“No, because we can tell we are sometimes going forward and sometimes back.”

“But look! we’re going north now.”

“Yes, I know we are,” said Vince; “and I’m beginning to know how it is.”

“Well, tell me. It’s so horrible to be puzzled like this.”

Vince was silent.

“Why don’t you speak?”

“Because I was thinking. Ladle, old chap, we’ve gone through too much, what with the seals’ cave, and being caught and then put down in that stifling hole over the gunpowder. We’re both off our heads—in a sort of fever.”

“I’m not,” said Mike shortly. “You are, or else you wouldn’t talk such stuff.”

“I talk such stuff, as you call it, because my father’s a doctor, and I’ve heard him tell my mother about what queer fancies people have when their heads are wrong.”

“Two people couldn’t be queer in the same way and with the same things. What’s the good of talking like that?”