34 Origin of the Cheddar Cliffs. 



spheric agency. It is true that rain-water, especially when 

 assisted by humus derived from the vegetable soil above, is 

 capable of enlarging crevices. But the erosion resulting 

 from its chemical action is limited to spaces where stalactitic 

 and stalagmitic deposition is not going on. This deposition 

 evidently rather tends to preserve caverns than facilitate 

 their destruction. The detachment of chips from rocks by 

 frost in favourable situations is a process likewise limited to 

 spaces where the chips have not accumulated to too great an 

 extent. All atmospheric agencies which can only remove 

 matter a short distance must tend to choke up or glut their 

 sphere of action. Without the assistance of a powerful 

 transporting agent they can never, in such situations as the 

 Cheddar ravine and its caves, make permanent progress in the 

 great work of denudation. Bat supposing atmospheric action 

 during millions and millions of years to be capable of producing 

 a vacuity as large as the Cheddar ravine, its form would still 

 remain to be explained. Sufficient time allowed, a colony of 

 ants might be considered capable of rearing a mountain mass 

 equal to the Alps, but an examination of the form of the Alps 

 would at once forbid the idea of insects having been the archi- 

 tects. Atmospheric agents, whether operating above or under 

 ground, are now producing nothing similar in form to the main 

 features presented by the Cheddar ravine. That the cliffs 

 have been modified in exposed situations by frost is evident, 

 but the modification has been in the direction of destroying 

 and not developing the characteristic forms of the cliffs. The 

 same remark applies more or less to the action of fresh-water 

 in caves. 



The common notion that the Cheddar ravine is a crack or 

 rent may, in a very limited sense, be correct. It is possible, 

 if not probable, that at first there may have been a narrow 

 winding fracture similar to that behind the High Tor at 

 Ma,tlock. It is, however, certain that no fracture ever occurred 

 sufficient to disturb the angle at which the strata dip in a 

 south-easterly direction, which on both sides of the ravine 

 exactly corresponds. A very little observation will be sufficient 

 to convince any one that the ravine has been mainly, if not 

 entirely produced by the abstraction of an immense mass of 

 limestone rock. The following diagram will show the strati- 

 graphical structure of the locality, the dotted lines representing 

 the strata which have been removed. 



From the foregoing observations I think it must appear 

 obvious that the clean removal of a stupendous quantity of rock 

 must form the burden of any satisfactory explanation of the 

 origin of the Cheddar Cliffs. It is true that in some places 

 the rocks are now crumbling, but there is no agent (with the 



