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Ch. XXVI.] 



IIOEIZONTAL BEDS OF THE VAL DEL BOVE. 





the same section in the Serra Giannicola, which are highly 

 inchned. In order to study the horizontal beds^ I made 

 two descents of the great precipice at different . points pre- 

 viously examined by very few geologists^ and observed a re- 

 markable resemblance of one of the old lava currents with 

 the lava of 1669, which overflowed 

 the neighbourhood of Catania, where there had been a rich 



some 



ground in 



vegetation, 

 into a layer 



The vegetable soil was there turned or burnt 



emindin 



of 



the red bands which separate so many of the lavas m 

 Madeira. Midway betAveen the top and bottom of the 



;Teat precipice, at a place called Teatro Grande, the ancient 



lava current is seen, which had evidently cooled on a jflat 

 surface, and the lower scoriaceous part of which reposed on 

 a red band of burnt soil, over which it had poured. Over- 

 lying the bottom scorise was a central mass of stony lava no 

 less than forty feet thick, divided by vertical rents, so as to 

 be almost columnar, and above this again was the usual 

 upper scoriaceous and highly vesicular division of the current. 



'No hypothesis, except that of the double axis, can give even 



a plausible explanation of the position of this powerful 

 current, which must have cooled on a fiat surface. But the 

 phenomena are quite reconcilable with the former existence 

 at this point of a saddle between the cones. 



When 



treating of Vesuvius, in the first volume, p. 633, 

 I gave the reader an account of the theory of elevation craters 



some 



Somma 



from 



The structure 



Mount 



eferred by the same school to a 



movement 



formations previously horizontal to be suddenly uplifted into 

 a mountain mass, so as to assume a conical form, the beds of 

 lava and scoriae being made to dip away in all directions 



from 



Even if it were true that the 



alternate scoriaceous and stony beds exhibited a quaquaversal 



mio 



above-mentioned hypothesis. Among others, I may mention 



imaofinm 



