An old man met them at the gate, and led the way in towards the middle of the crater, along a sort of cart road. After a while he stopped, and took up a large stone-as large as a man's head. This stone he threw down with great force upon the ground two or three times, to show how hollow the ground sounded. It did sound very hollow indeed, and the peculiar resonance which is produced here by this experiment is generally considered as proving that there is a great void space below the surface, and that the bottom of the crater may some day or other fall in.
At a little distance farther on, on the other side of the crater, and close at the foot of the ridge of earth that surrounds it, there was to be seen a column of dense smoke, or rather of vapor, coming up out of the ground.
The guide led the way towards this place, and all the party followed him. As they approached it, they heard a roaring sound, which grew louder and louder as they drew near. When they arrived at the spot, they saw that the steam was issuing from the mouth of a cavern that opened there; and as it came out, it made a noise like the roaring of a steam pipe when the engineer is blowing off steam.
Mrs. Gray and the three children stood gazing at this phenomenon for some time in silence. At length Rollo said, "What an astonishing blast that is, to be coming up out of the earth, day and night, continually and forever!"
"The ground is very hot all about here," said the boy. "See!"
So saying, he pointed to the old man, who was at work not far from the mouth of the cave, digging into the ground a little way with a sharp hoe. He dug down a few inches, and then took up a hoe full of the earth, and held it out to Rollo to try it with his fingers, that he might feel how hot it was. Rollo put his fingers upon the earth, but he could not hold them there an instant.
It seemed to Mrs. Gray that it must be dangerous to remain long in such a place; and so she prepared to move away, and Rollo and Josie, as they had now seen all that there was to be seen at this place, followed her. They went on by the road, round to another part of the crater, where there was some sort of manufactory of alum. The alum was made from the saline earth which was found there, and the evaporating basins used in the process, instead of being placed over a fire, were simply set in the ground, so that the process of evaporation was carried on by the natural heat of the soil.
After leaving this place, the party followed the circuit of the road still farther, until at last it brought them back to the place where they had entered the crater; and here, after paying the old man who had conducted them around, they passed out through the gate, and went down the lane to their carriage.
"Now to the amphitheatre," said Rollo, addressing the coachman.
So they all got into the carriage again, and the coachman drove down the lane; and after going back towards the town a little way, and making various turns, he stopped at last before a great wooden gate. A man in a certain uniform appeared at the gate and unlocked it, and they all went in.
They saw before them the walls of an immense ruin. The wall was of a curved form, and there were vast openings in it, like arches, below. The man in uniform, who was the custodian, as they call him, of the ruin, led the way along a path into one of these arches, and thence ascended a massive flight of old stone steps, to a place which commanded a view of the interior.
They saw that the amphitheatre was of an oval form, and was built with seats rising one above another, all around, to a great height. The seats were all of stone, and at regular intervals between them were flights of steps for going up and down. In the centre, below, was a large level space, called the arena. All around the arena, and under the seats, were immense galleries or passage ways among the arches, some of which were below the level of the ground. Some of these galleries were for the spectators to use in passing from one part of the building to another, and others were used for the dens and cages of the wild beasts that were kept there to fight in the arena, for the amusement of the people.
The guide led the way through all these places, and it was not until after walking about through them for some time that Mrs. Gray and the children obtained a full conception of the magnitude of the structure. The guide told them that it contained room for forty thousand people.
"What a dreadful place it must have been!" said Rosie, as she followed the guide round through the subterranean chambers.
"They used to hoist the cages that contained the wild beasts up through these openings," said the guide, pointing to some large circular openings in the masonry above, "and then open the gates, and let them out into the arena. The cages were so contrived that when the keeper opened the door to let the beast out, by the same motion he shut himself in, so as to be safe out of his way. He then, afterwards, got out behind, by another door."
There was a very wide and deep canal open in the centre of the arena, with a communication for water connected with a vast reservoir a little way off. By means of this canal the whole of the arena could be flooded with water, so as to form a little lake for naval battles. The guide took the party down to the bottom of this canal, and showed them a large, circular opening in the masonry below, for drawing off water. This opening connected with a conduit, which ran off towards the sea.
The spectacles which were exhibited by the ancients in such buildings as these were real combats of beasts with one another, or of beasts with men, and sometimes of men with one another. At first, the men who were compelled to maintain these combats were convicts, who were condemned to them as a punishment for their crimes. The beasts were lions, tigers, and other ferocious animals that were caught in the forests in Africa, or in other remote parts of the Roman empire, and brought to the great cities for this special purpose.
A great many of the early Christians were compelled to meet these beasts in such conflicts, in the persecutions which they endured. The rulers of the country chose to consider them as criminals for being believers in Jesus, and so doomed them to this dreadful punishment.
It was shocking to think of the scenes that had probably been enacted in this very amphitheatre; and Mrs. Gray and Rosie, after they had examined it in every part, were not sorry to go away.
Rollo next directed the coachman to drive to the Temple of Serapis. The curiosity of the Temple of Serapis, which stands on the shore, just at the entrance of the town, is, that it is partly under water. It seems that from the effects of earthquakes, or from some other similar agency, the whole coast in this region rises and falls in the course of ages, and that at the present time it is several feet lower than it was in the days of the Romans. The consequence is, that many structures which were originally built upon the land, are now partly or wholly submerged in the sea. In passing along the coast in a boat, you can see a great many of these ruins in the water. There is one, however, which can be seen without going out in a boat at all. It is a temple called the Temple of Serapis.
It stands on the margin of the shore, and the floor of it is now about a foot or two under water. This floor is very extensive, and a great many columns and other superstructures are still standing upon it, the whole of which can be easily explored by the visitor, by means of a raised stone pathway, made by the government, which traverses it in all directions. It is a very curious place indeed.
Rollo and his party were admitted to the ruin through a gate, kept as usual by the custodian appointed by the government; and then they walked all over the ruin upon the raised stone path. They looked down through the water, and saw the marble floor of the temple below, and the columns rising up from it with their bases submerged. There is proof that at one time these ruins were fifteen or twenty feet lower than they are now, and that they have since come up again. The next earthquake may depress the whole coast again, in which case the floor of the temple will be once more deep under water; or it may raise it so as to bring the ruins all up once more, high and dry.