After the raft was so far away that the boys and girls could not shout back and forth to each other, it seemed that it moved very slowly indeed. Yet as the hours wore on the distance between the shore of Palm Island and the raft could be plainly marked.

The figures of the trio upon the raft were dwarfed at last to the size of manikins. The sail looked like a palm-leaf fan. The raft itself, rising and falling on the surge, became very small, and to the girls’ anxious eyes it seemed nearer to that distant island than to this one on which they were marooned.

“Come,” said Ruth at last, sadly. “Let us go over to the spring and get some supper and go to bed. Watching them any longer will do no good. We cannot help. We can only trust that God will be good to us all. We’ll hope for the best.”

Even the usually voluble Agnes could say nothing cheerful in reply, and the two girls moved away from the point of their vigil.

CHAPTER XXI—A NIGHT ALARM

It was a very lonely evening for Ruth and Agnes Kenway. The boys had made the new camp near the spring as snug as possible. An outthrust rock partially sheltered them, and they had the smaller piece of sail-cloth to help keep them dry when they lay down. They had a good fire too.

But the wailing of the seabirds and the lap, lap, lapping of the little waves along the strand sounded very mournful in their ears. This tropic world was very empty and lonely!

Their minds not only reverted constantly to the question of the whereabouts of Tess and Dot, but the question of the safety of their boy friends and their guardian was now added to that first anxiety. Ruth and Agnes did not consider that they were in any immediate personal danger. The thought that they might be left indefinitely on this lonely island they resolutely kept out of the forefront of their minds. But wreck and disaster might have overtaken both the other parties.

Agnes had climbed the hill just before the night fell and tried to spy the raft again. But she could not distinguish it. In fact, that nearest island on which they had seen the flag flying was almost blotted out.

“We cannot see anything until morning,” Ruth told her. “I believe Mr. Howbridge and the boys got to the island. If the children are there, then it is all right.”