On Wednesday, then, the same day that Von Kluck was encircling Manoury, Von Hausen had all but pierced the French line at Foch's right wing. A bad gap had been formed because Langle de Cary, on the left wing of the Fourth Army, had held firm. There was almost a hole, therefore, ten miles wide, running slantwise behind Langle de Cary's left rear.
The Battle of the Marne is the most important victory of modern times. It saved France. In a measure it saved the world. As the victory hangs on a curious battle formation which developed that afternoon of Wednesday, September 9, its main features may be repeated. It is well to see how the various armies stood at midday of this decisive day.
At midday, Von Kluck was encircling Manoury, having drawn his right wing far to the north and west to do so. His left wing was in momentary danger of attack from the British, who had crossed the Marne. This wing was being driven north.
At midday, Von Buelow was being pushed northwards by the hammer blows of d'Esperey, whose army was fighting in fine fettle, aided by the British heavy artillery. This army was strong enough to lend a corps to help Foch to sustain the central German push. Von Buelow, then, also was being pushed north.
At midday, Foch's left wing, stiffened by the extra army corps, was holding the right wing of the Prussian Guard, but his right wing had been thrust ten miles out of the line by Von Hausen's drive. Von Hausen was therefore exerting every pound of force he owned to break through Foch's right wing, in other words, he was driving southeastward.
At midday, then, Von Buelow and Von Kluck, going northward and westward, were being dragged away from the Prussian Guard and Von Hausen, being dragged southward and eastward.
This thinned the German line, and it thinned it at a very dangerous point, just where the edge of the plateau of Champagne drops suddenly to the marshes of St. Gond.
Possibly Von Hausen was aware of this, but if so, it is evident that he thought that the piercing of Foch's line was only a matter of hours. In any case, Von Hausen was as certain of piercing the line next day as Von Kluck was certain of swallowing Manoury the next day.
At midday, Foch ordered the 42nd Division, one of the crack corps of the French Army, to fall back and rest. The order was thought to be a blunder and the men fumed, for, they thought, they were holding the Germans triumphantly. All through that sultry afternoon, while the skies grew blacker and blacker and the thunder rumbled in the distance, the 42nd Division waited with piled arms, hearing the sound of battle only two miles away. And all through that afternoon, Von Hausen summoned his reserves from behind the Prussian Guard, gathered every man he could get to hurl them into the gradually opening gap.
To the German Commander, the French feet were slipping, slipping, slipping on the brink of disaster and defeat.