Works for Improving the Navigation of the Ohio, Mississippi, and St. Lawrence.

To this head belong the works executed in the beds of the rivers themselves. The Mississippi is the beau idéal of rivers in regard to navigable facilities. From St. Louis to New Orleans, a distance of nearly 1200 miles, there is water enough for steamers of 300 tons throughout the year. Its yellow and muddy waters flow in a deep, although very circuitous channel, and its general breadth is from 800 to 1,000 yards, in places where it is not expanded to a much greater width by low, flat islands, thickly covered with trees. There are no sand-banks in this part of the channel, yet there are formidable dangers in the way of the inexperienced navigator; these are the trunks of trees, that have been carried away from the banks, as has been before mentioned, and in the removal of which the Federal government keeps steam snag-boats, the Heliopolis and Archimedes, employed; these boats are provided with a peculiar machinery by means of which they drag the trees up from the bed, and saw them into pieces of an inconsiderable length.

Captain Shreves, who has the command of these boats, and who invented the machinery, is also employed in constructing sunk dams of loose stones in the Ohio, which have the effect of increasing the depth of water in the dry season. He is at present engaged with a flotilla of steamboats in opening the bed of Red River, one of the great tributaries of the Mississippi, which the drift timber has choaked up and covered over through a distance of 165 miles. At Louisville, the Ohio, whose bed has generally a very slight inclination, has a descent of 22 feet in the distance of two miles, so as to be impassable for steamboats, except during the season of high water. The Louisville and Portland canal has been constructed by a company to avoid this obstruction; it is nearly one mile and three fourths in length, and cost 750,000 dollars. It receives the largest boats at a rate of toll which for the Henry Clay amounts to 175 dollars, and for the Uncle Sam 190 dollars. It has been proposed that Congress should buy this canal, and make the passage toll-free; and the importance of the navigation of the Ohio would justify the measure.

The St. Lawrence differs essentially from the Mississippi; instead of an expanse of muddy waters, it presents to the eye a clear blue surface. The Mississippi traverses a low, uninhabited, and uninhabitable region, of which the soil consists entirely of sand, or rather of mud deposited by the river-floods; not a stone as large as the fist is to be found, and only a few bluff points are met with which are above the reach of high water, and on which the pale inhabitants struggle unsuccessfully with the pestilential emanations of the surrounding swamps. The St. Lawrence flows through a broken, hilly, and sometimes rugged country, with a fertile soil, everywhere healthful, sprinkled with flourishing villages, which attract the eye of the traveller from a distance by their houses newly whitewashed every year, and their churches built in the French style with their spires covered with tin. The Mississippi, like the Nile, has its annual overflow, or rather it has two in each year, but the spring-floods are much the most considerable. The St. Lawrence, owing to the vast extent of the lakes which serve as a reservoir and feeder to it, always preserves the same level, the extreme range of its rise and fall being only about 20 inches. The St. Lawrence, from the beauty of its waters, from their prodigious volume, from the country which it waters, and from the groups of isles scattered over it, would be one of the first rivers in the world in the eyes of the artist, but in those of the merchant, it is of quite a secondary importance. Its transparent waters hardly hide the numerous rocks; the navigation is interrupted first by the Falls of Niagara, and after it leaves Lake Ontario by numerous rapids, cataracts, or rocks between that lake and Montreal, and none but an Indian or a French Canadian, would dare to descend these points in that portion of the river in a canoe; at several points, the most powerful steamer would be unable to make head against the current.

The spirit of emulation which has prevailed among the States of the Union, has extended to the British Provinces, to the English population, which, leaving the lower part of the river to the French, has occupied Upper Canada. The inhabitants of this Province have embraced the opinion, that if the chain of communication which is broken by the cataracts and rapids, could be made whole, much of the produce, which now finds its way to the Mississippi, or to the Pennsylvania and New York canals, would seek a more convement vent by the St. Lawrence, and that the British manufactures would take the same route up the river, through the ports of Quebec and Montreal, to the Western States. One canal has, therefore, already been executed around the falls of the Niagara, which forms a communication between Lakes Erie and Ontario; the Welland canal is 28 miles in length, exclusive of 20 miles of slack-water navigation. It is navigable by lake-craft of 120 tons, and has cost 2,000,000 dollars, nearly the whole of which was furnished by the upper Province, Lower Canada and the mother country having contributed a very trifling sum.

Since that work has been completed, the river below Lake Ontario has been surveyed, and it has been found that the aggregate length of the points not passable by steamboats of ten feet draft is only 30 miles, pretty equally divided between the two provinces. Upper Canada, which contains hardly 250,000 inhabitants, with no large towns and with little capital, has begun her portion of the work along the rapids within her limits. This work will be large enough to admit the passage of steamboats drawing nine feet water, and of the burden of 500 tons. I saw the labourers at work along the Long Saut Rapids at Cornwall, where there will be a cut of 13 miles in length; the estimated cost of this section is 1,250,000 dollars. The French population of Lower Canada, swallowed up in political quarrels, the result of which cannot be foreseen, neglects its essential interests in pursuit of the imaginary interests of national pride. It has done nothing towards continuing, within its limits, the great work, which has been begun by the poorer province of Upper Canada.