TRUE VOLCANOES. 243 



rious and very complicated causes, no general law can safely 

 be established with regard to the relation of the absolute ele- 

 vation to the frequency and degree of the renewal of combus- 

 tion. If in a small group the comparison of Stromboli, Ve- 

 suvius, and xEtna may mislead us into the belief that the 

 number of eruptions is in an inverse ratio to the elevation 

 of the volcanoes, other facts stand in direct contradiction 

 to this proposition. Sartorius von Waltershausen, who has 

 done such sood service to our knowledge of .zEtna, remarks 

 that, on the average furnished by the last few centuries, an 

 eruption of this volcano is to be expected every six years, 

 while in Iceland, where no part of the island is really secure 

 from destruction by submarine fire, the eruptions of Hecla, 

 which is 5756 feet lower, are only observed every 70 or 80 

 years.* The group of volcanoes of Quito presents a still more 

 remarkable contrast. The volcano of Sangav, 17,000 feet 

 in height, is far more active than the little conical mountain, 

 Stromboli (2958 feet) ; it is of all known volcanoes the one 

 which exhibits, every quarter of an hour, the greatest quanti- 

 ty of fiery, widely-luminous eruptions of scoria?. Instead of 

 losing ourselves in hypotheses upon the causal relations of 

 inaccessible phenomena, we will rather dwell here upon the 

 consideration of six points of the surface of the earth, which 

 are peculiarly important and instructive in the history of vol- 

 canic activity — Stromboli, the Lycian Chimara, the old vol- 

 cano of Masaya, the very recent one of Izalco, the volcano 

 Fogo on the Cape Yerd Islands, and the colossal Sangay. 



The Chimara in Lycia, and Stromboli, the ancient Stron- 

 gyle, are the two igneous manifestations of volcanic activity, 

 the historic proof of whose permanence extends the furthest 

 back. The conical hill of Stromboli, a doleritic rock, is twice 

 the height of the island of Volcano (Hiera, Thermessa), the 

 last great eruption of which occurred in the year 1775. The 

 uninterrupted activity of Stromboli is compared by Strabo 

 and Pliny with that of the island of Lipari, the ancient Me- 

 ligunis ; but they ascribe to " its flame," that is, its erupted 

 scoriae, " a greater purity and luminosity, with less heat."f 



* Sartorius von Waltershausen, Skizze von Island, s. 103 and 107. 



f Strabo, lib. vi., p. 276, ed. Casaubon; Pliny, Hist. Nat., in., 9: 

 " Strongyle, qua? a Lipara liquidiore rlamma tantum differt ; e cujus 

 fumo quinam rlaturi sint venti, in triduo praedicere incolte traduntur." 

 See also Urlichs, Vindiciaz PUniana?, 1853, Fasc. i., p. 39. The volcano 

 cf Lipara (in the northeastern part of the island), once so active, appears 

 to me to have been either the Monte Campo Bianco or the Monte di 

 Capo Castagno. (See Hoffmann, in Poggend.,^l72j?.,bd. xxvi.,s. 49-54.) 



