Close to the ground, a blot of light flashed swifter than a stroke of lightning, and a heavier, thicker smoke rolled away.

“That is one of ours.  We are answering their trench shells with an occasional ’one hundred and twenty.”

“How on earth is it that everybody is not killed?”

“Because the regiment has occupied the Quart so long that we know every foot, every turn, every shelter of it.  When we see a trench shell coming, we know just where to go.  It is only the newcomers who get killed.  Two months past, when a new regiment occupied the Quart during our absence en repos, it lost twenty-five men in one day.”

The first trench that I entered was a simple trench about seven feet deep, with no trimmings whatsoever, just such a trench as might have been dug for the accommodation of a large water conduit.  We walked on a narrow board walk very slippery with cheesy, red-brown mire.  From time to time the hammer crash of a shell sounded uncomfortably near, and bits of dirt and pebbles, dislodged by the concussion, fell from the wall of the passage.  The only vista was the curving wall of the long communication trench and the soft sky of Lorraine, lit with the pleasant sunlight of middle afternoon, and islanded with great golden-white cloud masses.  My guide and I might have been the last persons left in a world of strange and terrible noises.  The boyau (communication trench) began to turn and wind about in the most perplexing manner, and we entered a veritable labyrinth.  This extraordinary, baffling complexity is due primarily to the fact that the trenches advance and retreat, rise and fall, in order to take advantage of the opportunities for defense afforded by every change in the topography of the region.  I remember one area along the front consisting of two round, grassy hills divided by a small, grassy valley whose floor rose gently to a low ridge connecting the two heights.  In this terrain the defensive line began on the first hill as a semicircle edging the grassy slopes presented to the enemy, then retreated, sinking some forty feet, to take advantage of the connecting link of upland at the head of the ravine, and took semicircular form again on the flat, broad summit of the second hill.  In the meadows at the base of these hills a brook flowing from the ravine had created a great swamp, somewhat in the shape of a wedge pointing outward from the mouth of the valley.  The lines of the enemy, edging this tract of mire, were consequently in the shape of an open V. Thus the military situation at this particular point may be pictorially represented by a salient semicircle, a dash, and another salient semicircle faced by a wide, open V. Imagine such a situation complicated by offensive and counter-offensive, during which the French have seized part of the hills and the German part of the plain, till the whole region is a madman’s maze of barbed wire, earthy lines, trenches,—­some of them untenable by either