BucklancTs Formation of the Valley of Kingsclere, ^51 



acquaintance with the geological arrangement of a district, and 

 a comparison with parallel cases elsewhere, have suggested 

 reasonable explanations of local phenomena, which must 

 otherwise have remained in their original obscurity. Amongst 

 these may be classed Dr. Buckland's observations on valleys 

 by elevation, and Mr. Martin's reasoning on the Weald de- 

 nudation. In treating of geology generally, we shall probably 

 take occasion to recount some instances where it has been 

 safely applied as a science of induction. Meanwhile, we shall 

 depart somewhat from the regular course we had prescribed, 

 for the purpose of noticing the memoirs to which we have 

 referred. 



The services of local observers are most usefully em- 

 ployed when, like Mr. Martin and Mr. Mantell, they devote 

 themselves to the examination of districts strictly within 

 their immediate cognizance. The circumstances of resi- 

 dence and protracted observation are by no means to be 

 lightly estimated ; and when to these are added an extended 

 acquaintance with distant parts of the geological system, and a 

 habit of looking to general features rather than of scrutinising 

 uncertain details, they confer upon this order of contributors 

 an advantage which cannot be too highly appreciated. It is 

 true, the great outlines of our strata have been traced, but 

 some are less perfectly sketched than others. Many extensive 

 intervals yet remain to be filled up, and an immense field is 

 still unexplored with that degree of accuracy which is requi- 

 site to the complete developement of all its parts, and a tho- 

 rough knowledge of its internal structure. A long time will 

 elapse ere the whole work shall have received these elaborate, 

 yet not the less characteristic, touches, so as to exhibit the 

 true features of our country. By the formation of local 

 scientific institutions, by the establishment of provincial collec- 

 tions of natural history, by the cooperation of numerous indivi- 

 duals eminent for their earnest support of these enquiries, and, 

 above all, by the concentration of its most distinguished advo- 

 cates in the metropolitan society of geologists, the progress 

 of this great undertaking will be rapidly accelerated. We 

 need not add, that to contribute towards the same end, and to 

 diffuse yet moi:e widely a knowledge of this department of 

 natural science, are aniong the leading objects of this Journal. 



The district which forms the subject of Mr. Martin's me- 

 moir, is that portion of Sussex and Kent which retains its 

 Saxon appellation of the Weald. This is a quarter so abound- 

 ing in objects of peculiar interest, that it has previously 

 occupied some of our most experienced geologists in investi- 

 gating them. Possessing characters, in the arrangement and 



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