Don't go so near the edge, Ralph.

It makes me shudder." When the little party had returned to the cavern, the captain and the two ladies had a long talk about the lake.

They all agreed that the existence of this great reservoir of water was sufficient to account for the greenness and fertility of the little plateau outside.

Even if no considerable amount of water trickled through the cracks in the rocks, the moisture which arose from the surface of the water found its way out into the surrounding atmosphere, and had nourished the bushes and vines.
For some time they discussed their new-found water-supply, and they were all glad to have something to think about and talk about besides the great danger which overhung them.
"If it could only have been the lake without the Rackbirds," said Mrs.Cliff.
"Let us consider that that is the state of the case," remarked Edna.

"We have the lake, and so far we have not had any Rackbirds." It was now nearly noon, and the captain looked around for Ralph, but did not see him.