The most important part to destroy in the centers of resistance _are the edges_, for the attack breaks through easily enough in the intermediate spaces but immediately comes under flanking fire. Moreover, a center of resistance whose borders are disorganized, becomes a harmless island, the attack of which by main strength would be terribly costly; for instance, the Labyrinth, Neuville-Saint-Vaast, Carency, which were passed by in less than an hour by groups arriving at the Cemetery of Neuville, at the La Folie Woods, and at the first houses of Souchez. _Therefore try especially to neutralize the borders_ by concentrating on them the fire of batteries suitably placed with a view to following the attack on the intervals. If one could put a _veil over the centers of resistance_ to isolate them and obstruct the view of the flanking works, the problem would be partly solved. It would then be necessary to have projectiles giving off large quantities of heavy smoke, which would spread out over the ground and dissipate very slowly. The intermediate works in the intervals are easy to take because of their small dimensions. On the 9th of May, they were generally found knocked to pieces. (_c_) _Preparation against Artillery._ _The infantry urgently demands that the hostile artillery be put out of action before the attack._ If the enemy artillery gets into action, the troops, crowded into the trenches, _boyaux_,[4] and parallels, have to suffer a painful bombardment, which causes losses and obliges everyone to hunt cover—an inauspicious attitude for troops which will have shortly to rush forward. Communications become difficult, the telephonic connections are broken, everyone gets nervous and perturbed. On the attack proper, artillery fire has an extraordinary disturbing effect; the bullets of the rifles and machine guns cause disorder by the sudden and serious losses they occasion, but the shells spread confusion almost solely by the sight and the crash of explosions. On the 9th of May, we hardly received any shells at all, not one during the attack itself, and this contributed in a large degree to the magnificent _élan_ of the first attacking waves. At Langemarck on the contrary, in a night attack on the trenches on the 4th of December, the unsilenced hostile artillery bombarded our trenches of departure, and I had my second section dispersed through being saluted by a rafale of shrapnel that had put the chief of section and the file closers, _hors de combat_.