A boat must never be allowed to move without men aboard or lines attached.  This would seem to go without saying, but for fear it does not I mention it for the sake of any who may want to try their skill at this work.  In the morning there was a pleasant smooth stretch for some distance, but it was soon passed, and cataract followed cataract till we counted ten.  Seven we ran with exhilarating speed; the other three demanding more respectful treatment, we lowered the boats by lines, when the noon hour was at hand and a halt was made for refreshments, five miles from the starting-point of the morning.  As soon as we had consumed the allowance of bread, bacon, and coffee, we took up our task by making two very difficult and tiring let-downs; that is, manoeuvring the boats in and out, among and over, the rocks alongshore by lines, with one or two men aboard, always on the lookout to prevent being caught by outer currents.  This brought us face to face with a furious fall, but one that seemed free from obstructions, and the order was to run it.  Accordingly, over we went, the boats shipping the great seas below and each one tapping the keel on a submerged rock at the start.  Owing to the trend of the canyon, and the lateness of the season, the sun now passed early from sight, the walls throwing the bottom of the gorge into deep shadow with a wintry chill that was quickly perceptible to us in our wet clothing.  The result was that our teeth chattered in spite of all we could do to stop the uncomfortable performance, and our lips turned blue.  To be soaked all day long near the end of September, in our climate, is not an agreeable condition.  Though less than seven miles was made this day we were forced to stop when the shadow fell and make a camp at the first opportunity.  It was only half-past three o’clock, but it had been sunset to us for half an hour.  Thus each working day was sadly shortened, for even where the bends were most favourable, the warm sun shone upon us only for the middle hours.  The walls were close together and very straight; they grew higher and more threatening with every mile of progress, so that it seemed as if another day or two would shut out the sun from the bottom altogether.  On account of our limited larder, if for no other reason, we were obliged to push ahead as rapidly as possible.  The next day we were at it early, easily running the first cataract, but just below it an immediate landing was imperative at the head of another which no man in his senses would think of running.  Some hard work put us below that, and then came one far worse.  The morning was gone before we saw its foam receding behind us.  The following day, on summing up, after much severe toil, and stopping to repair boats, it was found that we had gone only a mile and a half!  At this rate, we thought, when would we see the end of this gorge?  But in the morning our wet clothes were put on without a murmur from any one, and once more we renewed the attack.  The worst fall the