else, and we know now how many of them we should require, and it is certain that we could easily carry enough to last us three weeks or more. And if we make a bee-line for the wire we ought to reach it within three weeks or less. Besides, if we escape on foot they will not know where to look for us. We shall have cover among the trees, whereas in the air we shall have no cover."
"Not even if we escape in an invisible car?"
"There is none of the cars invisible to them."
"Ah! so I was beginning to think."
"I am quite sure of it."
"Well, go on."
"Still, three weeks may not be enough. We may not be able to make a bee-line. Probably we shall meet with some impassable scrub, or other obstacle, and so our food may run out, and we may die miserably after all. But if we escape in one of the cars the whole risk will be over, and our fate will be decided one way or another within twenty-four hours."
"Very well," said I, "we shall try it the night after next."
Then I told him of my appointment next day with Signor Davelli.
He looked very grave. "That's the biggest risk of