A PRELIMINARY REPORT ON CLAYS OF FLORIDA 
199 
Fire tests: 
Temperature. 
Linear Shr. 
Per Cent. 
Absorption. 
Per Cent. 
Porosity. 
Per Cent. 
Color. 
950°C. 
0.5 
13.11 
36.50 
Brick red. 
1050 
1.0 
13.12 
36.20 
Brick red. 
1150 
2.0 
13.23 
34.16 
Brick red. 
1190 
2.6 
11.08 
31.70 
Brick red. 
1230 
2.1 
11.79 
28.70 
Brick red. 
1310 
3.0 
12.34 
30.70 
Brick red. 
A similar clay exposed about one-half mile north of Springside, 
Sec. 29, T. 9 S., R. '26 E., may also be used for a good grade of 
structural materials. It has an overburden of about one foot, ranges 
from twelve to twenty feet in thickness and underlies an extensive area 
in this region. This clay adjoins the Georgia Southern and Florida 
Railroad at Springside. A sample taken one-half mile north of the 
station has the following physical properties: 
Physical Properties of Springside Clay (Lab. No. 0 - 4 . 4 .). 
Plasticity, judged by feel... 
Water of plasticity. 
Linear air shrinkage. 
Volume air shrinkage. 
Modulus of rupture, average 
Slaking test. 
Overfires at cone 12. 
Fire tests: 
Excellent. 
25.10% 
11.1 % 
28.57% 
791.4 pounds per square inch. 
1 hour. 
Temperature. 
Linear Shr. 
Per Cent. 
A bsorption. 
Per Cent. 
Porosity. 
Per Cent. 
Color. 
950°C. 
0.1 
12.60 
29.70 
Brick red. 
1050 
0.9 
13.70 
31.00 
Brick red. 
1150 
0.6 
12.31 
29.40 
Brick red. 
1190 
1.4 
11.45 
29.75 
Brick red. 
1230 
1.4 
10.44 
25.75 
Brick red. 
1310 
1.4 
8.69 
17.50 
Dark red. 
Numerous other good common-brick clays occur in the region be¬ 
tween Crescent City and Lake George. A brick plant was formerly 
operated at Denver where a common brick was made. Some of these 
clays are very similar in properties to those west of Palatka, and others 
$eem to be identical with the Shell Bluff clay, found on the opposite side 
of Crescent Lake in Flagler County. (See Shell Bluff Clay, page 158.) 
Sandy clays, which may be used for a fair grade of common brick, 
are also found on the east side of the St. Johns River, near Orange 
Mills and San Mateo. 
