On the left bank of the Seine the southwestern camp is situated, including Versailles, whose main forts are those of St. Cyr, Haut-Bue, Villeras and Palaiseau, to which the large redubt of Bois d'Arey and the forts of Chatillon and Hautes-Bruyeres, situated a little to the rear, belong likewise. To invest this strongest fortress of the world the line of the Germans ought to have a length of 175 kilometers and to its continuous occupation, even if the ring of the investing masses were not very deep, a much greater number of troops would be necessary than were used in 1870 for the siege of Paris. GERMAN AMMUNITION CAPTURED A correspondent at Nanteuil, September 12, thus described the capture of a German ammunition column while the Germans were feeling their way toward Paris: "The seven-kilometer column was winding its way along Crepy-en-Valois when General Pan sent cavalry and artillery to intercept it. The column was too weakly guarded to cope with the attack, and so was captured and destroyed. This capture had an important bearing on the subsequent fighting. "A noticeable feature of the operations has been the splendid marching qualities of the French troops. This was displayed especially when two divisions, which were sent to intercept the expected attempt of the Germans to invest Paris, covered eighty kilometers (49½ miles) in two stages." ALLIES PLAN TO PROTECT PARIS The plan of the Allies on September 1 was to make a determined stand before Paris, in the effort to protect the city from the horrors of a siege. With their left wing resting on the strongly fortified line of the Paris forts and with their right wing strengthened by the defensive line from Verdun to Belfort, they would occupy a position of enormous military strength. If the Germans concentrated to move against their front the French reserve armies could assemble west of the Seine, move forward and attack the German invading columns in flank. If in their effort to continue the great turning movement the Germans pushed forward across the Seine and attempted by encircling Paris to gain the rear of the allied armies, the French could mass their reserve corps behind their center at Reims, push forward against the weakened German center in an attack that if successful would cut off the German invading columns and expose them to annihilation. Such were the conditions and the possibilities when the German advance reached its climax on September 4. [Illustration: POSITION OF HOSTILE ARMIES, SEPTEMBER 4, 1914 Heavy dotted line denotes battle front of the Allies; lighter line the position of the German Troops.] CHAPTER XI BATTLE OF THE MARNE _German Plans Suddenly Changed--Direction of Advance Swings to the Southeast When Close to the French Capital--Successful Resistance by the Allies--The Prolonged Encounter at the Marne--Germans Retreat With Allies in Hot Pursuit for Many Miles_.