His mighty antagonist, on the other hand, was advancing to the encounter with such large resources, and so thoroughly equipped, that no fewer than three Army Corps were left behind, because even the admirably man managed and numerous German railway lines were not able to carry them at once to the banks of the Rhine. Moreover, General von Moltke, the Chief of the Great Staff, had, in 1868–69, carefully reasoned out plans, which were designed to meet each probable contingency, either a march of the French through Belgium, an early irruption into the Rhenish provinces, or the identical scheme upon which the Emperor founded his hopes; while, if the French allowed the Germans to begin offensive operations on French soil, then the method of conducting the invasion, originally adopted, would come into play. The memorandum on this great subject, the essential portions of which have been published by its author, Von Moltke, is, for breadth, profundity, and insight, one of the most instructive to be found in the records of war. This is not the place to deal with its general or detailed arguments. For present purposes, it is sufficient to set forth the main operative idea. The contention was, that an army assembled on the Rhine between Rastadt and Mainz, and on the Moselle below Treves, would be able to operate successfully, either on the right bank of the main stream, against the flank of a French Army, which sought to invade South Germany; or, with equal facility, concentrate on the left bank, and march in three great masses through the country between the Rhine and Moselle, upon the French frontier. Should the French make a precipitate dash into the German country towards Mainz, then the Corps collected near that fortress would meet them in front, and those on the Moselle would threaten their communications or assail them in flank. The soundness of the reasoning is indisputable; its application would depend upon the prompt concentration of the Armies, and that had been rendered certain by careful and rigorously enforced preparations. The great Prussian strategist had calculated the move of troops and railway trains to a day; so that he knew exactly what number of men and guns, within a given area, he could count upon at successive periods of time; and, of course, he was well aware that the actual use to be made of them, after the moment of contact, could not be foreseen with precision, but must be adapted to circumstances. But he foresaw and prepared for the contingency which did arrive. “If,” he said, “the French desired to make the most of their railways, in order to hasten the assembly of all their forces,” they would be obliged to disembark, or as we now say, “detrain” them, “at Metz and Strasburg, that is, in two principal groups separated from each other by the Vosges.” And then he went on to point out how, assembled on the Rhine and Moselle, the German Army would occupy what is called the “interior lines” between