The Forum, with Vesuvius in the distance.] Several years afterwards, the Roman historian Tacitus wrote to the younger Pliny and asked him for information about the manner of his uncle's death. The two letters containing answers to this question are still extant. Pliny describes how his uncle was suffocated by ashes and sulphurous vapour on the shore. He had himself seen flames of fire shoot up out of the crater, which also vomited forth a black cloud spreading out above like the crown of a pine-tree. He went out with his mother to the forecourt of the house, but when the ground trembled and the air became full of ashes they hurried off, followed by a crowd of people. His mother, who was old, begged him to save himself by rapid flight, but he would not desert her. And he writes: "I looked round; a thick smoky darkness rolled threateningly over us from behind; it spread over the earth like an advancing flood and followed us. 'Let us move to one side while we can see,' I said,' so that we may not fall down on the road and be trampled down in the darkness by those behind.' We had scarcely got out of the crowd when we were involved in darkness, not such as when there is no moon or the sky is overcast, but such as prevails in a closed room when the lights are out." And he tells how the fugitives tied cushions over their heads so as not to be bruised by falling stones, and how they had repeatedly to shake off the ashes lest they should be weighed down by them. He was quite composed himself, and thought that the whole world was passing away.