C 3 ] 
mountain fo much, that in May its top was vifible 
above the rim of the ancient crater. The ' 7th 
of Augufl there i fined a fmall firearm of lava, from 
a breach in the fide of this little mountain, which 
gradually filled the valley between it and the ancient 
crater; fo that the 12th of September the lava over- 
flowed the ancient crater, and took its courfe down 
the fides of the great mountain ; by this time, the 
throws were much more frequent, and the red hot 
ftones went fo high as to take up ten feconds in their 
fall. Padre Torre, a great obferver of Mount Ve- 
fuvius, fays they went up a bove 1 000 feet. 
The 15th of October, the height of the little 
mountain (formed in about eight months) was mea- 
fured by Don Andrea Pigonati, a very ingenious 
young man in his Sicilian majefty’s fervice, who 
allured me that its height was 185 French feet. 
From my villa, fituated between Herculaneum 
and Pompeii, near the convent of the Calmaldolele 
(marked 7 in the inclofed Plan I.), I had watched 
the growing of this little mountain, and by taking 
drawings of it from time to time, I could perceive 
its increafe moft minutely ; I make no doubt but that 
the whole of Mount Vefuvius has been formed in 
the fame manner ; and as thefe obfervations feem to 
me to account for the various irregular firata, which 
are met with in the neighbourhood of volcanos, I 
have ventured to enclofe for your Lordfhip’s infpedion 
a<copy of the abovementioned drawings. 
The lava continued to run over the ancient 
crater in fmall fireams, fometimes on one fide, and 
fome times on another, till the j 8th of Odober, 
when I took particular notice that there was not the 
B 2 lead 
