"Nor can I. Let's have a look at that compass."
Tom fished it out of his pocket and extended it. He glanced at the dial and then uttered a cry of astonishment. The needle was dipping and plunging and behaving in a very odd manner.
"Gracious, what's the matter with the thing? Is it bewitched?" gasped Jack.
"It is certainly behaving in a very mysterious fashion. Something must have deflected it and led us out of our way."
"What could have done this?"
"I don't know, unless—hullo!"
Tom stooped and picked up a bit of stone which glittered with bright, shining particles.
"Iron pyrites!" he exclaimed. "I remember the professor back at school showing some to the geology class. No wonder the needle was deflected! Look, Jack, those cliffs yonder are almost solid masses of pyrites!"
"And those deposits of iron switched the needle of the compass?"
"Beyond a doubt."