Accordingly they started the next morning, and an hour after setting out were in the sweep of the rapids. The passage was an intensely exciting one. The Indians stood, paddle in hand, one at each corner of the front of the raft; their poles lay ready to snatch up in case any rock was approached, but the paddles were needed to keep the raft from being dragged out into the full force of the current. Here the water rose in steep ridges, and had the raft got among these it would have been torn to pieces almost instantly. At the same time it was desirable not to go too near the shore, as the risk from submerged rocks would be greater there. But Stephen saw that unless rocks came absolutely above the surface they would be swept over them, as the raft drew but two or three inches of water. Except in the middle, the stream rushed along with a surface broken only by tiny eddies. It was only by seeing how they flew past the banks that any idea could be formed of the speed at which they were travelling. In eight hours it was over. Several times the paddlers had to exert themselves to the utmost to avoid spots where great swells of water showed that there were rocks below the surface, but on no occasion did the Indians have to use their poles. The bed of the river widened sharply at the foot of the rapids, and just as Stephen congratulated himself that the passage had been safely made, he saw by an increase in the labour of the Indians that something was wrong. Standing up in the canoe he perceived that they had been shot out of the current into the back-water formed by the sudden widening of the stream, and that in this back-water was a very strong eddy sweeping round and round in a circle. This was about a hundred yards in diameter, with a depression in the centre, and round this the raft was carried at a rate that defied the efforts of the two paddlers to check. At one moment they were within twenty yards of a flat forest-covered shore, and the next were near the edge of the torrent pouring down the rapids. In vain the paddlers tried to edge the raft out little by little from the whirlpool. Not only was the current too strong for them, but its surface was dotted with floating logs and branches of trees that, like themselves, coursed round and round. As long as all were travelling at the same rate and in the same direction the danger of a collision was comparatively slight, but more than once when the rowers succeeded in gaining a short distance towards the outside edge of the whirlpool, they were forced to desist suddenly and paddle straight with the current, to avoid a great log bearing down upon them.