"Why, you know—on the left side," rejoined Jack, with some surprise.
"And the compass on the left wrist?"
"Yes. Why? Isn't it——"
"No, it ain't!" roared Pete. "I see it all now, perfusser; that thar shootin' iron has bin deflectin' ther needle."
"I fear so," rejoined the professor.
Under his direction, Jack moved the compass into various positions, and at the end of a quarter of an hour they arrived at the startling conclusion that they had travelled perhaps many miles out of their way. The metal of the weapons Jack carried having, as they saw only too clearly now, deflected the needle.
"What an idiot I was not to think of such a possibility!" exclaimed Jack bitterly.
"Not at all, my boy," comforted the professor. "The same thing has happened to experienced sea-captains, and they have navigated many miles off their course before they discovered their error."
"All of which, not bein' at' sea, don't help us any," grunted Pete. "Suppose now, perfusser, that you jes' figger out as well as you kin, how far wrong we hev gone."
"It will be a difficult task, I fear," said the professor.