NOTES 



337 



him, and he had published, in his youth, a volume about it. The 

 calamity which brought so much injury to the towns of Campania 

 was more especially likely to enlist his vivid interest, for the 

 region that had been convulsed was with him a well-known and 

 favourite part of Italy, where he often came to spend, on the 

 shores of the Bay of Naples, such leisure as the life in Rome 

 allowed him. Besides, it was the native district of Lucilius, to 

 whom the volume was addressed, and whose town of Pompeii 

 had suffered from the shock. 1 Hence he here plunges at once 

 into details of the damage caused by this particular earthquake. 

 As a prelude to his inquiry into the whole question of the origin 

 of such catastrophes, he indulges in reflections on their appalling 

 nature. Some of the unfortunate residents in the convulsed dis- 

 trict had fled from it, vowing never to return. But where, the 

 writer asks, can they be sure of safety, seeing that no quarter of 

 the world is exempt from this form of danger ? He urges that it 

 is at least some consolation to be assured that such calamities 

 are not the work of angry gods, as was popularly believed, but 

 are traceable to their own special causes in the processes of 

 nature (228). 



He then considers the various opinions entertained on this 

 subject by earlier writers, which, on the whole, he regards as crude 

 and inexact. The cause of earthquakes had been found in water, 

 fire, air, and the earth itself, or in a combination of several of 

 these agencies, or even in the co-operation of the whole of them. 

 As regards the action of water, he dismisses the opinion of 

 Thales (231), but in the statements of other authors, who maintain 

 the power of internal water in causing earthquakes, he sees a greater 

 probability of truth. He fully admits the existence of large rivers 

 and extensive lakes inside the earth, and that in these dark unin- 

 habited regions flooded rivers undermining their banks, and a 

 swollen sea lashed into fury by the subterranean winds, may com- 

 municate shocks to the surface of the earth (234). 



That fire is the origin of earthquakes had been held by various 

 philosophers, who, however, differed as to the manner in which 

 the fire acts. Anaxagoras thought it was by explosions caused 

 from the collision of underground clouds (236) ; others held that 

 the immense mass of vapour produced by the subterranean 

 conflagrations as it accumulates may exert such a pressure as to 



1 In Seneca's letters, frequent reference is made to his visits to the district. 

 He seems generally to have taken a villa at Baiae, or some adjacent place on 

 that western part of the coast. He appears to have been a poor sailor, glad 

 to make for the nearest landing-place between Baiae and Naples, so as to 

 escape from the pangs of sea-sickness. On one of his excursions he revisited 

 Pompeii, and was set into a reverie of his youth there. See his Letters, 

 49, 5i. 53, 55, 57, 7o, 77- 



