the action, this route was extended up the Bohain-Vaux Andigny Road to the farm which had been selected as a joint Brigade Headquarters for the two fighting Brigades. For this extension, the poles of a German permanent route were employed, one cable being slung on the poles at a height of 15 feet above the ground, and the other run along the ground. The latter was fastened to each pole of the permanent route in order to localize breaks caused by shell fire. This route was reinforced by both wireless and visual, but the cable held so well, in spite of heavy shelling, that the latter systems were only employed to a limited extent. The Headquarters of the 137th Brigade was in Bohain itself and was connected with the Headquarters of the Battalion holding the front to the west of the wood by both cable and wireless. The latter proved very useful during the early hours of the attack, when the German barrage made it impossible for some hours to maintain lines to this unit.
Aeroplane photographs had supplied material for very complete maps of the German defences in all the more open portions of the area to be attacked and, during the 16th October, a heavy preliminary bombardment was carried out. Special attention was paid to wire-cutting, and destructive fire was directed for some hours on the hamlets of Regnicourt and Andigny les Fermes and on all known strong-points.
Zero hour was finally fixed for 5.20 a.m. on the 17th October and, well before that time, the attacking Brigades had formed up, with a front of 2,000 yards, on a line one hundred yards south-east of the Bohain-Vaux Andigny Road, the inter-brigade boundary being about Vallée Hasard. The 139th Infantry Brigade advanced on the right of the Divisional Sector and the 138th Infantry
