It was clear that in this squatting war all traditions had crumbled hopelessly and wilted away. The monstrous engines belched fire and destruction. From the caverns themselves, deeply cut in the once fertile fields, issued a storm of shot and shell from machine-guns, from mortars of an old-fashioned type, from cannon of the newest type—every imaginable engine of destruction, down to the old hand-grenade, again in usage from a distant past—a past so ancient that Scott reminds us in _Rob Roy_ that "in those days this description of soldiers" (_i.e._ the Grenadiers) "actually carried that destructive species of firework from which they derive their name." Thus every device known to man’s inventive and destructive brain was directed into a new and diabolical channel, and from time to time the vast engines employed emitted a rending noise as if the earth were spitting flame and its rocky ribs had shattered into quivering fragments—a volcano in its most fearful mood, sending forth a mad jumble of rocks and a living stream of lava devastating and devouring. A gaunt and desolate country haunted by the melancholy crows, resounding with clacking detonations of fusillades and a hoarse bass of heavy cannon, is the place of invisible war. One rubs shoulders with it without being aware of it. One comes suddenly upon it in all innocence. A journalistic friend, at the beginning of the war, dashed into its area all unknowing that he had come on top of it. To his unpractised eye the lines were no more clearly marked than the Equator or the North Pole. And, of course, every effort is made to conceal the battle-field. Beet-root grows riotously on battlements, guns hide behind trees and are covered with branches, so that the airman, peering from his height, sees nothing but the flicker of leaves. The line hides itself as soon as it fights, and without loss of time prepares against a possible retreat. That is the method of it. Should it be driven back, there are strong positions in the rear for the rallying, for the defence _à outrance_, and for the counter-attack. Fronts have two or three lines of shelter trenches, deep enough to cover a man and generally a yard in width. These trenches are proportioned to the effectives employed. They contain redoubts and blockhouses where guns are placed; they are linked by zigzag paths, and, as a last resort, with a trench of cement, a veritable fortress where are cannon as well as machine-guns. These covered over and fortified trenches nearly always contain rest chambers and magazines for rifles and the different sorts of ammunition required.