“That’s queer,” murmured the lad. “It’s raining mud—or else—” he paused a moment, as the remembrance of the booming sound returned to him. “No,” he added, “there must be a spouting, boiling spring around here. That’s what it is! I’m on the track of it now.”
Fenn dashed off to the left, through the forest. He was eager to see what had caused the curious shower of mud. In a few minutes he came to a little clearing in the woods—a clearing remarkable, among other things, from the fact that the ground there was devoid of snow. There was a warm, damp look about it, too, as when, in a snow storm, the sidewalk over a bakery oven is devoid of the white flakes.
But that was not the most curious thing that met Fenn’s eyes. He made out numerous mud turtles crawling about over the patch of ground that was free from snow. There must have been a score of the reptiles.
Then, as Fenn looked, a curious thing happened. He had just noted that, in the centre of the clearing, there was a large patch of water, and, a moment later the middle of this spring seemed to lift itself bodily up. Up and up the water spouted, and in an instant its comparative purity was changed to a deep mud color, as a miniature geyser of earth and liquid shot upward.
“A mud volcano!” exclaimed Fenn, as he understood what the phenomenon was. “A mud volcano! This explains the mystery of the turtles!”
An instant later he was under a shower of mud from the boiling spring.