“This must be a pretty deep one, then,” said Harry, “for we are going down at a pretty steep incline now.”

They pushed on, passing through many great masses of rock, and still going down at a decided angle until at length they came out upon a bare, rocky shore with huge masses of rock to the right and left, and beyond a line of reefs over which the surf was dashing, all being white both beyond and inside the reefs.

“We are on the other side of the island!” exclaimed Jack, “and we have not climbed our hills at all or else they were so slight that we did not notice them.”

“I would not like to be in a vessel driven on this side of the island,” said Percival.  “See how the surf dashes over those reefs.  You would go to pieces in a short time.”

“That may be the reason why there are no people on it,” said Jack.  “It is not very big, I take it, and is probably difficult of access.  We seem to have come to it without knowing it, and if we had I don’t believe we would have gone near it.”

They stood watching the surf, and taking in various parts of the shore, seeing a great mass of rocks higher than those at hand, to the east of the larger mass close in to land, and at length Jack suggested that they return to the other side.

“We ought to be able to follow the path we made coming across,” he said, “and in any event, we know the general direction, and if we do go astray a bit it won’t matter.”

They set out upon their return, and came out not far from where they had started, finding Billy Manners and three or four of the boys on shore waiting for them.

“We thought you might be along soon,” said Billy.  “Would you believe it, they don’t know what this island is after all, don’t know the name of it, I mean.”

“How is that?” asked Harry.  “Isn’t it charted?”

“Yes, it is charted all right, but there is no name given to it.  The captain says it is a sort of lost island, and they never thought enough of it to give it a name or if it had one they didn’t think it was good enough to put on the chart.”

“Lost Island is a good enough name for us,” observed Jack.  “Suppose we call it that while we are here.  That will not be long, I suppose.”

“H’m!  I don’t know about that,” Billy returned.  “They have the yacht afloat all right.  They started the engines, and backed her off a sand bank or whatever it was we were on, and are now in fairly deep water, but as to leaving the island that is another matter.”

“How is it?” asked all the boys in a breath.

“Because there is a line of reefs stretching right across the mouth of the bay, and there seems to be no way of getting beyond them.  There seem to be openings here and there, but they are so narrow that the captain does not think it wise to try to go through them.”

“Then we are lost on Lost Island, and are lost ourselves,” said Jack.

CHAPTER V