VOL. XXVIII.] PHILOSOPHICAL TRANSACTIONS. 13 



almost innumerable: so that there hardly passes a month, much less a year, 

 without its breaking out with more or less violence, and doing more or less 

 damage. The greatest eruption that had happened for some time, was that in 

 1707, when in the height of summer, in the latter end of July, this mountain, 

 which had been quiet for some time, began to show some signs of an eruption; 

 for, at first those internal bellowings were heard, which resounded in the very 

 centre of the mountain, yet without any smoke or flame; then by degrees it 

 began to emit smoke and clear fire, which, especially in the night-time, illu- 

 minated all Campania; in the mean time, at different intervals, it made such a 

 terrible noise, that the reports of the largest guns are scarcely to be compared 

 with it: then it began to roll its ashes for several days and nights, conveying 

 them aloft every way into the air, and dispersing them into different quarters, 

 according as the wind happened to blow; sometimes into the sea, at other times 

 on the adjacent territories of Stabia, Nola, and Acerra; and, what was very 

 remarkable, a prodigious shower of stones, that destroyed both men and cattle. 

 After this it began to belch out at its gaping mouth a liquid torrent of bitumen, 

 called glarea, or grit; which at first appeared like a gentle stream of fire, 

 descending with the same slowness of motion, as is observable in melted pitch, 

 or the like viscid substances; this matter, which resembled molten glass, as it 

 cooled in its progress, became as hard as stone; it was observable, that the 

 superior surface of this matter, as it cooled, was converted into small spongy 

 stones, but its lower surface into a broad, hard, solid, flint, long used in paving 

 the highways, as if what lay next the air had admitted and retained some of its 

 particles, while its lower part became a solid compact mass, without any 

 vacuities. Among a great many phaenomena of this volcano, there were two 

 that had not been observed for several ages before: for, about the third or 

 fourth day it began to emit at its mouth flashes of lightning, almost like those 

 sometimes observed in the air, but of a serpentine form ; and very loud claps of 

 thunder were heard, so thick and frequent, that at first it was thought it would 

 rain, till it was perceived they proceeded from the mountain, and that the dark 

 clouds did not consist of vapours, but of large quantities of ashes. 



On the 2d of August, at 4 in the afternoon, there was such a thick cloud of 

 ashes hovering over Naples, as intercepted the rays of the sun; and the dark- 

 ness was so great, that people could not distinguish their friends in the streets; 

 in short, no midnight darkness exceeded it. If any ventured abroad with 

 torches, they were obliged to return home again; which only happened once 

 before, viz, in the emperor Titus's time, according to Ziphilin. — So that every 

 place was filled with the shrieks of women ; but the more prudent betook them- 

 selves to prayer to Almighty God^ and with apprehensions expected the event of 



