The crater was casting out huge stones, with detonations resembling the discharge of whole parks of artillery at once. From time to time the din ceased absolutely, then low and softly it began again, and gained force quickly till it crashed as loudly as before. When midnight was past, immense clouds of smoke began to pour out of all the craters, and lava broke out simultaneously from many points upon the slopes. Out of the chief crater rose the awful pine tree. The detonations grew more constant. There was still time to flee; but the spectacle was growing grander every moment, and inexperienced guides led forward a large party into the Atrio, where they stood watching such a sight as living men have rarely seen. At half-past three came the catastrophe. The whole of the great cone rent itself from top to bottom with an appalling crash, casting out a huge stream of fiery lava. At the same moment two large craters formed upon the summit, discharging showers of red-hot scoriæ, while the pillar of the pine tree rose up to many times more than even the vast height which it then stretched across the sky. A cloud of choking blinding smoke enveloped the visitors, a fiery hail rained down on them, the lava broke out immediately by them, and barred their retreat to the observatory. Eight medical students were engulfed by the fire, with others who were not known. Eleven more were grievously injured; and when the survivors were able to reach the observatory, it was in several cases but to die. The lava flow from this grand fissure was restrained for some time within the Atrio; but issuing thence at last divided, one branch threatening Resina, but stopping happily almost as soon as it reached the cultivated ground, while the larger branch ran through the Fossa della Vetrana, traversing its whole length of 1,300 metres in three hours. It dashed into the Fossa della Faraone, then again divided, one arm of the diminished stream destroying a great part of the villages of Massa and San Sebastiano, and flowing on so far in the direction of Naples that had it continued but for four-and-twenty hours longer it must have flowed into the city streets.