They have not gone far ere a low, half-stifled roar, from far beneath apparently, falls upon their ears. It is like the first angry growling of a lion ere he springs upon his prey.
They pause and listen. The sound is repeated, and they will venture no farther for the present.
But here, in this vast cavern, which, when lighted up by torches which have been brought on purpose--for Talbot had expected to meet with caves--its beauty is of so extraordinary a character that it cannot be described.
A great galaxy of shining pillars that are found to be some strange form of stalactite, emitting on every side more than the light and colour and glory of a billion of diamonds!
By torch-light they ventured somewhat farther on, until an awful crevasse interrupted their progress. So dark, so deep and awesome it seemed, that all hands drew back, almost in a sweat of cold terror. But it was apparently from the bottom of this fearful gully that the muttering noises proceeded now and then, and holding each other as they gazed far down the dark abyss, they could see tongues of lurid fire, blue, green, and deepest crimson, playing about. Yet no suffocating odour arose therefrom. Hence Captain Talbot concluded that some other outlet and current of air carried these away.
Retreating some distance towards the entrance, Duncan found a piece of rock, and hurled it towards the crevasse. The result was wonderful. The hurtling thunder was deafening, and the echoes came rumbling from every portion of the cave, and continued for many minutes. But whence, or why the sound of explosions, as if cannonading were going on in every direction? Not even Captain Talbot himself, scientist though he was, could give a sufficient answer to a question like this.
But this cave must be their camping ground to-night. So once more the big spirit-stove was lit, and they prepared to enjoy their well-earned supper.
Then they sat and smoked and yarned for quite a long time.
Nor did Talbot forget to splice the main-brace, and surely no men were ever more deserving of a dram, as Duncan and Conal called it, than the three brave fellows who had struggled so far up the mountainside with their heavy loads.
"This is not Saturday night, men," said the skipper, raising his mug of coffee with a suspicion of whisky therein, "but nevertheless I must propose once more the dear old toast: 'Sweethearts and wives', and may the Lord be near them."