SURFACE. 23 



may be said to be a huge wave of sand surging, rolling, 

 turning, and shifting with incessant activity. Where 

 there is six feet of water in the morning, there may by 

 noon be a bar with but an inch. By night the bar may 

 be gone and a deep channel in its place. These channels 

 are from ten to thirty feet wide, with generally perpen- 

 dicular sides. Some force will set a current in a par- 

 ticular direction across a bar. In a few moments a 

 channel from three to six feet deep is cut, through which 

 the water pours as in a mill-race. A shift or change 

 above diverts the current to some other direction, and in 

 almost as few moments the recent channel is filled up to 

 within a few inches of the surface of the water. As the 

 currents by turns set in almost every conceivable direc- 

 tion with reference to the general course of the stream, 

 so the channels may be parallel, oblique, or even per- 

 pendicular to that general course. Even leaving out 

 of consideration the danger of quicksands, it can be 

 readily seen that the crossing of such a stream is no 

 child's-play. A good place of entrance being found, the 

 horse and rider, stripped of every superfluous article, 

 wade in. For a few paces the horse steps along in water 

 but a couple of inches in depth. Without a moment's 

 notice or preparatory deepening, his fore feet go down 

 under him, and he plunges head first into swimming 

 water with a tremendous current. He has hardly re- 

 covered the shock, and struck out fairly in swimming, 

 before his chest strikes a wall of sand, on which, after 

 many struggles and plunges, he finally succeeds in ob- 

 taining a footing. Again he walks on in shallow water, 

 again to be plunged suddenly into a treacherous channel, 

 again to scramble, plunge, and strain to get out of it. 

 Imagine this done over and over again for twenty or 

 thirty times, and with an infinity of variations, and an 

 idea can be formed of the crossing of a plains river in 

 high water. All the streams which come from the moun- 

 tains are the same in this peculiarity. 



