A PRELIMINARY REPORT ON CLAYS OE ELORIDA 163 
MEDIUM BRICK. 
Weight 
Dimen- 
Area, square 
Load Unit load, pounds 
pounds. 
sions. 
inches. 
pounds. per square inch 
No. 1—4.3 
3.7x7.6 
28.12 
73,560 2,617 
No. 2—4.3 
3.6x7.7 
27.72 
73,190 2,640 
No. 3—4.2 
3.6x7.6 
27.36 
75,140 2,746 
Average . 
SOFT BRICK. 
Weight 
Dimen¬ 
A rea, square 
Load Unit load, pounds 
Pounds. 
sions. 
inches. 
pounds. per square inch 
No. 1—4.1 
3.7x7.8 
28.86 
106,200 plus 3,680 plus 
No. 2—4.0 
3.7x7.7 
28.49 
99,890 3,506 
No. 3—4.0 
3.6x7.6 
27.36 
106,200 plus 3,882 plus 
Average .... 
The Ocklocknee clay has the following physical properties: 
Physical Properties of the Ocklocknee Clay (Lab. No. 0-30). 
Plasticity, judged by feel.. Excellent. 
Water of plasticity..... 26.00% 
Pore water..... 0.52% 
Shrinkage water.... 25.48% 
Linear air shrinkage... 12.2 % 
Volume air shrinkage.. 33.2 % 
Modulus of rupture, average.. 988.0 pounds per square inch. 
Slaking test .... 2 days. 
Steel hard at cone 010. 
Fire tests: 
Linear Shr. 
Per Cent. 
0.2 
0.7 
0.8 
0.3 
0.3 
3.8 
4.3 
4.8 
Absorption. 
Per Cent. 
Porosity. 
Per Cent. 
Color. 
13.10 
28.40 
Reddish 
brown. 
14.22 
29.00 
Reddish 
brown. 
10.50 
25.50 
Reddish 
brown. 
9.75 
24.00 
Reddish 
brown. 
9.60 
23.20 
Reddish 
brown. 
9.05 
22.75 
Reddish 
brown. 
9.55 
20.30 
Reddish 
brown. 
8.42 
18.75 
Reddish 
brown. 
Temperature. 
950°C. 
1050 
1150 
1190 
1230 
1310 
1370 
1430 
Fig. 23. —General View, Ocklocknee Brick Co., Lawrence, 
Gadsden County. 
