To make confusion worse confounded, officers, runners, reliefs, ration parties, &c., as long as movement is restricted to the hours of darkness, find the greatest difficulty in acquiring a working knowledge of the geography of the defences. Moreover the Germans, in those days of short advances, were quick at recovering from the confusion in their artillery arrangements created by a successful attack. They were therefore always liable to bombard a newly-captured position heavily before the men had time to construct sufficient field-works to protect themselves from shell splinters. In the case of the front taken over by the Division on this occasion, the normal difficulties were accentuated by the fact that digging-in was only possible to a depth of from two to three feet. Everywhere in the Flanders mud, below that level water is encountered. It is therefore necessary to erect above ground double rows of traversed breastworks, between which the men must live and have their being. The difficulty of consolidation in this mud country requires to have been experienced to be fully appreciated. The work of maintaining breastworks, when completed, in a state of repair is considerable, as they cannot withstand a bombardment by artillery or trench-mortars. In consequence sections of the trenches are frequently levelled to the ground, and have to be reconstructed. The labour of maintaining them when once erected is, however, a small problem when compared with the difficulty of erecting them _de novo_ during active operations. In the first place, owing to the flatness and absence of cover from view, which is characteristic of Flanders, the work of construction is in the initial stages almost entirely confined to night work. As breastworks will only stand if their sides are graded at the proper slope, darkness makes this work infinitely more difficult. Moreover, breastworks during their construction and before they have reached their full thickness can be demolished by light field-guns, and be seriously damaged even by machine-gun fire. Of these two facts the enemy used to take full advantage. He also knew well that much of the work had to be done by men standing in the open on his side of the breastworks, and so made considerable use of machine-guns to inflict casualties on working parties thus engaged. There are other serious drawbacks to garrisoning breastwork trenches. Deep dug-outs cannot be mined in the clay in the normal way, again on account of water. Concrete shelters, which take a considerable time to erect, are therefore the only alternative form of shell-proof cover. Even these have a marked tendency to fill with water.