110 Dr. B E R G E R on the physical Structure 



chain is also very near its centre.* Brown-Willy, in the neigh- 

 bourhood of Bodmin, is, as h?.s ]:i'2en said, one thousand three hun- 

 dred and sixty-eight feet above the level of the sea, while the gra- 

 nitic cliffs at the Lands-end do not exceed sixty or one hundred 

 feet. It is however possible, that the neighbourhood of Craw- 

 Mere-Pool in Dartmoor forest, not far from the eastern extremity 

 of the chain, may be nearly as high as Brown-Willy. But it is 

 rare to find any general rule without some exceptions : thus, accord- 

 ing to Andre de Gy and Ramond, the highest points in the Vosgesf 

 and in the Pyrenees are out of the central chain. 



The low range of Cornwall presents a regularity in its compo- 

 sition, rarely found in great chains. Saussure has shewn the dis- 

 similarity between the two opposite sides of the Alps : on the 

 northern side, he informs us, the whole of the exterior range is com- 

 posed of mountains of limestone of considerable height and extent ; 

 on the south side, on the contrary, the schistose rocks, and even the 

 granite reach the plains, and if limestone do exist on this side, 

 it is of very rare occurrence, and does not form broad and continuous 

 chains as on the northern side.:}: 



Pallas has also observed in Russia and in Siberia, essential difFer- 

 ences between the opposite sides of the same chain of mountains. 

 Ramond remarked the great dissimilarity between the two sides of 

 the Pyrenean chain, the sandstones are rarely met with on the north- 



* This appears also to be the case in North Wales. The county of Caernarvon, from 

 Bardscy island, in a north-easterly direction, to the promontory of Penmaen-bach in 

 Conway bay, is occupied by a range of mountains the iiighest of any in Wales. They 

 gradually ascend from each extremity of the chain towards the centre, which is occu- 

 pied by Suowdon, the loftiest of all." Arthur Aikin's Tour through North Wales, 

 p. 97. 



+ I have recognized in the Vosges, the truth of the observations of Audi e de Gy. 



X Voyages daus los Alpes, § tl»Sl. 



