And the grim war-captains around, who knew the difference, nodded assent and said the word was wise. Yet thought they none the less of the youth because he felt that a renowned father made all the harder work needful in the son. But all day long, and for various other days, the dark little smithy was alight again, and merrily the clink of anvil rang. Little by little new plans were forming. A new strip of rings had to be let into that mail, for Ulf had grown larger. He had grown in other ways as well, and could see far into the needs for the future. So to his arms he had added a spearhead with a point like a needle. And now he took from an almost forgotten hiding-place a toy of his younger days. You would hardly know the use at first glance. Just two jawbones of some large animal, white and polished. But look closer at them. The outer side of the curve has been filed flat. There are holes drilled in the bone through which are rove leather strips. If with those strips the bones were laced to the bottom of your shoes, now-- "Skates!" you cry; and skates they were. Not keen enough perhaps to give a good honest stroke, yet speedy enough when used rightly in "roller-skate" fashion, and just as easy to get a fall with as any other kind. Ulf's nose tingled as he looked at them. It seemed to remember at least one bump. Then Ulf fell to hammering again at his bits of steel, and presently those flat surfaces of bone were shod with something harder, with keen cutting edges of corners that would never slip, no matter how glassy the ice beneath. Jarl Sigurd laughed when he heard of it and said that Ulf was still quite a boy. Edith was amazed, although that winter she took much pleasure in a pair of skates which were wondrous keen. But that was still in the future; meanwhile, Ulf said nothing, only smiled, and when he next sailed away he took his new toys with him. * * * * * Far up in the Arctic Circle, where the nights are six months long, day was fairly begun. That means, it had progressed till five or six weeks of our days might have been carved out of it, and the sun stood quite high above the horizon. It was so warm that the ice had begun to melt, and one great floe of it, ever so many miles wide, broke off from the rest and began to drift slowly southward. What made it break off was this:--here and there in the smooth plain great icebergs were frozen, huge mountains of ice, every one of them. The wind was blowing south, and each berg stood there like a great white sail. Underneath there was a current flowing southward; and every berg was many times larger under water than it was above, as you can see for yourself by dropping a piece of ice into a waterpail and measuring the difference. So the river of water flowing through the Arctic Ocean was pushing, pushing, and the wind above was pushing, pushing, until at last there came a thunderous crack, and the whole concern began drifting, drifting down to the warmer seas.