This was my big day.  The current was better than much of that above; I was getting used to the heat, and, instead of idly drifting, I pulled steadily at the oars.  The river twisted back and forth in great loops with the strong current, as is usual, always on the outside of the loops, close to the overhanging banks.  I would keep my boat in this current, with a wary lookout over my shoulder for fallen trees and sudden turns, which had a way of appearing when least expected.  At some such places the stream was engaged at undermining the banks which rose eight and ten feet above the water.  Occasional sections, containing tons of earth and covered with tall, slender willow trees, would topple over, falling on the water with the roar of a cannon or a continued salute of cannons; for the falling, once started, quite often extended for half a mile down the stream.  At one such place eighteen trees fell in three minutes, and it would be safe to say that a hundred trees were included in the extended fall.  The trees, sixty feet high, resembled a field of gigantic grass or unripened grain; the river was a reaper, cutting it away at the roots.  Over they tumbled to be buried in the stream; the water would swirl and boil, earth and trees would disappear; then the mass of leaf-covered timber, freed of the earth, would wash away to lodge on the first sand-bar, and the formation of a new island or a new shore would begin.

Then again, the banks were barren, composed of gravel and clay, centuries older than the verdure-covered land, undisturbed, possibly, since some glacial period deposited it there.  But a shifting of the channel directed the attack against these banks.  Here the swift current would find a little irregularity on the surface and would begin its cutting.  The sand-laden water bored exactly like an auger, in fast-cutting whirls.  One such place I watched for a half-hour from the very beginning, until the undermined section, fourteen feet high, began to topple, and I pulled out to safety, but not far enough to escape a ducking in the resulting wave.

Below this, instead of a firm earth, it was a loose sand and gravel mixture twenty feet above the river.  Here for half a mile the entire bank was moving, slowly at the top, gathering speed at the bottom.  While close to this I heard a peculiar hissing as of carbonated water all about me.  At first I thought there were mineral springs underneath, but found the noise was caused by breaking air bubbles carried under the stream with the sands.  All this day such phenomena continued, sliding sand-banks and tumbling jungles.  In these latter places some cattle had suffered.  Their trails ran parallel with the stream.  No doubt they had one or two places where they drank cut down to the stream Knowing nothing of the cutting underneath, they had been precipitated into the flood, and now their carcasses were food for swarms of vultures gathered for an unholy feast.

What powerful, graceful birds these scavengers are, stronger than the eagle even, tireless and seemingly motionless as they drift along searching every nook and cranny for their provender!  But aside from a grudgingly given tribute of admiration for their power, one has about as much respect for them as for the equally graceful rattlesnake, that other product of nature which flourishes in this desert land.