406 



Ou many large rivers, and, in some instances, on 

 smaller ones, there are two and sometimes three allu- 

 vial banks on each side, except where the river passes 

 through a mountainous district. On this important 

 subject, it may not be amiss to offer a few remarks 

 previous to proposing any interrogatories. 



The lands immediately bordering upon a river, and 

 which form the first bank on each side, are generally 

 considered as the intervales or meadows, and, if allu- 

 vial, have generally a gradual descent from the river 

 for a half a mile, and from that to two miles or more, 

 where there commences another bank or range of hills, 

 likewise of alluvion, from twenty to sixty feet or more 

 in height. This second tract of country or land, gene- 

 rally extends to the foot of the mountains, and varies in 

 breadth from one to several miles. 



These two, and sometimes three banks or tiers of 

 alluvial land, have been distinctly mentioned by seve- 

 ral travellers, as occurring on many rivers ; but no parti- 

 cular description has hitherto been given. of them, that 

 1 can find, neither have any remarks been offered that 

 are calculated to make us acquainted with their histo- 

 ry, or the cause of their formation. In a geological 

 point of view, they are extremely interesting and im- 

 portant ; so much so that, on a careful examination of 

 the order of their arrangement, in relation to the river 

 on which they lie, and the adjacent mountains or hills, 

 and their internal structure, no one will hesitate to ad- 

 mit, that they distinctly point to two important epochs 

 or events, that have taken place upon this globe, and 



