HOT SPRING COUNTY. 
113 
The light lead-colored clays forming the upper part of the clay 
bed merge into mottled clays below, and these in turn are followed 
by snuff-colored layers, while the lowest part of the bed visible is a 
dark-brown mucky looking clay. Fossil leaves occur only in the 
two lower members. If they ever existed in the upper part of the 
clay they have been destroyed by the action of percolating water. 
The depth of this clay bed was tested with an earth auger and 
was found to be 30 feet. The bed is more sandy below, however, 
and contains some iron pyrites, which injures it for pottery making. 
The light-colored upper part (10 feet) of Atchison's clay pit is 
used chiefly for the manufacture of pottery. This clay burns to a 
hard, solid body and is easily glazed with either the Seneca Falls or 
Albany slip clay or with salt. The lower bed, which consists of 
dark clay, is utilized for the manufacture of fire bricks, sawdust 
Fig. 11.— Section at Atchison's clay pit at Perla switch, Hot Spring County, ss, Sandstone; 
gr, gravel. 
being mixed with the clay to give the bricks the necessary texture 
and porosity. This clay burns to a light-cream color and the ware 
has a remarkable bell-like, metallic ring. 
Analyses of clays from Perla switch. 
[Brackett & Smith, analysts.] 
Light- 
colored 
pottery 
clay. 
Dark- 
colored 
brick 
clay. 
Silica (SiO>) 
- 73. 24 
19.61 
1.04 
.78 
5. 33 
72. 59 
Alumina (AI2O3) 
16.08 
Iron (ferric) oxide ( !'>•(). 1 
, 
1.18 
Lime (CaO) ] 
MapH>sia(Mg(), 
3.81 
Potash (lv 2 0)... [ v •> 
Soda (Na 2 0)....J 
Water (H 2 0) 
6.34 
water at no ii. r >° C 
100.00 
2.01 
5.40 
100. 00 
2.08 
On John Wilkerson's 
land 
in the 
X. 
i NE. 
1 
4 
sec. 
35, 
T. 4 S. 
, K. 17 
W., there is a deposit of light-colored pottery clay from which the 
48136— B11 1 1 . 351 —08 S 
