The conservation of natural resources, the creation of new ones is a topic which combines the qualities of science, service and utility. Of all our resources the soil is the most vital. Most of the others have some possibility of substitution, but for the soil there is no substitute. The forest burned to destruction can rise again if the soil remains. Some examination will show that the most vital part of the whole conservation matter is the preservation of the soil, and that soil conservation is 99 per cent the prevention of erosion. Soil robbery by unscientific agriculture can go to its most extreme lengths and reduce the soil to the depths of non-productivity; but scientific agriculture can, by the addition of humus and some fertilizer, soon restore such soil to high fertility. In these conditions of exhaustion the loss to fertility by soil leaching is small, because of the non-soluble character of the earth particles. Thus experiments at Cornell have shown that in the average foot of top soil from rather unproductive farms in a low state of production, there was plant food sufficient for 6,000 crops of corn. We have all seen a single thunder shower remove from a hillside corn field the fertility adequate for the making of a hundred crops of corn. American agriculture is peculiarly soil destructive. Three of our greatest money crops--corn, cotton and tobacco--require that the earth shall, throughout the summer, be loose and even furrowed with the cultivator, which prepares the ground for washing away, and by its furrow starts the gully. The second factor in this peculiarly destructive agriculture is the fact of our emphasis of rainfall in summer. Third in the list of factors of destruction is the rainfall unit, the thunder shower, which dumps water, hundreds of tons per hour on every hillside acre. A little examination of the facts and careful inclusion of the time element will show that the old-world saying, "After man the desert" is quite as true in the United States as in Europe and Asia, where it has been so fearfully proven in the seats of ancient empire. This soil resource destruction from erosion leads to the destruction of other valuable resources. We appear to be upon the eve of an epoch of waterway construction and experiment. The greatest injury to waterways is channel filling by down-washed mud. Pittsburgh has been praised highly for the energetic action of her Chamber of Commerce and citizens in appropriating money for the careful survey of drainage basins above the river, with the idea of obtaining knowledge preparatory to the building of reservoirs to check floods. They have forty-three reservoir sites, and the early construction of nineteen of these reservoirs is recommended.