280 COSMOS. 



far greater than that of Sangay, which also belongs to an 

 eastern Cordillera, and greater than that of Orizaba and 

 Jorullo. 



An interval of 540 miles destitute of volcanoes separates 

 the series of volcanoes of Peru and Bolivia from that of Chili. 

 This is the distance of the eruption in the desert of Atacaraa 

 from the volcano of Coquimbo. At 2° 34^ farther to the 

 south, as already remarked, the group of volcanoes of Chili 

 attains its greatest elevation in the volcano of Aconcagua 

 (23,003 feet), which, according to our present knowledge, is 

 also the maximum of all the summits of the New Continent. 

 The average height of the Sahama group is 22,008 feet ; con- 

 sequently 58G feet higher than Chimborazo. Then follow, 

 diminishing rapidly in elevation, Cotopaxi, Arequipa(?), and 

 Tohma, between 18,877 and 18,129 feet in height. I give, 

 in apparently very exact numbers, and without alteration, 

 the results of measurements which are unfortunately com- 

 pounded from barometrical and trigonometrical determina- 

 tions, because in this way the greatest inducement will be 

 given to the repetition of the measurements and correction 

 of the results. In the series of volcanoes of Chili, of which 

 I have cited twenty-four, it is unfortunately for the most part 

 only the southern and lower ones, from Antuco to Yantales, 

 between the parallels of 37° 20^ and 43° 40^, that have been 

 hypsometrically determinied. These have the inconsiderable 

 elevation of from six to eight thousand feet. Even in Tierra 

 del Fuego itself the summit of the Sarmiento, covered with 

 perpetual snow, only rises according to Fitzroy, to 6821 feet. 

 From the volcano of Coquimbo to that of San Clemente the 

 distance is 968 miles. 



With regard to the activity of the volcanoes of Chili, we 

 have the important testimony of Charles Darwin,* who re- 

 fers very decidedly to Osorno, Corcovado, and Aconcagua as 

 being ignited ; the evidence of Meyen, Poppig, and Gay, who 

 ascended Maipu, Antuco, and Peteroa ; and that of Domeyko, 

 the astronomer Gilliss, and Major Philippi. The number of 

 active craters may be fixed at thirteen, only five fewer than 

 in the group of Central America. 



From the five groups of serial volcanoes of the New Con- 

 tinent, which we have been able to describe from astro- 

 nomical local determinations, and for the most part also hyp- 

 sometrically as to position and elevation, let us now turn to 



* See Darwin, Journal of Researches in Natural History and Geology 

 during the Voyage of the Beagle, 1845, p. 275, 291, and 310. 



