THE MISSISSIPPI VALLEY. 7 



tous, and their surface rugged. While the opposite sides of the same moun- 

 tains, looking into the interior, are comparatively gentle, seamed with long 

 valleys which form the tributaries of the navigable rivers that there commence 

 their com'se to the distant ocean. 



The Andes descends abruptly to the Pacific, which it reaches in a short dis- 

 tance, discharging from its sides small but rapid streams that run into falls and 

 cataracts ; while the long plain which slopes up slowly from the Atlantic, and 

 forms the beds of the Amazon and La Plata, rises far on the sides of the moun- 

 tain before the mountain itself becomes a distinct elevation. 



It seems to be a rule in the natnral economy, that countries remote from the 

 ocean shall have outlets through great rivers of slow descent ; rivers which 

 serve primarily for their drainage, but so formed that they might be used, in the 

 progress of time, for the highways of civihzation. The plains of China are thus 

 supplied with the Amour, Russia with the Volga, Germany has the Danube, 

 Brazil and the States east of the Andes, the Amazon, Orinoco, and La Plata ; 

 all rivers of gentle descent, leading far into the interior, and all adjusted for 

 navigation. 



The Mississippi, Missouri, and Ohio, with their great arms, are the guerdon 

 bestowed upon the central valley of the United States. The physical charac- 

 teristics and capabilities of some of these it is here proposed to study. 



OF THE OHIO. 



In tracing the Ohio to its source, we must regard the Alleghany as its proper 

 continuation. 



This noble tributary rises on the borders of Lake Erie, at an average elevation 

 of 1,300 feet above the surface of the sea, and nearly 700 above the level of the 

 lake. The plain along which this river flows is connected with no mountain 

 range at its northern extremity, but continues its rise, with great uniformity, 

 from the mouth of the Ohio to the brim of the basin which encloses Lake Erie. 

 The sources of the tributary streams are generally diminutive ponds, distributed 

 along the edge of the basin of Lake Erie, but far above its surface, and so 

 sHghtly separated from it, that they may all be drained with little labor down 

 the steep slopes into that inland sea. 



From these remote sources a boat may start with sufficient water, within 

 seven miles of Lake Erie, in sight sometimes of the sails which whiten the 

 approach to the harbor of Buffalo, and float securely down the Connewango, 

 or Cassadaga, to the Alleghany, down the Alleghany to the Ohio, and thence 

 uninterruptedly to the Gulf of Mexico. In all this distance of 2,400 miles, the 

 descent is so uniform and gentle — so little accelerated by rapids — that when 

 there is sufficient water to float the vessel, and sufficient power to govern it, 

 the downward voyage may be performed without difficulty or danger in the 

 channels as they were formed by nature ; and the return trip might be made 

 with equal security and success with very little aid from art. 



