“Will it be safe? This may lead right down into the bowels of the volcano.”
“I think not,” said Panton, “but right away underground somewhere. Once upon a time when the volcano was in action it overflowed here or cut a way through the wall, and then the fiery stream forced its way onward, and was, no doubt, afterwards covered in by the stones and cinders hurled out by the mountain. Then, of course, after the volcano had played itself out, and the lake formed in the crater, it in turn overflowed, and the water ate its way along, as you see, right in the river of lava, which it followed naturally downwards.”
“And do you want us to follow the stream naturally downwards?” said Oliver.
“Of course. I’ve only been in about fifty yards, but it is certainly the most wonderful place I have ever seen. Look here.”
He picked from a crevice a great bunch of soft dark brown filaments, somewhat resembling spun glass.
“What’s that? Some kind of fibre?” cried Drew. “But how does it come here?”
“Is it fibre?” said Panton, smiling.
“No; too brittle. It is glass.”
“Yes. Obsidian—a volcanic glass.”
“But it looks like the result of glass-blowing,” said Oliver.