The next few days were spent in harassing the enemy parties working on their new positions, and in work on our own trenches. On the 8th and 9th the 6Oth Brigade was relieved by the 61st in the right sub-sector. Though the 60th went into reserve, the troops had not much rest, for by the 10th, 600 men of the Brigade were working nightly on the new line from Cork Cottages to Dragoon Farm, and 200 men were employed in burying cables. On the 11th an additional 600 men (300 from the artillery and 300 from the reserve brigade) were required to bury cables for the XIVth Corps. The last phase of these operations was carried out on the 13th, when the Canadians attacked in order to regain the lost ground. To assist them, the 20th Division was ordered to discharge gas and smoke along its front and then push out patrols, following these up by larger raiding parties if possible, at four selected points in the German line. Zero was 1.30 A.M. on the 13th. Owing to the short notice that had been given, it was found impossible to get all the gas cylinders into the trenches in time. By some mistake in one part of the line, the smoke bombs were thrown three minutes before zero. This unfortunately gave alarm to the enemy, who thus had time to put on gas masks. The gas, discharged at zero from 130 cylinders, went well and quickly. In three minutes practically all the rifle and machine-gun fire from the German trenches had ceased. The artillery barrage also began at zero, and was most effective. After twenty-five minutes it lifted to allow our infantry raiding parties to go forward. On the right one party of the Somerset L.I., under Captain J. N. C. Peard, was held up by the wire near Railway Wood. Owing to the gas this party had to put on gas masks, and while attempting to cut a passage through the wire 3 men were killed and Captain Peard and 10 men wounded. All the wounded, however, were brought back safely. A party of the 11th K.R.R.C. under Lieut. H. A. Denison got in at the Mound (south-west of Verlorenhoek), which was found to be practically obliterated by our trench mortar bombardment. This party beat off a counter attack, and returned with only five slight casualties. The left party got as far as the German wire and reconnoitered the position, but, being only a small patrol, did not attempt to enter the trenches. The 1st Canadian Division in a most successful attack regained Mount Sorrel and Observatory Ridge.