Great Neapolitan Earthquake of 1857/Part II. Ch. IV
CHAPTER IV.
JOURNEY SOUTHWARDS—AMALFI—SALERNO—VIETRI—LA CAVA—PLAIN OF PÆSTUM.
I now recur to my journey southwards. At Torre del Greco, Resina, and throughout the whole seaboard of the Bay, the shock was felt as sharply as at Naples; and generally over the whole plain of the Terra di Lavoro, in a direction from south to north: at Ottajana, to the southeast of Vesuvius, and close under the mountain, more than usual injury was done. The church of St. Michael was largely fissured, and that of St. Johannes Battista also. I did not visit that town, but an inhabitant, whom I met elsewhere, stated that the direction of shock was generally felt from south to north, but also seemed to come from Vesuvius, and the like facts were stated as to the village of Somma. Small and unindicating fissures were to be found, in the older and worse built houses, &c., everywhere. At Torre del Annunziata, the west façade of the church, is largely fissured in directions clearly indicating a wave-path, not far from south to north. Ancient fissures from former earthquakes at lower levels are visible in its walls.
At Sorrento Point, the direction of wave-path was described to me by several intelligent observers resident there at the time, to have been from S. to N., or very nearly so. I could not visit myself that locality.
In Pimonte, also, the façade of the Chiesa Madre was fissured, and part of the roof thrown in. At Sigliano, some houses were overthrown. At Gragnano, on the slope above Castellammare, a great many poor buildings were greatly shaken, as was also the case with all the villages, upon both the north and south sides of the mountainous peninsula, terminating with Punta della Campanella; but in the island of Capri, directly south of Naples, and but a few miles from this cape, the shock was scarcely perceived.
On the south side of this peninsula, Tramonte, Minori and Majori, were fissured, but uniustructively, from the character of the buildings. At Amalfi, the shock was alarmingly felt. The doors and windows rattled for ten or twelve seconds at each of the two shocks; but no injury occurred to any of the buildings, which are generally of a substantial and well-built character of masonry. The Padrone of the Hôtel des Capuchins, and also the chief apothecary of the place, were able to point out to me separately, the directions in which they perceived the shock; both statements closely agreed in pointing out an azimuth, which proved to be 133° W. of N.; i.e., from a S. W. to N. E. direction; and several facts indicated the occurrence of an orthogonal shock here, and at Atrani. They heard no noise.
The line of coast here is nearly E. and W., and so is the face of Palmieri's quay wall.I made inquiries here, as also at Salerno, amongst the fishermen and coasting sailors, as to whether any of them had felt the shock at sea, but could gain no intelligence of any such observer.
In the Ravina della Molini, behind the town of Amalfi, I observed some beds of ancient tufa deposited upon the precipitous sides of limestone at a considerable height above the present sea level.
Along the road between Amalfi and Salerno there are proofs of an elevation bodily of the land of from 300 to 400 feet since the formation and forcing up into a mountain range, of the great ridge of limestone that forms the peninsula. 1st. Beach gravel in wavy layers, quite similar to that on the existing shore, is found 300 feet above it at Punta d'Erchia. 2nd. Between that and Amalfi, in the limestone, the beds of which have a north and south strike, and dip slightly to the west, there are caves, the upper portions of the jaws and arches of which, some 70 or 80 feet above the existing beach, present the rounded and water-worn aspect, of long-continued action of the sea. Objects, such as the porphyry font at Amalfi, alleged to have been excavated from beneath the beach—ruins now existing below the sea level here and there, go for nothing, as along a line of coast so extremely precipitous as this, of shattered limestone, and so frequently shaken by earthquakes, whole cliffs, have doubtless frequently been shaken down, and plunged beneath the sea. The limestone all along, from the point of Capo del Tumulo, is metamorphic and altered, in its bedding and cleavage, and presents in many places, highly magnesian, and in some, trappean characters. Near Majori, fine masses of dark-brown stalactite occur, containing very large plates of calc spar. All this, with the scattered patches of tufa, on the south side of the peninsula, where they never could have come sub dio from Vesuvius, indicate that submarine volcanic action, was going on in these regions, before the bay of Naples was separated from that of Salerno at all, by the elevation of the great limestone ridge now between them.
At Vietri, which I visited in a violent storm of rain and wind, I could find no evidences of wave direction worthy of notice. At La Cava, the first very obvious trace of the earthquake challenged notice, in a long range of diagonal timber braces, sustaining the S.W. side of a range of house fronts, which had been thrown so as to lean outwards, bringing with them, the square piers of the old Roman-looking arcades, over which the houses are built (Fig. 119). In the latter were measurable fissures, though small; in the Casa Communale, and in the side and back walls, of some of the strange shadowy open fronted shops, that seem so identical with those of Pompeii, were a few others. From the whole I obtained three indications of wave-path- 15.30 E. of N.; S. to N.; 17 W. of N.—and also some indications of an orthogonal shock, W. to E. At the Benedictine monastery of La Trinita, a few miles from La Cava, I expected to have found much evidence of injury. It lies, in the gorge of a deep and sinuous mountain valley, of metamorphic limestone, hard and shattery, but with much diluvial covering in many places.
The buildings, sound and well constructed, of rubble ashlar chiefly, have generally escaped. There are, however, in two different places in its southern corridors, and near the great south corridor window, fissures of considerable length, and open at widest 0.4 inch. They indicate a wave-path from the southward, and in direction 16° 15’ W. of N., and also one 105° 30’ W. of N. or orthogonal. They felt the two shocks of 16th December severely at the monastery. Padre Morcaldi, the Archivario, was not conscious of any noise attending either of the shocks, nor had any one else in the monastery remarked any.
The forms of the small mountain valleys in this thickly inhabited region, are singularly winding and capricious (Fig. 120). A shock in whatever general direction acting here upon the houses and towers, perched on declivities, now rocky, now diluvial, and scattered here and there and facing every point of the compass, must produce effects in the highest degree complicated, or even unaccountable. I therefore resolved, in the first instance at least, to waste no time by further observation within it.
Salerno, though an ancient city, is generally well built: it lies low, along the shore of a pebbly beach, and apparently on pretty deep beds of loose material, and the land behind it, rises gradually into mountain slopes, and recedes into sinuous transverse valleys on limestone.
It has not suffered much, but there are abundance of large measurable fissures. I had a lengthy conversation with the Intendente of the province, Signor Ajosso (who was confined to bed and unable to go round the city with me). He stated that the shock was not sufficient to throw down furniture, or observably displace it, but that he saw it jerk the water out of a large earthen jug, which he pointed out in his bedroom, about 5 inches diameter of mouth, and which had been full, within 2 inches. Sketch Pl. 120.
Vincent Brooks, lith. London
Vietri. From Near the New Road.
Some china vases and table ornaments of common form, in his rooms were thrown upon the floor. Some of his officials lost their footing and fell, during the second shock. He heard no noise with either shock, nor has he heard it stated that there was any sound heard by any one at Salerno. He furnished me with a copy of the official list of the houses destroyed, persons killed and wounded, &c., in the several Communes of his province, and letters to the Sotto Intendenti in the various parts thereof, and a general authority, under his sign manual, to call upon the Guardia d'Urbani and Gendarmerie anywhere, if necessary to aid in my examinations. [1]
The walls of the Intendenzia are rather heavily fissured, especially through the window and door opes of the great stone staircase. The fissures in walls running E. and W., lean 10° to 13° from the vertical to the eastward: some are open 0.5 inch in 12 feet of length, and props and braces have been necessary.
The building is ordinal, and from three of the best fissures, I derive a wave direction, 53° W. of N.
The cathedral, a grand old structure, rich with the spoils of Pæstum, brought by Roberto Guiscardi, and of sound masonry, has its axial line (as I find is not uncommon in these very old Italian churches) not quite E. and W. The axis is 23° W. of N. There were two formidable fissures, one in the apse at the N. E. side, at , Fig. 121, the other at , in the western transept—both not far from vertical, and right down through 
Fig. 121. window and door opes to the ground level, from the roof. These were originated, the Sacristan informed me, by small thread-like cracks (filone) in 1851, but were widened and lengthened now, in December 1857. a is now about 0.75 inch open near the top, and the roof of the apse has been sufficiently injured to require struts betwixt ceiling and floor. The dislocation of the roof here, indicates a certain amount of emergence in the wave-path (but the fissures do not indicate any distinctly), 10° or 12° at most.
The direction I derive from them is 34° 30′ W. of N. There are upon various points of the cathedral and attached buildings many slender iron crosses, the iron flat bars of about 1 1/2 inch 3/8 inch thick, as in Fig. 122, none of 
Fig. 122. which present any signs of having been bent or twisted. They were all confined, however, by small diagonal stays of round iron, about 1/4 inch diameter. In the noble old cloister court, a long stone, part of the shaft of an old column that had leaned against a wall running nearly N. and S., was overthrown, and indicated a wave-path of about 60° W. of N.
Fissures, at the Tribunale, gave a wave-path 67° W. of N. These fissures also afforded pretty decisive evidence of the co-existence here of an orthogonal shook, or one from W. to E., but of very minor intensity, as was already noticed at Amalfi, Atrani, and La Cava.
Several other churches that I entered showed no sign of injury. I was informed that the church of Saldina with its Campanile, not far from Salerno to the northward, had been seriously dislocated, more than any at Salerno. Time would not admit my diverging to it.
Throughout the whole vast plain, from Salerno to Pæstum, no visible sign of the earthquake can be found. It was felt however, sharply and with alarm, all over it, and the people very generally say it came from the eastward, in so far as their very loose expression "levante ver, ponente," may mean so.
The outstretched plain between the mountains and the sea, is not perfectly level; it slopes very gently seaward, and consists of a great depth of diluvial and transported material, all small where visible. At Pæstum, and for a considerable distance round it, the fawn-coloured aqueous tufa, of calcareous matter filled with the impressions of recent plants of a paludal character—great arundos, alder leaves and twigs, &c.—is found horizontally, everywhere at from 6 to 12 feet beneath the surface, and no doubt overlies the limestone that supports the whole plain.
Of this tufa, the majestic, solitary, and awe-inspiring Doric temples were built, with the town walls of huge ashlar all laid dry, that alone remain of what was once a populous city. Upon the dreary winter afternoon, on which I examined its ruins, no sign of life enlivened the desolate plain, but a flock of screaming green plover; no sound was heard but the wind that sighed through the sedges and the distant and dismal howl of some goatherd's dog.
The formation of this tufa seems to indicate the upheaval of the great plain at a recent geological period. The lime has no doubt come, from the ground-up, and dissolved limestone, of the cretaceous formations, that constitute the lower mountain range, between the great mountain masses, of Apennine limestone and the sea. The latter occasionally comes forward in grand developments as at the Tusciano (Fig. 123), where the ranges under Monte Polveracchio show beds of vast extent and thickness, with a nearly horizontal strike parallel with the coast, and a noble sweeping curve, dipping steeply inland (about 30°) towards the N.N.E. Far beyond are high and jagged peaks, and a lofty sierra, thinly covered with a hoary head of snow, bounds the horizon, and glitters against the cold grey sky. Some twelve miles further south, the Salaris crosses the plain in a deep channel with heavy slob banks in the diluvium, about 270 feet wide, and with a rapid current, and turbid mud-stained water, of about 20 feet in depth. It drains a large area, in a course of more than a hundred miles, and the quantity of calcareous matter, both in solution by carbonic acid, and in suspension as mud, that it constantly brings into the sea, must be even now producing very sensible effects upon the coast, the dissolved lime forming the cement, that rapidly agglomerates and hardens the calcareous mud into stone. This process seems also to be that, upon which the formation of the calcareous breccias found in such vast masses in the Apennines, has depended.
Looking eastward towards, the valley through which the Salaris debouches upon the plain, between Eboli on the north, and the Bosco di Persano, the synclinal beds of limestone are developed upon the grandest scale (Fig. 124): from to is probably not less than twenty miles, and the same beds can be traced by the telescope at either side. Above and between these the upper limestone, of the collines, seems to lie unconformably. Upon one of the most prominent of these towards the south are perched, Capaccio Nuovo and Capaccio Vetico, with the great adjacent monastery; in all which, I was informed, the earthquake had been severely felt, but no considerable damage done. The general aspect of these branches of the Apennines, as I look back and into their recesses, is one of extreme confusion and dislocation, produced by long-continued and reiterated elevatory action of the most violent character, of which no just idea is given, by the surface configuration even of the largest maps, such as those of Bachler D'Albe and Zannoni; and such as it would require years of labour from the field geologist to analyse and describe.
At Pæstum I examined the ruins of the temples with care, for evidences of the shock, but they presented not the smallest indication of dislocation. Formed, as they are, of extremely massive blocks, laid without cement, and with all the top weight due to Greek Doric architecture, few buildings could be by form and structure more amenable to "promptings from beneath." A careful examination, however, led me to conclude that since their foundation, they had suffered nothing by earthquake, not even to the opening of a joint—a sufficient disproof of the common tradition, that Pæstum was deserted and reduced to ruin, by reason of the earthquakes that desolated the plain. So far from the truth is this, that Capaccio, up in the mountain to which the Pæstians are said to have migrated from the plain, has been repeatedly dislocated, and, apparently, the ruin of the whole town produced the founding of Capaccio Nuovo; the other and older being now nearly without inhabitants.
In fact, from whatever centre earthquake movement originates, along the mountain axis from Calabria northwards towards Melfi, &c., its spread is greatest and most rapid, in the lower and denser limestone of the higher central chain, and here, at the western seaboard plain, is almost limited by the line of outlying cretaceous collines; the blow transmitted from which through ten or fifteen miles of soft porous tufa and loose material, principally deep calcareous clays, is completely buffed and lost, before it reaches Pæstum and the shore.
The family and servants of the landowner at Pæstum, a great number of whom I found collected at the Casone, were unanimous that the shock of 16th December was simply "oscillatorio," and in direction "levante ovvero ponente," that they had felt but one shock, and had heard no noise. On causing some of them to point out separately for me, from the balcony by the hand, the direction in which they deemed the shock traversed, and comparing it with the azimuth compass, I found it was very nearly E. and W.
They said the dogs (of which they keep a great number of large formidable animals to take care of the buffaloes, &c.), had barked violently and universally, for a good while before they felt the shock. Most of the people were in bed. They could give no information as to the time beyond crude guesses. The shock had been felt, they said, far worse at Agropoli and below it, than with them; naturally so, for the limestone mountains jut out into bold promontories and come down to the sea at or near that town. At Capaccio Nuovo they said the shock had also been felt from E. to W., and more from the north, than with them at Pæstum.
- ↑ The Intendente is very much the representative of the ancient Roman Proprætor. He possesses enormous executive power, often grossly abused under the old régime. The civil, military, and ecclesiastical authorities are all more or less subject to his individual will.