route was put in hand early in February, running forward to Monac, partly to supplement the bury and partly to carry forward the head of the main route in anticipation of the advance next spring. The ground was found to be frozen as hard as concrete to a foot from the surface, and after ineffectual struggles with picks and crowbars, excavations for the pole holes were finally blasted with gun-cotton. As the forward end of this route came under direct observation, the last few hundred yards were run in cables hung on short stakes, each cable from a small bobbin insulator nailed to the side of the stake. This method was copied from the French, who had used it extensively in the area, and proved very satisfactory in this instance. In the meantime, aeroplane night-bombing and the shelling of back areas by long range guns, initiated in the latter stages of the Somme Battle, had developed to an unpleasant extent. Rarely did a day pass without some main route suffering from one or other of these agencies, and the consequent necessity for diverting the limited working parties from urgent construction to still more urgent repairs. The railheads of Maricourt and Bray were favourite targets, and again and again the unfortunate sappers were turned out of their blankets to stumble along a route in the pitch black night, and then struggle for hours with numbed fingers to evolve order out of a chaos of tangled wire and broken poles. This hostile aeroplane activity caused a rapid increase of anti-aircraft units. Batteries and searchlights were now dotted over the area, and the installation and maintenance of a separate and complete system of communication for the Anti-Aircraft Defence of the Corps area was now added to the Company’s duties, and the H.A. Signal Officer found himself occupied with communications for the Survey Groups and the installation of lines to their O.P.’s, and to the Microphone positions of the Sound Ranging Section now added to the H.A. Counter Battery organization.