136 
THE CLAYS OF ARKANSAS. 
The clay burns to a solid cream-colored body. It admits of both a 
salt and " Albany slip" glaze. Fire bricks made from this clay are of 
a light color. 
The following are the analyses of these clays: 
Analyses of clays from sec. 5, T. 15 S., R. 28 W. 
[Sample dried at 110°-115° C] 
Silica (Si0 2 ) 
Alumina (A1 2 3 ) 
Ferric oxide (Fe20' ! ) 
Lime (CaO) 
Magnesia (MgO) 
Potash (K 2 0) 
Soda (Na 2 0) 
Loss (H 2 0) 
Sand in air-dried specimen. 
Water at 110°-115° C 
Sandy clay 
at the 
bottom. 
100. 00 
3.33 
White clay 
used for 
pottery. 
74.76 
75.99 
13. 96 
16. 12 
3.44 
1.35 
.51 
| 
1.10 
1 1. 45 
} 
2.28 
J 
3.95 
5.09 
100. 00 
.75 
1.08 
CLAY INDUSTRY. 
Kind of clay used. — There are two -brick plants and one stoneware 
pottery in Miller County. The clay used for the manufacture of fire 
brick and stoneware comes from the Tertiary clays, which are doubt- 
less of the same age as those used at the Benton pottery, situated in 
sec. 9, T. 15 S., R. 28 W. In one of the pits clay was formerly obtained 
for the manufacture of stoneware. A sample of clay from this pit 
was analyzed : 
Analysis of clay from sec. 9, T. 15 S., R. 28 W. 
Silica (Si0 2 ) 74. 85 
Alumina "(A1 2 3 ) 17. 20 
Ferric oxide (Fe 2 O s ) 1. 12 
Magnesia (MgO) 1.13 
Loss on ignition 5. 70 
100. 00 
Sand in air-dried specimen 3. 44 
Water at 110°-115° C 1. 53 
Texarkana Brick Company. — At the plant of the Texarkana Brick 
Company, established in 1902, dry-pressed bricks are made from a 
semishale or clay. These bricks are molded in a Boyd dry-press 
machine and burned in up-draft clamp kilns. Five kilns are in use, 
each of which is 23 by 59 by 14 feet, inside measurements. Wood 
and oil are used for burning. The bricks are water-smoked for about 
ten days without wood and then a hot fire is kept up for about ninety 
hours. Oil is used for making the hot fire. The size of the green 
bricks is 8 J by 2f by 4J inches. The bricks have a shrinkage of about 
