VOLCANOES. 225 



tivity. In the time of Nero, men were disposed to rank Etna 

 among the volcanic mountains which were gradually becoming 

 extinct;* and subsequently ./Elian | even maintained that 

 mariners could no longer see the sinking summit of the moun- 

 tain from so great a distance at sea. Where these evidences 



these old scaffoldings of eruption, I might almost say 



still exist, the volcano rises from a crater of elevation, while a 

 high rocky wall surrounds, like an amphitheatre, the isolated 

 conical mount, and forms around it a kind of casing of highly 

 elevated strata. Occasionally not a trace of this enclosure is 

 visible, and the volcano, which is not always conical, rises 

 immediately from the neighbouring plateau in an elongated 

 form, as in the case of Pichiiicha,^ at the foot of which lies 

 the city of Quito. 



As the nature of rocks, or the mixture (grouping) of simple 

 minerals into granite, gneiss, and mica slate, or into trachyte, 

 basalt, and dolorite, is independent of existing climates, and is 

 the same under the most varied latitudes of the Earth ; so also 

 we find everywhere in inorganic nature, that the same laws of 

 configuration regulate the reciprocal superposition of the 

 strata of the Earth's crust, cause them to penetrate one another 

 in the form of veins, and elevate them by the agency of 

 elastic, forces. This constant recurrence of the same phe- 



and 219), and its geographical position was not so well determined. 

 I suspect that Etna would be found to be a Sicilian word, if we had any 

 fragmentary materials to refer to. According to Diodorus (v. 6.), the 

 Sicani, or aborigines preceding the Sicilians, were compelled to fly to 

 the western part of the island, in consequence of successive eruptions 

 extending over many years. The most ancient eruption of Mount Etna 

 on record is that mentioned by Pindar and ^Eschylus, as occurring under 

 Hiero, in the second year of the 75th Olympiad. It is probable that 

 Hesiod was aware of the devastating- eruptions of Etna before the period 

 of Greek immigration ; there is, however, some doubt regarding the word 

 At T- vi] in the text of Hesiod a subject into which I have entered at 

 some length in another place. (Humboldt, Examen crit. cle le Giogr*, 

 t. i. p. 168.) 



* Seneca, Epist. 79. 



t ^Elian, Var. Hist., viii. 11. 



[This mountain contains two funnel-shaped craters, apparently 

 resulting from two sets of eruptions : the western nearly circular and 

 having in its centre a cone of eruption, from the summit and sides of 

 which are no less than seventy vents, some in activity and others extinct. 

 It is probable that the larger number of the vents were produced at 

 periods anterior to history. Daubeney, op. cit., p. 488.] Tf 



Q, 



