It has been stated that the real reason why the Germans failed to reach Paris in their memorable drive of September, 1914, was that even their remarkable system of military railroads failed in this supreme crisis. If this be so, it must be that the task placed upon them was superhuman. For it was just such military trains as we have just seen, multiplied in dozens and in hundreds, that moved whole brigades to southern Galicia during the first two weeks of April, 1915--a distance, roughly speaking, equal to that from Boston to Detroit. It was the military plan for the railroads of Germany that brought the regiments out of the trenches in Arras in the last week in June of that same year and on the Fourth of July had them hammering at the might of Warsaw. And Warsaw is 800 miles from the low fields of Arras. Not until the war is over will the whole military workings of the German railroads be known. But examples such as these show that they did work. And it may be remembered that when the German army began flowing in a tidal fashion up over the Russian steppes they came to von Hindenburg and reminded him of Napoleon and the retreat from Moscow. And von Hindenburg showed his great teeth and remarked that Napoleon had had no railroads. "The bread which our soldiers eat today in Windau was baked yesterday in Breslau," he added. And it takes only a single glance at the map to see that Windau is approximately 500 miles distant from Breslau. "We drink German mineral water and we eat fresh meat direct from Berlin. If necessary, we can build fifty miles of railroad in two days. Therefore it is nonsense to speak now of the times and the strategy of Napoleon." * * * * * Here, then, is another of the great practical lessons that these three fateful years are teaching America. Consider now how she may avail herself of this particular lesson--the coordination of her great systems of more than a quarter of a million miles of standard steam railroads with an orderly and intelligent military plan, against any invasion. Other nations have had to build railroads with a particular relation to military strategy. Keen-minded Belgians and Frenchmen long ago noted the tendency of Germany to build double-track railroads to comparatively unimportant points upon her western front--since then they have had the opportunity to see the wartime efficiency of these lines, suddenly turned in an August from practical stagnation into busy, flowing currents of military traffic. Of the strategic value of double-track routes, much more in a moment. For this moment consider the location of the principal rail lines of the United States--particularly in their reference to the defense of the nation.