1 88 2. 39 Trans. N. V. Ac. Set. 



ganese, which is studded with thousands ot white spots caused by the 

 eftlorescence of the sulphate of magnesia. 



. Cleveland's Cabinet, in the same cave, is a very treasure house of 

 alabaster brilliants. Imagine symmetrical arches of fifty feet span, 

 where the fancy is at once enlivened and bewildered by a mimicry of 

 every flower that grows. Similar crystalline conservatories are to be 

 seen in other parts of Mammoth Cave, and also in Wyandot and other 

 Western caves. 



Earthquakes have had comparatively little to do with subterranean 

 scenery, though generally credited with having wrought many changes. 

 Among possible effects of earthquake shocks one of the most remark- 

 able is the dislodgment of huge masses of dripstone in Luray cavern ; 

 upon which new formations have since grown, whose brilliant white 

 contrasts vividly with the rusty red or rich bronze of the more ancient 

 deposit. Examples of this fresh formation are Titania's Vail, the Em- 

 press Column, and Brand's Cascade. The Fallen Column, twenty-one 

 feet long and twelve feet thick, has been regarded as cast down by an 

 earthquake shock. It was evidently wrenched away at some remote 

 period from its point of attachment above, and fell swaying to and 

 fro. 



Most of the variations in subterranean scenery, usually ascribed to 

 earthquakes, are really due to the chemical and mechanical action of 

 water. Acidulated water cuts into the limestone, searching out the 

 lines of weakness, until channels are made leading down to some sub- 

 terranean outlet. The agency of running streams carries on the work 

 begun by water freighted with carbonic acid. Sand and gravel borne 

 in with these" streams make of them powerful cutting-engines. 



Thus may be explained the huge pits and domes of Mammoth Cave ; 

 and in the same way the deep chasm known as Pluto's Ravine, in 

 Luray Cave. To the same cause I attribute the dislodgment of 

 the Fallen Column and other great stalactites in the latter cavern. My 

 theory is that Luray Cave was first hollowed out by acidulated water ; 

 then it was partly filled by dripstone ; then the outlet was stopped and 

 the entire cavern flooded with strongly acidulated water, whereby the 

 first set of stalactites was partly destroyed ; and when the outlet was 

 re-opened, or a new one found, then came the catastrophe that hurled 

 mighty masses down and left them as proofs that water may be as 

 energetic as fire. And finally the fresh set of stalactites was created, 

 out of the already refined materials, by the beauty of which the eyes of 

 the civilized world have been attracted. 



The scenery of certain caves is modified by the presence of consid- 

 erable bodies of running or standing water. Echo River, in Mammoth 

 Cave, is about three-quarters of a mile long, from 20 to 200 feet wide. 



