Over at Seven Pines the center of McClellan's army was about to be routed. Now it was that General Heintzelman personally collected about eighteen hundred men, the fragments of the broken regiments, and took a decided stand at the edge of the timber. He was determined not to give way. But this alone would not nor did not save the day. To the right of this new line of battle, there was a rise of ground. From here the woods abruptly sloped to the rear. If this elevation were once secured by the Confederates, all would be lost and rout would be inevitable. The quick eye of General Keyes took in the situation. He was stationed on the left; to reach the hill would necessitate taking his men between the battle-lines. The distance was nearly eight hundred yards. Calling on a single regiment to follow he made a dash for the position. The Southern troops, divining his intention, poured a deadly volley into his ranks and likewise attempted to reach this key to the situation. The Federals gained the spot just in time. The new line was formed as a heavy mass of Confederates came upon them. The tremendous Union fire was too much for the assaulting columns, which were checked. They had forced the Federal troops back from their entrenchments a distance of two miles, but they never got farther than these woods. The river fog now came up as the evening fell and the Southern troops spent the night in the captured camps, sleeping on their arms. The Federals fell back toward the river to an entrenched camp. Meanwhile at Fair Oaks Station the day was saved, too, in the nick of time, for the Federals. On the north side of the Chickahominy were stationed the two divisions of Sedgwick and Richardson, under command of General Sumner. Scarcely had the battle opened when McClellan at his headquarters, six miles away, heard the roar and rattle of artillery. He was sick at the time, but he ordered General Sumner to be in readiness. At this time there were four bridges across the river--two of them were Bottom's Bridge and the railroad bridge. To go by either of these would consume too much time in case of an emergency. General Sumner had himself constructed two more bridges, lying between the others. The heavy flood of the preceding night, which was still rising, had swept one of these partially away. In order to save time, he put his men under arms and marched them to the end of the upper bridge and there waited throughout the greater part of the afternoon for orders to cross. Before them rolled a muddy and swollen stream, above whose flood was built a rude and unstable structure. From the other side could be distinctly heard the roar of battle. The fate of the day and of the Army of the Potomac rested upon these men at the end of the bridge.