E. W. Evans on the Action of Oil- Wells. 161 
the fountain with condensed air. Sometimes it is thrown into 
the air a distance of 30 or 40 feet, and large quantities wasted. 
If the oil continues to be ejected till its surface in the cav- 
ity descends to the mouth of the tube, the fact first becomes 
known by a gurgling and spurting action, and the gas, or the 
greater portion of it, escapes, after which the pump becomes ne- 
cessary, and the same series of actions take place as in the first 
ease. But if the gas reaches its equilibrium with the hydrostatic 
pressure before the oil is reduced so low, we may then pump 
out the oil till the water rises to the mouth of the tube, after 
which we shall obtain mixed oil and water as before, till the 
whole supply of oil is exhausted, provided the pump is of suffi- 
cient working power to prevent interruptions by the too rapid 
rise of the water. 
Next suppose that the boring is at C and enters the water. 
If the gas has sufficient tension, water is raised until its surface 
in the cavity descends to the mouth of the tube, then mixed oil 
and water is obtained, then pure oil, after which the same cir- 
cumstances exist as in the second case. It must not be inferred, 
however, that when the water is not thrown to the surface there 
isno oil. It may happen that the pressure of the gas will raise 
a column of water only part of the way up the boring, and yet 
the well be found productive. Hence no considerable quantity 
of water should be passed without ascertaining by reducing it 
With the pump whether there is oil confined above it in some 
side chamber. The Shattuck well on the Little Kanawha had 
to be drained of water with a steam pump for two weeks before 
oil was obtained; but after that it yielded abundantly. 
