Jounston-Lavis—The Eruption of Vesuvius in April, 1906. 147 
the level of the crater-edge, and succeeding each other so rapidly (two or three 
minutes’ intervals) that they formed a continuous fountain of fire. The very 
large diameter of the fire column was due to there being two mouths of 
explosion, as sometimes one could see contemporaneously two fiery jets.”* The 
whole of the great cone was covered with a mantle of fire. At 7 p.m. the 
violence of the ejection was much increased, and the rumblings and reports of the 
voleano were much louder, accompanied by variously shaped electric discharges 
and thunder. At 10 p.m. some lapilli began to fall at Ottajano. At 10.30 to 
10.45 p.m., with terrible reports, mouths at I Cognoli and that of the Terzigno 
burst forth in activity, with the projection of incandescent scoria. One of the 
Cognoli mouths gave forth a flood of lava that swept down the steep slopes 
like water. Prof. Mercalli says it flowed a kilometre in the first 15 minutes. 
The bocca opposite Terzigno gave out such a flood of fluid that the stream that 
flowed towards Terzigno covered 4 kilometres in half an hour on a relatively 
gentle slope. The docca at Contrade Ciaramello again became active, and gave 
forth a copious stream of lava, which added to the flood. It followed the same 
route as that of the day before and the morning of the 7th, except that it 
added to the breadth and extent of the sheet. Opposite the Casa d’ Aponte it 
left a small island uncovered and threw off two or three tongues, the middle 
one of these, a voluminous one, to the east, towards the Rne. Pozzole and Mauor. 
Travelling due south, in a broad torrent, it further buried the Mass. Jaconelle 
and C. Napuano. Here part of it followed the ravine already mentioned, down 
which it poured, filling the gorge completely, and in some cases overflowing 
the banks. Later in the day, as the flood diminished by the outflow at the 
lower end, it left this ravine with morainic fringes of scoria on the edges of the 
valley, the banks smeared with a sheet of lava and a crust occupying its bottom 
(see figs. A, p. 160, and 8, 9, Pl. IX.). On reaching the lower end of this drain, 
and a flatter, broader, less-confined space, it spread out and destroyed a large 
number of houses in Boscotrecase. It cut the main road in that part of the 
town known as the Oratorio, flowing into the cutting of the Circum-Vesuvian 
railway, crossing the two new roads known as the Strada Nuova, and stopped 
before daylight of the 8th. 
The main stream, as a broad sheet, swept on, destroyed the western end of 
Boscotrecase, following down the Vallone del Oratorio; it reached the north-east 
end of the Cemetery of Torre Annunziata, spread around and enveloped the 
Mass. Sannino. It had crossed and further destroyed a part of the Circum- 
Vesuvian railway. Some time during the evening, the mouth near the Casa 
Fiorenza again became active and emitted a good quantity of lava, which flowed 
over that of April 5 and 6, that issued from the same spot, and as a long 
* «Grande Eruzione,” etc.—Mem. d. Pontit. Accad. Rom. d, Nuovi Lincei, vol. xxiv., p. 9. 
TRANS, ROY, DUB, SOC., VOL, IX., PART VIII, 2B 
