Page:Popular Science Monthly Volume 73.djvu/20

16 thoroughly equipped, yet inadequate to meet the conditions of the present time, will be relatively less able to cope with the rapidly growing demands for transportation facilities in the future. Already in the more densely populated portions of the country waterways once abandoned are being rehabilitated. The country can not long afford to ignore the possibilities presented by the development of the greatest natural highway in the world—the Mississippi and its navigable tributaries. It can not be denied that the improvement of our greatest inland waterways will be followed by vastly more important industrial and commercial advantages than can ever result from the opening of the Panama Canal. These advantages would be not to the people of the Mississippi Valley alone, but to the people of every county and corner of the Union through their dependence on the products of this region.

The project, however, is not at all simple—it is an undertaking fraught with problems which, unless met rightly at the start, must inevitably defeat the entire purpose of improvement. Like all big rivers, the Mississippi and its tributaries have bad habits, the worst of which are devastating floods, followed by very low stages of water at other times; rapid changes in the course through sapping of the banks; and constant shifting of the channel, often over night, on account of the formation of sand bars. In these respects our rivers are not necessarily any worse than others, in fact, they are not so bad as many of the great rivers of the world, but the correction of these habits becomes an unavoidable and serious question when efficient improvement for navigation is undertaken. The question of river control and improvement is most intimately connected with forestry, farming, mining and other industries, since they in many cases largely determine the particular problems with which man must deal. In the Ohio the overwhelming spring floods and low water stages of summer are the chief difficulties, with slack water dams doing much to remedy the latter condition and make navigation possible at all times. The sand-bar evil in the Missouri is so great and so perplexing that it completely overshadows the question of flood control and sapping of banks, which are in themselves of no slight importance. Along the lower Mississippi from St. Louis to the Gulf all three problems urgently demand attention, since this portion of the river represents the trunk line of the entire deep waterways system; and it is just here that the physical conditions surrounding the river make correction or control the most difficult.

From St. Louis southward, the river course follows a broad alluvial plain, which gradually increases in width to about 100 miles near the Gulf. This broad river flat is composed of a soft, highly-productive soil, fine-grained and of indefinite depth, in which the river has developed such a tortuous course that while the air-line distance from Cairo