WATER SUPPLY OP PASTERN AND SOUTHERN PEORIDA. 183 
Clay . 87-160 
Rock ..160-165 
Clay .165-200 
Sand .200-240 
Clay .240-275 
Rock .275-280 
Sand . 280-350 
Rock . 350-353 
Clay ...353-363 
Rock . 363-366 
Clay .366-375 
Rock .375-379 
Sand .379-400 
Clay ..400-440 
Soft rock .440-447 
Soft water-bearing rock .447-627 
Hard rock .627-630 
ST. JOHNS COUNTY. 
LOCATION AND SURFACE FEATURES. 
St. Johns County lies in northeastern Florida, bordering the 
Atlantic Ocean. On the north it joins Duval County and on the 
south Volusia County. The western boundary is formed by the 
St. Johns River. The county has a total length of sixty miles. 
In width it varies from eighteen to twenty-four miles. The total 
area is approximately 1,000 square miles. 
Owing to the location of St. Johns County between the St. 
Johns River, on the west, and the Atlantic Ocean, on the east, no 
great variation in elevation is to be expected. It is probable, 
however, that small areas in the interior of the county lie above 
the fifty-foot contour. In passing from St. Augustine to Jack¬ 
sonville, levels made by the Florida East Coast Railway show 
near the county line an elevation over a small area of 57 feet. 
The greatest elevation recorded between St. Augustine and Hast¬ 
ings is in the vicinity of Hurds. A line of levels run from the 
coast at St. Augustine, at the instance of Mr. B. A. Carter, gave 
for Hurds an elevation of thirty-eight feet. Revels obtained from 
the U. S. Engineers’ Office, Jacksonville, Florida, give, for a point 
