But now the lines or waves of men which had left the trenches in extended formation were broken up into separate little bodies, all independently engaged in various grim tasks. They had mounted La Boiselle hill, and moved down into the valley which still intervened between them and Bailiff's Wood and Contalmaison. Thus they were in the very centre of the labyrinth of the enemy's system of defences. An air of intolerable mystery and sinister hidden danger hung over it. Was it not possible that those brutes, those dirty fighters, the inventors of poisonous gas, liquid fire and flame jets, who had established themselves in the very vitals of the place, might not have other devilish inventions prepared for the wholesale massacre of their adversaries? The thought arose in the minds of many, and caused a vague sense of apprehension. The Germans, however, had no further hellish surprises. Even so, the place was baneful and noxious enough. The Germans had suffered terrible losses and were morally shaken by the artillery bombardment--gigantic, devastating, thunderous--which preceded the British advance. It is the fact, nevertheless, that most of the survivors had enough courage and tenacity left doggedly to contest every inch of the way. They lay concealed in all sorts of cunning traps and contrivances, apart from their demolished trenches. Machinery on the side of the British--in the form of big guns--had done its part. The time had come for the play of human qualities, the pluck, the endurance and the stout arm of the British infantry man. Snipers had to be dislodged from their burrows; hidden machine-gun posts had likewise to be found out and silenced. So the men of the Tyneside Irish were rushing about in small parties, shooting, bayoneting, clubbing, bombing; and the triumphant yells which arose here and there proclaimed the discovery of yet another lair of the foe. Many a stirring story of personal adventure could be told. Sergeant Knapp of Sunderland, who won his stripes in the advance, gives this account of his experiences-- "I had just taken the machine-gun off my mate to give him a rest when 'Fritz' opened fire on us from the left with a machine-gun, which played havoc with the Irish. Then I heard my mate shout, 'Bill, I've been hit,' and when I looked round I saw I was by myself; he, poor chap, had fallen like the rest. Now I had to do the best I could, so I picked up a bag of ammunition for the gun and started across 'No Man's Land.' Once I had to drop into a shell-hole to take cover from machine-gun fire.