266 Dr. Berger on the Geology of some parts 



day, than to a sudden subsiding of the strata at a period of time 

 far beyond the reach of all historical monuments. 



If the chalk hills constitute ridges separated by low troughs or 

 vales which have been filled up by alluvial depositions, may not the 

 bottom of one of these vales have once existed in the space now 

 occupied by the Southampton channel ; and thus the separation of 

 the Isle of Wight have taken place in consequence of an encroach- 

 ment of the sea on a portion of little elevated land, the loose 

 materials of which besides, could have presented but a feeble barrier 

 to the repeated assaults of the sea?* 



May not that narrow arm of the sea, which from Cowes-harbour 

 extends four miles inland to Newport, and which is improperly 

 called Medina river, be owing to a cause of that kind ; as also that 

 other still deeper arm of the sea which from Yarmouth runs to 

 Freshwater- gate, and makes almost a complete island of that portion 

 of the land which lies westward ? 



The shape of this channel, and its slanting declivity on both sides, 

 affords also a further presumption of the truth of this hypothesis. 



That I have not gone beyond the warrant of the facts in admitting 

 such a disposition, as has been described, of chalk-hills with vales 

 between them, may, I think, be clearly demonstrated from actual 

 observations. 



In Kent and Sussex are two ranges of chalk hills, the north and 

 south downs, with an alluvial valt between them. In Hampshire, 

 near Alresford, where the chalk begins to crop out, we pass over a 

 ridge of this rock in a transverse direction to its length j till near 



* " The ebb, at low water, between the coast of Hampshire and the Isle of Wight, 

 " runs so strong that it shoots into Poole harbour, (which lies in the line of its course) 

 *' so that when it is low water at Hurst-castle, it is high water here." Maton's Obs. on 

 the West. Count, vol. i. p. 28. 



