CHAPTER XVI THE RIDDLE Days passed and weeks rolled by. The four friends and their colored companion still remained on the mysterious island. The flag still flew from the hill and all day long one or another of the boys kept a lookout from a spot near by. No boat came to rescue them, however, and the little party of castaways had almost come to believe that the rest of their days were to be spent on this little island somewhere in an unknown sea. Once John on watch had seen smoke. Far off on the horizon appeared a smudge from the funnels of some passing steamer. It was too far away however to discover their signal or even to see their island. He had watched it hopefully until it finally disappeared over the rim of the ocean. That was the only sign of a vessel that had been sighted so fa

