and first, how shall we seal up this cave so that no one can
possibly suspect our having entered this place. That Peter has the eyes
of a lynx, and should he follow us, would not fail to discover all."

"In an hour hence," said Regnar, "no human being can stand where we are
now, and you can walk the stanchest hound over the ledge, without his
dreaming of what lies beneath. Come up to the top of the berg."

Taking their equipments, they left the grotto, and issued through the
narrow entrance. Regnar pointed to a shelving path, like a shallow
groove in the face of the cliff.

"Can we climb there?" said he.

"I should think so," answered La Salle; and taking an axe and the end of
the rope, he began to ascend the cliff along the shelving pathway. As he
ascended, he heard behind him the blows of an axe, and, turning, saw
Regnar cut a narrow cleft from the entrance of the cove to the level of
the way to the top of the berg. "Are you mad," asked La Salle, "that you
scatter your chips about the berg like that, and into the very
pathway?"

Regnar gave a finishing stroke to his work, and came lightly up the
path.

"I shall finish my work above," said he; and in a moment more they stood
upon the summit.

The brink of the pool lay near the edge of the cliff, and without
stopping to look around him, Regnar commenced cutting a deep, narrow
gutter from the pathway to the huge reservoir. As he struck the blows
which shattered the thin wall of ice between the pool and its new
outlet, the water poured in a stream a foot deep through the little
canal, and down the slanting ledge into the cavern below.

"I understand it now," said La Salle, "and I now know why you lashed the
body to its support."

"Yes," answered the boy, coolly, "should any try to break into yonder
tomb to-morrow, they would do so at the risk of their lives; but if we
have a week of frost, the cove will be full to its outlet of solid ice."

"But, Regnar, let us think of something else. Where are the islands we
saw last evening? We ought now to be near the southern shore of the
group."

"We have been wedged off to sea by stranded ice, I should judge; for
there, about fifteen miles to the northward, lies Amherst Island."

[Illustration]

CHAPTER XXI.

NORTHWARD AGAIN.--THE STEAMER.--TAKING TO THE BOAT.

"Yes, Regnar, we are now on the outer side of the pack, and the wind has
shifted to the southward again. Look to the eastward, Regnie. Has not
th