GEOGRAPHY OF CENTRAL FLORIDA 159 



Sand abounds nearly eveiywhere, and the pure white variety, 

 .such as characterizes the scrub, ought to be well suited for the man- 

 ufacture of glass. Sand-lime brick is made at Lake Plelen, in v^olu- 

 sia Count3^ 



The marl in low hammocks and the shell mounds are used to 

 some extent for road-making. Gypsum is found in a few low ham- 

 mocks, but apparently not in commercial quantities, unless in the 

 western part of Sumter County.* 



Peat abounds in the lake region and occurs in most of the others, 

 but has been little used as yet. It was discussed at considerable 

 length in the Third Annual Report, which the interested reader can 

 consult for details. 



Artesian water is easily obtained anywhere in the area, but it 

 does not rise above the surface except near the coast and larger 

 rivers and lakes, and at a few other places at low elevations. The 

 highest artesian pressure found in the State is along the Indian 

 River in southern Brevard County, where the water rises about 50 

 feet above sea-level, and is used in a small way for running dy- 

 namos, etc. Most of the water from deep wells contai-ns consider- 

 able salt, lime, sulphur, etc., but hardly ever enough to make it un- 

 fit for drinking purposes, except in some places near the upper St. 

 John's River, where the salt content is excessive. In the lime-sink 

 region, however, the water, is often too ''hard" for boiler purposes, 

 and water-softeners are used by the railroads. Rain-water cisterns 

 for private residences are used where the wlater is too deep to be 

 reached by dug wells, as in the lime-sink region, or too highly min- 

 eralized, as in some places along the east coast. Force-pumps are 

 also frequent in the lime-sink region and the higher parts of the lake 

 region, while ordinarv suction pumps prevail in the flatwoods. 



*The latest account of the Florida gypsum deposits, containing references 

 to important earlier papers, is by R. W. Stone in "Mineral Resources of the 

 United States for 1918" (U. S. Geological Survey), part 2, pp. 293-296. 



