INDEX 



177 



Rocks: 



cost of drilling in, 119. 



description of, 35-39. 



occurrence of water in, 40, 42-44, 83. 



porosity of, 29, 72. 



structures of, 38. 



Rocky Mountain water province, 65. 

 Run-off, amount of, 3. 

 Running water, convenience of, 151. 



Safety distance of wells, 81. 

 Sand: 



absorption of water by, 30. 



artesian flows from, 55. 



definition of, 36. 



driven wells in, 40. 



ground waters in, 40, 72, 82, 160-161. 



pollution conditions in, 40, 82. 



porosity of, 29. 

 Sandstone: 



artesian flows from, 55. 



cost of drilling in, 119. 



definition of, 37. 



drilled wells in, 42. 



ground waters in, 42, 82, 161. 



pollution conditions in, 82. 



porosity of, 29. 

 Sanitary tests of water, 165. 

 Schist: 



definition of, 38. 



ground waters in, 44. 

 Schistosity, definition of 39, 

 Screens: 



construction of, 114. 



corrosion of, 114. 



incrustation of, IOI. 



natural, 99, 100, ioi, 113. 



special, for clays and quicksands, 72, 



US- 



use of, in driven wells, 100. 



use of casing as, 115* 

 Seepage: 



amount of, 17. 



springs, 13, 14, 17. 



pollution by, See Pollution. 

 Shale: 



cost of drilling in, 119. 



definition of, 37. 



ground waters in, 82. 



Shale: 



pollution conditions in, 46, 82. 



porosity of, 29. 



Shooting to increase yield of wells, 113. 

 Sierra- Cascade water province, 67. 

 Sinks and sink-holes: 



pollution through, 18, 22, 26, 46. 



protection of, 26. 

 Siphons, use of, 152. 

 Slate: 



definition of, 37. 



ground waters in, 43, 82. 



pollution conditions in, 46, 82. 



porosity of, 29. 

 Soapstone: 



definition of, 38. 



improper use of term, 37. 

 Soda ash, use of, for softening water, 170. 

 Soils; 



absorption of water by, 29. 



porosity of, 29. 

 Solution passages, See also Caverns. 



waters in, 43, 72, 83. 

 Springs: 



definition of, 13. 



importance of, 21. 



nature of, 6. 



piping of, 27. 



pollution of, 21, 22, 25-26. 



protection of, 22, 26. 



purity of waters, 21. 



situation of, 13. 



size of, 13, 17. 



source of water of, 13. 



supplies from, 153. 



use of, 21. 

 Springs, types of: 



artesian, 14. 



fissure, 1 8. 



gravity, 14. 



seepage, 13, 14, 17. 



tubular, 17. 

 Standard drilling: 



cost of, 119. 



method of, 105, 107. 

 Steam jet, use of, to increase yield of wells, 



113- 



Stovepipe wells: 

 cost of, 119. 



