VOL. XXX.] PHILOSOPHICAL TRANSACTIONS. 31/ 



sighing, throbbing, churning, dashing, as it were, of waves, and sometimes a 

 noise like that of thunder or cannon, which was constantly attended with a 

 clattering, like that of tiles falling from the tops of houses into the streets. 

 Sometimes, as the wind changed the smoke grew thinner, discovering a very 

 ruddy flame, and the jaws of the crater, streaked with red, and several shades 

 of yellow. After an hour's stay, the smoke, being moved by the wind, gave 

 us short and partial prospects of the great hollow, in the flat bottom of which 

 I could discern two furnaces almost contiguous, that on the left seeming about 

 3 yards in diameter, glowed with red flame, and threw up red-hot stones with 

 a hideous noise, which, as they fell back, caused the fore-mentioned clattering. 

 May 8, in the morning, I ascended to the top of Vesuvius a second time, and 

 found a diff^erent face of things. The smoke ascending upright, gave a full 

 prospect of the crater, which is about a mile in circumference, and 100 yards 

 deep. A conical mount had been formed since my last visit, in the middle of 

 the bottom. This mount I could see was formed of the stones thrown up and 

 fallen back again into the crater. In this new hill remained the two mouths or 

 furnaces already mentioned; that on our left hand being in the top of the hill, 

 which it had formed round it, and raged more violently than before, throwing 

 up every 3 or 4 minutes, with a dreadful bellowing, a vast number of red-hot 

 stones, sometimes in appearance above 1000, and at least 300 feet higher than 

 my head as I stood on the brink. But there being little or no wind, they fell 

 back perpendicularly into the crater, increasing the conical hill. The other 

 mouth to the right was lower in the side of the same new formed hill. I could 

 discern it to be filled with red-hot liquid matter, like that in the furnace of a 

 glass-house, which raged and wrought like the waves of the sea, causing a short 

 abrupt noise, like what may be imagined to proceed from a sea of quicksilver 

 dashing among uneven rocks. This matter would sometimes overflow and run 

 down the convex side of the conical hill, and appearing at first red-hot, it 

 changed colour, and hardened as it cooled, showing the first rudiments of an 

 eruption, or, as it were, an eruption in miniature. Had the wind driven in our 

 faces, we would have been in no small danger of being stifled by the sulphu- 

 reous smoke, or being knocked on the head by lumps of molten minerals, which 

 we saw had sometimes fallen on the brink of the crater, upon those shot from 

 the gulph at bottom. But as the wind was favourable, I had an opportunity of 

 surveying this odd scene for above an hour and a half together; during which 

 time it was very observable, that all the volleys of smoke, flame, and burning 

 stones, came only out of the hole to our left, while the liquid matter in the 

 other mouth wrought and overflowed as has been already described. 



June 5, after a horrid noise, the mountain was seen at Naples to emit a 



