238 COSMOS. 



Fourth group, from 12,000 to 16,000 Pane or 12,792 to 

 17,056 English feet in height. 



The volcano of Tuqueres,* in the highlands of the provincia de los 

 Pastes : 12,824 feet, according to Boussingault. 



The volcano of Pasto :f 13,453 feet, according to Boussingault. 



The volcano Mauna-Roa:l 13,761 feet, according to Wilkes. 



The volcano of Cumbal, in the provincia de los Pastos : 15,621 feet, 

 according to Boussiugault. 



The volcano Kliutscheivsk\\ (Karatschatka) : 15,766 feet, according 



to Erraan. 







The volcano Rucu-Pichincha : 15,926 feet, according to Humboldt's 

 barometrical measurements. 



The volcano Timgiirahua: 16,494 feet, according to a trigonomet- 

 rical measurement^ by Humboldt. 



from the former place. The hill bears the same name (Tschichatscheff, 

 t. i., p. 455 ; William Hamilton, Researches in Asia Minor, vol. ii 

 p. 217). 



* The height here given is properly that of the grass-green mount- 

 ain lake, Laguna verde, on the margin of which is situated the sol- 

 fatara examined by Boussingault (Acosta, Vinjes Cientificos d los Andes 

 Ecuatoriales, 1849, p. 75). 



t Boussingault succeeded in reaching the crater, and determined 

 the altitude barometrically; it agrees very nearly with that which I 

 made known approximately twenty-three years before, on my journey 

 from Popayan to Quito. 



J The altitude of few volcanoes has been so over-estimated as that 

 of the Colossus of the Sandwich Islands. We see it gradually fall 

 from 18,410 feet (the estimate given in Cook's third voyage), 16,486 

 feet in King's, and 16,611 feet in Marchand's measurement, to 13,761 

 feet by Captain Wilkes, and 13.524 feet by Homer in Kotzebue's voy- 

 age. The grounds of the last-mentioned result were first made known 

 by Leopold von Buch in the Description Physique des lies Canaries, p. 

 379. See Wilkes, Exploring Expedition, vol. iv., p. 111-162. The 

 eastern margin of the crater is only 13,442 feet. The assumption of 

 a greater height, considering the asserted freedom from snow of the 

 Mauna-Roa (lat. 19 28'), would also be in contradiction to the result 

 that, according to my measurements in the Mexican continent in the 

 same latitude, the limit of perpetual snow has been found at 14,775 

 feet (Humboldt, Voyage aux Regions Equinox., t. i., p. 97 ; Asie Cen- 

 trale, t. Hi., p. 269 and 359). 



The volcano rises to the west of the village of Cumbal, which is 

 itself situated 10,565 feet above the sea-level (Acosta, p. 76). 



|| I give the result of Erman's repeated measurements in Septem- 

 ber, 1829. The height of the margin of the crater is exposed to alter- 

 ations by frequent eruptions, for in August, 1828, measurements which 

 might inspire equal confidence gave an altitude of 16,033 feet. Com- 

 pare Erman's Physikalische 13eobachtungen aufeiner Reise um die Erde, 

 bd. i., s. 400 and 419, with the historical account of the journey, bd. 

 Hi., s. 358-360. 



if Bouguer and La Condamine, in the inscription at Quito, give 

 16,777 feet for Tungurahua before the great eruption of 1772, and 



