TRUE VOLCANOES. 271 



According to these data the total number of volcanoes in 

 the five American groups is 91, of which 56 belong to the 



and Dr. Weddel (1847), have ascended the summit. In August, 

 1831, Meyen sa\v large columns of smoke rising; a year previous- 

 ly the volcano had thrown out scoria;, but never lava streams 

 (Meyen's Reise um die Erde, th. ii., s. 33). 



Volcan de Omato, lat. 16° 50'; it had a violent eruption in the year 

 1667. 



Volcan de Uvillas or Uvinas, to the south of Apo ; its last eruptions 

 were in the 16th century. 



Volca'i de Pichu-Pichu, 16 miles to the east of the town of Arequipa 

 (la(. 16° 25'), not far from the Pass of Cangallo, 9673 feet above 

 the sea. 



Volcan Viejo, lat. 16° 55', an enormous crater, with lava streams and 

 much pumice-stone. 



The six volcanoes just mentioned constitute the group of Arequipa. 



Volcan de Tacora or Chipicani, according to Pentland's fine map of 

 the lake of Titicaca, lat. 17° 45', height 19,738 feet. 



Volcan de Sahama* 22,351 feet in height, lat. 18° 7'; a truncated 

 cone of the most regular form; see p. 211. The volcano of Sa'- 

 hama is (according to Pentland) 927 feet higher than the Chim- 

 borazo, but 6650 feet lower than Mount Everest, in the Himalaya, 

 which is now regarded as the highest peak of Asia. According 

 to the last official report of Colonel Waugh, of the 1st March, 1 856, 

 the four highest mountains of the Himalayan chain are .; Mount 

 Everest (Gaurischanka), to the northeast of Katmandu, 29,000 feet; 

 the Ktmtschinjinga, to the north of Darjiling, 28,151 feet; the 

 Dhaulagiri (Dhavalagirir), 26,825 feet; and Tschumalari (Cham- 

 alari), 23,946 feet. 



Volcano of Pomarape, 21,699 feet, lat. 18° 8', almost a twin mount- 

 ain with the following volcano. 



Volcano of Parinacota, 22,029 feet, lat. 18° 12'. 



The group of the four trachytic cones Sahama, Pomarape, Parina- 

 eota, and Gualatieri, lying between the parallels of 18° 7' and 18° 

 25', is, according to Pentland's trigonometric measurement, higher 

 than Chimborazo, or more than 21,422 feet. 



Volcano of Gualatieri* 21,962 feet, lat. 18° 25', in the Bolivian 

 province Carangas ; very active, according to Pentland (Hertha, 

 bd. xiii., 1829, s. 21). 



Not far from the Sahama group, 18° 7' to 18° 25', the series of vol- 

 canoes and the entire chain of the Andes, which lies to the westward 

 of it, suddenly change their strike, and pass from the direction S.E. 

 ■ — N.W. into that from north to south, which becomes general as far 

 as the Straits of Magellan. I have treated of this important turning- 

 point, the notch in the shore near Arica (18° 28'), which has an an- 

 alogue on the west coast of Africa, in the Gulf of Biafra, in the first 

 volume of Cosmos, p. 292. 



Volcano of Isluga, lat. 19° 20', in the province of Tarapaca, to tho 

 west of Carangas. 



