The various supply bureaus were well organized to conduct the demobilization in this way. Before 1917 the bureaus had administered the production of supplies directly from their headquarters in Washington. After the war came, the volume of business grew beyond the capacity of such a system to handle it efficiently; and the principal production bureaus thereupon divided the country into manufacturing districts and placed district organizations, subsidiary to the bureau headquarters in Washington, in charge of them. The bureaus in Washington continued to execute contracts, but the work of superintending manufacture, inspecting products, and paying for supplies was placed in the hands of the district organizations. The Ordnance Department, for instance, established twelve manufacturing districts in the United States and one in Canada. The Director of Purchase, in charge of the production of quartermaster supplies, established fourteen such districts, which were called zones. The Air Service had eight districts and the Chemical Warfare Service four. All production for the Signal Corps, Engineers, Construction Division, and Medical Department was administered directly from Washington. This decentralization of the field administration of war industry had a marked effect upon its efficiency. The administrative officers in charge of a manufacturing district were men of high standing in the business and industry of their respective regions. They knew the manufacturers in those regions. They were always right at the spot when difficulties arose in securing raw materials and fuel and shipping priorities. Even more important, each district organization had within it a representative of the Finance Service of the Army. The War Department was empowered to make advance payments on contracts up to a considerable percentage of the value of work done or supplies actually delivered. These advances, as we have said before, enabled the munitions producers to finance their projects. The district organizations, maintaining finance officers in the field as they did, enabled the producers to obtain these advances in a minimum of time. Frequently the chief executive officers of the manufacturing districts were civilians. Each district board maintained a strong legal department and also numerous technical assistants, not the least among which were the cost accountants. Since a great portion of the war supplies were produced on the cost-plus plan, the war brought the cost accountant into great prominence, during both the period of production and the period of liquidation afterwards.