According to the reasoning of common sense, he ought to strike it at right angles.

But just then he recalled that the gorge did not follow a straight line.

Had it done so, he would have succeeded in what he had undertaken, but it was otherwise, and so he failed.
"I'll try a little more." With no little labor, he climbed to an eminence a short distance away, where he hoped to gain a glimpse of the promised land; but the most studied scrutiny failed to show anything resembling the pass.
"I'm lost!" he exclaimed, in despair..