CHANNEL OF PRAIRIE STREAMS. 49 



which the water has torn its way through the plain, 

 during" the freshets to which all these streams are 

 liable. As long" as the bottom is hard and even, of 

 course, the passage of these streams presents no spe- 

 cial difficulty at low water. At other times, where 

 the sand is fine, the current during a flood often scoops 

 out deep, though narrow channels, whose sides go 

 down suddenly, like a wall. If the stream is turbid, 

 it is very hard at times to detect these places ; so that 

 a man on horseback may enter the swift-flowing river, 

 where the water appears only a few inches deep; 

 and all at once the bottom seems to give way, and 

 the horse falls, as it were, into a hole, where swim- 

 ming at once becomes necessary, and where getting out 

 again is at times by no means an easy matter; for 

 the horse breasts the opposite bank, which is frequently 

 perpendicular also ; and should he succeed in getting his 

 forefeet upon the top, the edge, which is generally 

 running sand, at once gives way. 



In some districts of country these places are rendered 

 specially dangerous from the enormous quantity of this 

 impalpable sand with which the current is surcharged 

 when the stream is in flood. This sand is sometimes 

 carried down by the water in such quantities that 

 the current in such places seems to consist rather of 

 waves of moving sand, than of water. When this is 

 so, the weight of the stream is so enormous, that it is 

 apt to bear down and engulph in an instant, every- 

 thing that opposes it. Numerous fatal accidents have 

 occurred through unwary travellers incautiously enter- 

 ing these sand streams, where horses and men have 

 frequently been known to disappear for ever in the 

 twinkling of an eye. 



VOL. II. 4 



