8 PROFESSOR T. MCKENNY HUGHES, M.A. 



beast to inhabit. Sometimes, however, when all the hill is 

 full after some great thunderstorm, water spurts out of every 

 joint and spouts in torrents from each cave, and until the 

 cave is quite beyond the chance of such catastrophes, wo 

 cannot hope to find a clear, continuous record of its old 

 inhabitants. 



To give an example of a cave now being formed in one 

 part and periodically modified in another, I will carry you to 

 the flanks of Ingleborough, where the conditions are pecu- 

 liarly well suited for the formation of caves and for the 

 examination of all the accompanying phenomena. Many of 

 you are familiar with the form of the grand bluff known as 

 Ingleborough the most conspicuous feature as you look 

 north from Lancashire towards the borders of Yorkshire and 

 Westmoreland. Its flat cap of millstone grit ; its steep slopes 

 of rapidly-crumbling Yoredale shale, here and there braced 

 up by throughs of sandstone, or grit, or limestone ; its great 

 table of mountain limestone, on which these all stand ; and 

 its base of Cambrian and Silurian, altogether combine to 

 furnish some of the most charming bits of scenery and most 

 interesting bits of geology in the kingdom. On the S.E. 

 slopes of Ingleborough is a great hollow space where the 

 water runs off the impervious Yoredale shale and the patchy 

 drift down to the basement table of mountain limestone. 

 The drainage area is about a square mile, and the stream is 

 usually small and generally lost at once in the first open joints 

 of the limestone that it gets to. But a flush of rain-water 

 soon fills these crevices to overflowing, and the surplus water 

 rushes on 100 yards or so to a great chasm, known as Gaping 

 Gill Hole, into which it plunges with a roar. 'The air dragged 

 down, tangled in the water, ascends in a current, carrying 

 mist and spray far above the chasm's brink. I have watched 

 this wonderful abyss many a day of storm and sunshine. No 

 one has ever been to the bottom of it ; but I can tell you 

 something more about it that bears directly on the subject 

 we are considering. 



In that country, so favourable for the formation of all the 

 various kinds of swallow-hole, cave, and keld, I once had tho 

 good fortune to witness one of those grand storms which in a 

 few minutes change the face of nature, and in a few hours 

 leave a mark that ages may not efface. 



I had climbed some way up Ingleborough. It was a 

 glorious July morning. Myriads of insects were busy with their 

 own various pursuits. The haymakers were hard at work ; 

 more hurried, perhaps, as the weatherwise saw thickenings 

 towards the south, and felt the sultry heat that warned them 



