118 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORlT.
the well. In such cases the sand gains entrance or the well caves below the casing clogging or partly clogging the opening, thereby reducing or entirely stopping the flow.
NECESSITY OF GUARDING AGAINST WASTE OF ARTESIAN WATER.
The records that have been given above indicate clearly that useless waste of water should not be permitted. An artesian well draws not on an inexhaustible supply of water from some remote source,' but draws upon a-relatively local supply which is appreciably affected by continued use. A well permitted to flow uninterruptedly draws not only on the supply of the land on which it is located but affects also, the supply of the adjacent land. A state, a community, or an individual that permits the useless and reckless waste of artesian water will ultimately find a most valuable asset impaired by extravagance, and possibly no longer adequate.
It is urged by some well owners that to cut off a well or to stop the flow when not in use is unsaf e as sand or other material may get into and clog the well. The flow of the well can be reduced to one-third or one-fourth its normal volume and the danger from the accumulation of sand, when there is such danger, guarded against. Moreover where wells are cased, as they -should be to the Vicksburg Limestone, it is doubtful if there is danger of clogging and reducing or stopping the flow. A law restricting the waste of artesian water is urgently recommended.
SIMP LE METHOD OF DETERMINING FLOW OF ARTESIAN.** WELLS.
A simple method for measuring approximately the flow from an artesian well has been devised by Professor J. E. Todd, formerly State Geologist of South Dakota. The following is Professor Todd's method in full:
"It is often desirable to know the amount of water delivered by an artesian well. Frequently a contract calls for a certain amount. It is also well to know whether the flow is diminishing and how much.
"When a well is small, its flow may be measured easily with