From Delville Wood the main plateau extends for 4,000 yards east-northeast to Les Boeufs and Morval, and for about the same distance southeastward to Leuze and Bouleau Woods, which stand above and about 1,000 yards to the west of Combles. To bring my right up into line with the rest of my front it was necessary to capture Guillemont, Falfemont Farm, and Leuze Wood, and then Ginchy and Bouleau Woods. These localities were naturally very strong, and they had been elaborately fortified. The enemy's main second-line system of defense ran in front of them from Waterlot Farm, which was already in our hands, southeastward to Falfemont Farm, and thence southward to the Somme. The importance of holding us back in this area could not escape the enemy's notice, and he had dug and wired many new trenches, both in front of and behind his original lines. He had also brought up fresh troops, and there was no possibility of taking him by surprise. [Sidenote: Rain and unfavorable ground.] [Sidenote: Constant haze.] The task before us was, therefore, a very difficult one and entailed a real trial of strength between the opposing forces. At this juncture its difficulties were increased by unfavorable weather. The nature of the ground limited the possibility of direct observation of our artillery fire, and we were consequently much dependent on observation from the air. As in that element we had attained almost complete superiority, all that we required was a clear atmosphere; but with this we were not favored for several weeks. We had rather more rain than is usual in July and August, and even when no rain fell there was an almost constant haze and frequent low clouds. [Sidenote: British and French must advance together.] [Sidenote: Positions the French must capture.]