1859.] SCKOPE CONES AlfD CEATEKS. 515 



undervalue the accumulative powers of the eruptions of such moun- 

 tains. He speaks, for example, of " the mighty devastating lava- 

 pouring volcanos of Etna and the Peak of Teneriffe, and the abun- 

 dant scoriae-ejecting volcanos of Cotopaxi and Tunguragua*." But 

 the theory of upheaval certainly fails to answer the plain question, 

 What becomes of all these abundantly erupted matters, if, in the 

 course of ages, they do not accumulate into mountains ? That theory 

 unquestionably requires that the lavas and scoriae thrown up from 

 the central and higher vents of any volcanic mountain since its 

 original elevation should have left no traces (or next to none) on its 

 summit or slopes — should scarcely in any perceptible degree have 

 increased its height or bulk. It is not for me to reconcile this strange 

 inconsistency. It is admitted, no doubt, that some parasitic cones 

 of scoriae and beds of lava due to eruption are to be found about the 

 base of a volcano, where the inclination of the slopes is less than 3° 

 or 4°, But even on this, as on other points, the upheavahsts are by 

 no means consistent with one another, or with themselves. For ex- 

 ample, M. Dufrenoy, in his description of Vesuvius, asserts that not 

 only that mountain, but also the four small parasitic cones formed on 

 its lower slope, immediately above Torre del Greco, by the erup- 

 tion of 1760, were ''caused by an upheaval of pre-existing beds of 

 scoriae and lava, and not by the accumulation of ejected fragments t;" 

 and he even attributes to the same origin (in his own words, " up- 

 heaval, not accumulation") the formation of the small cones formed 

 in June 1834, upon the outer flank of the principal cone, and in the 

 interior of its crater. 



On the other hand, M. de Beaumont considers Vesuvius itself, as 

 well as its parasitic cones, to be of eruptive origin, and in his ' Me- 

 moir on Etna' admits all of the three or four hundred parasitic 

 cones which stud the flanks of that mountain — many of them, such 

 as the Monte Rossi, exceeding in bulk ten times those of Torre del 

 Greco — to be true '^ cones of eruption, the product of the accumula- 

 tion of ejected matters." Nay, he allows the same eruptive origin 

 to the whole terminal and central cone of Etna, containing the 

 existing crater, and which rises more than a thousand feet above the 

 ' Piano del Lago,' a sort of platform at its basej ; and it is only to the 

 intennediate cone terminating upwards in this platform, and down- 

 wards in the lower slopes studded with cones of eruption and coated 

 with their lava-streams (which he calls " la gibbosite centraW), 

 that he applies his theory of sudden upheaval. Moreover, M. de 



* Kosmos, iv. p. 164. t Memoires suj* le Vesuve, pp. 331 & 318. 



J I may say here that the platform of Etna, the Piano del Lago, presents no 

 difficulty requiring so extraordinary a solution. It is without doubt merely a 

 truncation of the ancient cone of Etna at the period of some early paroxysmal 

 eruption, — the crater then formed having been subsequently filled up by erup- 

 tions, and the upper cone raised within a still later period upon the flattened 

 summit so produced. It is, in fact, a parallel case to the platform which, for 

 some years before 1822, formed the siimmit of Vesuvius, and upon which several 

 minor cones with craters were at intervals thrown up, and to the precisely similar 

 state of things which, after the filling up of the crater formed in 1822, existed 

 on the same summit from 1834 to 1850. (See fig. 5, p. 517, and fig. 17, p. 532.) 



