BucMand^s Formation of the Valley of Kingsckre, 263 



to form the south side of what is called the London basin, from 

 Marlborough Downs to the Straits of Dover. 



" Let him also suppose, that, whilst this is in progress, and all 

 the immense intervening masses are fissured and crumbled by 

 convulsion, a flood of water, powerful beyond comprehension, 

 at the same instant, or immediately after, rushing over, and 

 entering the broken surface, sweeps the whole contents of what 

 is now the weald excavation before it, into the North Sea - — 

 itself but a part of the abyss just then opened, perhaps by the 

 same concussion, to receive them. 



« Or, let 



"* A change come o*er the spirit of his dream. 

 That is not all a dream.* 



Let him suppose this part of our island lifted up out of the 

 ocean by an impelling power from below, some parts of it more 

 steadily and evenly, others with such irregular and successive 

 heavings, as to produce the effects above spoken of; disrup- 

 tion of the central parts, and such Assuring and rending of the 

 circumference, as an irregular action is calculated to produce 

 upon a ponderous and frangible material. 



" Such a dream, splendid as it may be, will fall far short of 

 the reality of those changes that can be demonstrated to have 

 taken place in parts of the world, well understood to be more 

 ancient than these under consideration. 



" If the mind is staggered at the immensity of such an 

 operation, let it be answered, that the Weald Valley is but a 

 small furrow on the earth's surface. And let our thoughts 

 revert for comparison to many greater natural phenomena; 

 to the height of the Himalaya, which may be well supposed 

 to have felt the power of the same ocean stream, perhaps to 

 have been lifted out of it, or to the five miles of depth, which 

 may be given to that ocean ; and then consider how small a 

 proportion the aggregate ten miles holds to the diameter of 

 the globe itself. 



" Noihing is great, nor nothing little, in the operations of 

 nature ; and such disclosures as these sink into insignificance 

 before the wonders of astronomy ! The mind is lost in the 

 contemplation of the immeasurable power to which it is indif- 

 ferent, that 



" * Now a bubble bursts, and "now a world.' " 



Without entering into the detail of the strata beneath the 

 chalk, which are exposed by the Weald denudation, it will be 

 sufficient here to state that they are recognised by the names of 

 malm-rock, or green sand, the gault or blue marl, and the upper 

 ferruginous sand, all of which are now classed by the author 

 under the comprehensive term glauconite* Beneath this occurs 



