Even more: in another way they have made living cheaper. The half-rail-and-half-water route from the Pacific coast to New York via New Orleans, which the Jetties first made possible, forced the transcontinental railways to cut down their time for shipping freight over one half. The tonnage by this newer route has increased enormously, and its competition has affected commerce by reducing all rates from the Mississippi Valley and the West and the Pacific slope to the Atlantic seaboard and to Europe. As a consequence bread has been made cheaper to all the great populations that require the food products of the central zone and the Pacific slope.
Another very different but curious change is probably largely due to the Jetties. Before their construction only very light-draught ships could safely reach New Orleans; but it was so favorite a cotton port that many owners would build vessels of unusually light draught, in order that they might make one trip a year to New Orleans with them, although the rest of the time they sailed to deeper ports. As soon as it became known over the shipping world that New Orleans was now open to deep-draught vessels, a great many new ones were built. Thus the Jetties, as much as any other cause, brought in the era of great ships.
It has been calculated from statistics, which it is not necessary to give here, that the annual saving to producers of the Mississippi Valley brought about by the fall of rates, the saving in marine insurance, and the saving in time, due to the Jetties, is $5,000,000; and it is furthermore calculated that the annual money value of the Jetties to the people of the country at large is, by a very conservative estimate, $25,000,000.
Even the Jetties, however, were not the end of Eads's efforts toward the improvement of the Mississippi. For several years before their completion he had been delivering addresses urging the application of the same system to the entire alluvial basin of the river from the gulf to Cairo. People were in despair as to what to do to prevent the breaking of the levees (the results of which are as "terrible to the dwellers on those flats as the avalanche to people who live on the sides of steep mountains"), and the distress and prostration created by the awful spring floods. Most people thought there were two possible remedies,--to build more and higher levees, and to drain off some of the volume of the river through the Louisiana bayous. But Eads insisted that the requisite move was to reduce the excessive width of certain stretches of the river with willow mattresses; by uniformity of width to produce uniformity of depth, and consequently uniformity of current. This would facilitate the discharge of floods, and would tend to lessen the need of any levees, whereas drawing off any of the volume of water, he said, would increase the elevation of its surface slope, and thus necessitate higher levees.