A preliminary re;port on CLAYS OF FLORIDA 
159 
Physical Properties of State Hospital Road Clay (Lab. No. 0-79). 
Plasticity, judged by feel... Poor. 
Water of plasticity. 32.25% 
Pore water. 5.40% 
Shrinkage water. 29.85% 
Linear air shrinkage. 17.50% 
Volume air shrinkage. 45.75% 
Steel hard at cone 010. 
Fire tests: 
Temperature. Linear Shr. Volume Shr. Color. 
Per Cent. Per Cent. 
950°C. 2.5 6.7 Brick red. 
1050 2.5 7.6 Brick red. 
One of the Chattahoochee limestone residual clays, which is an ex¬ 
ception to the average condition found in the county, occurs in the north¬ 
east edge of River Junction where a-plant manufacturing common brick 
was operated in 1907 by Mr. Ed Royston. The product of this plant has 
been used in the construction of several buildings in River Junction and 
Chattahoochee. This deposit is located only a few rods from the Atlantic 
Coast Line and Seaboard Air Line Railway tracks. Four railroads, the 
Atlantic Coast Line, the Seaboard Air Line, the Louisville and Nash¬ 
ville, and the Apalachicola Northern, meet at River Junction, thus 
affording shipping facilities to points in west Florida and southern 
Georgia and Alabama. 
The Royston deposit is irregular in thickness but is as much as 
fifteen feet in places and underlies a fairly extensive area in a small 
valley at River Junction. 
This is a red-burning clay of medium shrinkage and good drying 
qualities and working. It may be used for ordinary structural materials 
such as. common brick, hollow-block ware, drain tile, etc. 
It has the following physical properties: 
Physical Properties of Royston Clay, River Junction (Lab. No. 0-71) 
Plasticity, judged by feel.... 
Water of plasticity. 
Pore water .. 
Shrinkage water. 
Linear air shrinkage. 
Volume air shrinkage. 
Modulus of rupture, average 
Slaking test. 
Excellent. 
28.45% 
1 . 66 % 
26.79% 
11.7 % 
29.4 % 
451.8 pounds per square inch. 
2 minutes. 
