300 Dr. Donati on the 



men a which it exhibited, the volcano remained until the night 

 of the 20th of March. But on the morning of the 21st, the 

 scene was entirely changed, and became very striking. Two 

 additional volcanic apertures opened ; one to the north, about 

 twenty feet in diameter; the other very small, and situated be- 

 tween this and the one which gave the first signal of volcanic 

 action. Loud explosions and violent shocks reverberated, not 

 only through the interior of Vesuvius, but were felt as far as the 

 city of Naples. The eastern mouth incessantly ejected matter 

 in a state of fusion, peperidicularly to the height of forty or 

 fifty feet in the air ; and when a current of fire was thrown out 

 by one it was immediately succeeded by a jet from the other. 

 A constant motion of ascent and descent was felt, and volumes 

 of smoke were disengaged, of various colours white, reddish, 

 blue and black. 



The northern mouth, perfectly circular in form, gave from 

 ten to fifteen violent shocks every minute ; and threw into the 

 air melted substances, sometimes with brownish white, and 

 sometimes with azure-blue smoke : the liquid lava now flowed 

 from the margin in various directions, and spreading itself in 

 the air, formed a hemisphere of transparent glass, which, 

 either from the impossibility of extending itself, or from the 

 pressure of the air, or because the internal vapours forced 

 themselves a passage through it, broke in many directions, and 

 fell again into the fiery fountain whence it arose. 



The little mouth, every one or two minutes, gave a shock 

 considerably stronger than those of the larger one. Opening 

 itself into an ample basin, it ejected the very materials of which 

 it was formed, and those which were continually falling on it 

 from the lateral apertures. The scoriaceous lava, brown on 

 the surface, but liquid within, beat against the interior sides of 

 the cone, rising by degrees with a waving motion. The phe- 

 nomena did not preserve the same character as on the pre- 

 ceding days, but increased with gigantic progress ; at every 

 shock the whole cone trembled, and an undulatory motion 

 extended as far as to Resina and other parts of the surrounding 

 country ; the smoke continued to rise in large globes at the 

 summit of the crater. 



At two o'clock I went round the perimeter of the cone, to 



