WELL BORING AND TUBING 35 



brine as well as the inflow of surface water. The rubber 

 has the whole weight of the casing to support and therefore 

 fills all crevices. This is brought about by breaking joints 

 in the casing so that the whole weight comes on the rubber. 

 The weight of the tube comes on the thread of the collar 

 and tube above, the collar resting on the casing head. This 

 weight is enough to keep the brine from leaking out at the 

 top, at a pressure of about 300 lbs. If the pressure of the 

 brine should happen to be sufficient to overcome the weight 

 of the tube the collar would rise in its seat and the brine 

 flow off at the top. 



Wells which are connected are reversible, that is to say, 

 water can be pumped down one and up the other alternately. 



At Saltvale the process of pumping employed by the 

 Crystal Salt Co is based on the theory that it is preferable 

 to take the brine from as low a depth as possible, because 

 there is a tendency for the strong brine to become stronger 

 at the expense of the weaker brine above, and besides, the 

 brine on account of greater specific gravity sinks to the 

 bottom below the water. For this reason it is better to 

 pump brine up the tubing rather than up the casing because 

 the tube is forced to take the saturated brine while the 

 casing, not being down to the bottom, as it ends several 

 hundred feet above, is forced to take the less saturated brine. 



The forcing principle, i. e. the forcing down one and up 

 another, is said to have been invented by the Crystal Salt 

 Co. and is used by them for connected wells and isolated 

 wells. The capacity is obviously greater for there is no limit 

 to the amount of water which may be forced into a well 

 except the capacity of the pumps and the size of the cavity 

 already made, a larger cavity producing a greater degree of 

 saturation, on account of a longer period of contact with the 

 salt. In the old method in which a lifting pump is used the 

 capacity depends on the cylinder and length of stroke. 



Caving in of the rock frequently causes much trouble. 

 The rock becomes undermined by the dissolving out of the 



