160 THE CLAYS OF ARKANSAS. 
A short distance north of Russellville the thickness is reduced to 3 
or 4 feet. 
In area this clay covers sees. 4, 5, and 9 and the greater portion of 
sec. 8, T. 7 N., R. 20 W. It is also scattered through sees. 10, 11, 
12, 13, and 14 of the same township and range. At Galla Creek 
station on the Little Rock and Fort Smith Railway, in sec. 19, T. 7 
N., R. 19 W., it appears as a dark-yellow clay. 
CLAY INDUSTRY. 
Common bricks are made by the Mena Brick Company at its plant 
2 miles southwest of Mena from a thin bed of clay overlying the 
shale. The clay is partly residual, since it contains many fragments 
of shale. The clay is first run through a Success crusher, then 
through a pug mill of the same make, and finally through a stiff-mud 
machine. About 4,000 bricks are made daily. The machine is run 
by a 40-horsepower engine. Usually 10 men are required to run the 
plant— ^two men in the pit, two feeders (one to temper the clay), one 
sander, two off-bearers, and two truckers. About one-half of the 
time is employed in molding and one-half in burning. 
Another plant belonging to the same company is located 1^ miles 
from Mena, but it will probably be sold and removed to De Queen. 
There is a brick plant at Russellville, known as the Russellville 
brick works, but nothing further is known concerning it. 
There is a small brick plant at Atkins, with a capacity of 5,000 to 
6,000 a day. The bricks are made by hand and burned in common 
scove kilns. It requires from two to five days for drying and ten to 
twelve days for burning. The bricks are made from the residual 
clay of the Paleozoic rocks. The size of the molds is 9 by 4 by 2§ 
inches; when burned the bricks measure 8J by 3f by 2\ inches. 
PRAIRIE COUNTY. 
GENERAL GEOLOGY. 
The southern half of Prairie County lying w^est of White River is 
level prairie land. The part that lies north of township 2, with the 
exception of a small area around Desarc, is chiefly wooded " slash 
land." The soil of the country east of White River is entirely allu- 
vial, and the surface stands but a few feet above the low-water mark 
in White River. 
Throughout the county White River has formed a bluff of varying 
height along its west bank. At Devall Bluff the level of the prairie 
land west of the river is 25 to 40 feet higher than the high-water 
mark in the river. The elevation of the depot at Devall Bluff is 186 
feet, ox about 7 feet lower than the depot at Helena. 
