Tim wasn’t sure that Pud was right about the current, and there was so little of it that Pud couldn’t prove his assertion until he had stopped the launch. Then, as it continued slowly on in the direction it had been going, and as a piece of cardboard dropped over by Tim floated in the same way, the question seemed decided. Ten minutes later the stream branched, and Pud, about to choose the left branch as naturally the correct one, was surprised to find the current flowing toward him at the mouth. He stopped the boat and they made certain of it. The left-hand stream flowed into the one they were in. That was puzzling, since according to their sense of direction the right-hand stream would lead them farther northward, and they wanted to go south! They discussed the matter for several minutes while the launch, still flying a bedraggled pirate flag from the stern, nestled against the wet bushes. In the end they reached the decision that, for all they knew, what seemed to them north might well be south. No one could remember which way they had started from the camping spot. If they had unwittingly taken the stream leading eastward, what seemed to them to be north would really be south. If the sun had been shining they could have solved the riddle easily enough. And so they could had there been a compass aboard, but a compass was one thing――almost the only thing, one might have thought――they hadn’t brought along. It seemed the safest course to follow the current, since as Pud, not knowing River Swamp, argued, the current must lead toward the river. They took the right-hand stream and went on. In the course of the next two miles they passed several smaller waterways, all, they judged, flowing into the present one, and gradually the stream grew wider. The engine began to sputter about ten o’clock and, in spite of Pud’s earnest endeavors to find the trouble, went dead in one cylinder. They hobbled along for another mile, and then Pud ran up to a bank and sent Harmon ashore with a line. To alleviate their troubles somewhat the rain almost ceased and the gray became an opaline whiteness that seemed to promise clearing. Striving to recall all that Andy Tremble had told them about the engine, the two boys started methodically to work. Pud reported a gasoline tank more than half full. Tim examined the carburetor gingerly and gave it a clean bill of health. Together they went at the battery and followed the wires back. Then out came the spark plugs and were frowned over and cleaned. And finally, being put together again, the engine displayed no inclination to start until Pud had thrice primed it. Then it did start half-heartedly and, as before, on one cylinder. Only, and this they were both certain of, it was now the other cylinder!