TKUE VOLCANOES. 



II. ISLANDS OP THE ATLANTIC OCEAN. 



The volcano Esk, upon the island of Jan Mayen, ascended 

 by the meritorious Scoresby and named after his ship; 

 height scarcely 1600 feet. An open, not ignited summit- 

 crater ; basalt, rich in pyroxene and trass. 



South-west of the Esk, near the North Cape of Egg Island, 

 another volcano, which, in April 1818, presented high erup- 

 tions of ashes every four months. 



The Beerenberg, 6874 feet in height, in the broad, north- 

 eastern part of Jan Mayen (lat. 71 4") is not known to be a 

 volcano. 46 



Volcanoes of Iceland : Oerafa, Hecla, Rauda-Kamba . . . 



Volcano of the island of Pico 46 in the Azores : a great 

 eruption of lava from the 1st May to the 5th June, 1800. 



The Peak of Teneriffe. 



Volcano of Fogo, 41 ono of the Cape de Verde Islands. 



Prehistoric volcanic activity. This on Iceland is less defi- 

 nitely attached to certain centres. If we divide the volcanoes 

 of the island, with Sartorius von Waltershausen, into two 

 classes, of which those of the one have only had a single 

 eruption, whilst those of the other repeatedly emit lava- 

 streams at the same principal fissure, we must refer to the 

 former, ftauda-Kamba, Scaptar, Ellidavatan, to the south- 

 east of Reykjavik . . . . ; to the second, which exhibits a 

 permanent individuality, the two highest volcanoes of Ice- 

 land Oerafa (more than 6390 feet) and Snaefiall, Hecla, <fcc. 

 Snaefiall has not been in activity within the memory of man, 

 whilst Oerafa is known by the fearful eruptions of 1362 and 

 1727 (Sart. von Waltershausen, Skizze von Island, a. 108 



45 Scoresby, Account of the Arctic Regions, vol. i, pp. 155 169, tab. 

 v and vi. 



46 Leop. von Buch, Descr. des lies Canaries, pp. 357 369, and Land- 

 grebe, Naturgcschichte der Vulkane, 1855, Bd. i, s. 121 136 : and with 

 regard to the circumvallations of the craters of elevation (Caldeiras) 

 upon the Islands of Saint Michael, Fayal and Terceira (from the maps 

 of Captain Vidal) (see page 226). The eruptions of Fayal (1672) and 

 Saint George (1580 and 1808) appear to be dependent upon the prin- 

 cipal volcano, the Pico. 



* See pages 248 and 262. 



