The Mississippi below the mouth of the Ohio is an entirely changed river. Above that stream, it is similar to most other inland waterways, having tolerably stable banks and not much change in width. Below Cairo, however, the deposits forming the banks are composed of alternate layers of sand and mud or clay, the sand having been deposited by running water, and the mud in comparatively still water, so that the sand-layers are readily washed out, thus causing the banks to cave whenever the current sets against them. Below the influx of the Ohio, the river traverses alluvial bottom lands of inexhaustible fertility, and usually stretching to a width of forty miles or more. These alluvial lands have a general southern slope of about eight inches to the mile, and stretch five hundred miles to the southward, the river winding through them in a devious course for eleven hundred miles, occasionally on the eastern side washing bluffs of one to three hundred feet. The slope is sufficient to create high velocities in the current, making a very unstable channel, constantly shifting laterally and causing the river to develop into a serpentine form, one bend following another continuously. The immediate river, wherever it may be at the time, is confined by banks of its own creation, which, like all sediment-bearing rivers, are highest near the stream itself. Thus apparently following a low ridge through the bottom lands, the resistless mass of muddy water sweeps onward with swiftness, eroding its outer banks in the bends and rebuilding them on the opposite points, frequently forming islands by its deposits, and as frequently removing them, as the direction of flow may be modified by the unending changes in progress. Chief among these changes is the formation of "cut-offs." Two vast eroding bends covering several miles of distance gradually approach each other until the water forces a passage across the narrow neck. As the channel distance between these bends may have been many miles around, the sudden "cut-off" makes a cascade of several feet, through which the torrent rushes with a roar heard far away. The sandy banks dissolve like so much sugar, in a single day the course of the river is radically changed, and steamboats pass where a few hours before was cultivated land. The checking of the current at the upper and lower mouths of the abandoned channel soon obstructs them with the deposits, and in a few years forms a crescent-shaped lake, of which there are so many in the bottoms adjacent to the river. The convex bank in a bend is built up as rapidly by the deposits as the opposite concave bank washes off, so that the river does not usually become any wider in the bends on account of the process. The deepest water is always next to the concave or wasting bank, where the most current flows. It is not an unusual sight along this extraordinary river to see an ancient and well-constructed house hanging over the caving bank, destined