The United States Military Railroad in France, it should clearly be understood, was not a railroad system such as we build in America by patient planning and toil and the actual upturning of virgin soil. While many millions of dollars were expended in its construction, it was not, after all, a constructed railroad. In any legal or corporation sense it was not a railroad at all. It was in fact an adaptation of certain lines--side lines wherever possible--of long-existent French railways. To best grasp it, one must first understand that the greater part of French rail transportation is divided into five great systems. Four of these--the Nord, the Etat, the Paris-Lyons-Méditerranée, and the Orléans--shoot many of their main stems out from the heart of Paris, as the spokes of a wheel extend out from its hub. These spoke lines, if I may be permitted the phrase, long since were greatly overburdened with the traffic which arose from the vast army operations of the French, the British, and the Belgians. The problem was to make the French railway system bear upon its already much-strained back the additional transport necessities of our incoming army of at least two million men within the first twelve months of its actual operations. Between the radiating spoke lines of the French railways leading out from the great hub of the wheel at Paris is a network of smaller and connecting lines, the most of them single-tracked, however. The whole structure, in fact, greatly resembles a huge spider's web; far more so than our own because of its more regular outlines. Colonel Wilgus and Colonel William Barclay Parsons, the designer of the first New York subway system, who accompanied him in the first inspection of the army transportation problem in France, quickly recognized this spider's web. And a little inspection showed them the great burden that its main spokes already were carrying; convinced them of the necessity of using other lines for the traffic of the American Army. For it was known even then that in addition to carrying the men themselves there would have to be some 50,000 tons a day transported an average distance of six hundred miles for an army of two million men.