As they advanced the roaring of the mud geyser diminished. The professor continued to be much interested in the condition of Nature about them as they climbed the hill. The uprooted trees, and the huge trunks broken off by the final upheaval of the earth, made the old gentleman look very serious indeed.
"There has been a mighty change in the face of Nature," he said thoughtfully. "You boys were saved from death by a miracle, I have no doubt."
"We were all knocked senseless for a time," Mark told him.
"Indeed? And so were we at the camp. All of us lost consciousness. Dear, dear! what happened during those minutes that we were all unconscious? Something of the greatest importance—some great change took place that now we can scarcely understand." "And what do you make of that over yonder?" queried Jack, suddenly pointing toward the northern horizon.
A deepening glow had appeared in that direction. Rapidly it increased until there appeared above the horizon the edge of a huge disk. Its light was mellow like the moon's; but whoever heard of the moon rising in the North?
"What can that possibly be, Professor?" cried Mark as they all gazed in wonder at the rapidly increasing body rising into complete view.
Professor Henderson shook his head slowly. For once he was surely at a loss to explain a scientific phenomenon. The huge globe, evidently reflecting palely the sun's light, mounted upward more rapidly than the moon ever crossed the heavens.
"All nature has gone mad!" gasped Professor Henderson at length. "Have we discovered a new celestial body? I never heard of such a thing—so near to us, too! Come, hurry on, boys. Let me get and mount the telescope. This new mystery must be solved."