"That's it exactly. Only I didn't know that fog! So far as I could tell, it spread over all England and Ireland, too, with some left over for France! Only one thing for it, of course. I knew I'd get away from it if I kept on flying. So I steered by the sun as well as I could, and kept on until my petrol began to run short, and a cylinder began missing. And then, just as I was wondering whose windows I'd break when I went down, it began to thin out, and slipped away as quickly as it had come. And I was right above the golf links on Wimbledon Common. I volplaned down, and landed on a putting green, and an old colonel who'd been invalided home from India said I'd done it on purpose, and he was going to have me court-martialled!" Frank laughed heartily at the story. But at the same time, he suspected Captain Greene's purpose in telling it. He thought the captain wanted to keep his spirits up, and make him forget that he had never had a flight before, and he admired and liked him more than ever in consequence, even though, as he told himself, it wasn't necessary. "Hello! I think we're getting near your spot, young 'un," said Greene, abruptly. He dipped down, and Frank peered down to see where they were. "Yes," he cried, in assent. "There's the hill we were coming down when we saw them, just as we rounded that turn. That's the road they were marching along, and there, over to our left, are the woods. I wonder if they're still there." "We'll soon know," said Greene. "Now for a little climbing. I'm not afraid of being hit, but orders are to find them without being seen, if we can manage it. So we'll try the high spots for a bit." At once the monoplane began climbing, ascending in great spirals. Frank was absorbed by the sensation. He found that he could see the ground receding without feeling any qualms, and said so. "You're lucky," said Greene, briefly. "Made me feel queer first few times I tried it, I can tell you. You're probably a born flyer--and the chances are you'll never do much of it, I suppose! Always the way!" Frank, looking down, saw that they were moving away from the woods which they were to reconnoitre, and mentioned it. "Got to," said Greene, briefly. "Then we'll fly back. We can't climb in a straight line. When I went out for altitude once, I made twelve thousand feet, and when I finished climbing I was nearly fifteen miles, in a straight line, from where I started. Let's see. Got that flashlight I gave you? Play it right on the board there till I tell you to stop." Frank obeyed, shooting the little spear of light on the various instruments in front of the aviator. "All right. Hold it there. My barograph, you see. Gives me my height by showing the change in atmospheric pressure. That's how we calculate height. Not very exact, because all sorts of things vary the pressure. But it's near enough. A thousand feet! That's good enough. I don't believe they're looking for us. We don't usually scout behind our own lines."