On the 5th our infantry again went into the line, and I took over command of the artillery, which included, in addition to my own brigades, the 7th D.A., the 16th R.H.A. Brigade, and an Anzac Brigade. That afternoon a mine exploded in Mory, killing one and wounding two of my men, and also wounding some artillery mules. In the evening a similar mine went off in Ervillers with disastrous effect, killing five and wounding seven men of D/312. These mines, which we often met with later, were worked by a corrosive acid, acting on a wire holding a spring hammer; when the acid had eaten through the wire, which might be within a period ranging from a few hours to several weeks, according to the relative strengths of the acid and the wire, the hammer struck a detonator, and the mine exploded; a typically Hunnish method of warfare. For the next few days guns were actively employed in wire cutting, and the enemy responded by a vigorous shelling of the valley. Capt. J. Willey and 14 men of B/310 were wounded on the 7th, and between the 6th and the 9th three other officers were hit, Major F. A. Arnold Forster, and Lieuts. P. K. B. Reynolds and H. C. Ashby. Five Military Medals were awarded for gallant work on these days. On the 9th April the Third and First Armies on our left began a big forward movement, to be known as the Battle of Arras, and by the evening of the 13th they were in possession of the Vimy Ridge and the whole of the Wancourt branch of the Hindenburg Line, and had taken about 16,000 prisoners, together with a large number of guns and mortars. Our share in the operations was to make holding attacks and to keep as many of the enemy as possible glued to our front. One of the trench mortar batteries, V/62, was lent to the 51st Division, and took part in the capture of the Vimy Ridge. On the last day of the battle C/312 suffered heavily, losing the Sergeant-Major, three Sergeants, and four other ranks killed, eight men wounded and four guns knocked out. Capt. G. L. C. Hudson was wounded on the 13th, and Lieut. K. B. Nicholson on the 14th; the latter officer was awarded the Military Cross for the following services: "On the 13th April, 1917, Lieut. K. B. Nicholson entered a dug-out in which both a gas shell and a high explosive shell had burst, and bravely attempted to save the men inside. Later on in the day, though suffering from the effects of the gas, he went to the O.P. with the Battery Commander, and while under heavy shell fire volunteered to go back over the wire, thereby keeping up communication with the battery. The following day, while still suffering from the gas, he again repaired to the O.P. under heavy gas fire, remaining there until he was finally wounded in the head by a fragment of high explosive shell. By his actions on the days under review this gallant officer showed a fine example of devotion to duty." Our casualties in the artillery up to this date amounted to 14 officers and about 150 other ranks.