244 THE WORLD. 



and again suddenly resume all their former character. Thus 

 Vesuvius, which had been extinct from time immemorial, al- 

 though its crater was clearly formed by some ancient volcanic 

 action; suddenly rekindled in the reign of Titus, and buried the 

 cities of Herculaneum, Pompeii, and Stabiae, 'under its ashes. 

 After this effort it again slumbered, the memory of its former 

 power faded away; trees and grass grew on its summit, when sud- 

 denly in 1630, it renewed its action. At this time, the crater, 

 according to the' account of Bracini, who visited Vesuvius not 

 long before the eruption of that year, "was five miles in circum- 

 ference, and about a thousand paces deep; its sides were covered 

 with brushwood, and at the bottom there was a plain on which 

 cattle grazed. In the woody parts wild boars frequently harbored. 

 In one part of the plain, covered with ashes, were three small 

 pools, one filled with hot and bitter water, another salter than the 

 sea, and a third hot but tasteless." Suddenly, in December 1530, 

 these forests and grassy plains were blown into the air, and their 

 ashes scattered to the winds ; seven streams of lava poured at the 

 same time from the crater, and overflowed several villages at the 

 foot, and on the side of the mountain; since that time there has 

 been a constant series of eruptions. Etna after slumbering for 

 ages, burst forth and destroyed the city of Catania; the accounts 

 of its previous eruptions having been considered by the inhabit- 

 ants as fables. 



Subterranean noises, and the appearance, or increase of smoke, 

 are the first symptoms of approaching volcanic action. This is 

 soon accompanied by a trembling of the earth, and louder noises; 

 the air darkens, and the smoke, thick with fine ashes, increases. 

 The stream of smoke rises like an immense black shaft, high up 

 into the air, and arriving at a point where its density is the same 

 as the atmosphere, spreads out like a vast umbrella, overshadow- 

 ing the whole country with its dark gloom. Such was the ap- 

 pearance as described by Pliny, the Elder, who witnessed the 

 eruption of Vesuvius which overwhelmed Pompeii, in A. D. 79. 

 Occasionally, lightning flashes illuminate the dark cloud, and 

 streams of red hot sand, like flames, shoot up into the sky, at- 

 tended with louu explosions. The shocks, and tremblings of the 



