THE EARTH. 



tie more than one half of the height of the 

 former. The Andes, upon being measured 

 by the barometer, are found above three 

 thousand one hundred and thirty-six toises 

 or fathoms above the surface of the sea." 

 Whereas the highest point of the Alps is 

 not above sixteen hundred. The one, in 

 other words, is above three miles high ; the 

 other about a mile and a half. The highest 

 mountains in Asia are Mount Taurus, Mount 

 Immaus, Mount Caucasus, and the mountains 

 of Japan. Of these, none equals the Andes 

 in height ; although Mount Caucasus, which 

 is the highest of them, makes very near ap- 

 proaches. Father Verbiest tells of a moun- 

 tain in China, which he measured, and found 

 a mile and a half high. b In Africa, the moun- 

 tains of the Moon, famous for giving source 

 to the Niger and the Nile, are rather more 

 noted than known. Of the Peak of Teneriffe, 

 one of the Canary Islands that lie off this 

 coast, we have more certain information. In 

 the year 1727, it was visited by a company 

 of English merchants, who travelled up to the 

 top, where they observed its height, and the 

 volcano on its very summit. They found it 

 a heap of mountains, the highest of which ri- 

 ses over the rest like a sugar-loaf, and gives 

 a name to the whole mass. It is computed to 

 be a mile and a half perpendicular from the 

 surface of the sea. Kircher gives us an esti- 

 mate of the heights of most of the other great 

 mountains in the world; but as he has taken 

 his calculations in general from the ancients, 

 or from modern travellers, who had not the 

 art of measuring them, they are quite incredi- 

 ble. The art of taking the heights of places 

 by the barometer, is a new and ingenious in- 

 vention. As the air grows lighter as we as- 

 cend, the fluid in the tube rises in due pro- 

 portion : thus the instrument being properly 

 marked, gives the height with a tolerable de- 

 gree of exactness ; at least enough to satisfy 

 curiosity. 



Few of our great mountains have been es- 

 timated in this manner; travellers having, 

 perhaps, been deterred, by a supposed im- 

 possibility of breathing at the top. However, 

 it has been invariably found, that the air in 

 the highest that our modern travellers have 



Ulloa, vol. i. p. 442 



ascended, is not at all too fine for respiration. 

 At the top of the Peak of Teneriffe, there was 

 found no other inconvenience from the air, 

 except its coldness ; at the top of the Andes, 

 there was no difficulty of brea tiling perceived. 

 The accounts, therefore, of those w^ho 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 paint those obstacles as insur- 

 mountable, which they themselves have not 

 had the fortitude or perseverance to sur- 

 mount. 



The difficulty and danger of ascending to 

 the tops of mountains, proceeds from other 

 causes, not the thinness of the air. For in- 

 stance, some of the summits of the Alps have 

 never yet been visited by man. But the rea- 

 son 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 feel 

 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 their being so 

 continually assaulted by thunders and tem- 

 pests. All 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 tempest has hitherto been 

 able to destroy. 



Nevertheless, time is every day, and every 

 hour, making depredations; and huge frag- 

 ments 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 terrible picture than one 

 of these enormous rocks, commonly larger 

 than a house, falling from its height, with a 

 noise louder than thunder, and rolling down 

 the side of the mountain. Doctor Plot tells 

 us of one in particular, which being loosened 

 from its bed, tumbled down the precipice, and 

 was partly shattered into a thousand pieces. 

 Notwithstanding, one of the largest frag- 



b Verbiest, a la Chine. c Phil. Trans, vol. \. 



