Of the lessons the most obvious was that the barrage must be slower and of greater depth. General Nugent, in notes written after the battle as a comment upon captured orders of the Fourth German Army, made some interesting suggestions in this regard. He stated in the first case that the Germans could now no longer shell the area over which our troops were advancing, since their own troops were distributed in depth upon it. However much damage their barrage did to our supports, it did little or none to the leading troops. It was, however, more important to facilitate the advance of the latter than to protect the rear area during an attack. If both could not be accomplished, the artillery covering the front of assault should be strengthened at the expense of counter-battery groups. The creeping barrage, he suggested, might be slightly reduced to one 18-pounder per twenty-five yards, and augmented by a sweeping barrage, concentrated to cover about ten yards a gun, each group sweeping right and left along the front allotted to it, with a higher burst and greater searching effect upon shell-holes. The pace of the creeping barrage must be reduced, and there must be more frequent pauses. During these the sweeping barrage and a 60-pounder barrage in front of it might sweep and search. He also made some remarks upon the possibility of control of the barrage by the infantry, the advantages of which are too obvious to merit discussion, and the difficulties of which are equally apparent. But the most interesting of General Nugent's suggestions were with regard to the formations of the infantry. "With the adoption," he wrote, "of a new form of German defensive tactics, consisting of small parties dotted about a wide area, the disadvantages of long lines of attack are that lines have small manœuvring capacity and lack depth. It is for consideration whether mobile company columns echeloned in depth on a narrow front, each a self-contained tactical unit with a machine-gun and trench mortar, each operating within an allotted zone, would not be a more suitable tactical formation than the present system, which breaks up under machine-gun fire and in badly shelled ground into a number of isolated groups without cohesion or leaders." It is to be noted that when, on September the 20th, the 9th (Scottish) Division attacked at Frezenberg, the creeping barrage advanced the first two hundred yards in eight minutes; then slowed to a hundred yards in six minutes; halted on the first objective--four to five hundred yards--no less than an hour, and went forward again at the snail pace of a hundred yards in eight minutes. As regards the infantry, the attack was carried out by lines of sections in file at about twenty yards' interval. The system of "leap-frogging" was also employed instead of special groups for "mopping up." This attack was a complete success.[40] [Illustration: Map III. The Battle of Langemarck, 1917.] FOOTNOTES: