which favour the opinion that they have suffered, in 

 course of time, a considerable diminution, and that 

 from the accumulation of small irregular masses, and 

 grains, apparently of the same substance, lying upon 

 and about these rocks : but who can pretend to say 

 that these are not the debris of the incompact or im- 

 perfectly formed mass that served as the covering as 

 it were of the rocks, and which being destitute of a ce- 

 ment have fallen into sand. This part or portion, it is 

 readily admitted, does not nor cannot resist the opera- 

 tions of those agents. But do the great masses of 

 these rocks, when perfectly formed, betray unequivo- 

 cal signs of disintegration from this cause ? Are they 

 all in the form of boulders with their corners rounded 

 down as they inevitably must be if reduced by frost? 

 On the contrary, are not their points and angles entire, 

 presenting a rude and craggy surface ? I will venture 

 to answer that in most instances they are so. If not 

 however, why is it that masses detached from a ridge 

 of this kind of rock, and employed in civil architec- 

 ture, and exposed to all the vicissitudes of seasons 

 and temperature, should remain uninjured and without 

 any visible change, for an immense period of time, 

 though equally subject to the pelting of rains, the ab- 

 sorption of water, and the severity of the most in- 

 tense cold and frost ? Perhaps it will be urged that 

 materials of this kind employed in perpendicular 

 walls, are not so liable to the effects of wet and cold, 

 as when buried under ice and snow through a succes- 

 sion of seasons : but why is it, that when employed 



