Biggles of 266

"Ah, that's a trade secret, sir!" replied Biggles mysteriously. "But I am going to tell you, because it is only fair to Lacey, whose assistance made it possible. We flew over together, and landed in a field about forty miles over the Lines. He carried eight spare tins of petrol--four in his cockpit and four lashed to his bomb-racks, He came back home; I refuelled and went on. I had just enough petrol to get back, as you saw."