He did not have to go far when he paused, where the width was barely six feet—not enough to afford much of a leap for sturdy lads of their years.
"That's easy," added Jack, measuring it with his eye.
"You must remember one thing, Jack. There's something in the air of this part of the world which makes a mile look no more than a few hundred yards. Suppose that that other bank is fifty feet off!"
It was an alarming thought, and Jack recoiled as if again on the edge of the brink. But he was quick to see the absurdity of the idea.
"If that is so, then the canyon must be several miles deep. But we would better make sure."
It was easy to do this. Hunting around until a chip from one of the boulders was found, Jack tossed it across the abyss. It fell as he expected, proving that, wonderfully deceptive as is the atmosphere of the West, it cannot mislead in instances like that which confronted them.
"That makes it right. I am not afraid to make the leap; are you?"
"Not a bit; but wait."
Near them lay a stone, so large that it required their united strength to move it. By hard work they rolled it to the edge of the canyon and tumbled it over, carefully watching its descent. A curious thing followed. At first it shot straight downward for a hundred feet, when it impinged against a projecting point of the mountain wall, knocked the fragments in every direction, as if it were a ball fired from a thousand-pounder, and bounded against the opposite side, further down, scattering fragments again. By this time it had achieved an almost inconceivable momentum, and was shooting downward at a terrific rate.
In the depths of this narrow canyon, where the sunlight never penetrated for more than a few minutes at a time, it was always twilight. At the bottom it was almost dark, so that the stream would hardly have been visible but for its yeasty foam. At some point near the base, when the flinty stone was speeding forward like a meteor, it abraded a harder portion than before. Instantly a stream of fire shot out, such as sometimes flashes from a murky cloud in the sky, and, as if it were an echo of the impact, the splash and thunderous thump were heard by the boys at the top.