The lava of this eruption, meeting with this said excavation, flowed into it, instead of pursuing its road over the lava of 1855, and thus invaded highly cultivated ground and towns of considerable value, extending to the very walls of a country-house belonging to the celebrated painter, Luca Giordano. This lava stream, having surmounted the obstacles which the heaps of scoriæ in the Atria del Cavallo presented to it, ran with great velocity (notwithstanding its being greatly widened out in the Fossa del Vetrano), so that between 10 a.m. and 11 p.m. it traversed about five kilometres of road, occupying a surface of five to six square kilometres. If it had not greatly slackened after midnight, from the failure of supply at its source, in twenty-four hours more, by occupying Ponticelli, it would have reached Naples, and flowed into the sea. Although I had often visited the two villages of Massa and St. Sebastiano, previously greatly injured by the lava of 1855, yet I could not well estimate, upon now seeing them again, the number of houses which had disappeared. Massa seemed to me diminished by about one-third, and St. Sebastiano by somewhat less than a fourth. But the way of escape was open to the inhabitants of Massa; whilst a great river of lava occupying the road leading to St. Giorgio a Cremano would have hindered the flight of the inhabitants of St. Sebastiano, if they had been dilatory. The lava stream now separating the two villages is little less than a kilometre in width, and is about six metres in height. On the night of the 26th April, the Observatory lay between two torrents of fire, which emitted an insufferable heat. The glass in the window-frames, especially on the Vetrana side, was hot and cracking, and a smell of scorching was perceptible in the rooms. The cone, besides being furrowed by the lava streams just described, was traversed by several others, which appeared and disappeared. It seemed completely perforated, and the lava oozed as it were through its whole surface. I cannot better express this phenomenon, than by saying that _Vesuvius sweated fire_. In the day-time, the cone appeared momentarily covered with white steam jets (fumaroles), which looked like flakes of cotton against the dark mountain-side, appearing and disappearing at brief intervals.