It was an ideal opportunity for the employment of pack transport. Once the enemy had been pushed off the ridge it was secure from ground observation, while, as for German aeroplanes, they had no chance to cross our lines, so complete was the British mastery of the air. The pack was one of the successes of the battle. Officers commanding battalions had in most cases picked their headquarters in the enemy's lines days before, and told their transport officers they would expect them at such an hour with the rations, just as if they had been holding the most placid trenches on the front. They were not disappointed. Indeed, mules were moving up with grenades, water, and wire, before ever the Black Line was reached. The transport officers of the battalions showed in this action that long months of stagnation in the war had not robbed them of their initiative. The forward slopes of the Messines Ridge, ere dusk put for a while a decent veil upon it, presented a ghastly spectacle to bear witness to the destructive power of modern artillery. The ground had been literally ploughed up. L'Enfer Wood, which had remained a considerable copse of stunted trees through years of shell-fire, was now but an indeterminate collection of stumps. Some of the concrete structures had disappeared. The Steenebeek stream was a stream no more. Its path was marked by mud thicker than elsewhere, and where its bed had been the shell-holes were full of water. There were a number of dead Germans in the valley, with their faces turned toward the hill. They had run back before the dreadful moving wall of the British barrage, and had been caught by it in the marshy ground. Some lay on their faces, arms outstretched. It was a sight that, at normal times, would have filled the breast of everyone who witnessed it with pity and horror. But in such moments the wells of these emotions are almost dried up.