For, directly after the echo, there was a strange whispering noise as of cinders sliding one over the other a long distance away and right up towards the crater above their heads.
As naturalists they knew on the instant what this meant, and it struck all in the same way—that it resembled the falling of a little hard granulated ice in a mountain—the starting of an avalanche. And as the ash and cinder, with the vitrified blocks of stone, lay loose on the mighty slope, they felt that it was quite possible for the firing of the gun to have caused an avalanche of another kind.
In a few seconds they knew that this was the case, for the whispering rapidly increased into a loud rustling, which soon became a rush, and directly after increased to a roar; and now, for the first time, they began to realise how vast the mountain was in its height and extent, for the rushing sound went on and on, gathering in force, and at last Drew exclaimed, as he gazed upward at an indistinct mist apparently travelling down towards them,—
“Come on; we shall be swept away.”
“No, no,” cried Panton and Oliver, almost in a breath; “We may be as safe here as anywhere. Perhaps we should rush into more danger.”
And now the warm, ruddy glow of the setting sun was obscured by rising clouds, which they at once grasped were dust; a semi-darkness came on, and through this they had a glimpse of the mountain-side all in motion and threatening to overwhelm them where they stood.
It was hard work to master the feeling of panic which impelled them to run for their lives, but fortunately they had strength of mind enough to stand fast while the tumult increased, and, joining hands, they kept their places with hearts throbbing, half-suffocated by the dust which now shut them in, while, with a furious roar, the avalanche of cinder, stones, and ashes swept by, not twenty yards from where they stood, and subsided amidst the cracking of boughs and tearing up of trees at the edge of the forest.
It was like the dying sighs of some monster, the sound they heard directly after growing fainter and fainter, till there was the mere whisper made by trickling ashes, then even that subsided, and they stood in a cloud of dust, listening while it slowly rolled away. At last, as they gazed downward, there, below them, to the right, was a huge opening torn into the forest, with broken limbs, prostrate trunks, and great mop-like roots standing up out from a slope of grey cinders and calcined stones.
“What an escape,” muttered Oliver. “Warning: we must not fire again near the mountain.”
“Hark!” cried Panton. “There it is again.”