ing 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