ON AQUEOUS AND IGNEOUS METEORS, 7I9 



throw out, in more or less abundance, smoke, ashes, and pumice stones, or 

 light cinders; but their most formidable effects are produced by a torrent of 

 ignited lava, which, like a vast deluge of liquid or semiliquid fire, lays 

 waste the country over which it runs, and buries all the works of human art. 

 In jNIarch, I767, Vesuvius began to throw out a considerable quantity of ashes 

 and stones, which raised its summit in the course of theyearnoless than 200 feet, 

 forming first a little mountain of pumice stones within the crater, which by 

 degrees became visible above its margin. The smoke, which was continually 

 emitted, was rendered luminous at night, by the light derived from the fire 

 burning below it. In August some lava had broken tlirough this mountain, 

 and in September it had filled the space left between it and the former crater. 

 On the 13th and 14th of October there were heavy rains, which perhaps 

 supplied the water concerned in the eruption that shortly followed. On the 

 morning of the 19th, clouds of smoke were forced, in continual succession, 

 out of the mouth of the volcano, forming a mass like a large pine tree, which 

 was lengthened into an arch, and extended to the island of Caprea, 28 miles 

 off: it was accompanied by much lightning, and by an appearance of meteors 

 like shooting stars. A mouth then opened below the crater, and discharged 

 a stream of lava, which Sir William Hamilton ventured to approach within a 

 short distance, imagining that the violence of the confined materials must 

 have been exhausted; but on a sudden the mountain opened with a great 

 noise at a much lower point, about a quarter of a mile from the place where 

 he stood, and threw out a torrent of lava, which advanced straight towards 

 him, while he was involved in a shower of small pumice stones and ashes, and 

 in a cloud of smoke. The force of the explosions was so great, that doors 

 and windows were thrown open by them at the distance of several miles: the 

 stream of lava was in some places two miles broad, and 60 or 70 feet deep; it 

 extended about six miles from the summit of the mountain, and remained hot 

 for several weeks. In 1794 a still more violent eruption occurred: it was 

 expected by the inhabitants of the neighbourhood, the crater being nearly 

 filled, and the water in the wells having subsided. Showers of immense 

 stones were projected to a great height; and ashes were thrown out so co- 

 piously, that they were very thick at Taranto, 250 miles off; some of them 

 also were wet with salt water. A heavy noxious vapour, supposed to be 

 carbonic acid, issued in many places from the earth, and destroyed the vine- 

 yards in which it was suffered to remain stagnant. A part of the town of 

 Torre del Greco was overwhelmed by a stream of lava, which ran through it 



