But his warning was too late. Even as he screamed his command, the balanced rock toppled over and rolled heavily down the slight incline right into the mouth of the roof exit of the cave.
“Oh! if it would only go through!” was Hal’s wild wish. But it didn’t. The runaway sprang past his friends, lantern in hand, and made a hasty examination.
The bowlder was wedged fast, effectually blocking their only avenue of escape from the steep-walled mountain.
CHAPTER XVIII
THE ISLAND IN THE AIR
For a minute, perhaps, not a word was uttered. The hopelessness of their situation was all too evident to the five boys. No one dared to suggest that the passage from which they had rolled the bowlder would lead to any possibility of escape.
“Now you have done it!” Hal gasped at length. “How in the world are we ever going to get out of this?”
Nobody answered. There was no reply to make. The situation was too fearful to permit of excuses or shifting responsibility.
Hal was the only member of the party who did not seem to be paralyzed. He advanced toward the bowlder and flashed his lantern over it. The opening in the rocky cliff was not entirely closed, but the rock was wedged in such a position that it was folly to try to make an exit here. The top of the crevice filled by the big stone converged almost to a point, the rest of the opening, eight or ten feet long and three or four feet wide, being over a sheer drop of thirty feet. There was no possibility of creeping around the bowlder and gaining a footing on the slanting cave wall.
“C-can’t we break the ground here and make the stone fall down?” suggested Ferdinand in chattering accents.
“Break the ground?” Hal replied fiercely.