To the left of the wood the trench lines, which were not continuously connected up, curved in a south-westerly direction towards Bazentin-le-Petit, leaving the wood as the apex of an acute salient. In this section of the front the trenches seemed to fulfil no tactical requirements. There was no depth to the defensive system; the trenches were little more than knee-deep, and were choked with dead. Work on a single communication trench--High Alley, running from the Crucifix at Bazentin to High Wood--had been begun. The Germans held a strong redoubt in the eastern corner of High Wood. In this corner the contours were such that there was a depression in the ground similar in shape to a saucer. The Germans had fortified this saucer, and garrisoned it with machine-guns, mostly sited so as to fire to a flank. They could thus, by firing eastwards from this redoubt, rake No Man's Land in direct enfilade. By firing westwards, they could place an enfilade barrage of low trajectory bullets which swept the rides through the wood. This redoubt was surmounted by wire entanglements, the tops of the pickets being just visible when looked at frontally and from our foremost saps. Passing through the north-east corner of the wood was a strong switch line, which ran from Flers through High Wood towards Martinpuich. This was a well-dug, heavily-traversed trench protected by wire, but during this period had no completed dug-outs in it. Air photos, however, showed where work on the shafts of several dug-outs had been begun. The whole of this area had been the scene of repeated encounters, as the ground amply testified. In the undergrowth of the wood, and in the standing corn which covered the whole area, lay the dead of many different regiments. The result was that, owing to the scorching summer weather, the troops in the line lived in an atmosphere of pollution and in a positive torment of bluebottle flies. In one sap in particular, as one moved along it the flies rose in such clouds that their buzzing sounded as the noise of a threshing-machine. In this sap the sentries could only tolerate the conditions by standing with their handkerchiefs tied over their mouths and nostrils. By 3 A.M. on 22nd July, the 154th Infantry Brigade had completed the relief of the 33rd Division. The 13th Brigade of the 5th Division were on their right, and the 57th Brigade of the 19th Division on their left. Of the 154th Brigade two battalions held the line, the remaining two being in support and reserve in Bazentin-le-Grand Wood and Bazentin-le-Grand.