The sun was completely hidden by the smoke, but the heat was stifling. The crackling of the burning timber sounded as if it were a few feet distant. Bill jumped backward when he heard the first falling tree. The tree dropped with a crash which resounded throughout the valley. He could not imagine what had caused the noise at first, for it had come so unexpectedly. It reminded him of the first bomb that he had heard when the Germans bombed the airdrome from which he was flying in France—no advance warning, nothing to herald its approach, just the crash and “wham” of the exploding bomb. After thinking it over, he was sure that it was a falling tree which had caused the noise. There was nothing else around which could have caused the same shattering roar. It must have been a large tree, too.