13 



bank. Many banks sink or are washed away in inundations,' 

 when the channel sets against thera. 



Rapids. Many ripples become rapids at low water, and all 

 the rapid disappear at high water, even those called the falls, 

 which lie below Louisville. They are several passages of the 

 river between rocky ishaids, the waters flowing with great ra- 

 pidity; but hardly ever pitching over, except on the Kentucky 

 side of the falls, where at very low water there is a small fall of 

 less than two feet. Their noise is heard at a great distance. A 

 Canal will soon be cut on each side of thera. Letart's rapids 

 and the Hurricane rapids are the most dangerous after the falls, 

 yet they are merely large rock ripples. 



Bayous. They are narrow channels into which the waters 

 flow at a certain stage of rise, forming temporary islands; 

 they are not uncommon in the lower vallies, and are sometimes 

 called cut offs; the longest lies below Evansville, forming oc- 

 casionally a very large island opposite Hendersonville. 



Inundations. The Ohio is subject to periodical rises and 

 to many adventitious ones. The highest happens in the spring, 

 when the snow melts in the Alleghany mountains, and it has 

 sometimes risen to fifty feet above the low water at some par- 

 ticular places, covering ail the islands and bottoms of the first 

 banks, and overflowing the towns built on those bottoms, such 

 as Marietta, Shippingport, Lawrenceburgh, Shawneetown, &c. 

 to the depth of ten feet or more. Another happens in the fall 

 alter the first rains; both subside pretty soon. Many others oc- 

 €ur throughout the year, occasioned by rains. They are either 

 general or partial, sudden or gradual; but during the months of 

 July, August, and September the waters are very low, while in 

 January and February, they are covered with floating ice and 

 even frozen over in the northern and upper part. The over j 

 Sowings do not rise so high in the lower valleys; but they ex- 

 pand more over the bottoms, often leaving behind pools and 

 marshes. 



Phenomena. Eddies and whirlpools are common, particu- 

 larly at high waters; but not dangerous. A natural echo is 

 heard throughout the narrow valley. Fogs are common dur- 



B 



