FORMATION OF THE CAVE. / 



corridors, can convey anything like an adequate idea of the place. 

 After spending fifteen hours within its chambers, it is absolutely 

 nauseating to read the descriptions which have been current in the 

 letters of newspaper correspondents for a quarter of a century, 

 and even the vigorous and picturesque language of Bayard Taylor 

 becomes tame and commonplace when it attempts to describe this 

 subterranean wonder of the world. 



How and when the cave was made, were the leading questions 

 in the minds of the geologists. They do not believe that the cave 

 was the immediate result of some violent upheaval of the strata, 

 which left these vast crevices and chambers of which the cave is 

 composed ; neither do they share the popular belief that the rapid 

 and violent action of some subterranean stream of water has 

 worn these deep channels through the limestone ; on the contrary, 

 they find conclusive evidence that the same agencies are at work 

 and the same changes in progress to-day that have been slowly, 

 steadily and quietly, through vast periods of time, accomplishing 

 the marvellous wonders that now astonish the beholder. The cave 

 is wrought in the stratum known as the St. Louis limestone, which 

 in some places reaches a thickness or depth of four hundred feet. 

 This stone is dissolved whenever it is subjected to the influence of 

 running or dripping water impregnated with carbonic acid gas. 

 Water exposed to the air readily absorbs this gas, and surface water 

 percolating through small fissures of the limestone, dissolves it. 

 Another fact should be stated. When, during this process of so- 

 lution, the water becomes thoroughly impregnated with lime, it 

 loses its power to dissolve the stone. The following conditions, 

 then, were essential to the productions of the cave, assuming what 

 is not disputed by geologists, that the place where the cave now is, 

 was once nearly solid limestone. First, that there should be fis- 

 sures in the strata, allowing the ingress of the surface water. Sec- 

 ondly, there should be a place or places of exit for the water charged 

 with limestone in solution. Without the latter, the water would 

 become charged with lime, fill up the crevices, and the dissolving 

 process would cease. These conditions are all present to-day, and 

 have remained the same during the countless ages that have passed 

 away while the work has been in progress. There have doubtless 

 been times in the history of the cave, when, owing to a greater 

 flow of water, the work has progressed more rapidly than at pres- 

 ent, but that the results have been accomplished in the manner 

 stated, rather than by the process of attrition by rapid currents of 

 large volumes of water, seems to be the general opinion of scien- 

 tific men. This theory is strengthened by the fact that where the 

 cave attains its greatest heights, and reaches its lowest depths, 

 the dripping waters have never ceased their labors, and are busily 

 at work to-day. In the Mammoth Dome, for instance rarely 

 seen by visitors, on account of the dangers and fatigue incident to 

 the journey where the chasm attains a height and depth of more 



