the late Eruption of Mount V esuvius. 9 i 
certainly, since the top fell in, cannot be much short of two 
miles in circumference. One cloud heaped on another, and 
succeeding one another incessantly, formed in a few hours such 
a gigantic and elevated column of the darkest hue over the 
mountain, as seemed to threaten Naples with immediate de- 
struction, having at one time been bent over the city, and ap- 
pearing to be much too massive and ponderous to remain long 
suspended in the air ; it was besides replete with the ferilli\ 
or volcanic lightning, which was stronger than common light- 
ning, just as Pliny the younger describes it in one of his 
letters to Tacitus, when he says fulgoribus ilia et similes el 
majores erant. 
Vesuvius was at this time completely covered, as were all 
the old black lavas, with a thick coat of these fine light-grey 
ashes already fallen, which gave it a cold and horrid appear- 
ance ; and in comparison of the abovementioned enormous 
mass of clouds, which certainly, however it may contradict our 
idea of the extension of our atmosphere, rose many miles 
above the mountain, it appeared like a mole-hill ; although, 
as you know, Sir, the perpendicular height of Vesuvius 
from the level of the sea, is more than three thousand six 
hundred feet. The Abb£ Braccini, as appears in his printed 
account of the eruption of Mount Vesuvius in 1631, measured 
with a quadrant the elevation of a mass of clouds of the same 
nature, that was formed over Vesuvius during that great erup- 
tion, and found it to exceed thirty miles in height. Doctor 
Scotti, in his printed account of this eruption, says that the 
height of this threatening cloud of smoke and ashes, measured 
(but he does not say how) from Naples, was found to be of an 
elevation of thirty degrees. All I can say is, that to my eye 
N 2 
