While the 6th Army, within sight of the Ourcq, was suffering its great agony, while the “effect of suction” was showing itself in the Anglo-French pursuit of Kluck, very different were the first results at the centre of the long crescent of the Allied front. Kluck was saved by his quick resolution, together with Marwitz’s able work in covering the rear. Bülow was in no such imminent danger. His communications with the north were at first perfectly safe. The situation of his right wing, which must either fall back or lose contact with the I Army, was awkward; but, doubtless, Kluck’s success would soon re-establish it. The circumstances indicated for the remainder of the II Army and the neighbouring Saxon Corps an instant attempt to break through the French centre, or at least to cripple it, and, with it, all Joffre’s offensive plan. The very strategic influence which helped the British and d’Espérey, therefore, at first threw a terrible burden upon Foch and the “detachment” which on September 5 was renamed the “9th Army”; yet it was by this same influence that, in the end, though by the narrowest of margins, he also won through. [Illustration: The MARNE RE-CROSSED. Morning of Sept. 9.] The theatre of this struggle is the south-western corner of the flat, niggardly expanse of La Champagne Pouilleuse, lying between the depression called the Marshes of St. Gond and the Sezanne–Sommesous railway and highroad. It is very clearly bounded on the west by the sharp edge of the Brie plateau; on the east it is bordered by the Troyes–Châlons road and railway. Sezanne on the west, and Fère Champènoise at the centre, are considerable country towns; the right is marked by the permanent camp of Mailly. To the north of Sezanne, the hill of Mondemont, immediately overlooking the marshes and the plain, and the ravine of St. Prix, on the Epernay road, where the Petit Morin issues from the marshes and breaks into the plateau, are key positions. The Marshes of St. Gond (so called after a seventh-century priory, of which some ruins remain) witnessed several of the most poignant episodes of Napoleon’s 1814 campaign “from the Rhine to Fontainebleau.” They were then much more extensive. Between the villages of Fromentières and Champaubert, there survives the name, though little else, of the “Bois du Desert,” where 3000 Russian grenadiers are said to have been slain or captured by Marmont’s cuirassiers, while hundreds of others were drowned. A month later, Blücher was back from Laon attacking on the same ground; and Marmont and Mortier were in full retreat along the road to Fère Champènoise. Pachod’s national guards, the “Marie Louises,” turned north to the marches of St. Gond as to a refuge. The Russians and Prussians surrounded them; and only a few of the French lads escaped by the St. Prix road. To-day the marshes are largely reclaimed and canalised; but this clay bed, extending a dozen miles east and west, and averaging more than a mile in breadth, fills