Two tributaries are to be considered in this river valley which thus forms so natural a post of defense. Both flow in from the south, the Suippe, which joins the main stream at Neufchatel-sur-Aisne and the Vesle, on which stands the ancient city of Rheims. This river joins the Aisne a little over seven miles east of Soissons, which is itself twenty miles east of Compiegne. The line taken by the German armies for their stand was not the river itself, but the northern ridge. At no place more than a mile and a half from the river, it was always within gunfire of any crossing. Every place of crossing was commanded by a spur. Every road on the north bank was in their hands, every road on the south bank curved upward so as to be a fair mark for their artillery. As the German drive advanced, a huge body of sappers and miners had been left behind to fortify this Aisne line, and the system developed was much the same along its entire distance. There were two lines of barbed-wire entanglements, one in the bed of the stream which would prevent fording or swimming, and which, being under water, could not easily be destroyed by gunfire from the southern bank. Above this was a heavy chevaux-de-frise and barbed-wire entanglement, partly sunk and concealed from view; in many places pitted and covered with brushwood. Above this, following approximately a thirty-foot contour, came a line of trenches for infantry, and fifty yards behind a second line of trenches, commanding a further elevation of fifty feet. Two-thirds of the way up the hill came the trench-living quarters, the kitchens, the bakeries, the dormitories, and so forth, and the crest of the hill bristled along its entire length with field guns, effectually screened by trees. On the further side of the ridge, in chalk pits, were the great howitzers, tossing their huge shells over the ridge and its defenses into the river itself, and even on the south bank beyond. Truly, a position of power, and one that the boldest of troops might hesitate to attack. It is quite possible that had the entire strength of the German position been known, no attempt to cross would have been made, but there was always a possibility that the counterchecks of the German army were no more than the rear-guard actions of the three or four days immediately preceding. Yet Sir John French seems to have expected the true state of affairs, for he remarks in his dispatches: "The battles of the Marne, which lasted from the morning of the 6th to the evening of the 10th, had hardly ended in the precipitate flight of the enemy when we were brought face to face with a position of extraordinary strength, carefully intrenched and prepared for defense by an army and staff which are thorough adepts in such work."