I 



CHAPTER XVIII. 



DISTRIBUTION OF LAND AND WATER. 



The disquisitions contained in the preceding chapters have 

 been devoted to the description and the elucidation of the 

 phenomena offered to common observation by a single 

 river-basin — that of the Thames. But, it has been in- 

 cidentally remarked, that this is only one of the many river- 

 basins of Great Britain ; and it is now needful to see what 

 lies beyond its boundaries. If we cross its northern water- 

 parting we enter the basin of the Ouse ; if we proceed west- 

 wards, we pass into that of the Severn ; while, to the south, 

 lie the basins of the Med way, which is almost an affluent of 

 the Thames, and of several smaller rivers. Each of these 

 basins, or any which lie beyond them, might have served 

 as our text ; though few are so well adapted for the purpose 

 as that of the Thames. 



Passing from river-basin to river-basin, the observer 

 would find bolder rehefs than he has met with in the 

 Thames valley, in the almost mountainous hills of Wales, 

 Cumberland, and Scotland ; the strata would often possess 

 a different composition, and would contain organic remains 

 of other kinds ; and the rainfall and other climatal con- 

 ditions would, sometimes, differ widely from those of the 



