118 Mr. Pentland's Observations on the Peruvian Andes. 



tude, is nearly parallel to the meridian), — even supposing the 

 intervening space to be perfectly horizontal, and not inter- 

 rupted, as I have already shown it to be, by the elevated mass 

 of the western cordillera, — some of the peaks of which, as well 

 as the trachytic dome which towers over the valley of Chu- 

 quibamba, N.N. W. of Arequipa, rise to an elevation exceeding 

 22,000 feet*." 



I am therefore at a loss to imagine how two gentlemen, 

 possessing the acknowledged acquirements of Messrs. Brue 

 and de Montbret, could have raised such an objection to the 

 accuracy of my observations as that conveyed in the paper of 

 the latter ; since a reference even to the old and inaccurate map 

 of South America, by Olmedilla de la Cruz, or to the incorrect 

 compilation of Alcedo, must have rendered evident to the 

 merest tyro in geographical science, the physical impossibility 

 of descrying an eminence no more than 24,200 British feet 

 above the level of the ocean, from a distance which exceeds 

 100 nautical leagues. 



On the northern prolongation of the eastern cordillera of 

 the Bolivian Andes, and nearly in the centre of the snowy range 

 above mentioned, rises, in latitude 15° 30' S., the Nevado of 

 Sorata, from the midst of a group of snow-capped pinnacles, 

 some of which attain an elevation of 23,000 feet. The Nevado 

 of Sorata is situated to the east of the large Indian village of the 

 same name, and is elevated 25,200 feet above the level of the 

 sea, or 12,450 feet above the waters of the lake of Titicaca: — 

 as deduced from a trigonometrical measurement taken from 

 the shores of the lake, and from a determination (made at a 

 less distant station) of the height of that portion of the sum- 

 mit which is placed above the superior limit of perpetual snow ; 



* The city of Arequipa, one of the handsomest in South America, is si- 

 tuated at the western base of the western cordillera, in the midst of a fer- 

 tile valley, watered by the streams of the Arequipa and Inquocajo, which 

 descend from the adjoining Andes. The valley of Arequipa is bounded on 

 its northern and eastern sides, by three snow-capped mountains ; that in 

 the centre, the volcano of Arequipa, resembling in form, and being nearly 

 equal in elevation to Cotopaxi : whilst towards the south and west the 

 valley is separated from the shores of the Pacific Ocean, by a low range of 

 trachytic eminences j and by an arid sandy desert which occupies an extent 

 of fifty miles in breadth. The mean of my observations, as deduced from 

 an extensive series of meridian altitudes of Achernar, Canopus, a. Arietis, 

 Capella, and Saturn, places the house of the British consulate at Arequipa 

 in latitude 16° 23' 58" ; and in longitude 71° 20' 0" W. resulting from ob- 

 servations made with two good chronometers, and from several sets of 

 lunar distances. The elevation of Arequipa above the level of the neigh- 

 bouring ocean, is 7797 feet; being the mean of 170 barometrical observa- 

 tions, made during thirteen successive days with an excellent barometer by 

 Fortin, and calculated according to the formula of Laplace, 



a limit 



