The eruption of Vesuvius that buried Pompeii destroyed Herculaneum at the same time. Some historians contend that the occurrences were not identical in point of time; but, after all, it makes little difference to us whether the two cities were simultaneously destroyed or not. The probability is, and it is pretty well settled, that while the ashes and stones from the crater of Vesuvius were blown upon Pompeii, the lava and mud flowed in the direction of Herculaneum, and covered it. A third city, Stabiæ, was destroyed at the same time—a fact which is not generally known. Castellamare, a well-known summer resort near Naples, stands on the site of Stabiæ, whose excavations, not having promised very well, were filled up soon after they were begun. The lava which flows from a volcano during violent eruptions is a composition of melted stone and oxide of iron. The stone is mainly feldspar and hornblende. There is a good deal of sulphur also in the lava when it rises in the volcano, but the most of it is thrown out in the form of sulphurous fumes. The lava very much resembles the slag or scoriæ flowing from an iron foundery, and, when suddenly cooled, it assumes a glassy character. When it consolidates or cools, it forms what are known as volcanic rocks. If the streams of lava are cooled under no other pressure than that of the atmosphere, they assume a porous appearance. Lava, cooled under the surface of the water is much more compact, and where it is cooled under heavy masses of earth and rock, it becomes quite solid. [Sidenote: STARTING FOR VESUVIUS.] Our party visited Herculaneum after making a journey to Vesuvius. We wished to see the volcano first, and afterwards to explore the city which it had destroyed. We rode out of Naples, after our usual struggle with the hackman, and at Resina left our carriage to proceed on horseback. About half the population gathered to see us off. A staff, or heavy stick, is considered indispensable, and each of us purchased one from the crowd of boys and men, whose wooden material was sufficient for starting a small forest. I think our selection was made from about two hundred and forty-seven sticks, which they simultaneously presented in our faces, and with the demands of the venders and the piteous appeals of forty or fifty beggars, we had, for a few minutes, a concord of sweet Italian sounds. As soon as we had bought the sticks we used them to clear away the crowd, and as we were all young, reasonably powerful, and as indignant as we were powerful, we made a clear circle around us in a very short time. Then we bargained for animals on which to ride. I obtained a horse, something like those with which the famous Mackerel Brigade was equipped. [Sidenote: REMARKABLE STEEDS.]