VESUVIUS MONS(Οὐεσούϊος, or Οὐεσούβιος: Monte Vesuvio), sometimes also called by Latin writers VESEVUS,and VESVIUS or VESBIUS(Βέσβιος, Dio Cass.), a celebrated volcanic mountain of Campania, situated on the shore of the gulf called the Crater or Bay of Naples, from which it rises directly in an isolated conical mass, separated on all sides from the ranges of the Apennines by a broad tract of intervening plain. It rises to the height of 4020 feet, and its base is nearly 30 miles in circumference.
Though now celebrated for the frequency as well as violence of its eruptions, Vesuvius had in ancient times been so long in a quiescent state that all tradition of its having ever been an active volcano was lost, and until after the Christian era it was noted chiefly for the great fertility of the tract that extended around its base and up its sloping sides (Verg. G. 2.227; Strab. 5. p. 247), a fertility which was in great measure owing to the deposits of fine volcanic sand and ashes that had been thrown out from the mountain. There were not indeed wanting appearances that proved to the accurate observer the volcanic origin and nature of Vesuvius: hence Diodorus speaks of it as bearing many signs of its having been a burning mountain in times long past(Diod. 4.21); but though he considers it as having on this account given name to the Phlegraean plains, he does not allude to any historical or traditional evidence of its former activity. Strabo in like manner describes it as surrounded by fields of the greatest fertility, with the exception of the summit, which was for the most part level, and wholly barren, covered with ashes, and containing clefts and hollows, formed among rocks of a burnt aspect, as if they had been eaten away by fire; so that a person would be led to the conclusion that the spot had formerly been in a state of conflagration, and had craters from which fire had burst forth, but that these had been extinguished for want of fuel(5. p. 247). He adds that the great fertility of the neighbourhood was very probably owing to this cause, as that of Catana was produced by Mount Aetna. In consequence of this fertility, as well as of the beauty of the adjoining bay, the line of coast at the foot of Vesuvius was occupied by several flourishing towns, and by numbers of villas belonging to wealthy Roman nobles.
The name of Vesuvius is twice mentioned in history before the Christian era. In B.C. 340 it was at the foot of this mountain that was fought the great battle between the Romans and the Latins, in which P. Decius devoted himself to death for his country. (Liv. 8.8.) The precise scene of the action is indeed uncertain, though it was probably in the plain on the N. side. Livy describes it as haud procul radicibus Vesuvii montis, qua via ad Veserim ferebat;but the situation of the Veseris is wholly uncertain. [VESERIS] Again, at a later period (B.C. 73) we are told that Spartacus, with the fugitive slaves and gladiators under his command, took refuge on Mount Vesuvius as a stronghold, and by a sudden sally from it defeated the Roman general Claudius Pulcher, who had been sent against him. (Flor. 3.20.4; Plut. Crass. 9; Appian, App. BC 1.116; Vellei. 2.30; Oros. 5.24; Frontin. Strat. 1.5.21.)
But it was the fearful eruption of the 24th of August, A.D. 79, that first gave to Vesuvius the celebrity that it has ever since enjoyed. That great catastrophe is described in detail in a well-known letter. of the younger Pliny to the historian Tacitus; and more briefly, but with the addition of some fabulous circumstances, by Dio Cassius. (Plin. Ep. 6.16, 20; Dio Cass.—23; Vict. Epit. 10.) It is remarkable that in recording this, the earliest eruption of the mountain, Pliny particularly notices the form assumed by the cloud of ashes that, rising from the crater in a regular column to a considerable height, afterwards spread out laterally so as to form a head like that of a stone-pine: an appearance which has been observed in many subsequent eruptions. The other phenomena described are very much the same as are common to all similar eruptions: but the mass of ashes, sand, and pumice thrown out was so vast as not only to bury the cities of Herculaneum and Pompeii at the foot of the volcano under an accumulation many feet in depth, but to overwhelm the more distant town of Stabiae, where the elder Pliny perished by suffocation, and to overspread the whole bay with a cloud of ashes such as to cause a darkness more profound than that of night even at Misenum, 15 miles distant from the foot of the mountain. (Plin. l. c.) On the other hand the outflow of lava was inconsiderable, and if any streams of that kind broke out at this time they probably did not descend to the inhabited regions: at least we hear nothing of them, and the popular notion that Herculaneum was overwhelmed by a current of lavais certainly a mistake. [HERCULANEUM] So great and unexpected a calamity naturally excited the greatest sensation, and both the poets and the prose writers of Rome for more than a century after the event abound with allusions to it. Tacitus speaks of the Bay of Naplesas pulcerrimus sinus, ante quam Vesuvius mons ardescens faciem loci verteret.( Ann. 4.67.) Martial, after descanting on the beauty of the scene when the mountain and its neighbourhood were covered with the green shade of vines, adds:—Cuncta jacent flammis et tristi mersa favilla(4.44); and Statius describes Vesuvius as Aemula Trinacriis volvens incendia flammis.( Silv. 4.4. 80.)
(See also Val. Flacc., 4.507; Sil. Ital.; Flor. 1.16.5.)
A long interval again elapsed before any similar outbreak. It is probable indeed that the mountain continued for some time at least after this first eruption to give signs of activity by sending forth smoke and sulphurous vapours from its crater, to which Statius probably alludes when he speaks of its summit still threatening destruction ( necdum lethale minari cessat apex, Silv. 4.4. 85). But the next recorded eruption, and probably the next of any magnitude, occurred in A.D. 203, and is noticed by Dio Cassius (Dio Cass. 76.2). This is probably the one alluded to by Galen ( de Meth. 5.12), and it seems certain from the description given by Dio Cassius of the state of the mountain when he wrote (under Alexander Severus) that it was then in a state of occasional, but irregular, activity, much resembling that which exists at the present day. (Dio Cass..) The only other eruption that we find mentioned under the Roman Empire occurred in A.D. 472 under the reign of Anthemius. (Marcellin. Chron. ad ann.) A fourth, which took place in the reign of Theodoric king of the Goths (A.D. 512), is noticed by both Cassiodorus and Procopius, who describe in considerable detail the phenomena of the mountain. It appears certain that these later eruptions were accompanied by the discharge of streams of lava, which caused great mischief to the surrounding country. (Cassiod. Ep. 4.50; Procop. B. G. 2.4, 4.35.)
It would be foreign to our subject to trace the history of the mountain through the middle ages, but it may be mentioned that its eruptions seem to have been far more rare and separated by longer intervals than they have been for more than two centuries past; and in some instances at least these intervals were periods of perfect quiescence, during which the mountain was rapidly losing its peculiar aspect. Even as late as 1611, after an interval of little more than a century, the sides of the mountain were covered with forests, and the crater itself was overgrown with shrubs and rich herbage. (Daubeny on Volcanoes, p. 225.)
At the present day Vesuvius consists of two distinct portions: the central cone, which is now the most elevated part of the mountain; and a ridge which encircles this on three sides at some and is separated from it by a level valley or hollow called the Atrio del Cavallo. This outer ridge, of which the highest point, near its N. extremity, is called Monte Somma, was probably at one time continuous on all sides of the circle, but is now broken down on the S. and W. faces: hence the appearance of Vesuvius as viewed from Naples or from the W. is that of a mountain having two peaks separated by a deep depression. This character is wholly at variance with the description given by Strabo, who tells us that the summit was nearly level,but with clefts and fissures in it, from which fire appeared to have formerly issued (5. p. 247). Hence it is probable that the mountain was then a single truncated cone, and that the vast crater-like hollow of which the Atrio del Cavalloforms part, was first created by the great eruption of A.D. 79, which blew into the air the whole mass of the then existing summit of the mountain, leaving the present ridge of Monte Sommastanding, enclosing a vast crater, within which the present cone has gradually formed. (Daubeny on Volcanoes, p. 215; Lyell's Principles of Geology, p. 365, 8th edit.) It has indeed been frequently assumed from the accounts of the operations of Spartacus already mentioned (Flor. 3.20; Plut. Crass. 9) that the mountain had even then a crater, within which that leader and his band were enclosed by the Roman general: but it is very doubtful whether the passages in question bear out this interpretation, which seems at variance with the account given by Strabo, whose description has every appearance of being derived from personal observation.
(Concerning the history of the different eruptions of Vesuvius see Della Torre, Storia del Vesuvio, 4to., Napoli, 1755; and the geological work of Dr. Daubeny, ch. xii.)
[E.H.B]