MENDIP BOXE CAVEKNS. 33 



Charter-house mine, and about three miles from Cheddar, 

 may be seen a very clear and characteristic form of the 

 " Swallet." The stream which has been used to wash the 

 " slimes," separating the lead ore from the refuse mud and 

 Band, becomes, as might be expected, heavily charged with 

 carthy and mineral matter. You watch its rushing flow, 

 all muddy and discoloured, as it leaves the works, and all 

 at once it disappears. It is swallowed up (hence the local 

 name) through one of the many fissures commnnlcating 

 from the surface with the subterranean river-beds which 

 run through the heart of Mendip. In this particular case, 

 no fissure is visible, but the water sinks into the ground, and 

 again makes its appearance at Cheddar, discolouring and 

 defiliug the stream as it rushes from its rocky source. In 

 other cases the fissures are open and on the surface. An 

 instance of this kind occurs in a field on Ubley Hill firm, 

 on the Eastern side of the ränge. A stone dropped into 

 the hole may be heard for several seconds in its downward 

 course. Many of these fissures, no doubt, act as feeders 

 to the subterranean Channels which pour out their abun- 

 dant streams from the extemal clefts in the rocky sidcs of 

 the Mendip Hills, as at Cheddar, and at Wookey Hole. 



The agencies, which for the most part produced these 

 effects, at the same time gave origin to many caverns, 

 opening immediately from the surface. The Caverns at 

 Uphill, Banwell, Hutton, &c, in which bonos have been 

 found, belong to this class. The mouths or original en- 

 trances of the caves have in almost all cases been closed, 

 or covered over with earthy matter and gravel. During 

 the period of the earth's history in which the animals to 

 which these bones belonged, lived, the caverns were morc 

 accessiblc from without than they are now. Indications 

 of the original outlets are visible in some, and Mr. Board 



vol. vir., 1856-7, paut .11. e 



