518 PEOCEEDINQS OF THE GEOLOGICAL SOCIETY. [Feb. 2, 



heaval cone," intermediate between the terminal cone and the lower 

 region of parasitic eruptions, has that very " continuous rectilinear 

 slope" which he announces to be the special characteristic of an 

 " eruptive cone " (as may be seen in fig. 5, from M. de Beaumont's 

 own view). So that his test, if it were worth anything, would reverse 

 his own conclusion. 



The outer slopes of a volcanic cone, almost without exception, 

 correspond to the internal arrangement of its component beds • or 

 strata, which have consequently what is called a quaquaversal dip 

 from the central axis. This general rule is not disputed, but rather 

 insisted on by the upheavalists. Yet this particular and very re- 

 markable arrangement is exactly what would be necessarily occa- 

 sioned by the falling of successive layers of ejected fragmentary 

 matters, and the flowing of successive streams of lava from a cen- 

 tral vent, round which they must accimiulate in what may be called 

 an "annular talus;" while, on the other hand, the upheavalists 

 have failed to show how such an arrangement is likely to be, or 

 indeed could be, so uniformly produced by upheaval. There are 

 said to be, and possibly there may be found, two or three in- 

 stances of a nearly similar quaquaversal stratification in non-volcanic 

 rocks. Among the infinite diversity of foldings and squeezings 

 which such stratified rocks have undergone by repeated elevations 

 and subsidences, it would be indeed extraordinary if here and there 

 something of the kind should not have occurred. But what the 

 upheavalists have not attempted to account for is, that whilst in non- 

 volcanic strata such instances, if to be met with at all, are the rarest 

 possible exceptions, in the strata composing volcanic hills they are 

 the universal rule. If the same process of upheaval has occasioned 

 the elevation of both classes of rocks, how is it that the character 

 and amount of elevation observable in the two are not the same, 

 but on a general view so completely different ? How do the up- 

 heavalists account under their theory for the broad fact, that in 

 all volcanic cones, however large, the inclination of the component 

 beds is so similar, and uniformly limited to a maximum of 30° 

 or 40° — ^in short, precisely that of a talus ? How has it happened 

 that so tremendously violent a process as the (supposed) sudden 

 upheaval of a mass of horizontal strata some thousands of feet in 

 thickness and hundreds of square-miles in area, into a mountain 

 like Etna, and numerous others, has in every case tilted these strata 

 with such extreme regularity in a circular quaquaversal arrange- 

 ment, dipping almost symmetrically at about the same moderate 

 angles ? Why are the strata, if upheaved by violence, not found in 

 long linear anticlinal ranges^ and occasionally dipping at angles of 

 60°, 80°, and 90°, or completely vertical, like the stratified rocks, 

 which no one doubts to have suffered violent elevation ? 



Again, M. EKe de Beaumont illustrates the kind of elevatory shock 

 by which he supposes a volcanic cone to have been upheaved and 

 its crater formed, by that of a sudden blow given from beneath to a 

 horizontal siu-face of glass or ice, producing what he calls an etoile- 

 msnt, or s^ar-fracture. No illustration could be more fatal to his 



