No one spoke, it was as if they were too much stricken by awe, as they gazed at this outlet of the earth’s inner fires, wondering at the way in which solid rock was turned by the intensity of the heat into a fluid which now in places they could see was in a state of ebullition, and formed rings flowing away from the boiling centre like so much water.

Then, all at once, as if moved by the same set of nerves, they all turned and fled, for without the slightest warning, a part of the lake shot up some fifty feet in the air, like some great geyser, but instead of boiling water it was fluid rock of dazzling brightness even in the sunshine. Then it fell with a sound of hideous splashing, and as they turned to gaze back there was a little rising and falling, and then all was still once more, and the surface rapidly scummed over and grew silvery and dull.

“I wouldn’t have missed this for anything,” cried Panton, breaking the silence as they stood watching the lake, and then, amid many expressions of wonder and awe at the grandness of the scene, they began to make their way along the well-defined rim of the crater. But slowly, for inside there was not a level space, all being a chaos of riven and scattered masses of slag, obsidian, and scoria, ragged, sharp and in part glazed by the fluid rock.

“It aren’t what I thought it would be, Mr Oliver Lane, sir,” said Smith, scraping the perspiration from his face with a thin piece of the obsidian which he had picked up, while Wriggs followed his example for a few moments and then threw his piece down.

“What did you expect?” said Oliver.

“On’y a big hole, sir, running right down into the middle o’ the world; and I thought we should be able to see into the works.”

“Works! What works, man!” said Oliver, smiling.

“Why, them as makes the world turn round; for it do turn round, don’t it?”

“Of course, but not from any cause within.”

“I say, Tommy, mind what yer at with that there bit o’ stuff,” growled Wriggs.