g the Nature of this Mountain._--Down
to the commencement of the Christian era this mountain had given no
ostensible indication that it contained within itself a powerful focus
of volcanic energy. True, that some vague tradition that the mountain
once gave forth fire hovered around its borders; and several ancient
writers, amongst them Diodorus Siculus and Strabo, inferred from the
appearances of the higher parts of the mountain and the character of the
rocks, which were "cindery and as if eaten by fire," that the country
was once in a burning state, "being full of fiery abysses, though now
extinct from want of fuel." Seneca (B.C. 1 to A.D. 64) had detected the
true character of Vesuvius, as "having been a channel for the internal
fire, but not its food;" nevertheless, at this period the flanks of the
mountain were covered by fields and vineyards, while the summit,
partially enclosed with precipitous walls of the long extinct volcano,
Somma, was formed of slaggy and scoriaceous material, with probably a
covering of scrub. Here it was that the gladiator Spartacus (B.C. 72),
stung by the intolerable evils of the Roman Government, retreated to the
very summit of the mountain with some trusty followers. Clodius the
Praetor, according to the narration of Plutarch, with a party of three
thousand men, was sent against them, and besieged them in a mountain
(meaning Vesuvius or Somma) having but one narrow and difficult passage,
which Clodius kept guarded; all the rest was encompassed with broken and
slippery precipices, but upon the top grew a great many wild vines; the
besieged cut down as many as they had need of, and twisted them into
ladders long enough to reach from thence to the bottom, by which,
without any danger, all got down except one, who stayed behind to throw
them their arms, after which he saved himself with the rest.[2] "On the
top" must (as Professor Phillips observes) be interpreted the summit of
the exterior slope or crater edge, which would appear from the narrative
to have broken down on one side, affording an entrance and mode of
egress by which Spartacus fell upon, and surprised, the negligent
Clodius Glabrus.

[Illustration: Fig. 6.--Probable aspect of Vesuvius as it appeared at
the beginning of the Christian era; seen from the Bay of Naples.]

In fancied security, villas, temples, and cities had been erected on
the slopes of the mountain. Herculaneum, Pompeii, and Stabiae, the abodes
of art, luxury, an