Mr Black on the Eruption of Mount Vesuvius. 39 



There was a splendid display of electric flctslies in the 

 pillar of cloud and in the dust clouds, besides the lightning 

 of the thunderstorms, and it was beautifully seen at night 

 and was of a very dazzling description. 



Sea. — The Bay of Naples continued calm throughout the 

 whole period of the eruption, though the ships in the harbour 

 were somewhat affected by the inland earthquakes. 



Acoustic FJieiiomena. — These were of the most extraordinary 

 and violent description, and frightened the inhabitants, and 

 were called the roaring and bellowing of the volcano, and 

 were most terrible during Saturday 27th, Sunday 28th, and 

 Monday 29tli, and must be distinguished altogether from the 

 thunder of the storm-cloud. 



Property and Life. — Two very distressing events happened 

 to the populations — one was the appalling loss of life to 

 excursionists from Naples on Friday morning 26th, when 

 the floor of the Atrio burst open, and a deluge of lava over- 

 whelmed and destroyed them ; the other was the destruction 

 and submergence of the villages of Massa di Somma and 

 Sebastiano on Friday by the north-west stream of lava, and 

 these were really towns of several thousand inhabitants each, 

 and had good houses. 



General Flight of the Fojnclation. — All the towns round the 

 base of Vesuvius were early deserted by their inhabitants, 

 who fled in thousands into Naples and to the further country, 

 and left their property unprotected — such was the intensity 

 of the panic. 



Froducts of the Eruption. — The chemical products distilled 

 and sublimated from the volcano this time were steam, 

 muriatic acid, sulphur, chlorides of sodium, iron, copper, 

 and ammonium, which became afterwards condensed on the 

 sides and lavas of the mountain. 



The quantity and character of the solid projectiles were 

 very remarkable, and consisted of bombs or globular masses, 

 great pieces of rock and fragments of scoria, and many of 

 these were seen red-hot in the pillar of vapour, and were 

 projected the height of a mile above the crater itself 

 frequently. 



Earthquakes. — Local ones occurred in isolated spots round 



