ARTESIAN SPRING-WELLS. 47 



fresh-water mussels, and of land snails. All 

 these remains were just like those which are found 

 after floods on the banks of little rivers and 

 brooks. These could not have reached the bottom 

 of the spring-well by oozing through the ground, 

 but only through actual channels open to the air. 

 The same remark applies to one of these wells at 

 Elboeuf near the Seine, from which several small 

 living eels were once thrown up. 



The boring tool, in sinking these shafts, some- 

 times strikes into spacious underground caverns, 

 filled with water; when this occurs the rods, as 

 soon as the resistance ceases, plunge suddenly 

 down often to a depth of twenty or thirty feet. 

 In some instances it has been observed that the 

 water gushed up with such force as to shake the 

 boring-rods in the shaft. It has also happened 

 that when the auger has been drawn up, the water, 

 starting after it, has overflowed all the surrounding 

 place before it could be stopped. 



The original purpose of sinking artesian wells 

 was to obtain drinking water, and in several cases 

 brine-springs. The abundance of water yielded 

 by many of these wells, and the fact that their 

 temperature was almost always higher than that of 

 the air, have since found for them many useful ap- 

 plications. At some places in the north of Trance, 

 the jet, as it escapes from the earth, has been found 

 capable of driving a mill-wheel. 



