WATER SUPPLY OP EASTERN AND SOUTHERN EEORIDA. 147 
sure, or height above the ground to which the water will rise like¬ 
wise increases. The head is, in reality, only a measure of the 
pressure. The amount of flow is within limits dependent upon 
the amount of pressure. Other conditions remaining the same, 
an increased pressure will result in an increased flow. For the 
records regarding pressure, it is necessary to rely chiefly upon the 
Jacksonville and St. Augustine wells already referred to. 
At 680 feet the pressure of the artesian water in the Jackson¬ 
ville well was 12 pounds per square inch, or sufficient pressure to 
cause the water to rise vertically in a pipe 27.72 feet. At 900 feet 
the pressure, as shown by the gauge, was 15 pounds, or sufficient 
to cause the water to rise 34.65 feet. 
The Ponce de Teon Hotel well, at St. Augustine, afifords valu¬ 
able information as to the possibility of obtaining increased head, 
in this section of the State, by drilling to greater depths. This 
well was drilled to a total depth of 1,440 feet. A measure of the 
head was made at frequent intervals while drilling. The first 
considerable flow obtained at St. Augustine is under a pressure, 
causing it to rise about 32 feet above sea. At the depth of 350 
feet the head was found to have increased to 38 feet above sea. 
At the depth of 520 feet the head had increased to 42 feet, a total 
gain of 10 feet. The head at greater depths than 520 feet is not 
specifically recorded. 
INCREASED TEMPERATURE WITH INCREASED DEPTH. 
The temperature of the water at St. Augustine was found to in¬ 
crease with the depth. The temperature of the water in the Ponce 
de Leon well, at the depth of 35 feet, is reported as 62 degrees F. 
At approximately 100 feet the temperature was 72 degrees F. At 
170 feet the temperature was 74 degrees F. The increased flow 
obtained at 177 feet showed a temperature of 76 degrees F. At 
520 feet the temperature of the water in the pipe was found to be 
79 degrees F. At 1,110 feet the temperature was 80 degrees F. 
Between 1,170 and 1,225 feet the water taken from the sand pump 
showed a temperature of 85 degrees F. Water taken from the 
sand pump, between 1,340 and 1,390 feet, showed a temperature 
of 86 degrees F. 
