tc 



^ 



•M 



'V 



5 tIl»->. . 



ai 



IS 



'as 



> 



"have 



til 



h 



.n 



y^j deepen 

 on all thei: 

 wliioli pan 



^' out fei 



rreat cont; 

 ■tire leC- 



V 



as beent: 



the vallej; 





conjecto 



i ^ 



jpter, * 

 .ill"' 



ins *• 

 ell- 



bt*" 





Ch. XXVI.] PEOBABLE OEIGIN OF THE MOUNTAIN. 



41 



tinned to near the snmmit of tlie old cone of Somma^ before 

 that monntain was trnncated in the year 79. 



In like manner I conceive that^ long before the historical 

 era, Monnt Etna may have been furrowed on all sides by 

 valleys dnring a long interval of comparative rest, or, perhaps, 

 a total suspension of eruptions. 



The vast deposits of alluvial matter, more than 100 feet 

 thick, which are seen along the coast eastward of the Val del 

 Bove, between Giarre and Mangano, and which may some- 

 times be traced up to the height of 400 feet, attest the 

 enormous amount of erosion w^hich the eastern flanks of 

 Etna have undergone at a remote period. 



smal 



m 



of renewed activity to which the lateral cones are principally 

 due. The lavas pouring out successively on the northern, 

 western, and southern flanks obliterated all the ancient 

 valleys on those three sides, and would have done the same 

 on the eastern flank of the cone had they not been inter- 

 cepted in their course by that huge chasm, the Yal del Bove, 

 which they have already, in great part, filled up. Three 

 valleys or ravines, which have escaped obliteration, deserve 

 notice as bearing the same relation to the margin of the Yal 

 del Bove which the valleys on the north of Vesuvius (those of 

 the Casa del? Acqua and others, described at page 634, 

 Yol. I.) bear to the Atrio del Cavallo. These three valleys 

 on the south-east side of Etna are the Yalle del Tripodo, the 

 Yalle dei Zappini, and the Yalle di Calanna, the position of 



Map 



The first of them. 



difiicult 



Zafarana, is scarcely ever visited by travellers. It is a beau- 

 tiiul, wooded-alpine ravine down which a torrent flows. On 

 reaching the head of this ravine, or the col which divides it 

 from the Yal del Bove, a truly splendid view is obtained of 



am 



scribed. Althou 



above the level of the sea, it forms 



part of a 



ortheSerradelSolfizio. 



pment 



Map 



The depth of the 



