The grand advance was signalized by a long-distance bombardment of towns in the rear of the American lines. Heavy shells from German naval guns fell in regions far behind the actual battle area, some reaching points twenty to thirty miles distant. It was mainly a night display, marked by a constant hurtling of projectiles from ten-and fifteen-inch naval guns, and canopied the whole countryside with a blaze of light. The German purpose was to batter towns and communication lines beyond the defense line and to harass the movement of supplies and reenforcements. The Marne curls to a salient northward at Jaulgonne, and the peak of this bend provided the first crossing for the Germans. Descending upon this point in great force, they succeeded in crossing the river in the face of a destructive fire from American machine gunners and infantry, who fought and died where they stood. The salient could not be held, being exposed to fire from three sides. Westward of it toward Château-Thierry, and eastward toward and beyond Dormans, the German advance likewise could not be stayed, and there was a general withdrawal of American forces along the river bank. The Germans succeeded in crossing at ten points between Château-Thierry and Dormans. They threw many pontoon bridges over to bear their troops. Shoals of canvas boats were also brought into requisition. These proved more serviceable than the bridges, the laying of which was repeatedly thwarted by American fire. Protected by the heavy bombardment, the boats managed to carry the members of the kaiser's famed Tenth Guard Division, twenty to each boat; but very few of them got back. American guns foiled their passage three times. Machine gunners clung to their posts on the river bank here and there till the last moment. They poured deadly streams of bullets into the enemy, and only withdrew when their guns were so hot that they could not be fired. One group happened to be in a place where the Germans were anxious to erect a bridge, but their efforts were fruitless. The American bullets piled up the German dead on the opposite side of the river every time the enemy started to cross. South of Jaulgonne the enemy crossed the Marne on six pontoon bridges, hurriedly thrown over the stream, and masses of infantry swarmed forward. The artillery constantly had the bridges under the heaviest fire, and at least two direct hits were made, two of the bridges being blown up. The task of preventing German swarm, despite these checks, proved too great, and the Americans fell back to the base of the salient made by the river.