The 4th Battalion made the advance, having the 1st in support, under the covering fire of the First Canadian Artillery Brigade. The troops were conscious that they were engaged in a desperate venture, but their comrades were in peril, and there was no hesitation as they dashed into the storm of fire that swept the field from the enemy's guns. The attack was pressed, though the casualties reached an alarming figure. Colonel Birchall, commanding the 4th Battalion, who, waving a light cane, encouraged and rallied his men, was killed. The loss of their beloved commander fired the troops with renewed energy, and with hoarse cries they dashed forward against the enemy to avenge his death. So fierce was the onslaught that the Germans were overwhelmed and the first line of trenches was won after a hand-to-hand conflict. The importance of this victory--won in the face of almost certain death--saved the Canadian left, and not only that, but it maintained at a critical moment the integrity of the Allied line. For the 4th Canadian Battalion did more than capture the German trench: they held it against the most determined German assaults until April 25, 1915, when the decimated and weary remnants of the battalion were finally relieved. The success of the attack was not a little due to the admirable work of the First Artillery Brigade under Lieutenant Colonel Morrison, whose battery of four 18-pounders was later supplemented by two heavier guns, and served with great efficiency throughout the struggle. Colonel Morrison for his services was given command of the artillery of the Second Division with the rank of brigadier general. Another officer who contributed to the victory was Captain T. E. Powers of the Signal Company of General Mercer's command. Though the enemy's heavy shell fire repeatedly cut the signal wires, communication with the front line of the attack was never lost. General Turner's Third Brigade, which, as previously noted, was holding the Canadian left on April 22, 1915, and after attacking had taken over the defense of the new Canadian salient, had also sent a detachment to establish a line between the wood and St.-Julien. Here they were subjected to a heavy gas attack followed by two enemy assaults. They were unprovided with the means for protecting themselves against the gas, but a wet handkerchief stuffed in the mouth was found to afford relief, and they held their ground beating off the heavy attacks in which the enemy lost heavily. The assault on the wood, as previously narrated, followed.