With the dawn it became of most pressing importance {53} to do something to lessen, if not to fill, the huge gap which yawned between the left of the Canadians and the canal, like a great open door five miles wide leading into Ypres. Troops were already streaming north at the call of Smith-Dorrien from all parts of the British lines, but the need was quick and pressing. The Canadian 1st Brigade, which had been in reserve, was thrown into the broad avenue down which the German army was pouring. The four battalions of General Mercer's Brigade--the 1st (Ontario), 4th, 2nd, and 3rd (Toronto)--advanced south of Pilken. Nearer still to St. Julien was the wood, still fringed by their comrades of the 10th and the 16th, while to the east of St. Julien the remaining six battalions of Canadians were facing north-eastwards to hold up the German advance from that quarter, with their flank turned north-west to prevent the force from being taken in the rear. Of these six battalions the most northern was the 13th Royal Canadian Highlanders, and it was on the unsupported left flank of this regiment that the pressure was most severe, as the Germans were in the French trenches alongside them, and raked them with their machine-guns without causing them to leave their position, which was the pivot of the whole line. [Sidenote: The crisis.] Gradually, out of the chaos and confusion, the facts of the situation began to emerge, and in the early morning of April 23 French saw clearly how great an emergency he had to meet and what forces he had with which to meet it. The prospect at first sight was appalling if it were handled by men who allowed themselves to be appalled. It was known now that the Germans had not only broken a five-mile gap {54} in the line and penetrated two miles into it, but that they had taken Steenstraate, had forced the canal, had taken Lizerne upon the farther side, and had descended the eastern side as far south as Boesinghe. At that time it became known, to the great relief of the British higher command, that the left of the Canadian 1st Brigade, which had been thrown out, was in touch with six French battalions--much exhausted by their terrible experience--on the east bank of the canal, about a mile south-east of Boesinghe. From that moment the situation began to mend, for it had become clear where the reinforcements which were now coming to hand should be applied. A line had been drawn across the gap, and it only remained to stiffen and to hold it, while taking steps to modify and support the salient in the St. Julien direction, where a dangerous angle had been created by the new hasty rearrangement of the Canadian line.