54 ICHTHYOLOGIA OHIENSIS 



islands, the waters flowing with great rapidity ; 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 them. Letart's rapids and the Hurricane 

 rapids are the most dangerous after the falls, yet 

 they are merely large rock ripples. 



[I. 361] Bayous. They are narrow channels into 

 which the waters flow at a certain stage of rise, form- 

 ing temporary islands; they are not uncommon in 

 the lower vallies, and are sometimes called cut offs ; 

 the longest lies below Evansville, forming occasion- 

 ally 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 particular 

 places, covering all the islands and bottoms of the 

 first banks, and overflowing the towns built on those 

 bottoms, such as Marietta, Shippingport, Lawrence- 

 burgh, Shawneetown, &c. to the depth of ten feet or 

 more. Another happens in the fall after the first 

 rains ; both subside pretty soon. Many others occur 

 throughout the year, occasioned by rains. They are 

 either general or partial, sudden or gradual; but dur- 

 ing 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 overflow- 

 ings do not rise so high in the lower valleys ; but 

 they expand more over the bottoms, often leaving 

 behind pools and marshes. 



