swollen by the fall freshet of the Ohio, after which it subsides again, and remains low during the winter. The distance from New Orleans to the mouth of the Missouri is estimated at about twelve hundred miles; its current in the main channel of {259} the river is supposed to have an average velocity of three miles and three quarters per hour, in a moderate stage of the water; but when the river is high its velocity is considerably accelerated. Its water is turbid, being charged with a fine argillaceous mud, of a light colour, derived exclusively from the Missouri. The Missouri is a very wild and turbulent river, possessing the ruder features of the Mississippi, but destitute of the gentleness characteristic of the latter in many places. The obstructions to the navigation of the Missouri, although they are of the same character with those of the Mississippi, are far more numerous and formidable than those of the latter. The channel is rendered exceedingly intricate by means of sand-bars and islands, and the navigation in many places is very hazardous, on account of the multiplicity of rafts, mags, sand-bars, &c. with which the channel is beset. No part of the river is exempt from these obstructions for any considerable distance, particularly when the water is low. As this river in connexion with some of its principal tributaries traverses a considerable variety of climates, embracing more than ten degrees of latitude, a succession of spring freshets invariably takes place, and maintains an elevated stage of water from the breaking up of winter early in March, to the middle, and sometimes the last of July, when the summer freshet, yielded by the most northerly of its tributaries, takes place. During this period there is a sufficient depth to admit boats of almost any burthen; but during the residue of the year it can hardly be called navigable, except for boats drawing no more than twenty-five or thirty inches. The river is usually blocked up with ice during the winter season. The average velocity of its current, in a middling stage of water, may be estimated at four miles and one third. In time of a high freshet it moves with an {260} accelerated velocity, equal to five or five and half miles per hour.