12 PHYSICAL GEOGRAPHY OF 



going table, that the Ohio river at Pittsburg is, at low water, 134 feet above the 

 level of Lake Erie ; and that the plain of the surface of that lake, extended to 

 the south, will pass 700 feet below the sources of the Alleghany, 395 feet below 

 the town of Franklin, 134 feet below Pittsburg, 55 feet below low water at 

 Wheeling, and would cut the inchned plain of the Ohio between Parkersburg 

 and Marietta, and at a point about 100 miles south of Lake Erie. 



It is not at all necessary to refute this proposition as a practical measure ; but 

 it is useful to extend the plain of the lake, so as to ascertain what positions it 

 commands in the valley of the Mississippi. It is by carrying such levels over 

 the country that we best illustrate, and best learn to appreciate, the great fea- 

 tures of its physical formation. 



While it would be impracticable to turn the waters of Lake Erie into the 

 Ohio, nothing would be more feasible than to divert all the head waters of the 

 Alleghany from their course, and precipitate them over the borders into the 

 basin of Lake Erie, down a slope of more than 700 feet in perpendicular height 

 and in a succession of cataracts that would rival Niagara in subhmity. 



Such a work might be productive of no useful result, but it could be effected 

 more easily than many undertakings that have been successfully achieved in this 

 country. 



PROFILE OF THE OHIO AND ITS TRIBUTARIES. 



The accompanying diagram (Fig. 2) will illustrate the comparative slopes of 

 the Ohio river and its principal tx'ibutaries, and serve in some degree to exhibit 

 their relative susceptibility for improvement. The reader will not fail to observe 

 the regularity and symmetry of the curve in profile, formed by the line of descent 

 followed by the Ohio and its chief prolongation, the Alleghany river. From the 

 summit of the Alleghany mountains, where the slender tributaries of this arm of 

 the Mississippi rise opposite to those of the western branch of the Susquehanna, 

 down to the mouth of the Ohio, this great river flows with almost unbroken 

 regularity. Rapid at first where it leaves the mountain sides, it becomes more 

 and more gentle in each hundred miles of its way, until its accumulated 

 waters flow mto the Gulf of Mexico. 



But the beautiful adjustment of this great artery of commerce can be best 

 appreciated by a comparison of its profile with that of other important rivers, 

 even of its own family. 



The great Kanawha is one of the largest tributaries of the Ohio, into which 

 it flows at a point computed to be 714 miles above the confluence of the latter 

 stream with the Mississippi. If we examine this river on the profile, we shall 

 find that it descends more rapidly than the Ohio, even in the first section of 87 

 miles above its embouchure ; but stifl, for that distance, up to the foot of Loup 

 Creek shoals, possessing the general characteristics of its recipient. For that 

 distance, also, the Great Kanawha is either navigable, or susceptible of being 

 made permanently so by furnishing its channel an abundant supply of water. 



