Orders were thus issued for as much ground as possible to be gained in High Wood by sapping forward. Progress was also to be made between High Wood and the Divisional right boundary, by digging-in posts in advance of the existing front line during the night, and ultimately connecting them up into continuous trenches. The actual labour of digging in the wood was considerable, as beneath the soil there lay a tangled mass of thick roots, in many cases too stout to be severed by a spade. The work, therefore, was slow and arduous, axes and billhooks having to be employed as well as picks and shovels. The enemy, however, paid little attention to the working parties. On the right it was considered likely that, as there was no cover, the enemy would interfere considerably with digging operations. An apparatus was therefore employed, known as the Bartlett Forcing Jack. The Bartlett Jack was designed to drive iron pipes loaded with tin canisters of ammonal (containing two lb. of ammonal per foot run) through the ground at a depth of from four to five feet. When a sufficient length of pipe had been driven into the ground in the required direction, the charge was exploded. The explosion blew a fissure in the ground which served as a trench. In this instance the labour of carrying the pipes and ammonal up to the line, and of working the task, proved incommensurate with the results obtained. This was particularly so when it became evident that considerable liberties could be taken by working parties without interference from the Boche. On the night 3-4th August General Burn decided to employ a considerable working party and boldly "jump" a trench some 200 yards in front of the existing front line. That is to say, instead of sapping forwards and digging "T" heads at the ends of the saps for the posts to occupy, and finally connecting the "T" heads together so as to form a continuous trench, a continuous fire trench was dug in the first instance during the night, and occupied by a garrison at dawn. Subsequently communication trenches were cut to connect this trench with the support line, Seaforth Trench. The Germans thus on 4th August woke to find that the whole of the Divisional front line, exclusive of the wood, had advanced some 200 yards towards them. When the Division was relieved on 7th August, more than half High Wood was in our hands and consolidated. The redoubt in the eastern corner was, however, as formidable as ever. To the right of the wood the line had been advanced some 300 yards, while to the left the position had been so consolidated that there was no gap in the lines, and the flank was properly secured.