"All right," said Jim, and was quickly in the tree-top.
"It looks like a rough, broken ridge, stretching clear to shore. I guess we'll have to climb over it. I can't see any break."
"Where do you think is the easiest place?"
"About straight ahead, where you see that highest point. Right beside it is a kind o' low spot, I think."
"Well, then," said the Captain, "we'll aim for that. Hurry up your lunch, Katy, and let's be off."
Half an hour later they arrived at the bad place.
"It must be a hummock," said Katy, "such as I have read about in Dr. Kane's book—only not so large, I suppose. He says that the ice-sheet, or floe, gets cracked and separated a little; then the two floes will come together again with such force that they lap over one another, or else grind together, and burst up edgewise along the seam."
"That's just the way this is; but, hummock or no hummock, it must be crossed," said Aleck.
"Mebbe I could find a better place," suggested Jim, "if I should go along a little way."