VOL. III.

210,000

pickled ditto, or river fishery, herring, shad, salmon, mackarel

81,000

2. Skins and furs,

3. Product of wood,

iron,

and, in their course to the Chesapeake, to break through all the mountains. From the Susquehannah, the principal chain assumes a more eastwardly direction, and, washed on the north by the lateral valley of the river Mohawk, whilst it gives rise southwardly to the Delaware, it terminates, under the name of Catskill mountain, in view of the tide water of the Hudson.

This description has been introduced for the double purpose of pointing out all the rivers which can afford the means of communication, and of showing the impracticability, in the present state of science, of effecting a canal navigation across the mountains.

The most elevated lock canal of which a correct description has been given, is that of Languedoc, and the highest ground over which it is carried, is only 600 feet above the sea. It is not believed that any canal has been undertaken, or at least completed in England, of an elevation exceeding 430 feet above the waters united by it. The Allegheny mountain is generally, and from observations made in several places, about 3,000 feet above the level of the sea. The precise height of the dividing ridge was ascertained by the commissioners, who laid out the United States road from Cumberland on the Potomac to Brownsville on the Monongahela, at 2260 above the first, and at 2150 feet above the last river. Cumberland, from the levels taken by the Potomac company, is itself 735 feet above tide water. Although some more advantageous and less elevated places may be found, particularly amongst the ridges which divide some of the upper branches of the Susquehannah from the corresponding streams emptying into the river Allegheny, there is none which is not of an elevation much beyond what has ever been overcome by canals in any other country. The impracticability arises from the principle of lock navigation, which, in order to effect the ascent, requires a greater supply of water in proportion to the height to be ascended, whilst the supply of water becomes less in the same proportion. Nor does the chain of mountains through the whole extent, where it divides the Atlantic from the western rivers, afford a single pond, lake, or natural reservoir. It may be added as a general feature of American geography, that except in the swamps along the southern sea coast, no lake is to be found in the United States, south of 41 degrees north latitude; and that almost every river north of 42 degrees, issues from a lake or pond.

The works necessary in order to facilitate the communications from the sea ports across the mountains to the western waters, must therefore consist either of artificial roads extending the whole way from tide water, to the nearest and most conveni

ent navigable western waters; or of improvements in the navigation of the leading Atlantic rivers, to the highest practicable points, connected by artificial roads across the mountains, with the nearest points from which a permanent navigation can be relied on, down the western rivers.

The principal considerations in selecting proper directions for those communications, are, the distance from the navigable western waters, both to tide water, and to the nearest navigable Atlantic river, and the extent of navigation, either natural or susceptible of improvement, which may be afforded by the rivers. Distance alone is mentioned, so far as relates to roads, because the mountains, however insuperable for canals, offer no important impediment to land communications. So far from being an insurmountable barrier to commercial intercourse between the two great sections of the union, it is now ascertained that those mountains may almost in every direction be crossed by artificial roads, as permanent, as easy, and less expensive, than similar works in the lower country. For congress having, contrary to current opinion, directed that the road from Cumberland to Brownsville should be laid out so that its ascent should not in any place exceed an angle of five degrees with the horizon; no difficulty has been experienced in effecting the object without cutting through hills, and although the road thus laid out, be, in a distance of 72 miles, two or three miles shorter than that heretofore in use.

Although the distance from the sea to the principal dividing mountain through its whole length, between the western sources of the Susquehannah and those of the Savannah, be nearly the same, yet the Atlantic bays, penetrating the coast at different depths and in different directions, the distances from the sea ports to the nearest western navigable waters, vary considerably. Taken in straight lines from each port to the nearest branch, beyond all the mountains, of each of the four great western rivers, they may be stated as follows:

From Philadelphia to the confluence of Conemaugh and Loyalhannon, branches of the Allegheny,

Miles.

220

From the City of Washington to the confluence

of the rivers Monongahela and Cheat, From Richmond to Morris's on the Kenhawa, below all the falls of that river,

150

210

From Savannah or Charleston to any navigable branch of Tennessee, the distance exceeds

300

The distance from the same western points, to the upper

navigation of the corresponding Atlantic rivers, cannot be stated

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