156 FLORIDA GEOLOGICAL SUREY-15TH ANNUAL REPORT

pany about one mile north of Molino station. The Dolores Brick Company has been located here about twenty years, but the Pensacola Brick Company is just completing the erection of its plant and is now in readiness to market its product. The McMillan Brick Company formerly operated a plant about three miles north of Molino. 
 The clay exposed in this locality is eighty or more feet in thickness. Sixty feet of clay are exposed in one of the Dolores pits and borings twenty feet deep in the floor of workings did not penetrate the bottom. The clay also extends for a considerable distance northward and westward.
 In each exposure at this locality the clay is cross-bedded and is interstratified with numerous sand layers. The sand layers are thin while the clay strata are thick and relatively pure. The run of bank is used at both plants and the sandy material is thoroughly mixed with the pure clay. The raw clay is brownish-gray in color, has good plasticity and working qualities and dries easily. It is a light, red-burning clay.
 Both plants using this clay make face brick and common brick. Their principal markets are in west Florida and southern Alabama, Mississippi and Louisiana. Pensacola, Mobile and New Orleans are the heaviest users of the Dolores product.
 This clay may be equally well used for hollow block ware, fireproofing, and drain tile. It is not suitable, however, for paving brick, sewerpipe, or other vitrified products. It has the following physical properties:
 Physical Properties of Dolores Brick Company Clay (Lab. No. o-i).
 Plasticity, judged by feel ............ Excellent.
 W ater of plasticity................. 22.90%
 Pore water ........................ 1.05%
 Shrinkage water ................... 21.85%
 Volume air shrinkage............... 21.05%
 Linear air shrinkage................ 7.3 %
 Modulus of rupture, average........ 237.4 pounds per square inch.
 Slaking test ....................... 1 hour.
 Steel hard at cone 15.
 Fire tests:
Temperature. Linear Shr. Absorption. Porosity. Color.
 Per Cent. Per Cent. Per Cent.
 950*C. 0.3 17.31 34.15 Light red.
 1050 0.3 17.13 33.68 Light red.
 1150 0.3 16.18 33.33 Brick red.
 1190 0.3 13.51 31.98 Brick red.
 1230. 0.7 13.36 31.00 Brick red.
 1310 0.7 12.89 30.68 Brick red.
 1370 0.7 12.47 29.80 Brick red.
 1430 1.7 9.03 26.84 Brick red.