After Mr. George and the children had been standing upon the brink of this abyss some time, watching the explosions, the guide who had come up with them from the Hermitage beckoned to Mr. George, and saying something at the same time in Italian, made signs as if he wished the party to go with him to some other place.

"Come, boys," said Mr. George; "he wants us to go with him."

"Where does he want us to go?" asked Rollo.

"I don't know," said Mr. George. "I cannot understand what he says; but let us go and see."

So the whole party followed the guide, Mr. George leading Rosie by the hand. The guide conducted them along a narrow path through the sand, which led away from the crater behind a hill which formed one of the sides of it at a place where it was so steep below the path down the mountain side, that Rosie was almost afraid to go. Mr. George, however, held her firmly by the hand, and he charged Rollo and Josie to follow very carefully. After going on in this way for some distance, they came to another crater very similar to the first, only the sides of it, instead of being formed, like the first, of perpendicular cliffs, consisted of steep, sloping banks of volcanic sand and gravel. There was, however, the same pitchy bed of lava spread out all over the bottom of it below, and in the centre a black cone thirty feet high, with a fiery furnace mouth at the top, glowing with heat, and throwing out continually the same thundering puffs of steam, and projecting the same masses of melted lava and hot stones into the air.

"Ah, here is another crater!" said Mr. George.

"Yes," said Rollo; "only it is smaller than the first. I like the first the best."

While they were standing on the narrow ridge which formed the brink of the crater, looking down, their guide by their side, another guide came by, conducting two young men; and they, instead of stopping on the brink, as Mr. George and his party had done, began at once to go down. There was a sort of track in the sand down the slope, and in this track the young men, half walking, half sliding, descended.

"Why, uncle George!" exclaimed Rollo, "they are going down into the crater. Let Josie and me go too."

Mr. George saw by a glance that the descent into the crater must be safe, for the young men were led by one of the regular mountain guides; and besides, there was a track in the sand, showing that other parties had gone down before. So he said that Rollo and Josie might go.