This principle was based on the Napoleonic distinction between supplies required during an advance and those required during a concentrated halt.
This system has been considerably modified by the immense development of mechanical transport. The principle of supply now followed is that "field units should always have with them or within reach two days' rations and forage and an iron ration, and that the supply service should keep these stocks 'H. Camon, Guerre napolionienne.
replenished by delivering one day's rations and forage every day at a point within easy reach of the troops." No hard and fast rule can be laid down as to the source from which supplies shall be drawn, and all local resources are utilized as fully as possible in order to save unnecessary transportof supplies from the base. Food collected from local resources during a period of concentration will usually be stored in supply depots for subsequent issue to the troops. Such supplies should first be drawn from those districts adjoining the immediate area of con centration through which the army will not pass. Supplies within the area of concentration are left, as far as possible, for the use of the local inhabitants.
Generally, then, a force operating in Europe would be main tained in food, forage, fuel, and petrol from the base by rail and mechanical road vehicles, due allowance having been made for such supplies as can be obtained locally by formation supply officers, by purchase, or on requisition. As regards requisitioning, the rule is that only officers of a service detailed for the duty are authorized to purchase or requisition, but in cases of emergency requisitions may be carried out by the officer commanding the troops for whom the supplies are required. Authority to requisi
tion is not delegated to any but a commissioned officer, and requisitioning on the part of a warrant officer, n.c.o., or man is treated as plundering, unless the case is one of extreme urgency and no commissioned officer is present. All purchases and requisi tions should be made through the local civil authorities. Mobile re serves of supplies do not normally exist but would be found from reserve mechanical transport units and allotted to formations to meet special circumstances. When it is impracticable for a force on the move to be reached by a daily supply convoy, it will usually be accompanied by a supply column carrying supplies for several days. In such a case the radius of action of the force is limited by the amount of food accompanying it.
In savage or undeveloped countries the conditions are far less favourable and each case has to be dealt with on its merits. Such warfare formerly used to necessitate an almost complete de pendence on magazine supply, as communications were necessarily uncertain and difficult. These conditions are more or less being overcome by the development of cross-country mechanical ve hicles. Nevertheless the supply difficulties in expeditions in the Sudan, West Africa, or on the Indian frontier still far outweigh all difficulties of country or enemy. (X.)