Chap. IX. GEOLOGICAL KECOED. 2S5 



worn by the waves and pared all round into perpendicular 

 cliffs of one or two thousand feet in height ; for the 

 gentle slope of the lava-streams, due to their formerly 

 liquid state, showed at a glance how far the hard, rocky 

 beds had once extended into the open ocean. The 

 same story is still more plainly told by faults, — those 

 great cracks along which the strata have been upheaved 

 on one side, or thrown down on the other, to the 

 height or depth of thousands of feet ; for since the crust 

 cracked, the surface of the land has been so completely 

 planed down by the action of the sea, that no trace of 

 these vast dislocations is externally visible. 



The Craven fault, for instance, extends for upwards 

 of 30 miles, and along this line the vertical displace- 

 ment of the strata has varied from 600 to 3000 feet. 

 Prof. Ramsay has published an account of a downthrow 

 in Anglesea of 2300 feet ; and he informs me that he 

 fully believes there is one in Merionethshire of 12,000 

 feet ; yet in these cases there is nothing on the surface 

 to show such prodigious movements ; the pile of rocks 

 on the one or other side having been smoothly swept 

 away. The consideration of these facts impresses my 

 mind almost in the same manner as does the vain en- 

 deavour to grapple with the idea of eternity. 



I am tempted to give one other case, the well-known 

 one of the denudation of the Weald. Though it must 

 be admitted that the denudation of the Weald has been 

 a mere trine, in comparison with that which has 

 removed masses of our palaeozoic strata, in parts ten 

 thousand feet in thickness, as shown in Prof. Ramsay's 

 masterly memoir on this subject. Yet it is an admirable 

 lesson to stand on the North Downs and to look at the 

 distant South Downs ; for, remembering that at no 

 great distance to the west the northern and southern 

 escarpments meet and close, one can safely picture to 



