On the outbreak of hostilities there is appointed for each theatre of war an _Inspector-General of Railways and Lines of Communication_ who, receiving his orders from the Chief of the General Staff, co-ordinates the two groups of services, and ensures harmony in their joint working. For the operation of the railways, as applied to military purposes, there is a _Director of Field Railways_ who, acting under the Inspector-General, controls the whole railway service. Through the Line Commissions or Commandants subordinate to him he conveys to the railway authorities the necessary demands or instructions in respect to military transport, and, in concert with his superior officers, he fixes the boundary between the lines to be operated on a peace footing and those that are to be subject to military working. In the discharge of these and other duties he is assisted by a staff composed partly of military men and partly of railwaymen. Each officer concerned in the transport arrangements has a recognised deputy who can act for him in case of need. Of _Line Commissions_, placed in charge, for military purposes, over the lines of railway in certain districts, and becoming _Line Commandants_ on the outbreak of war, there were twenty under the revised Regulation of 1899, the number being increased in 1904 to twenty-one. The headquarters of these Commissions are at such centres of traffic as Berlin, Hanover, Erfurt, Dresden, Cologne, Altona, Breslau, etc. They serve as intermediaries between the higher military authorities and the railway administrations with which they are associated. Each Line Commission consists, normally, of a staff officer of the active army and a prominent railway functionary, the former having a non-commissioned officer, and the latter a railway official, as secretary, with such further assistance as may be needed. Subordinate, in turn, to the Line Commissions are the _Station Commissions_, which, receiving instructions from the former, see to the carrying out of the necessary transport requirements either at their particular station or on the section of line of which they are placed in charge. While full provision is thus made for the representation of the military element in the conduct of rail-transport in time of war, with a view to ensuring its efficiency, precautions are no less taken to avoid repetitions of earlier troubles due to questions of responsibility and control, and, more especially, to the interference of military officers in the technical operation of the railway lines. On this subject the Field Service Regulations of 1900 stated (paragraph 496):-- Railways can only fully accomplish their important and difficult task during war if no serious hindrances to their management are created by the conduct of the troops. In the later Regulations of 1908 it was said (paragraph 527):--