348 



MOUNT VESUVIUS, 



of^Moi^t Ve- ^^^^^ ^^'^ ^^^'"' ^^ °"'' ^^cursion of the preceding night had 

 suvius. Ji'^t enabled us to form any idea concerning the progress of 



the lava, we set out again to observe this extraordinary 

 phctnomenon. 



Passing through the villages of Portici, Resina, and Torre 

 del Greco, we entered inclosures, consisting of vineyards and 

 corn-fields, into which the lava had penetrated ; we approach- 

 ed the current, and I was surprized to find the progress of the 

 lava so different from the conception I had formed of it. 



I had always imagined that the substance of the lava, re- 

 sembling melted glass, ran in the same manner, and advanced 

 uniformly like a river of fire ; and indeed it is extremely pro- 

 bable that in a great number of eruptions it actually exhibits 

 this appearance. On the present occasion, I saw nothing but 

 an accumulation of stones, some of which were of prodigious 

 magnitude, heaped one upon another to the height of fifteen 

 or twenty feet, and about half a mile in breadth. This formid- 

 able ma^s advanced slowly, following a progression produced 

 solely by the falling of the different bodies, between which 

 there was no adhesion, and which, in obedience to the impulsion 

 they had received on issuing from the crater, rolled from the 

 most elevated point and covered the surface of another stratum. 

 In this manner the stones rolled over one upon another, till 

 the front rank having attained the same height as that which 

 produced it, began in its turn to pour down the ignited bodies 

 that came tuinbling upon it. 



All this intestine motion was accompanied with a noise, 

 refembling the decrepitation of salts, but much more loud 

 and brisk. The fire was fed by various combustible matters, 

 as sulphur, bitumen, and metals, which might be known by 

 their flames ; but there was no appearance either of complete 

 fusion, of of the commencement of it. The stones resisted the 

 the pressure of a stick, which I several times endeavoured, but 

 m vain, to thrust into them. 



Meanwhile the devastation occasioned by the progress of this 

 torrent, presented a horrid spectacle. The trees which sup- 

 ported the vines, and the vines themselves, were burned by the 

 extreme heat bf this mass of matter, even before it reached 

 them; and the bright and clear light produced by their com- 

 jbijstion, indicated the exact con^owr of the progress of the lava. 



The 



