196 
FLORIDA GEOLOGICAL SURVEY—15TH ANNUAL REPORT 
Two sandy clays occur at the “Y” on the Seaboard tracks as they 
enter Lake Wales. A section here is: 
Section of Clay Strata at Seaboard “Y” at Lake Wales. 
Feet 
Sand . 3 
Clay, gray, sandy . 5 
Clay, black . 3 
These two clays have similar properties. Both are sandy and are 
suited for nothing more than a very poor grade of common brick. The 
black, lower clay has the following physical properties: 
Physical Properties of Seaboard “Y” Black Clay, Lake Wales (Lab. No. 0 - 51 ). 
Plasticity. 
Water of plasticity. 
Pore water. 
Shrinkage water . 
Linear air shrinkage... 
Volume air shrinkage.. 
Fair. 
19.50% 
0.63% 
18.87% 
6.90% 
15.30% 
Modulus of rupture, average. 
Slaking test. 
135.3 pounds per square inch. 
24 hours. 
Fire tests: 
Temperature. Linear Shr. 
Per Cent. 
A bsorption. 
Per Cent. 
Porosity. 
Per Cent. 
. Color. 
950°C. 1.9 
15.80 
33.75 
Cream. 
1050 2.5 
15.58 
34.40 
Cream. 
1150 2.9 
14.68 
32.60 
Cream. 
1190 2.9 
14.54 
31.60 
Cream. 
A sample of clay from the Peace Valley Farms Company’s prop¬ 
erty, near Winter Haven, was tested by the Bureau of Standards in 
1914. 1 
The results indicate that this clay is suitable only for a poor grade 
of common brick. Its physical properties are: 
Physical Properties of Peace Valley Farms Clay, Bureau of Standards. 
(Sample No. 22 ). 
Plasticity, judged by feel. Fair. 
Water of plasticity. 24.9 % 
Linear air shrinkage. 6.28% 
1 Sellards, E. H., Report on Tests for Paving Brick, Florida Geol. Survey Press 
Bulletin No. 7, 1915. 
(Bricks were made some twenty years ago from a whitish marly clay just east of 
Carter’s on the Atlantic Coast Line, near the head of the Peace River, but the venture 
does not seem to have been a success. R. M. Harper.) 
