From the Flemish coast southward past Lens the great gun duel between the British and Germans continued without ceasing. The Germans had brought up vast stores of ammunition and poured shells into Nieuport, Ypres, and Armentieres, and for miles around sprayed the country at large with the hope of smashing hidden British batteries. To this wide sweeping storm of fire the British were replying with far greater violence, sending two shells to the enemy's one, a rivalry of destruction that had not been surpassed on any previous occasion since the war began. Except for occasional raids the infantry remained quiescent under this gunnery. North of Arras and east of Ypres the British raids netted a considerable number of prisoners and machine guns. The fury of the British fire was not without effect on the generally stolid and imperturbable Germans, for at Fontaine-les-Croisilles they ran away without firing a shot when a British raiding party rushed forward to attack. The three weeks' bombardment in Belgium closed on the morning of July 31, 1917, when British and French troops launched an attack on a gigantic scale along a front of nearly twenty miles from Dixmude on the north to Warneton on the south. The Allies won a notable victory, capturing in the first day of the battle ten towns and over 5,000 prisoners, including ninety-five officers. The attack began a little before 4 o'clock in the morning, just when the first faint light of dawn was breaking, German trenches had been either leveled or were completely wiped out by the preceding bombardment. The shelling increased in violence as the troops of the Allies left their positions and rushed forward to attack. The first and second German lines were carried almost without opposition, but at some points the Germans held up the advance with machine guns from their rear positions. These the British stormed, and lost considerable men in the operation, but they were comforted with the thought that the German losses were much heavier. As a result of the day's operations the British had advanced their line on a front of over fifteen miles from La Basse Ville, on the river Lys, to Steenstraete on the river Yser.