364 THE BOTTOM OF THE SEA, 



grow insensibly ; but, during tempests, the sub- 

 marine configuration of the mouth changes com- 

 pletely, and it is unsafe for ships to attempt an 

 entrance until numerous soundings have been made. 

 In spite of his native audacity, even our American 

 pilot felt it necessary to cast the lead repeatedly. 



" At last we entered the course of the river itself, and 

 joyfully felt the rush of the current against the sides 

 of the vessel. Nevertheless, although sailing up the 

 Mississippi, we could not see the banks of this won- 

 derful river — it appeared to us like a river flowing in 

 the middle of the sea. The only indication of the 

 submarine banks which had been built up between 

 the salt and fresh water, was an occasional muddi- 

 ness just above the more elevated portions of the 

 banks, or perhaps here and there the bank itself was 

 visible in dim outline. As we ascended the river, 

 the outlines became more connected ; what had pre- 

 viously appeared as disconnected or accidental ele- 

 vations in the submarine soil now acquired the ap- 

 pearance of a continuous line of demarcation, and 

 speedily assumed a more solid and definite appear- 

 ance, until ultimately it rose, a solid bank, above 

 the level of the surrounding water. At this point 

 also the har, or alluvial dam formed across the river, 

 attains its greatest elevation. 



" So far the water ploughed by our keel, and left 



