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shown a far more advanced appreciation of\the value of 

 science in all its departments, than had many an older 

 state which had simply looked with favor on geological 

 surveys so far as it was thought they would give imme- 

 diate returns in pecuniary value. He then proceeded to 

 give a general account of the geology of the region, em- 

 bracing the great cavernous country of which the Mam- 

 moth Cave and its vicinity form only a small part. He 

 traced the present drainage of the region, and showed 

 how a large part of the surface of the country was cut 

 up by sink holes, or large circular depressions, in which 

 the rain water accumulated and was then drained off by 

 subterranean streams, to unite with the water of the Green 

 River and its tributaries at a lower level, forming the 

 caves through the immense beds of subcarboniferous lime- 

 stone. He then explained how the caves, which exist in 

 immense numbers throughout this whole limestone region, 

 had been formed by the action of the carbonic acid in the 

 rain water, and also by the wearing away of the rock by 

 the sand and stones carried along by the streams. He 

 said that no one could examine the caves without being 

 convinced that their formation was wholly due to aqueous 

 action in this way, and that in those chambers where the 

 water was still at its work one could hardly fail to under- 

 stand the process. In this way the caves have been cut 

 for miles in extent, and to the depth, in some instances, of 

 nearly three hundred feet from the surface. The upper 

 chambers, or early river beds, become dry as the subter- 

 ranean streams cut their way lower and lower into the 

 limestone, just as the outside rivers cut their way deeper 

 and deeper into the valleys. Many of the caves near the 

 surface have become entirely dry from this deeper drain- 

 age, while in others at a little lower level, or in situations 

 where the water from above has percolated through the 



