To establish this defensive flank the 169th Brigade on the right was to push forward of Leuze Wood and occupy a position roughly north and south with its left flank astride the sunken road from Combles, about 300 yards east of the edge of Leuze Wood. The 167th was to clear Bouleaux Wood in two stages and establish a line parallel to and about 100 yards in front of its east edge. The 1/4th Londons were to follow up the advance of the 167th Brigade and then "leapfrog" through it on to the German third line immediately in front of Morval whence they would connect up between the left of the 167th Brigade and the right of the 6th Division. The 15th September was on the greater part of the battle front a day of big successes. At an early hour Flers fell before our assault, and by the afternoon the British line had been pushed far beyond it; the whole of High Wood was taken, and before nightfall Martinpuich and Courcelette on the left had been added to the gains of the day. On the extreme right, however, the advance suffered a rather severe check. The Guards, who occupied the left of the Corps front, were able to make solid advances between Flers and Lesbœufs, but the 6th Division adjoining them were held up by the Quadrilateral at Ginchy, whose brave defenders still maintained their position most stubbornly; and this failure naturally reacted on the 56th Division who occupied a narrow wedge between the Quadrilateral and the Combles ravine. At 5.50 a.m. the three tanks which were to make their début with the Division left their departure points for the first objective, and at 6.20 a.m. the infantry assault was launched. Almost three hours later, at 9 a.m., the 1/4th Londons left their bivouacs in Angle Wood Valley and moved forward in artillery formation towards the battle position on the crest between the north edge of Leuze Wood and the west face of Bouleaux Wood. Progress was not rapid owing to the heavy state of the ground, and under the German shell fire a good many casualties were sustained. The advance was made, however, in good order, and with admirable steadiness. The 169th Brigade made very slight advances on the south of Leuze Wood; while the 167th managed to secure the part of its first objective which lay outside Bouleaux Wood. The 8th Middlesex of the latter Brigade even made a heroic attempt to reach the second objective, but had to be brought back. The enemy barrage was heavy and fell, as it so often had in the Somme battles, between the assaulting columns and their starting-point, thus cutting them off from supplies and reinforcement, while the accurate intensity of their machine-gun fire from their positions in the Quadrilateral made advance an utter impossibility. After ten hours' fighting, during which the assaulting Brigades did all that men could do, the Corps Commander telephoned to Gen. Hull that the Division would make no further attempt against Bouleaux Wood that day.