Although many descriptions and maps of the country round about Loos have been issued, it may not be out of place to attempt one more brief outline, from which the general trend of the operations from September 25, 1915, onward can be followed. Descriptions of a country that one does not know being invariably flat and unconvincing, it may suffice to lay down the main features in a very few words. From the La Bassée Canal southward to Souchez is a purely coal-mining district, one of the most important in France, an undulating country devoid of natural features, but abounding in artificial ones, such as chimney-stacks, mine-shafts and dump-heaps. The miners' villages, locally termed _corons_, group themselves about the pit-heads, and form two long lines of almost continuous brick and mortar, separated by a shallow valley, normally under cultivation, but now lying fallow and deserted, varying in width from a few hundred yards to a couple of miles or so. In the centre of this valley lies Loos, a village of some two thousand inhabitants, conspicuous for miles round from the huge double shaft, the famous Pylons, that rise nearly three hundred feet above the surface of the plain. Of the two lines of villages, that surrounding the mines owned by the Compagnie des Mines de Béthune, and consisting of Cambrin, Vermelles, Philosophe, Mazingarbe, Les Brebis, Grenay, Maroc, and Aix Noulette, was, about the middle of September, held by the Allies. The eastern line, consisting of Auchy, Haisnes, Cité St. Elie, Hulluch, Benifontaine, Vendin, Cité St. Auguste, Lens and its countless suburbs, and Liévin, was, at the same period, held by the enemy. Along the course of the valley, but well up the western slope of it, so that the village of Loos lay a mile within them on the German side, ran the two opposing lines, with their maze of support and reserve trenches, their sinuous lines of communication trenches leading up the slopes of the valley to the villages in rear. From our observation posts in Maroc the whole of the southern sector of these parallel works could be plainly seen, the line of each trench through the green overgrowth of weeds being conspicuously marked by the white chalk thrown up in excavating them. Behind these again, two long black arms stretched out towards us, with a sinister look as though inviting us to leave the comparative security of our trenches and rush to the attack of the body from which they grew, the city of Lens. In reality nothing but embankments formed by the continual deposition of refuse from the mines, these two arms, the northern known as the Double Crassier, the southern as the Puits XVI embankment, had been transformed by the enemy into exceedingly strong positions, mined, entrenched, fortified by every known means, the westernmost ramifications of the fortress into which Lens had been converted. Opposite the extremity of the Puits XVI embankment the Allied armies met, the right of the British line resting