250 COSMOS. 



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

 17,056 English feet in lieigU. 



The volcano of Tugiieres, 33 in the highlands of the Provincia de Ion 



Pastes: 12,824 feet, according to Eoussingault. 

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

 The volcano Mauna-Roar* 13,761 feet, according to Wilkes. 

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



feet, according to Boussingault. 



The volcano KliutschewsW 7 (Kamtschatka) : 15,766 feet, according 

 to Erman. 



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

 barometrical measurements. 



33 The height here given is properly that of the grass-green mountain 

 lake, Laguna verde, on the margin of which is situated the solfatara 

 examined by Boussingault (Acosta, Viajes Cientificos a, los Andes Ecuato- 

 riales, 1849, p. 75). 



34 Boussingault succeeded in reaching the crater, and determined 

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

 made known approximately 23 years before, on my journey from 

 Popayau to Quito. 



35 The altitude qf 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 Ccok'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 Horner in Kotzebue's voyage. 

 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, pp. Ill 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 Centrale, t. iii, p. 2C9 and 

 359). 



36 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). 



37 I give the result of Erman's repeated measurements in September, 

 1829. The height of the margin of the crater is exposed to alterations 

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

 inspire et^ual confidence gave an altitude of 16,033 feet. Compare 

 Erman's Physikalische Beobaclitungen auf einer Reise um die Erde, Bd. i, 

 s. 400 and 419, with the historical account of the journey, Bd. iii, 

 g. 358360. 



