This calculation, by which the conditions of modern war are compulsorily affected, makes it highly necessary that the system of supplies and rations should be carefully organized. The restoration of any destroyed railways, the construction of light railways, the organization of columns of motor transport waggons and draught animals, must be prepared by every conceivable means in time of peace, in order that in war-time the railroads may follow as closely as possible on the track of the troops, and that the columns may maintain without interruption continuous communications between the troops and the railhead. In order to keep this machinery permanently in working order, and to surmount any crisis in bringing up supplies, it is highly advisable to have an ample stock of tinned rations. This stock should, in consideration of the necessary mass-concentration, be as large as possible. Care must be taken, by the organization of trains and columns, that the stock of tinned provisions can be quickly renewed. This would be best done by special light columns, which are attached to the army corps outside the organization of provision and transport columns, and follow it at such a distance, that, if necessary, they could be soon pushed to the front by forced or night marches. There is naturally some reluctance to increase the trains of the army corps, but this necessity is unavoidable. It is further to be observed that the columns in question would not be very long, since they would mainly convey condensed foods and other provisions compressed into the smallest space. An immense apparatus of train formations, railway and telegraph corps, and workmen must be got ready to secure the efficiency of a modern army with its millions. This is absolutely necessary, since without it the troops in modern warfare would be practically unable to move. It is far more important to be ahead of the enemy in this respect than in any other, for there lies the possibility of massing a superior force at the decisive point, and of thus defeating a stronger opponent. However careful the preparations, these advantages can only be attained if the troop columns do not exceed the maximum strength which can be fed from the rear, if the necessary forward movement is carried out. Everything which an army corps requires for the war must be kept within these limits.