^66 MarMs Geological Memoir, and 



ation of watery erosion, the friction of their own streams, or the 

 debacle of the lake itself. That this could not have been the 

 case, is proved by the existence of more than one of them.' 

 The first that gave way would render all the rest unnecessary 

 and impossible; and if every drain had had its separate pool, 

 the water would never have risen high enough in either of 

 them, separately, to force a passage through so many obstacles. 



" If, on the other hand, it be proved that these masses are 

 deeply fissured, it is also proved that they have been in motion. 

 And the formation of such a channel as here described, in a 

 direct line through such heterogeneous materials, must have 

 been the result of a simultaneous movement of the whole, let 

 the moving power be what it might. That this operation was 

 coeval with the catastrophe which left the material features of 

 this part of the world such as we see them, is apparent from 

 a collective view of the concomitant phenomena. And whe- 

 ther the Sussex and Surrey hills, with their accompanying 

 strata, were severed by the disruption and dispersion of the 

 intervening parts, or simply by the sliding down of the whole 

 mass, which is much less probable, or the joint effect of these 

 causes, the slightest inclination or obliquity of the basis, upon 

 which it must be supposed to rest, would be sufficient to open 

 the fissures in the direction in which we see them." [Martin, 

 p. 74.) 



" To the eye of the practised observer, the Weald valley 

 presents the appearance of a great water channel after a flood ; 

 some parts of it clean and clear from all incumbrance, others 

 loaded with drift; the banks in some parts torn clean away, 

 in others heaped up with rubbish." [Martin, p. 84.) 



But, with regard to the notion that the exposure of the strata 

 beneath the chalk, in the Weald valley, is solely the effect of 

 denudation, Mr. Martin is inclined to support Dr. Buckland's 

 views, in withholding his assent to that hypothesis. " I am 

 disposed fully to allow," observes Dr. Buckland, " that the 

 force of water has been sufficient to sweep away the greatest 

 portion of the loose and shattered fragments, which, after the 

 elevation I am assuming, nmst have covered the axis of this 

 valley, and which must still have remained there, in the form 

 of rubbish, had there been no subsequent diluvial action to 

 drift them away. But I think the slightest inspection of the 

 sections of the Weald will at once convince us, that no power 

 of denudation by water could have produced the doubly in- 

 clined position of the entire body of the strata within this dis- 

 trict, as well as of the chalk by which it is surrounded ; and 

 that we must here again have recourse to a force producing 

 elevation from beneath, along the axis of the valley, if we 



