And there were, of course, the necessary number of roundhouses, and the like, to complete the organization of the self-sufficient railroad. Not far away was a tremendous assembling and repair plant for airplanes, the operators of which had all been trained in the French factories, so that they knew the planes to the last inner bolthead. The last assembly-plant was far from least in picturesqueness. It was for the construction, from numbered pieces shipped from Switzerland, of 3,500 wooden barracks, each about 100 feet long by 20 wide, and of double thickness for protection against French weather. [Illustration: _Copyright by the Committee on Public Information._ U. S. locomotive-assembling yards in France.] The most amusing of the incidental depots was called the Reclamation Depot, at which the numerous articles collected on the battle-field by special salvage units were overhauled and refurbished, or altered to other uses. Nothing was too trifling to be accepted. The "old-clo' man" of No Man's Land was responsible for an amazing amount of good material, made at the Reclamation Depot from old belts, coat sleeves, and the like. Many a good German helmet went back to the "square-heads" as American bullets. In the same American district there was a great artillery camp, with remount stables, containing thousands of horses and mules. Under French tutelage, the American veterinarians had learned to extract the bray from the army mule, reducing his far-carrying silvery cry to a mere wheeze, with which he could do no indiscreet informing of his presence near the battle-lines. So the mule-hospital was one of the busiest spots in the port. A short distance from the port, the engineers built a 20,000-bed hospital, the largest in existence, comprising hundreds of little one-story structures, set in squares over huge grounds, so that every room faced the out-of-doors. Between the port and the hospital, and beyond the port along the coast, were the rest-camps, the receiving-camps, and a huge separate camp for the negro stevedores. Near enough to be convenient, but not for sociability, were the camps for the German prisoners, who put in plenty of hard licks in the great port-building. Midway between all this activity at the coast and the training and fighting activity at the fighting-line there was what figured on the army charts as "Intermediate Section," whose commanders were responsible for the daily averaging of supply and demand. In the intermediate section, linked by rail, were the supplementary training-camps, schools, base hospitals, rest-areas, engineering and repair shops, tank-assembling plants, ordnance-dumps and repair-shops, the chief storage for "spare parts," all machinery used in the army, cold-storage plants, oil and petrol depots, the army bakeries, the camouflage centre, and the forestry departments, busy with fuel for the army and timber for the engineers.