114 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
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 Jacksonville 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 Leon Hotel well at St. Augustine affords valuable information as to the possibility of obtaining increased head in this section of the Stat. by drilling to greater depths. This well was drilled to a total depth of 1440 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 abcut 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 io feet. The lead at greater depths than 520 feet is not specifically recorded.
INCREASED TEMPERATURE WITH INCREASED DEPTH.
The teinpern.ture of the water at St. Augustine was founI to increase 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 ioo0 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 I, i io feet the temperature was 8o degrees F. Between I,I70 and 1,225 feet the water taken from the sand pump showed a temperature of 85 deprees F. Water taken from the sand pump between 1,340 and 1,390 feet showed a temperature of 86 degrees F.
This record of the Ponce de Leon well at St. Augustine is supplemented by the record from the new city well at Jacksonville. In the Jacksonville well the following temperatures were recorded: At a depth of 498 feet the temperature of the water flowing from the pipe was 71 degrees F. At 635 feet the temperature was 74 degrees F. At 900 feet the temperature still registered 74 degrees F. These measurements made as the water escapes from