122 RAMBLES OP A NATURALIST. 



only have covered the walls of the Torre del Filosopho 

 to the depth of merely a few feet. 



M. de Beaumont, indeed, admits that the pheno- 

 mena of upheaval, which formerly gave origin to the 

 mountain, are being reproduced in our own day, 

 although with less intensity. He is of opinion that 

 many of the cones, and more particularly the ter- 

 minal cone, probably possess a solid nucleus, formed 

 by upheaval, and that their external shape is due to 

 a covering which is formed by the ejections of the 

 crater, which thus disguise and modify the inequa- 

 lities of the slopes. Finally, according to M. de 

 Beaumont, Etna has not yet attained its greatest 

 altitude, and according to his view, each new erup- 

 tion tending to upheave it, may augment its height 

 to an appreciable extent. 



This mode of considering the eruptions does away 

 with the apparent contradiction to which we drew 

 attention, and facts are not wanting to justify this 

 extension of his theory. In a great number of 

 eruptions, the fluid lava has reached the very sum- 

 mit of the orifice, and has flowed over the margins 

 of the great crater. The lava could not reach this 

 elevation unless it were upheaved by an enormous 

 power, whose action could not be limited to the 

 vertical tube of the crater, but would necessarily 

 be elsewhere exerted, and perhaps even over the 

 entire mass of the mountain. Thus fissures have 

 several times been observed which formed a sort 

 of radiation along the face of the volcano, the lines 

 all converging towards the crater. After the erup- 

 tion had passed, the margins of some of these fis- 



