"I'm pretty sure that fellow meant he wouldn't come for a few days," Andy said. "But if he did happen to come and found us at work on a raft, it would be too disappointing for anything."
"Well, one of us could go up to the rocky ledge and keep watch all the time, couldn't we," said Jill eagerly. "We could easily see anyone coming, then, and give warning in time to let you and Tom hide everything."
"Yes—of course," said Andy. "That's a good idea! Take it in turns of about two hours each. You go first, Jill, and Mary next."
So Jill went up to the rocky ledge and sat there. She could see the cave-beach of the next island and had a good view of any boat that might come over the water.
No boat was to-be seen—but all that day the islands were very noisy indeed! Seaplanes flew over many times, their engines roaring loudly. Three came down in the calm water opposite the cave-beach. Jill watched them carefully.
Stores were taken to the cave, as she could plainly see. The seaplanes roared away after a time—but all that day others flew over the islands, and the children wondered to see so many.
"Well, there's one thing that's lucky," said Andy with a grin. "Those seaplanes make such a noise that no one could possibly hear the sound of any hammering to-day—so I vote we get on with it and make as much noise as we like now there's a chance!"
So the sound of hammering was heard on the children's island that day, as Andy and Tom nailed twelve big planks crosswise to twelve others below. Then on top of the two crosswise rows Andy nailed yet another row of shorter planks to make the raft really solid and heavy.
The boys added a kind of rim to the raft to prevent things rolling off too easily. Andy was clever at carpentry and he knew all the best tricks of making each plank hold the other fast It was a very solid-looking affair that began to take shape by the time that night came.
Andy had found a strong post that would do for a mast, but he did not mean to put this up till the raft was almost ready to launch. "We can't very well hide a raft with a mast." he said. "It is easier to hide a flat raft with no mast, if that man pays us a visit too soon."