In advancing toward their termination, and at their embouchure, the great rivers present several striking peculiarities. It has already been remarked, that a junction of two large streams often occurs without any expansion of the surface of their waters being the consequence, but a greater velocity of current and depth of channel. In some cases, instead of a wider course being created by increased volume of water, there is actually a narrower bed. Thus the Mississippi is a mile and a half wide, and the Missouri half a mile wide, at their confluence, yet from that point to the mouth of the Ohio, the medium width of the united rivers is but three-quarters of a mile, and through the lower parts of its course the main stream has, if any thing, a less surface-breadth, though vast accessions are made to it by the Arkansas, Red River, and others of great depth and body of water. Most of the tributaries of the Mississippi also, are wider a thousand miles apart from it than at the point of junction, and the same feature is characteristic of other great streams, that as they increase their volume of water and approach their termination, they flow in narrower though deeper channels. The Nile is not so broad at Cairo as at Siout, nor so broad at Siout as at Thebes. At Assouan, high up the stream, it is 3900 feet wide; at Oudi, 36 miles above Cairo, it is 2900; and at Rosetta, near its mouth, but 1800. This is one of the many examples of benign adjustment with which the realms of nature teem; for hereby a rich legacy of fertile soil, usually found at the mouths of rivers, is saved from submergence, and becomes the inheritance of man. In their junction with the sea, rivers display the diversity of sometimes pouring forth their waters through a single mouth, and distributing them into a variety of channels; circumstances mainly dependent upon the country through which they flow being easily susceptible of excavation or not, and upon the power of the stream. The Ganges pours its flood through the many channels here represented. [Illustration]