156 THE CLAYS OF ARKANSAS. 
occupies the surface of the country between Crowleys Ridge and 
L'Anguille River, west of Harrisburg. The similarity is made more 
evident by comparing the analysis of the loess above given and the 
one following. 
Analysis of upper layer of the "buckshot land" from Harrisburg, sec. 25, T. 11 N., R. 3 E. 
[R. N. Brackett, analyst.] 
Silica (Si0 2 ) 87.50 
Alumina (A1 2 3 )- 6. 10 
Iron oxide (Fe 2 3 ) 2. 69 
Lime(CaO) 63 
Magnesia (MgO) 36 
Potash (K 2 0) 38 
Soda (Na 2 0) 65 
Phosphoric acid (P 2 5 ) 13 
Loss on ignition 1. 95 
TOO. 49 
Air-dried sand 77. 48 
CLAY INDUSTRY, 
t 
Common wet-mud bricks are made by W. P. Lancaster and 
J. B. Huey at Harrisburg. The product is made from the reworked 
Columbia or loess, which is 8 feet thick. The clay is tempered in 
soak pits, molded by horsepower machinery, dried on pallet and racks, 
and burned in up-draftscove kilns. The plant has a capacity of 8,000 
bricks a day. Five to six days are required for drying, and ten to 
twelve days .for burning. The green bricks can not be taken from 
the molds and placed in the sun immediately. 
POPE COUNTY. 
GENERAL GEOLOGY. 
A part of Pope County and all of the other counties farther west 
along Arkansas River lie within the area of the Carboniferous coal- 
bearing rocks. The coal-bearing rocks in these counties do not differ 
greatly from those in Conway, Faulkner, White, and Pulaski counties 
farther east, where coal is not present, but the presence of the coal 
beds adds another factor that must be taken into account in dealing 
with the clays and clay industries. 
The coal-bearing rocks in Pope County and the counties to the west 
are folded like those of the region to the east and southeast; in places 
these folds are sharp, in others they are gentle. The clay shales are 
interbedded with sandstones and with coal. As a rule they are com- 
pact where they lie under other beds, but where they have been 
exposed for a long time to the weather they become soft and plastic. 
In color they vary from almost black through various shades of gray, 
