Then, if the army should be compelled to retreat before the enemy, there should be available a sufficiency of forces skilled in the art of rapidly and effectively destroying lines, bridges, viaducts, tunnels, or other railway property, with a view to retarding the enemy's movements until, it may be, reinforcements can be brought up in sufficient number to check his further progress. If, alternatively, the army should advance into the enemy's country, there must again be a provision of Railway Troops fully qualified by previous training and experience both to repair quickly the demolitions or the damage which the enemy will have carried out on his own lines and to construct hastily such new lines--light railways or otherwise--as the circumstances of the moment require. These things done, and still further advance being made into the invaded territory, the need will also arise for a staff capable of operating, under war conditions, the lines of which possession has been taken, in order that communications with the advanced front and the forwarding of reinforcements and supplies can still be maintained. All these and many other things, besides, must needs be thought out and prepared for in time of peace, long in advance of any probable or even any possible war. They are, in fact, made the subject of exhaustive and continuous study alike by military officers specially entrusted with the task and by railway managers commanding all the technical knowledge requisite for making arrangements calculated to ensure the prompt and efficient satisfaction of all such demands for military rail-transport as may, with whatever urgency, and under whatever conditions, some day be put forward. Still more practical do the preparations in peace for war become when they include the construction of a network of strategical railways expressly designed to facilitate the mobilisation of troops, their speedy concentration on the frontier, or their movement from one point of attack to another at the theatre of war. CHAPTER X ORGANISATION IN GERMANY In no country in the world was the desirability of preparing in time of peace for military rail-transport in time of war recognised earlier than in Germany. In none has the practice of such preparation in peace been followed up with greater study and persistence. As shown in Chapter I, the military use of railways led to the proposal and discussion in Germany of definite schemes for such use as early as 1833; and it is not too much to say that, from that date down to the outbreak of the World-War in 1914, the whole subject had received there an ever-increasing degree of attention from the military authorities, and, also, from a large body of writers as a question of the day in its relation more especially to German expansion.