TRUE VOLCANOES. 243 



of Quito was then frequently enveloped in darkness for days 

 together by the falling, dust-like rapilli. 



To the rarer class oi volcanic forms which constitute elon- 

 gated ridges belong, in the old world, the Galungung, with a 

 large crater, in the western part of Java ; 10 the doleritic mass 

 of the Schiwelutsch, in Kamtschatka, a mountain- chain upon 

 the ridge of which single domes rise to a height of 10,170 

 feet ; n Hec'a, seen from the north-west side, in the normal 

 direction upon the principal and longitudinal fissure over 

 which it has burst forth, as a broad mountain-chain, fur- 

 nished with various small peaks. Since the last eruptions of 

 1845 and 1846, which yielded a lava-stream of 8 geographical 

 miles in length and in some places more than 2 miles in 

 breadth, similar to the stream from Etna in 1669, five caldron- 

 like craters lie in a row upon the ridge of Hecla. As the 

 principal fissure is directed N. 65 J E., the volcano, when seen 

 from Selsundsfjall, that is from the south-west side, and 

 therefore in transverse section, appears as a pointed conical 

 mountain. 12 



If the forms of volcanoes are so remarkably different 

 (Cotopaxi and Pichincha) without any variation in the 

 matters thrown out, and in the chemical processes taking place 

 in the depths of their interior, the relative position of the 

 cones of elevation is sometimes still more singular. Upon 

 the island of Luzon, in the group of the Philippines, the still 

 active volcano of Taal, the most destructive eruption oi' 

 which was that of the year 1754, rises in the midst of a 

 If.rge lake, inhabited by crocodiles (called the laguna de 

 Bomlon). The cone, which was ascended in Kotzebue's 

 voyage of discovery, has a crater-lake, from which again a 

 cone of eruption, with a second crater, rises. 13 This descrip- 



10 Junghuhn, Reise durch Java, 1845, s. 215, Tafel xx. 



11 See Adolf Erraan's Reise um die Erde, which is also very important 

 in a geognostic point of view, Bd. iii, s. 271 and 207. 



12 Sartorius von Waltershausen, Physisch-geographische Skizze von 

 Island, 1847, s. 107, and his Geognostischer Atlas von Island, 1853, 

 Tafel xv and xvi. 



13 Otto von Kotzebue, Entdeckungs-Reise in die Sildsee und in die 

 Berings-Strasse, 18151818, Bd. iii, s. 68; Reise- Atlas von Choris, 1820, 

 Tafel 5; Vicointe d'Archiac, Histoire des Progres de la Geologie, 1847, 

 t. i, p. 544 ; and Buzeta, Diccionario Geogr. estad. Historico de las islat 

 Filipinos, t.ii (Madrid, 1851), pp.436 and 470471, in which, however, 



