Metz, and some thousands of volunteers who had joined him in the march, made his appearance to the west of Dumouriez on the very evening when Westerman and Thouvenot, two of the staff-officers of Dumouriez, galloped in with the tidings that Brunswick's army had come through the upper passes of the Argonne in full force, and was deploying on the heights of La Lune, a chain of eminences that stretch obliquely from southwest to northeast opposite the high ground which Dumouriez held, and also opposite, but at a shorter distance from the position which Kellerman was designed to occupy.
The allies were now, in fact, nearer to Paris than were the French troops themselves; but, as Dumouriez had foreseen, Brunswick deemed it unsafe to march upon the capital with so large a hostile force left in his rear between his advancing columns and his base of operations. The young King of Prussia, who was in the allied camp, and the emigrant princes, eagerly advocated an instant attack upon the nearest French general. Kellerman had laid himself unnecessarily open, by advancing beyond Dampierre's camp, which Dumouriez had designed for him, and moving forward across the Aube to the plateau of Valmy, a post inferior in strength and space to that which he had left, and which brought him close upon the Prussian lines, leaving him separated by a dangerous interval from the troops under Dumouriez himself. It seemed easy for the Prussian army to overwhelm him while thus isolated, and then they might surround and crush Dumouriez at their leisure.
Accordingly, the right wing of the allied army moved forward in the grey of the morning of the 20th of September to gain Kellerman's left flank and rear, and cut him off from retreat upon Châlons, while the rest of the army, moving from the heights of La Lune, which here converge semicircularly round the plateau of Valmy, were to assail his position in front, and interpose between him and Dumouriez. An unexpected collision between some of the advanced cavalry on each side in the low ground warned Kellerman of the enemy's approach. Dumouriez had not been unobservant of the danger of his comrade, thus isolated and involved, and he had ordered up troops to support Kellerman on either flank in the event of his being attacked. These troops, however, moved forward slowly; and Kellerman's army ranged on the plateau of Valmy "projected like a cape into the midst of
