Down! down with the speed of the wind! The boat flashed between the black stones. Then it was raised aloft, light as a feather, to crash into the back-lashers. The din deafened Ken; the spray blinded him. The boat seemed to split a white pall of water, then, with many a bounce, drifted out of that rapid into little choppy waves, and from them into another long, smooth runway. Ken rested, and had nothing to say. Pepe shook his black head. Hal looked at his brother. George had forgotten his rifle. No one spoke. Soon Ken had more work on hand. For round another corner lay more fast water. The boat dipped on a low fall, and went down into the midst of green waves with here and there ugly rocks splitting the current. The stream-bed was continually new and strange to Ken, and he had never seen such queer formation of rocks. This rapid, however, was easy to navigate. A slanting channel of swift water connected it with another rapid. Ken backed into that one, passed through, only to face another. And so it went for a long succession of shallow rapids. A turn in the winding lane of cypresses revealed walls of gray, between which the river disappeared. “Aha!” muttered Ken. “Ken, I’ll bet this is the place you’ve been looking for,” said Hal. The absence of any roar of water emboldened Ken. Nearing the head of the ravine, he stood upon the seat and looked ahead. But Ken could not see many rods ahead. The ravine turned, and it was the deceiving turns in the river that he had feared. What a strange sensation Ken had when he backed the boat into the mouth of that gorge! He was forced against his will. Yet there seemed to be a kind of blood-tingling pleasure in the prospect. The current caught the boat and drew it between the gray-green walls of rock. “It’s coming to us,” said the doubtful George. The current ran all of six miles an hour. This was not half as fast as the boys had traveled in rapids, but it appeared swift enough because of the nearness of the overshadowing walls. In the shade the water took on a different coloring. It was brown and oily. It slid along silently. It was deep, and the swirling current suggested power. Here and there long, creeping ferns covered the steep stone sides, and above ran a stream of blue sky fringed by leaning palms. Once Hal put his hands to his lips and yelled: “Hel-lo!” The yell seemed to rip the silence and began to clap from wall to wall. It gathered quickness until it clapped in one fiendish rattle. Then it wound away from the passage, growing fainter and fainter, and at last died in a hollow echo. “Don’t do that again,” ordered Ken.