Jack had paused, so that both were looking at the grizzly, whose huge head and massive shoulders protruded above the edge of the canyon.

While they looked the head dropped from sight, followed by the forefeet, whose claws scratched over the flinty surface as they slipped backward.
Knowing what had occurred, Jack and Fred ran to the edge and looked down.

They were in time to see the mountainous bulk tumbling into the vast chasm.

The body maintained a horizontal posture, as in life, until it struck a projecting point which sent it bounding against the other side, where the impact added to the tendency of the first blow, and the body turned over and over, like an immense log rolling down hill.
Despite the gloom of the abyss the sun was shining so brightly, and was in such a favorable position, that everything was seen with distinctness.
Peering downward, the awed and grateful boys saw the black mass suddenly strike the foamy waters and send the spray flying in all directions.

It disappeared for a moment and then popped up like a rubber-ball, and went dancing down the current toward the break in the walls which they had visited a brief while before.
Still silent and watching, they observed it dancing up and down with the violence of the stream until its motion was arrested by striking an obstruction, which held it motionless.