On the left the 154th Brigade carried all their objectives as far as the Black line, according to plan, though they were engaged in some stiff fighting. The 4th Seaforth Highlanders carried out their initial operation with complete success, and opened the way for the rest of the advance, as had been arranged. The 152nd Brigade, however, met with difficulties from the start. The 6th Gordon Highlanders, attacking the trenches they had raided, reached all their objectives behind the barrage. On their left the 6th Seaforth Highlanders experienced some heavy fighting both in the second and third German lines. Indeed, so strong was the resistance encountered by the 6th Seaforth Highlanders that when the 5th Seaforth Highlanders attempted to advance through them to form up under the barrage, they found them still engaged with the enemy. The 5th Seaforth Highlanders had no other alternative than to join in the mêlée and help to clear the ground for their own advance. The German fought magnificently, and was well supported by his artillery. In front of the 6th Seaforth Highlanders he had evacuated his front line, and was thus able to bombard it without danger to his own troops. In consequence, the 6th Seaforth Highlanders suffered some casualties from shell-fire before they reached their second and third objectives. The casualties thus sustained caused gaps in the attacking waves, which enabled the enemy to man his machine-guns effectively after the barrage had passed. Each machine-gun that thus came into action required a separate minor operation on the part of the infantry to subdue it. The following figures, compiled by General Burn, illustrate the nature of the fighting:-- "The 6th Seaforth Highlanders lost 326 officers and men in capturing the Black line. "One company of the 5th Seaforth Highlanders detailed to capture the Blue line suffered 90 casualties before reaching the Black line. "A second company of the 5th Seaforth Highlanders, detailed for the Blue line, had used all its rifle grenades before reaching the Black line. "Only one officer of the 6th Seaforth Highlanders, detailed for the capture of the Blue line, reached it; the remainder were all either killed or wounded." It will thus be seen that in the centre success was only achieved by the gallantry and determination of the officers and men engaged. Two tanks had been allotted to the Division to assist the infantry advance, but they were both out of action before they had reached the leading infantry, and so did not in any way contribute to the success of the attack.