171 October, 1822. 177 



floor, and conceal the volcanic orifice. The extreme periphery 

 of the crater in some parts juts over these precipices, so that 

 on attaining its margin you look directly down into the gaping 

 cavity. In others, a steep inclined plane, of no great width, 

 intervenes between the edge of the cliffs and the acute ridge in 

 which the interior and exterior slopes terminate. On this 

 inner and shelving surface it is necessary on many points to 

 pass while ipaking the tour of the crater ; in general, it affords 

 ^ firm pnd safe footing, being formed of the fine sand which 

 was the last product of the late eruption, and into which the 

 foot sinks to some depth ; but, when the surface of this slope 

 is hardened by frost into an unyielding and slippery crust, 

 (which was the case on the morning of my first visit,) the 

 passage is extremely perilous. The danger is, in fact, the same 

 on the outer as the inner slope, since a slide or a false step 

 would be probably fatal on either side ; but the idea of falling 

 iflto the crater is more appalling than that of rolling down the 

 exterior of the cone. 



The cliffs that encircle the great cavity by no means follow 

 any regularity of curve, but project or recede in salient and 

 retiring angles. Their abrupt faces which are rocky, jagged, 

 and unpicturesque in the extreme, present sections of many 

 currents of lava, some of which are of great thickness and 

 extent, lying one above the other in a direction more or less 

 approaching to the horizontal. Most of them offer a columnar 

 division of the most marked and decisive kind. Some are 

 almost as regularly prismatic as any ranges of the older basalts. 

 In some the spheroidal concretionary structure on a large scale 

 is equally conspicuous. Between the currents of lava are inter- 

 posed shapeless beds of volcanic conglomerate, consisting of 

 fragments of all sizes heaped together in cliaotic confusion. 

 These, as well as the beds of lava, are occasionally intersected 

 by vertical or nearly vertical dikes, similar to those of Somnia 

 above the^^m di Cavallo. 



The whole scene presents, perhaps, an unparalleled example 

 of the horribly sublime. The deep and yawning gulf, on the 

 verge of which the spectator must hang to observe its terrors ; 

 N 2 



