“‘My uncle was at this time, with the fleet under his command, at Misenum, in the gulf of Naples. On the twenty-fourth of August, at about one in the afternoon, my mother desired him to observe a cloud, which appeared of a very unusual shape and size. He had just returned from enjoying the benefit of the sun; and, after bathing in cold water, and taking a slight repast, was retired to his study: he immediately arose, and went out upon an eminence, from which he might more distinctly view the phenomenon. It was not, at this distance, discernible from what mountain the cloud issued; but it was found afterwards to proceed from Vesuvius, about six miles distant from Naples. I cannot give you a more correct, or exact description of its figure, than to represent it by that of a pine-tree; for it shot up a great height, in the form of a tall trunk, which spread at the top into a sort of branches; occasioned, I suppose, either by the force of the internal vapour, which impelled the cloud upwards, decreasing in strength as it advanced, or, that the cloud, being pressed back by its own weight, expanded itself in the manner I have mentioned: it appeared sometimes dark and spotted, and sometimes bright, as it was either more or less impregnated with earth and cinders. [Illustration: Page 162. Page 175.] “‘This uncommon appearance excited my uncle’s philosophical curiosity to take a nearer view of it. He accordingly ordered a light vessel to be prepared; and offered me the liberty, if I thought proper, to attend him. I chose rather to continue the employment in which I was engaged; for it happened that he had given me a certain writing to copy. “‘As he was going out of the house, with his tablets in his hand, he was met by the mariners, belonging to the galleys stationed at Retina, from which they had fled in the uttermost terror; for that port being situated at the foot of Vesuvius, they had no other way than to escape by sea. They conjured him, therefore, not to proceed, and expose his life to imminent and inevitable danger. In compliance with this advice, he exchanged his original intentions; and, instead of gratifying his philosophical spirit, he resigned it to the more magnanimous principle of aiding the distressed. “‘With this view he ordered the fleet immediately to put to sea, and went himself on board, with an intention of assisting, not only Retina, but the several other towns, which stood thick upon that beautiful coast.