198 FLORIDA GEOLOGICAL SURVEY-I5TH ANNUAL REPORT

 Fire tests:
Temperature. Linear Shr. Absorption. Porosity. Color.
 Per Cent. Per Cent. Per Cent.
 950*C. 0.2 12.26 30.40 Brick red.
 1050 0.3 13.92 30.60 Brick red.
 1150 0.3 12.55 28.00 Brick red.
 1190 0.3 11.60 26.00 Brick red.
 1230 1.3 10.83 26.40 Brick red.
 1310 11.50 28.60 Brick red.
 1370 11.01 28.00 Brick red.
 1430 8.19 19.10 Brick red.


 The old Herman Brown brick plant was located on Rice Creek, about three miles southwest of Rice Creek Station in Sec. 16, T. 9 S., R. 26 E. Common brick, hollow block and drain tile were produced. This deposit is located three miles west of the Atlantic Coast Line Railroad and two miles north of the Georgia Southern and Florida Railroad. The abandoned plant was located on the bank of the creek which offers water transportation facilities to Jacksonville and other points on the St. Johns River.
 The clay is twelve feet thick, underlain by sand and has an overburden of about one foot of soil. The exact extent of this deposit is not known, but more than forty acres are known to be underlain by it.
 A vitrified product cannot be produced, but this clay is suitable for the manufacture of a good grade of structural materials. Its physical properties are:


 Physical Properties of Herman Brown Clay, Rice Creek (Lab. No. o-62).
 Plasticity, judged by feel........... Excellent.
 Water of plasticity................. 22.25%
 Pore water ........................ 1.32%
 Shrinkage water .................. 20.93%
 Linear air shrinkage............... 10.0 %
 Volume fire shrinkage.............. 26.45%
 Modulus of rupture, average........ 546.2 pounds per square inch.
 Slaking test ....................... 3 hours.