It was the only thing of the kind; but as we opened the reach more, I perceived it was the head of a long sand-bank, or rather of a chain of shallow patches stretching down the middle of the river. They were discoloured, just awash, and the whole lot was seen just under the water, exactly as a man's backbone is seen running down the middle of his back under the skin. Now, as far as I did see, I could go to the right or to the left of this. I didn't know either channel, of course. The banks looked pretty well alike, the depth appeared the same; but as I had been informed the station was on the west side, I naturally headed for the western passage.

     No sooner had we fairly entered it than I became aware it was much narrower than I had supposed. To the left of us there was the long uninterrupted shoal, and to the right a high, steep bank heavily overgrown with bushes. Above the bush the trees stood in serried ranks. The twigs overhung the current thickly, and from distance to distance a large limb of some tree projected rigidly over the stream. It was then well on in the afternoon, the face of the forest was gloomy, and a broad strip of shadow had already fallen on the water. In this shadow we steamed up -- very slowly, as you may imagine. I sheered her well inshore -- the water being deepest near the bank, as the sounding-pole informed me.