3o Sir William Hamilton's Account of 
behind us, the noise was much louder, and more alarming 
than that we had heard in our first position, at least a mile 
nearer to Vesuvius. After some time, and which was about 
two o'clock in the morning of the 16th, having observed that 
the lavas ran in abundance freely, and with great velocity, 
having made a considerable progress towards Resina, the town 
which it first threatened, and that the fiery vapours which had 
been confined had now free vent, through many parts of a 
crack of more than a mile and a half in length, as was evident 
from the quantity of inflamed matter and black smoke, which 
continued to issue from the new mouths abovementioned with- 
out any interruption, I concluded that at Naples all danger from 
earthquakes, which had been my greatest apprehension, was 
now totally removed, and we returned to our former station at 
S. Lucia at Naples. 
All this time there was not the smallest appearance of fire 
or smoke from the crater on the summit of Vesuvius; but the 
black smoke and ashes issuing continually from so many new 
mouths, or craters, formed an enormous and dense body of 
plouds over the whole mountain, and which began to give 
signs of being replete with the electric fluid, by exhibiting 
flashes of that sort of zig-zag lightning, which in the vol- 
canic language of this country is called ferilli , and which is 
the constant attendant on the most violent eruptions. From 
what I have read and seen, it appears to me, that the truest 
judgment that can be formed of the degree of force of the 
fermentation within the bowels of a volcano during its erup- 
tion, would be from observing the size, and the greater or 
less elevation of those piles of smoky clouds, which rise out 
of the craters, and form a gigantic mass over it, usually in the 
