“Right; so it is. Volcanic glass-blowing. This must have been driven out of some aperture in the burning mountain during an eruption, steam acting upon flint and lime when in a state of fusion.”
“But where are you going to get your flint and lime from to make a glass like this?” said Oliver.
“Who can say? From the interior of the earth, or from deposits made by the sea.”
“I don’t see that,” said Drew.
“Indeed! Why, haven’t you silicious sand, the lime from the coral and shells and soda from the seaweeds of thousands of years. Plenty from that supply alone, without calculating what may be beneath us. Now then, forward: I’ll lead, and we had better all go carefully, in case of there being any chasms. As far as I’ve been the floor was all like this, smooth and just faintly marked by a grain formed by the flow.”
He took a candle, and, holding it high above his head, led the way, closely followed by Oliver.
“No fear of our losing our way,” said the latter. “We have only to keep on by the side of the stream, and then notice which way it flows. If we go against it, we must be right in coming back.”
The way widened as they progressed, and was to a small extent down-hill, but not sufficiently so to make the water rush onwards, only sufficient for it to glide along in a glassy smooth fashion, keeping up the same mysterious whispering which grew as they went on into the darkness, not seeming to be louder, but so to speak as if there were more and more of this strange murmur extending onward and onward to infinity.
Once they all stopped to look back at the light which shone in through the cavern’s mouth, and looking dazzlingly bright as it played upon the water gliding in softly from the lake, but soon growing softer and opalescent, and gradually dying away. Five minutes later, when Oliver turned back to look again, he found that they must have unconsciously descended, for there was only a faint dawn of light upon the roof of the cave, and a minute later all was black.
“Now,” said Drew, with an involuntary shiver which he turned off as being from the temperature. “What are you going to show us? for it’s getting chilly here.”