In front of the left wing of his forces, which was now established to the west of the Vosges south of the Lunéville-Donon line, there was nothing but the open and unfortified Trouée de Charmes (the wide plain south of Nancy between Epinal and Toul), and the attenuated army of General Dubail. If they had succeeded in breaking through that human barrier, and if their companion Army Corps north of Lunéville had been equally successful in disposing of General de Castelnau’s army (two rather large suppositions) it is possible that they may have intended to bring up fresh forces and heavier siege guns for the investment of Epinal and Toul, and that the main army, without waiting for their reduction, would have been pressed forward to effect the contemplated junction with the armies operating from the north, just as von Kluck and von Hausen advanced to Namur and Charleroi while at least one of the forts of Liége was still holding out. But at any rate General Dubail’s army had to be dealt with first, and to this work they turned their immediate attention. As for Epinal, which was directly in front of their left flank, they found that it, like Belfort, was protected for some miles in front of its forts by a formidable network of trenches and wire entanglements, against which they decided not to run their heads, though the salient just north of Bruyères in the line of their furthest advance on this sector seems to show that they meant to make the attempt at first. That was the second stage in the process of shortening the lower leg of the compasses. The position defended by Dubail’s army after the retreat from the Vosges extended from a point a few miles south of Lunéville to the Bonhomme, along the line forming the diagonal of an approximate square, (with a side twenty miles long) of which Lunéville, the Donon, the Col de Bonhomme and Epinal (nearly due south of Lunéville) were the four angles. This tract of land is watered by three smallish rivers, the Vesouze, the Meurthe, and the Mortagne, all rising in the Vosges, and flowing through shallow valleys towards Lunéville. Along the banks of each of them there is a good road and a railway. The Vesouze follows very nearly the north side of the square, and the chief towns on it are Cirey and Blamont. The Meurthe and the Mortagne flow close together, from south-east to north-west, one on each side of the diagonal. On the Meurthe the chief towns are St. Dié, Raon l’Etape, and Baccarat, and on the Mortagne, to the west of it, Rambervillers and Gerbéviller. The three rivers, after meeting in Lunéville or just below it, continue their joint course through Nancy to Frouard, five miles further north, where they join the Moselle, which rises near Belfort and flows to the west of the three other rivers through Epinal, Charmes, and Bayon, to Toul, from which it makes a steep bend to the east to Frouard, where it is joined by the Meurthe, and then flows nearly due north past Pont-à-Mousson to Metz.