116 EAMBLES OF A NATURALIST. 



is precisely what occurs at each eruption on the 

 great cone, the secondary cones, and the lateral slopes. 

 These fragments preserve in the Val del Bove the 

 characteristic parallelism of stratification of which 

 we have already spoken. This fact would, therefore, 

 be inexplicable, if we did not admit that they must 

 have spread in a uniform manner over nearly hori- 

 zontal surfaces. 



Thus, on examining the profile of Etna, we observed 

 that the regular declivities of the terminal cone and 

 of the lateral slopes were suddenly interrupted by 

 those of the central elevation, of which the Yal del 

 Bove is only a portion. Hence we concluded that 

 this elevation could not be formed by the same pro- 

 cess which gave origin to the cone and to the lateral 

 slopes-. The study of the lava beds leads us to the 

 same conclusion; while, moreover, this observation 

 teaches us that the strata of the Val del Bove must 

 have been solidified on a horizontal surface. 



To explain how a mountain of more than 10,000 

 feet in height has taken the place of a plain, 

 and how it is that we meet at Piano del Lago with 

 the same strata which dip below the campagna of 

 Milo, we must admit that some force has upheaved 

 this portion of the earth's crust. Such indeed 

 is the conclusion at which M. de Beaumont has 

 arrived. According to his opinion, the central 

 elevation is the primitive nucleus of Etna, and this 

 nucleus has been formed by upheaval.* 



* It will be readily understood that in the brief exposition of the 

 facts which justify this conclusion, we have merely adduced some 

 of the most striking. We would, however, refer our readers for 



