. Water Supply and Irrigation Papers of the United States Geological Survey . Fig. 28.—Common dug well; shallow in water. inches, the thermometer at F. The height of partialvacuum in suction pipe, as indicated by vacuum gage, was feetabove base; height of absolute vacuum, as indicated by vacuum gageabove the base line, was feet; height of valve seat of steam pumpabove base, feet. Fig. 30 shows the effect of pumping, of stop-ping the pump, and of rain, upon the height of ground water in one ofIRR (57—02 5 64 MOTIONS OF UNDERGROUND WATERS. [no, 67. the wells. The pu
. Water Supply and Irrigation Papers of the United States Geological Survey . Fig. 28.—Common dug well; shallow in water. inches, the thermometer at F. The height of partialvacuum in suction pipe, as indicated by vacuum gage, was feetabove base; height of absolute vacuum, as indicated by vacuum gageabove the base line, was feet; height of valve seat of steam pumpabove base, feet. Fig. 30 shows the effect of pumping, of stop-ping the pump, and of rain, upon the height of ground water in one ofIRR (57—02 5 64 MOTIONS OF UNDERGROUND WATERS. [no, 67. the wells. The pumping was at the rate of 2,010 gallons an hour,except for several stops indicated on the diagram. Fig. 31 illustrates a very excellent apparatus designed by Hoadleyfor the experimental study of well phenomena in the laboratory. The. Fig. 29.—Diagram illustrating the changing position of the water table near a 3-inch wellduring ten consecutive hours of continuous pumping at an average rate of 2,313 gallons an hour.(After Hoadley.) sand is held within a 48-inch cylindrical curb of wire cloth, so placedin a larger tank as to leave a 1-inch space all round, which can bekept filled with water to supply the sand during experimental pump-ing from a well at the center of the cylinder. Numerous brass tubesdrilled with fine holes occupy positions in the sand at various dis- SLICHTER.] COMMON OPEN WELLS. 65 tances from the central well and communicate with appropriate gagesof glass tubes, from which the position of the ground-water surface inthe sand can be determined at any time, as shown in the lower pariS fig. 31. The capacity of surface wells depends upon several factors. Per-haps the most important is the degree of fineness of the material of thewater-bearing stratum. The size of the soil grains not only controlsthe
Size: 1437px × 1739px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorunitedst, bookcentury1900, bookdecade1900, bookyear1902
