STATISTICS ON MINERAL PRODUCTION 
31 
Otis Phosphate Co. (P. J., J. H. and 
F. C. Norfleet, Lessees) ............Benotis, Fla. 
Palmetto Phosphate Co.2 Rector St., New York, N. Y., and Tiger Bay, 
Fla. 
Phosphate Mining Co. ....55 John St., New York, N. Y., and Nichols, 
Fla. 
L. N. Pipkin.Mulberry, Fla. 
Seminole Phosphate Co.Croom, Fla. 
Societe Universelles de Mines, Indus¬ 
trie, Commerce et Agriculture.Pembroke, Fla. 
Southern Phosphate Development Co. .Inverness, Fla. 
Southern Phosphate Corporation.25 Broad St., New York, N. Y., and Lakeland, 
Fla. 
Swift & Co.. .Union Stock Yards, Chicago, Ill., and Bartow, 
Fla. 
T. A. Thompson.Ft. White, Fla. 
SAND AND GRAVEL 
The sand produced in Florida is used principally for building, paving 
and road-making, filtering, molding, cutting, grinding and blast pur¬ 
poses. The gravel produced is reported as used for roofing material and 
for railroad ballast. Deposits of clayey sand and gravel occurring in 
the southern part of Jackson County have been quarried and used for 
road-surfacing materials. The production of sand and gravel for the 
year 1920 was 132,749 short tons, valued at $117,601. 
The companies reporting the production are as follows: 
Crystal River Rock Company, Crystal River. 
Interlachen Sand and Gravel Company, Interlachen. 
Lake Weir Washed Sand Company, Lake Weir. 
Tallahassee Pressed Brick Company, Havana. 
Tampa Sand and Shell Company, Tampa. 
SAND-LIME BRICK 
The materials used in the manufacture of sand-lime brick are sand 
and lime. The bonding power of the brick is due to the chemical reac¬ 
tion between these ingredients. The chemical changes occur in the 
presence of heat, pressure and moisture, and result in the formation of 
hydro-silicates of calcium and magnesium. 
The sand used in the manufacture of sand-lime brick should be com¬ 
paratively pure, with some variation in the size of the grains. The mix¬ 
ture of sand, lime and water is cut into the form of bricks and conveyed 
to a hardening cylinder and subjected to a temperature and pressure 
which vary according to the method of treatment. 
