Between the Blue line and the Black line there were no organised defences, except the communication trenches and a few sections of fire trench connecting one communication trench with another. The Brown line itself consisted on the left of two heavily-wired fire trenches containing numerous dug-outs. On the right, however, the work had not been completed, and consisted of a section of unfinished fire trench, with a deep sunken road running behind and parallel to it. On the whole Divisional front the advance to the Blue line lay over a considerable forward slope; beyond the Blue line it continued over a large plateau, finally dropping down on to the Brown line on the reverse slope beyond the plateau. Prior to the attack a considerable amount of gas was employed against the enemy. Livens projectors, a form of smoke which discharged a cylinder of gas a considerable distance, were chiefly employed. On one occasion on the Divisional front, Mr Livens, the inventor of these projectors, observed their effect from an aeroplane. Four-inch Stokes mortars were also extensively used for firing gas bombs. In fact, the enemy was gassed on 4th April, 5th April, and 8th April, over 600 drums of gas being discharged into the trenches. The bombardment of the enemy's lines began in earnest on 4th April, and from that date wire-cutting by the artillery and 2-inch trench-mortars became intense. The trench-mortar batteries carried out their daily task of wire-cutting with the greatest gallantry, as the Germans developed an intense dislike to them, and retaliated on them heavily with artillery whenever they opened fire. On more than one occasion the artillery fired rehearsals of the creeping barrage, which, as far as could be observed, were very accurate. These practice barrages disclosed the fact that, as soon as they were opened, the enemy could put down a heavy bombardment of 4·2 and 5·9 howitzers on to our front line in about two minutes. Some batteries of 9·45 mortars had also been placed in positions from which they could deal with particular centres of resistance on the German lines. It was when in charge of one of these mortars that Sergeant Gosling, R.F.A., won the first Victoria Cross for the Division. A mortar was fired, but the charge was faulty, and though the shell left the gun, it fell only a few feet in front of the emplacement. Sergeant Gosling immediately sprang from the emplacement, drew the shell from the ground, into which it had buried its nose. He then unscrewed the fuze and threw it away before it could detonate the shell. The fuze was set for seventeen seconds, so that by the time Sergeant Gosling had reached the shell and drawn it from the ground, it was a question of only a few seconds before it would explode. The sergeant had, however, the presence of mind to take a fuze-key from his pocket, unscrew the fuze, and thus save the lives of the detachment.