The regiments that crossed the river at Vailly found themselves in even a worse plight.  No sooner had they crossed than the bombardment began, and the Germans knew every range in the place accurately.  More than that, the line of trenches was open to enfilade fire from a hidden battery, which did not unmask until the trench was filled with soldiers.  This Eighth Brigade had to retire in disorder.

The Fifth Brigade, attached to the First Army Corps under Sir Douglas Haig, an Irish and Scotch group of regiments, were the most successful of all.  The bridge at Pont Arcy had been destroyed, but still one of its girders spanned the stream.  It would have been tricky walking, even under ordinary circumstances, but nerve racking to attempt, when from every hill and wood and point of land, Maxims, machine guns and a steady rifle fire are concentrated on the man crossing that one girder.  By the afternoon, the engineers attached to the First Army Corps had also established a pontoon bridge, and the whole brigade crossed the river in the evening and dug itself in.

Late on Sunday afternoon, however, a weak spot showed itself in the German line and Sir John French threw the First Division of the First Army Corps across the river near Bourg.  Some of the infantry crossed by a small pontoon bridge and a brigade of cavalry started to follow them.  When they were in mid-stream, however, a terrific storm of fire smote them.  The cavalry pushed on, but could not ride up the hill in the teeth of the bombardment.  The infantry were eager to go, but nothing was to be gained by the move, so the cavalry returned over the pontoon, by a most extraordinary occurrence not having lost a single member in the three hours it had been scouting on the hostile side of the Aisne.  The infantry intrenched themselves solidly to await the morning.

The main forces of the First Division were especially lucky.  Using the canal aqueduct they made their way toward Bourg, and drove the Germans back toward the main ridge.

More than three-quarters of the summit of the ridge had been won, the entire Second Infantry Brigade was across, the Twenty-fifth Artillery Brigade was across, ready to support, and General Bulfin, instead of tiring his men by making them intrench there, ordered them to rest, throwing their outposts in front of the hamlet of Moulins.

This ended the first day’s fighting on the battle of the Aisne.  Of the Third Army Corps, a small body of men had reached Chipres.  There they had been joined by a small force from the Second Army Corps.  In the First Army a strong detachment dug itself in not far from Pont d’Arcy.  The incomparably superior position of the Germans, their huge numbers, their possession of innumerable guns, made even this shaky tenure dangerous, though all held on.  Sir John French had tested and found out the German strength and the result was not encouraging.