THE EARTH. 1 1 » 



Andes, there was no difficulty of breathing perceived. Tl)« 

 accounts, therefore, of those who have asserted that they were 

 unable to breathe, although at much less heights, are greatly to 

 be suspected. In fact it is very natural for mankind to pain^ 

 those obstacles as insurmountable, which they themselves have 

 not had the fortitude or perseverance to surmount. 



The difficulty and danger of ascending to the tops of mouii 

 tains, proceeds from other causes, not the thinness of the air. 

 For instance, some of the summits of the Alps have never yet 

 Deen -vasited by man. But the reason is, that they rise with 

 such a rugged and precipitate ascent, that they are utterly inac- 

 cessible. In some places they appear like a great wall of six or 

 seven hundred feet high ; in others, there stick out enormous 

 rocks, that hang upon the brow of the steep, and every moment 

 threaten destruction to the traveller below. 



In this manner almost all the tops of the highest mountains 

 are bare and pointed. And this naturally proceeds from theii 

 being so continually assaulted by thunders and tempests. Al. 

 the earthy substances with which they might have been once 

 covered, have for ages been washed away from their summits ; 

 and nothing is left remaining but immense rocks, which no tem- 

 pest has hitherto been able to destroy. 



Nevertheless, time is eveiy day, and every hour, making de- 

 predations ; and huge fragments are seen tumbling down the 

 precipice, either loosened from the summit by frost or rains, or 

 struck down by lightning. Nothing can exhibit a more teirible 

 picture than one of these enormous rocks, commonly larger than 

 a house, falling from its height, with a noise louder than thun- 

 der, and rolling down the side of the mountain. Doctor Plot tells 

 us of one in particular, which beingloosened from its bed, tumbled 

 down the precipice, and was partly shattered into a thousand 

 pieces. Notwithstanding, one of the largest fragments of the 

 same, still preserving its motion, travelled over the plain below 

 crossed a rivulet in the midst, and at last stopped on the other 

 side of the bank ! These fragments, as was said, are often 

 struck off by lightning, and sometimes undermined by rains ; 

 i)ut the most usual maimer in which they are disunited from the 

 mountain, is by frost : the rains insinuating between the inter- 

 t-oes of the mountain, continue there until there comes a frosts 

 md then, \%hen converted into ice, the water swclln with an ir- 



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