VESUVIUS. 



181 



which only one eruption, and that an unimportant one 

 (in 1500), took place. ' It was remarked,' says Sir 

 Charles Lyell, f that throughout this long interval of 

 rest, Etna was in a state of unusual activity, so as 

 to lend countenance to the idea that the great Sicilian 

 volcano may sometimes serve as a channel of discharge 

 to elastic fluids and lava that would otherwise rise to 

 the vents in Campania.' 



Nor was the abnormal activity of Etna the only 

 sign that the quiescence of Vesuvius was not to be 

 looked upon as any evidence of declining energy in 

 the volcanic system. In 1538 a new mountain was sud- 

 denly thrown up in the Phlegraean Fields a district 

 including within its bounds Pozzuoli, Lake Avernus, 

 and the Solfatara. The new mountain was thrown up 

 near the shores of the Bay of Baiae. It is 440 feet 

 above the level of the bay, and its base is about a mile 

 and a half in circumference. The depth of the crater 

 is 42 1 feet, so that its bottom is only six yards above 

 the level of the bay. The spot on which the mountain 

 was thrown up was formerly occupied by the Lucrine 

 Lake ; but the outburst filled up the greater part of 

 the lake, leaving only a small and shallow pool. 



The accounts which have reached us of the formation 

 of this new mountain are not without interest. Falconi, 

 who wrote in 1538, mentions that several earthquakes 

 took place during the two years preceding the outburst, 

 and above twenty shocks on the day and night before 

 the eruption. e The eruption began on September 29, 

 1538. It was on a Sunday, about one o'clock in the 



