Ch. XL] ERRATIC BLOCKS. 149 



deluge, as most extravagant. It cannot be disputed that, if 

 part of the unfathomable ocean were suddenly converted into 

 a shoal, a great body of water would be displaced, and a dilu- 

 vial wave might then inundate some previously-existing conti- 

 nent. A line of shoals, therefore, or reefs, consisting of 

 shattered and dislocated rocks, and surrounded on all sides by 

 a great depth of sea, ought first to have been pointed out by 

 the paroxysmalist as one of the protruded masses which may 

 have caused a recent deluge. The subsequent upthrow of 

 these same reefs to an additional height of ten, fifteen, or 

 twenty thousand feet, converting them suddenly into a moun- 

 tain ridge like the Andes, would displace a great volume of 

 atmospheric air, not of water, and if the velocity of the move- 

 ment were sufficiently great, might occasion a tremendous 

 hurricane. 



If it be said that a convulsion sufficiently violent to raise the 

 Andes would probably extend far beyond the immediate range of 

 the mountain chain, we reply that, according to that theory, it 

 was not the Andes, but some other unknown tract, part perhaps 

 of the present bed of the Pacific, which occasioned the flood. 

 And if we indulge in conjectures as to what may have happened 

 in contiguous regions at the time when the Cordillera arose, we 

 ask whether those regions may not have sunk down, so as to cause 

 a subsidence instead of an uplifting of the oceanic waters ? 



But leaving the farther discussion of these speculative views, 

 let us return to the origin of the larger erratic blocks of Alpine 

 origin. It has been often suggested, that ice may have con- 

 tributed its aid towards the transfer of these enormous blocks, 

 and, as the transporting power of ice is now so conspicuously 

 displayed in the Alps, the idea is entitled to the fullest consi- 

 deration. 



Those naturalists who have seen the glaciers of Savoy, and 

 who have beheld the prodigious magnitude of some fragments 

 conveyed by them from the higher regions of Mont Blanc to 

 the valleys below, to a distance of many leagues, will be pre- 

 pared to appreciate the effects which a series of earthquakes 



