back."

"Are you s-s-s-sure of t-t-t-this?" asked the professor.

"Certain," replied Frank; "I have been watching the progress of other
pieces of drifting ice and the current seems to take a distinct curve
here and radiate backward toward the pole."

"Then we are saved--hurray!" shouted Billy, dancing about on the
slippery ice, and falling headlong, in his excitement, on the
treacherous footing it afforded.

"No use hollering till we are out of the woods," said Frank; "the
current may make another turn before we land near the ships."

This checked the enthusiasm and the boys all fell to anxiously
watching the course their floe was likely to pursue.

"There's our whale," shouted Billy, suddenly. "Look what a smash on
the nose he got."

The great monster seemed to have recovered from its swoon and was now
swimming in slow circles round the floe, eyeing the boys malevolently,
but not offering to attack them. Evidently it was wondering, in its
own mind, what it had struck when it collided with the boat and the
floe.

The floe drifted onward, with the vessels' forms every moment growing
larger to the boys' view. All at once a welcome sound rang out on the
nipping polar air.