him a slap with its flipper that could be heard from stem to stern.

"Take that," Flossy seemed to say, "and leave my tail alone!"

The vessel was now kept farther to the east, and every day they passed
between great patches of ice, big pieces of which kept striking the ship
with such a noise that when anyone wanted to be heard he had to shout
aloud.

The professor was very busy now, taking soundings almost every day, and
doing all kinds of clever work that even Tom, smart as he was, couldn't
understand. But in the evenings he still played with the children, or
amused them by showing them, through magnifying-glasses, some of the
wonderful things he had brought up from the bottom of the ocean.

It was all very strange and beautiful, and the children were enchanted.
But their greatest treat was when he brought some little glass tanks
containing forms of animal life they had never seen before, and were
never tired of watching. Only Professor Pete didn't--because he said he
couldn't--bring them out every night.




CHAPTER IV


On and on sailed the beautiful _Valhalla_. East and west, but always
north, went she.