From March the 12th onward was instituted a series of nightly bombardments, in which the now considerable heavy artillery at the disposal of the XVIII. Corps took part, of valleys and dead ground forming probable assembly positions. Tests of the action to follow the preconcerted Corps message, "Man Battle Stations," were carried out. Bridges had long been prepared for demolition and allotted to particular sections of the Field Companies. Small mine-fields had been constructed in case of the employment of tanks by the enemy. Grugies Valley was starred with machine-guns, to sweep its length with zones of flanking fire. It was felt by officers and men of the Division that what the limited means at its disposal permitted had been accomplished. The worst misgivings were with regard to the gaps between keeps and redoubts in the Forward Zone, owing to the paucity of numbers available for its defence. There was no touch between the battalion headquarters forts in the Line of Redoubts; they were in no sense mutually supporting. There was little to prevent the enemy from breaking through in the intervals, pushing forward his main advance almost unembarrassed by them, while special detachments swallowed them at leisure. Much noise of enemy traffic was heard at night from the 17th onward. On the evening of the 18th two Germans entered our lines on the front of the 107th Brigade to give themselves up. They declared they had deserted to avoid the coming battle, which would not now be long delayed. They confirmed the suspicions of massed trench mortars on the front. They had seen great numbers of troops, particularly of artillery. St. Quentin, they said, was packed with men. On the night of the 20th a raid was carried out by the 61st Division, resulting in the capture of prisoners who stated that the attack was to be launched the following morning. A special bombardment was therefore carried out from 2-30 to 3 a.m., with heavy rolling barrages on likely positions of assembly. The great moment, for which, it is scarce exaggeration to say, men were waiting all the world over, came at 4-35 a.m. on the morning of March the 21st. The infantry of the 36th Division was then disposed as follows: RIGHT BRIGADE: 108TH BRIGADE. Forward Zone: 12th Rifles. Battle Zone: 1st Irish Fusiliers. Divisional Reserve: 9th Irish Fusiliers. CENTRE BRIGADE: 107TH BRIGADE. Forward Zone: 15th Rifles. Battle Zone: 1st Rifles. Divisional Reserve: 2nd Rifles. LEFT BRIGADE: 109TH BRIGADE. Forward Zone: 2nd Inniskillings. Battle Zone: 1st Inniskillings. Divisional Reserve: 9th Inniskillings.