Our hero, arriving at the cave's mouth at the instant of his friend's fall, was horror-struck to see him slide on his side toward the edge of a dark abyss, over which the water trickled.
"Help, Bob!" cried Jack, in vain trying to regain his feet.
Our hero clearly saw the fearful danger of his comrade's position.
Jack's feet were already over the edge.
"I am gone! Help!" he gasped.
Then, with a stifled cry, he disappeared over verge of the abyss.
Chapter VIII.—A Remarkable Story.
"Jack! Jack!" shouted Bob.
A sound as of falling rocks or ice blocks reached his ears, but no answering voice.
The echoes of the falling masses died away.