“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.

Peterkin was on a voyage of discovery, and one of his chief objects seemed to be to keep clear of the ice, which had grown very heavy indeed.

It was a delightful holiday for the children as yet, but for the professor a time of harder work than many know anything about at all.  It was really wonderful how this busy little man found time to play with the children, with Flossy and with the dogs, or even to play his fiddle.  But this, he would have told you, was his way of taking exercise; and he told Pansy that if it were not for her he didn’t think he should ever be able to find the island of gold he was in search of.

Do not think, though, it was all and always plain sailing.  There were dangers of many kinds.  Sometimes storms would suddenly rise and blow for a day or two at a stretch.  At such times the sun was hidden, and the cold became intense.  The waves that broke on board were turned into ice, covering the decks and bows, and giving to the ship a wondrous appearance.

One evening, after a gale like this had blown over, the stowaways, who had not dared to show face all day, were told to come up on deck.

What a sight!  Why, the Valhalla was like a ghost-ship.  The decks were white, and the bulwarks too.  Every rope and stay seemed made of frosted silver, while great icicles hung everywhere around.

It was very dark this evening, so that the children at first could hardly see anything.  But Pete soon had them all hoisted up on to the bridge.

And now he turned on the electric and coloured lights—­crimson, blue, and orange.  Then, what a sight was there!  It was one that caused Pansy and Aralia quite to forget the beauty of a pantomime they had seen the winter before.

They stood spell-bound, and would not have been a bit surprised if all the deck had suddenly been crowded with fairies, with silver wands, garlands of flowers, and wings of pearly gauze.  But the only fairies were the sailors, and every one of these looked like a very old man, because heads and beards were white with frost and snow, and little icicles hung round their hats.