Driven by stern necessity, the Germans became the most intelligent and successful farmers of the world. Their average yields of all crops per acre exceeded those of any other country, and were from one and a half to two times as large as the average yield in the United States. The German farmer raised two and one half times more potatoes per acre than the average for the United States. He was aided by an adequate supply of cheap farm labor and by unlimited supplies of potash at low prices, since Germany, among her few important natural resources, possessed a virtual monopoly of the world's potash supply. Try as they would, however, the German farmers could not feed and clothe more than about forty of Germany's nearly seventy millions. Even this was a tremendous accomplishment, which can be the better appreciated if one attempts to picture the State of Texas feeding and clothing four of every ten inhabitants of the United States. Strenuous efforts were made by the German Government to increase this proportion. Moorlands were reclaimed and extensive projects for such reclamation were being prepared when the war came. The odds were too great, however, and the steady shift of population toward the cities made it increasingly difficult to cultivate all the available land and likewise increased the amount of food required, since there is an inevitable wastage in transportation. What this shift of population amounted to is indicated by the fact that whereas the aggregate population of the rural districts in 1871 was 63.9 per cent of the total population, it was but 40 per cent in 1910. During the same period the percentage of the total population living in cities of 100,000 population or over had increased from 4.8 to 21.3. In the most favorable circumstances about three-sevenths of the food needed by Germany must be imported. The government had realized that a war on two fronts would involve a partial blockade, but neither the German Government nor any other government did or could foresee that a war would come which would completely encircle Germany in effect and make an absolute blockade possible. Even if this had been realized it would have made no essential difference, for it must always have remained impossible for Germany to become self-supporting.