of a mile below camp there was a general disappearance of the waters.  We could see nothing of the great rapid from the level of the boats, though we caught an occasional glimpse of the leaping, tossing edges, or tops, of the huge billows rolling out beyond into the farther depths of the chasm.  About eight o’clock in the morning all was ready for the start.  The inflated life-preservers, as was customary in our boat, were laid behind the seats where we could easily reach them.  The Major put his on, a most fortunate thing for him as it turned out, but we who were at the oars did not for the reason before mentioned,—­that they interfered with the free handling of the boat.  The men of the Canonita took positions where they could observe and profit by our movements.  Then out into the current we pushed and were immediately swept downward with ever-increasing speed toward the centre of the disturbance, the black walls springing up on each side of the impetuous waters like mighty buttresses for the lovely blue vault of the September sky, so serenely quiet.  Accelerated by the rush of a small intervening rapid, our velocity appeared to multiply till we were flying along like a railway train.  The whole width of the river dropped away before us, falling some twenty-five or thirty feet, at least, in a short space.  We now saw that the rapid was of a particularly difficult nature, and the order was given to attempt a landing on some rocks at its head, on the left.  At the same instant this was seen to be impossible.  Our only safety lay in taking the plunge in the main channel.  We backwatered on our oars to check our speed a trifle, and the next moment with a wild leap we went over, charging into the roaring, seething, beating waves below.  Wave after wave broke over us in quick succession, keeping our standing-rooms full.  The boat plunged like a bucking broncho, at the same time rolling with fierce violence.  As rapidly as possible we bailed with our kettles, but the effort was useless.  At length, as we neared the end, an immense billow broke upon our port bow with a resounding crack.  The little craft succumbed.  With a quick careen she turned upside down, and we were in the foaming current.  I threw up my hand and fortunately grasped a spare oar that was fastened along the outside of the boat.  This enabled me to pull myself above the surface and breathe.  My felt hat had stuck to my head and now almost suffocated me.  Pushing it back I looked around.  Not a sign of life was to be seen.  The river disappeared below in the dark granite.  My companions were gone.  I was apparently alone in the great chasm.  But in a moment or two Powell and Hillers, who had both been pulled down by the whirlpool that was keeping all together, shot up like rockets beside me, and then I noticed Jones clinging to the ring in the stern.  As we told Powell, after this experience was over, he had tried to make a geological investigation of the bed of the river, and this was not advisable.  Hillers and I climbed