging, and in consequence the area is covered with small pits. As 
soon as these become inconveniently deep another excavation is started 
in another place. The stripping, when there is any, is thrown care- 
lessly to one side, thereby covering up and rendering useless a cer- 
tain amount of clay. 
In the second place, it would seem advisable to season the clays 
somewhat, instead of sending them direct from the pit to the mill. 
By a little extra care, which might necessitate supervision of the 
negroes working the clay pits, the average quality of the material 
sent to the mill could be raised. Frequently the mixture of clays 
from different pits would greatly improve the product. Finally, it 
would seem advisable to push the fire-brick industry in every possible 
way. At present this product is manufactured on a very small scale, 
and little attention is devoted to the technology of the subject. It 
seems probable that it is in this direction, rather than in the line of 
stoneware, that the clay industry of the district will progress. 
