ms not," was the Professor's response. Again they waited. George
walked to the stakes and back again. He stepped aside to look at Harry
on the hill, and again returned to the observation stakes.

"Singular that the ship hasn't moved in twenty minutes or more."

Then, enthusiastic at the mere thought, he cried out, as he ran toward
the Professor: "Do you think they have seen our signal? Have they
stopped; and are they returning?"

"Either that or they have changed their course, and are now leaving us
dead ahead."

This was a blow to the poor boy, whose hopes, brought about by the
apparently checked motion of the ship, were now dashed to the ground,
when the Professor continued: "They are sailing away, I am sorry to
say."

He left the observation stakes. Poor Harry was still signaling
frantically. The Professor told Harry that further effort in that
direction would be useless, and he slowly and sadly came down the hill.

They looked at each other most sorrowfully, and the boys could scarcely
restrain their tears, while the Professor carefully avoided their gaze,
or seemed not to notice their grief.

"It is one satisfaction to know," said Harry, as he dolefully looked
across the broad sea, "that vessels do come this way, and that it is not
out of the world entirely."

George quickly recovered. "Why not make a big signal flag for
Observation Hill?" This was seconded by the Professor.

"And while we are about it why not make a good old American flag?" was
Harry's comment.

The cave had been forgotten in this incident. When their wondering and
questionings had ceased, the descent was made around the point, and the
entrance soon reached.

The two lamps were now lighted, and the explorations began.

"I think it is advisable," was the Professor's first observation, "that
we go in a hundred feet or so, and then mount one of our lamps in a
conspicuous place. We can then proceed with the other as far as the
water, and if any accident happens it will not cause trouble to both of
the lights. We can always have one of them to fall back on."

When they had gone the distance determined on, a secure ledge was
selected, and Harry placed the light so it would cast its beams along
the cave.

"Be careful now, we are near the water."

The Professor had now the other light, and the boys led the way, so the
beams from the light shone past ahead of them. They went beyond the
point where the water had been found previously, but