A PRELIMINARY REPORT ON CLAYS OE ELORIDA 
169 
Physical Properties of Brooksville Tampa Northern Clay (Lah. No. 0 - 21 ). 
Plasticity, judged by feel. 
Water of plasticity. 
Linear air shrinkage.. 
Volume air shrinkage. 
Modulus of rupture, average. . 
Slaking test. 
Steel hard at cone 010. 
Overfires at cone 9. 
Excellent. 
34.50% 
15.2 % 
41.2 % 
147.0 pounds per square inch. 
3 minutes. 
Fire tests: 
T emperature. 
Linear Shr. 
Per Cent. 
A bsorption. 
Per Cent. 
Porosity. 
Per Cent. 
Color. 
950°C. 
0.0 
7.60 
18.50 
Salmon. 
1050 
2.8 
7.08 
18.30 
Brown. 
1150 
3.8 
6.88 
16.20 
Gray. 
1190 
5.8 
6.42 
15.70 
Gray. 
1230 
3.8 
5.82 
10.10 
Gray. 
A clay is exposed in the northeastern edge of Brooksville and vicin¬ 
ity which is unfitted for any kind of burned product. Its plasticity is very 
poor and its shrinkage is high. This clay warps badly, but is compara¬ 
tively free from cracking. Its physical properties, which are given for 
the purpose of illustration, are: 
Physical Properties of Brooksville Clay (Lah. No. 0 - 56 ). 
Plasticity, judged by feel. . . . 
Water of plasticity. 
Pore water. 
Shrinkage water. 
Linear air shrinkage. 
Volume air shrinkage. 
Modulus of rupture, average 
Slaking test .. 
Steel hard at cone 010. 
Poor. 
38.45% 
4.90% 
33.55% 
18.8 % 
35.8 % 
218.0 pounds per square inch. 
5 minutes. 
Fire tests: 
Temperature. 
Linear Shr. 
Per Cent. 
A bsorption. 
Per Cent. 
Porosity. 
Per Cent. 
Color. 
950°C. 
3.2 
6.46 
17.20 
Salmon. 
1050 
4.2 
6.02 
16.30 
Salmon. 
1150 
6.7 
6.61 
16.60 
Gray. 
1190 
7.0 
5.49 
13.40 
Gray. 
A brownish-gray, slightly sandy clay occurs in the Annuttalaga 
Hammock about one-half mile north of Brooksville and extends north¬ 
ward for about two miles. The thickness of the deposits is not known, 
but is as much as eight feet in places. The clay is suitable for a soft, 
porous common building brick of only fair quality. Its physical prop¬ 
erties are: 
