Masterpieces of Science 



vines were growing over the sides of the crater 

 and it was in the natural fortress formed by this 

 great amphitheatre that Spartacus the Thracian, 

 with his little band of gladiators, took up his 

 position at the beginning of the Servile War in 

 the year 72 B. c. Earthquakes, as already 

 pointed out, are often the heralds of volcanic 

 eruptions; and the first notice which the old 

 dwellers around Vesuvius received of its re- 



Fig 55. Summit of Vesuvius in 1767 



newed activity was from a series of earthquakes 

 which began, as far as we know, in A. D. 63, and 

 continued intermittently for about sixteen years. 

 These disturbances culminated in the great 

 eruption of A. D. 79, which has been described 

 in two letters written by Pliny the Younger to 

 Tacitus. The elder Pliny, the author of the 

 famous Historia Naturalis, was, at that time, 

 in command of the Roman fleet off Misenum. 

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