EARTHQUAKES AND VOLCANIC DISTURBANCES IN 1883. 



285 



In Ischia. A shock occurred on the island 

 of Ischia, in the Bay of Naples, at 9.50 p. M. 

 on the 28th of July. The towns of Casamic- 

 ciola, Forio, and Lacco Ameno were almost 

 entirely destroyed, with terrible loss of life. 

 Serrara, Fontana, and other smaller villages, 

 suffered much damage. The shock was felt 

 in the town of Ischia, where it was severe 

 enough to injure some of the buildings. The 

 vibrations traveled great distances, and were 

 even indicated by the seismograph in Rome. 

 The number of deaths was estimated at from 

 2,000 to 3,000 ; the number of persons maimed 

 and injured was about 600. 



This island is one of the most attractive 

 bathing resorts in Europe. The resident popu- 

 lation is about 26,000, and there are usually 

 several thousand summer visitors; but there 

 were fewer than the ordinary number at the 

 time of the catastrophe. The village of Casa- 

 micciola is much visited for its thermal waters. 

 It was only two years since this place was 

 half destroyed by an earthquake, March 4, 

 1881 ; but its attractions as a sanitarium and 

 summering place were sufficient to outweigh 

 the dangers. 



A pantomime performance was going on in 

 a summer-theatre in front of the large Manzi 

 health establishment, and in the hotels the 

 guests were assembled in the music and read- 

 ing-rooms, when the catastrophe occurred. In 

 fifteen seconds the village was a heap of ruins. 

 A deafening subterranean roar accompanied the 

 shock, which was followed by slighter vibra- 

 tions, that brought the tottering buildings to 

 the ground. Those who were not crushed 

 under the ruins, or struck down by falling 

 fragments after gaining the street, rushed with 

 cries of terror to the beach, and, seizing every 

 boat and floating thing, sought safety on the 

 water. In the theatre and hotels every light 

 was extinguished, and blinding clouds of dust 

 enveloped the whole village in darkness. The 

 Etablissement Manzi, Grand Hotel, Villa Sau- 

 vet, and Grande Sentinella escaped with com- 

 paratively little damage ; but the other hotels 

 and boarding-houses, among them the Piccola 

 Sentinella, the favorite inn of English and 

 American visitors, were destroyed, with most 

 of their numerous inmates. 



The village of Casamicciola and the land- 

 scape surrounding it were so completely oblit- 

 erated that no feature of the topography could 

 be recognized. The ground was rent with deep 

 cracks several inches wide. Of most of the 

 houses and villas nothing was left but indistin- 

 guishable mounds. In some places landslips 

 carried away roads and vineyards. 



Firemen and sappers and miners arrived im- 

 mediately to disinter the dead, and rescue those 

 who were still living under the debris. King 

 Humbert came with his staff to encourage and 

 aid the distressed, and public and private relief 

 was extended to the thousands who were de- 



E rived of the means of subsistence. In Forio, 

 acco, and Serrara hundreds of peasants were 



killed, and a great number of houses were de- 

 stroyed. Barano suffered considerable dam- 

 age. The census of 1881 makes the total num- 

 ber of inhabitants in the island 26,903, of whom 

 6,574 dwelt in the town of Ischia, which es- 

 caped injury. The population of the communes 

 in the main part of the island which were af- 

 fected was as follows: Forio, 6,791 ; Barano, 

 4,598; Casamicciola, 4,217; Serrano- Fontana, 

 1,972; Lacco Ameno, 1,761. 



The island of Ischia is entirely of volcanic 

 formation, with the exception of a number 

 of argillaceous elevations of marine formation. 

 The village of Casamicciola was built upon 

 such a clayey deposit, produced by the disin- 

 tegration of the tufa of the volcano of Epomeo, 

 which stands in the center of the island. Lacco 

 stands partly upon this tufa, which forms the 

 foundation of the island, and partly upon an 

 overlying deposit of trachytic lava. Forio, on 

 the west coast, as well as the villages in the 

 south of the island, is built upon tufa. The 

 distribution of hot springs, stufas, or jets of 

 steam, and fumaroles on the island indicates 

 the existence of two clefts in the tufa, one ex- 

 tending in a curved east-and-west line near 

 the north coast, and the other crossing the 

 island in a transverse direction. Casamicciola 

 stood at about the intersection of the two lines 

 of fracture. At Casamicciola, Forio, and Lacco 

 Ameno the shock was at first vertical, then un- 

 dulatory, the wave traveling at Forio from 

 northeast to southwest, at Lacco Ameno from 

 southeast to northwest, and at Casamicciola 

 first from west to east "and then from north to 

 south. For several days previous to the earth- 

 quake slight shocks, accompanied with rum- 

 blings, were perceived. The springs of Gurgi- 

 tello, near Casamicciola, showed irregularities 

 of flow and temperature. The fumaroles of 

 Monte Cito, south of that village, which are 

 usually almost entirely inactive, gave strong 

 indications of volcanic action, emitting jets of 

 steam and sulphurous acid, and giving forth a 

 strange hissing sound. 



The source of the disturbance is supposed to 

 be the expiring volcano of Mount Epomeo, the 

 residual activity of which is manifested in the 

 thermal springs and jets of gas and steam aris- 

 ing through the two fissures. Prof. Palmieri, 

 of Naples, attributed the excessive violence of 

 the shocks at Casamicciola to the existence of 

 great caverns underneath the spot, the sup- 

 ports of which were weakened by the action 

 of thermal waters, and gave way when agi- 

 tated by the seismic shock. Others explain 

 it on the hypothesis of the two fissures inter- 

 secting there, which would make Casamicciola 

 the center of any volcanic disturbance on- the 

 island, and upon the theory of Mallet. This 

 theory is, that a seismic wave passing from a 

 comparatively inelastic soil to one of great 

 elasticity changes its direction as well as its 

 velocity, and is partly refracted and partly re- 

 flected. East of Casamicciola, between it and 

 Ischia, are the volcanoes of Rotaro and Mon- 



