12 PROFESSOR T. MCKENNY 1IUGHES, M.A. 



As we cannot follow these watercourses down from above 

 through all their subterranean wanderings, let us go down 

 into the valley below where the water comes down, and see if 

 we can work our way back into the hill towards the foot of 

 the great chasm, and see what is going on there. It is here 

 we find what is more properly a cave being formed. The 

 water drops from one level to another, then runs along 

 between the beds, and drops again. By putting your ear to 

 the fissured rock in one place, you can hear, from the deep 

 recesses of the earth, the sound of a waterfall that man has 

 never seen. Not far off, a beautiful clear river flows out of 

 the lower cave. This is 600 feet below the swallow-hole, 

 where the water enters on the hill above. When the rain 

 floods the stream above, this, too, runs turbid. Some 20 feet 

 above it is the entrance to the other cave, the celebrated 

 Ingleborough Cave, a more ancient outfall for the water, 

 which now runs at the lower level. 



This cave was explored many years ago by Mr. James 

 Fairer. I have followed it for about a quarter of a mile, and, 

 with some others, been let down to a lower level at the end. 

 We squeezed our way along till we came to a long, deep cave, 

 full of water, which seemed to flow gently towards the mouth 

 of the lower cave. In the great flood of 1872, all the sub- 

 terranean caves and fissures were filled, and the water spouted 

 out of the upper cave, carrying along with it great masses of 

 rock, which helped to break up the stalagmitic floors and 

 barriers. This flood was so exceptional that most of the 

 debris was carried clean away ; but we saw, when we examined 

 the ground round the mouth of the cave, and the well-known 

 passages inside, what had been going on ; how stalagmitic 

 floors had been undermined, broken up, and re-deposited, and 

 how the torrent debris was sometimes left in the embayed 

 corners of a limestone cave. But this was a cave not far 

 above the existing watercourse. When a cave has been 

 formed in the side of a rapidly-deepened gorge, where, how- 

 ever high the flood may rise, the water can never sweep it 

 out with a rush, gentler processes of denudation and depo- 

 sition still go on. The debris that falls about the mouth 

 ponds back the rain, and gathers in the fissured rock, and 

 turns in the rivulet that would have trickled down the hill 

 The damp clay clings to the rock and frets away its surface, 

 and things washed in work their way down along the face 

 of the opening, gradually-weathered limestone, and lie in clay 

 washed down with them. 



It is easy to distinguish the chemically-fretted rock from 

 that which has been worn, smoothed, and rounded by the 



