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 choked up and covered over through a distance of 165 miles.[BZ] 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.[CA] 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.