The base of the German salient ran from Montdidier east and a little south, by way of Noyon, and linked up with the old line between St. Gobain and Anizy-le-Château, nine miles west of Laon, a distance of thirty-two miles in all. Just as the northern extremity of the German salient was flanked by the Arras ridges, so the southern extremity of thirty-two miles was flanked in the east by the watershed of the Oise and the Aisne, and eastward from the valley of the Oise, where it is joined by the ridge lying parallel to the Chiry-Lassigny highway. The Allies holding the ridges north and south of the German salient were in a favorable position, and it seemed unlikely that the Germans would attempt to push farther westward without trying to capture the high approaches on their flanks. It was known to the Allies through their aerial observers that the German armies, reenforced by new divisions that had been brought from Russia, were massing for another powerful attack. On March 28, 1918, strong German forces drove back the British line south of the Somme to a line running west of Hamel, Marcelcave, and Demuin in the direction of Amiens. On the same date the Germans launched a terrific drive in the Scarpe sector with the purpose of capturing Arras and Vimy Ridge. Six German divisions were flung against the British positions, while four were held in reserve, but they failed to break through. To the south between Boiry and Serre eleven divisions attacked the British positions, but were forced back. On the same date, in the Montdidier region, the French under Pétain not only held their ground but made gains. In the course of the evening and part of the night the Germans made violent attacks in the endeavor to eject the French from the villages of Courtemanche, Mesnil-St. Georges, and Assainvillers, which were won the day before, but in every instance were driven back with heavy losses. The French followed up their success by driving the enemy out of Monchel, which they occupied. To the north of Montdidier Franco-British troops continued to hold the Germans on the Avre River and in front of Neuville, Mezières, Marcelcave, and Hamel. It was evident that the great German offensive was losing force. The fighting was still intense at some points, but no operations were attempted on such a colossal scale as marked the fighting in the first week of the battle. At many places along the front of attack the Germans were being driven back and at others French and British were holding their positions firmly. Artillery battles had now taken the place of infantry fighting to a great extent, a sure sign that the German armies were in an exhausted condition and needed time to re-form and recuperate. As the Germans had been unable to drag much artillery with them during their advance the French had the advantage.