t the
cave must be explored. He was determined on that point.

The yaks were brought out and a start made for the cliffs. After
unhitching them from the wagon and unyoking the animals, so they could
feed in the meantime, the oil lamps were taken out and carefully
examined. The Professor had suggested the advisability of carrying with
them two of the spears, which, it will be remembered, formed part of the
weapon equipment of their last voyage, and those, with the guns, were
considered sufficient for any foe likely to be in the cave.

Harry, on this occasion, volunteered to mount Observation Hill for their
daily trip of observation. He returned by the time the yaks were
disposed of and the implements prepared, as stated.

"I suggest," said the Professor, "that we keep constantly on the alert
now for any vestiges of driftwood, or other objects which we are likely
to find along the shore."

As a result the progress was slow, and the scrutiny keen on the part of
all. As they rounded the last large projecting rock, just before
entering the gorge which led to the cave, Harry jumped on a rock, waving
his hand, and crying, as he pointed seaward: "A sail! A ship! See it?"

The agitation of George was beyond all description. Harry kept repeating
the words. He was entirely beyond control.

"Be calm; do not become excited. Harry, you are the most nimble; run to
Observation Hill: here take the large sheet in the wagon; wave it there,
and keep up the signaling; they may see you."

The ship, although far away, was plainly made out, but its character
could not be determined. It was evidently a large sailing vessel. Just
imagine what must have been the feelings of the party at the sight of
the ship, although so far away. Would they see the signal?

In the commotion that followed, what was the Professor doing? He quickly
placed two stakes in line with the ship, and watched it patiently. "It
is moving to the west."

George's curiosity induced him to look over the Professor's shoulder,
and thus enable him to follow the movement of the boat, and by means of
which he could see the sails slowly move past the distant stake.

The Professor scarcely moved. "What is Harry doing? Is he still
signaling?"

"Yes; he hasn't stopped since he reached the hill."

The stake nearest the Professor was again moved over a trifle as the
ship moved on, and they watched and waited.

"Why, the ship hasn't moved for the last ten minutes."

"It see