Take, for example, an instance so recent as to have been contemporary with men not yet old,—the Turkish position at Plevna in 1877. This stopped the Russian advance on Constantinople for almost five months. Why? Because, if they had gone on, Plevna would have been close to their line of communications, and in a central position relatively to their forces at the front and those in the rear, or behind the Danube. It was also so near, that, if the enemy advanced far, the garrison of Plevna could reach the only bridge across the Danube, at Sistova, and might destroy it, before help could come; that is, Plevna possessed an interior line towards a point of the utmost importance. Under these circumstances, Plevna alone arrested the whole Russian movement. In the recent war between Japan and Russia,[23] the Port Arthur fleet similarly threatened the Japanese line of communications from Japan to Manchuria, and so affected the whole conduct of the war. It was central, as regards Japan and Liao-Yang, or Mukden. Study of such conditions reinforces knowledge, by affording numerous illustrations of the effect of position under very differing circumstances. Let us now go back from the Danube with its Center, North, and South, to the communications between the Spanish coast and the Austrian army in Germany. Should the House of Austria in Spain desire to send large reinforcements to the Danube, or to the Rhine, by way of Italy, it can do so, provided it controls the sea; and provided also that France has not shaken its hold upon North Italy. Such a condition constitutes open and safe communications. If, however, command of the sea is not assured, if the French navy, say at Toulon, is equal to the Spanish navy in the neighborhood, there is danger of a reverse; while if the French navy is superior locally, there is great danger not merely of a reverse but of a serious disaster. In such a case the French navy, or the port of Toulon, flanks the Spanish line of communication; again an instance of position. As to position, Toulon would correspond to Plevna and Port Arthur. This instance illustrates, however, as Port Arthur conspicuously did, that the value of a position is not in the bare position, but in the use you make of it. This, it is pertinent to note, is just the value of anything a man possesses, his brains or his fortune—the use he makes of either. Should the French navy be decisively inferior locally to the Spanish, Toulon loses its importance. As position it is still good, but it cannot be used. It is an unavailable asset. So at Plevna, had the garrison been so small that it could not take the field, the place either would have been captured, or could have been watched by a detachment, while the main Russian body moved on. At Port Arthur, the inefficiency of the Russian navy permitted this course to the Japanese. They watched the place by navy and army, and went on with their march in Manchuria. Even