When Quambo was enjoying his pipe, he was never in a hurry to move, so we sat on longer than we should otherwise have done.  I considered, at length, that it was time to move; when, looking up the stream, across the broad expanse I have mentioned, I caught sight of a light canoe skimming rapidly over the surface.  It was approaching us; so, prompted by curiosity, we agreed to wait its arrival at the shore--for it did not occur to us it could possibly descend the rapids.  It kept, however, in the middle of the current, and before we had got far from where we had been sitting I saw that it was about to make its way amid the tumbling waters.