232 cosmos. 



over which it has burst forth, as a broad mountain chain, 

 furnished with various small peaks. Since the last erup- 

 tions of 1845 and 1846, which yielded a lava stream of 

 eight geographical miles in length, and in some places more 

 than two miles in breadth, similar to the stream from .ZEtna 

 in 1669, five caldron-like craters lie in a row upon the ridge 

 of Hecla. As the principal fissure is directed N. 65° 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.* 



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 erup- 

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

 of a large lake inhabited by crocodiles (called the Laguna 

 de Bombon). 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, f This descrip- 

 tion reminds one involuntarily of Hanno's journal of his 

 voyage, in which an island is referred to, inclosing a small 

 lake, from the centre of which a second island rises. The 

 phenomenon is said to occur twice, once in the Gulf of the 



* Sartorius von "Waltershausen, Physiscli-geographische Skizze von 

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

 Tafel xv. and xvi. 



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

 Berings-Strasse, 1815-1818, bd. iii., s. 68 ; Reise-Atlas von Choris, 1820, 

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

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

 Filipinas, t. ii. (Madrid, 1851), p. 436 and 470, 471, in which, however, 

 the double encircling of a crater in the crater-lake, mentioned alike 

 accurately and circumstantially by Delamare, in his letter to Arago 

 (November, 1842, Comptes rendus de V Acad, des Sciences, t. xvi., p. 756), 

 is not referred to. The great eruption in December, 1754 (a previous 

 and more violent one took place on the 24th September, 1716), de- 

 stroyed the old village of Taal, situated on the southwestern bank of 

 the lake, which was subsequently rebuilt at a greater distance from the 

 volcano. The small island of the lake upon which the volcano rises 

 is called Isla del Volcan. (Buzeta, loc. cit.) The absolute elevation 

 of the volcano of Taal is scarcely 895 feet. It is, therefore, like Cosi- 

 ma, one of the lowest. At the time of the American expedition of 

 Captain Wilkes (1842) it was in full activity. See United States Ex- 

 ploring Expedition, vol. v., p. 317. 



