516 PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb. 2, 



Beaumont likewise admits the Peak of TenerifFe, as well as Yesu- 

 vius, into his category of cones of eruption and accumulation ; 

 nay, he even instances their " regular and straight slope from top to 

 bottom " as the distinguishing and characteristic feature of eruptive 

 cones *. 



So, too, MM. de Buch and Humboldt both recognize as ^' cones of 

 eruption and accumulation," not only the lateral or parasitic cones 

 of Etna, but the thirty or more cones of Lanzarote in the Azores, and 

 all the puys or scorial cones of Central Prance, about a hundred in 

 number, and many of them of great size. 



It would appear from these admissions as if it were only to the 

 very largest volcanic mountains composed of repeated beds of lava 

 and conglomerate, which are generally supposed to be the product of 

 numerous successive eruptions from the same central vents, that the 

 majority of the upheavahsts — MM. de Humboldt, de Buch, and de 

 Beaumont — apply their theory. This, however, is not the fact, be- 

 cause these same geologists, one and all, join with M. Dufrenoy in 

 asserting all the small tuif-cones and craters of the Phlegrsean Fields 

 near N'aples to be the result of upheaval alone, including even the 

 Monte Nliovo itself, which was thrown up in the year 1538 by an 

 eruption that lasted three days and nights, according to the testimony 

 of numerous observers, several of whom have left us a clear account 

 of the phenomena ! 



Thus, to recapitulate a few of the inconsistencies and discrepancies 

 of the upheavalists, de Buch and Humboldt assert both Somma 

 and Vesuvius, the Peak of Teneriffe and all Etna, *' as we now see 

 them," to be due to sudden upheaval, although, at the same time, 

 they admit them to have been in active eruption for multiplied ages. 

 M. de Beaumont declares Somma, and the nucleus or central portion 

 alone of Etna, to be upheaved, but Yesuvius, the Peak of Teneriffe, 

 and the upper cone of Etna to be eruptive, as well as all the para- 

 sitic cones of the latter mountain. M. Dufrenoy attributes Somma, 

 Yesuvius, and its parasitic cones to upheaval alone. And while all 

 admit the minor cones and craters of Auvergne, the Yelay, and Lan- 

 zarote to be eruptive, all declare those of the Phlegrsean Fields to be 

 solely due to upheaval ! 



These inconsistencies of the advocates of the upheaval-theory 

 render it difficult to suppose that they understand it themselves. 

 It is, indeed, a hopeless task to endeavour to discover in their works 

 any clear notion of what they consider to be the distuictive character 

 of " upheaved" as contrasted with '* erupted" volcanic cones. 



One of them, however, M. de Beaumont, seems to recognize the 

 necessity of some guide of the kind, and undertakes the task. He 

 declares the distinction to consist in '^ the continuous rectninear 

 slopes " of erupted cones ; while those of upheaved cones are " more 

 irregular, and graduate insensibly towards horizontality as they ap- 

 proach the base f." And it is on this ground expressly, of regularity 

 of form and slope, that he asserts Yesuvius, the Peak of Teneriffe, 



* Memoires, vol. iv. p. 157. t Ibid. p. 96. 



