n6 DOMESTIC WATER SUPPLIES FOR THE FARM 



of danger would not only be expensive but would also often shut 

 off desirable water supplies, the size of the hole is reduced and 

 a short section of casing (just long enough for the purpose) is 

 lowered into the hole and set as described in the preceding 

 paragraph. Sometimes several strata have to be thus cased off, 

 the size of the hole being necessarily decreased each time, since 

 the drill in further work must be operated through the smaller 

 pipe. 



Packing. Packing consists in forming a water-tight joint be- 

 tween the outside of the casing and the rock, and is necessary to 

 prevent the water from passing upward along the outside of the 

 casing, or to prevent the shallower and perhaps contaminating 

 water from being drawn downward along the casing into the well. 



Formerly flaxseed was extensively used, bags being placed at 

 the points where the casings were to be set. The drill was then 

 lowered on the bag, breaking it apart and forcing the seeds into 

 the opening between the pipe and the rock where, in contact with 

 the water, they rapidly expanded and closed the opening. 



Cement and asphalt have also been used, but have not been 

 found satisfactory in this country. Here rubber packers, made 

 in a great variety of forms and sizes especially for the purpose, 

 have been found to be most economical and effective. Several 

 forms are so constructed that they may be removed, brought to 

 the surface for examination, and later reset at will. 



Plugging. Plugging means the complete obstruction of the 

 well by the insertion of some material or apparatus designed for 

 the purpose. Wells are usually plugged to prevent objectionable 

 supplies of water, oil, etc., from entering below the higher and 

 better supplies which it is desired to use. The nature of the 

 plug used in water wells is not greatly different from that used in 

 oil wells, which in Ohio is defined by law as "a dry wooden plug 

 not less than three feet in length, equal to the diameter of the 

 hole." Over this, according to the same statute, there must be 

 placed "at least seven feet of sediment or drillings, or cement 

 and sand." 



