Once more considering the source of the Marne, near Langres, it will be noted that the River Meuse rises near by, flowing north by east to Toul, and then north-northwest past Verdun to Sedan, where it turns due north, flowing through the Ardennes country to Namur, in Belgium. To the east of the Meuse lies the difficult forest clad hill barrier, known as the Hills of the Meuse; to the east extends (as far as Triaucourt) the craggy and broken wooded country of the Argonne, a natural barrier which stretches southward in a chain of lakes and forests.
West of this impassible country of the Meuse and the Argonne lies the plain of Champagne-Pouilleuse, which is almost a steppe, bare and open, only slightly undulating, overgrown with heath, and studded here and there by small copses of planted firs, naught but a small portion of the whole being under cultivation. Between the Forest of the Argonne and this great plain, which is over a hundred miles long from north to south and forty miles in width, lies a short stretch of miniature foothills, with upland meadows here and there, but crossed in every direction by small ravines filled with shrubs and low second-growth timber. Here lies the source of the Aisne, a river destined to live in history; and on the farther side begins the great plain.
On the west of the plain of Champagne rises, 300 feet, with a curious clifflike suddenness, the Plateau of Sézanne. The effect is as though a geological fault had driven the original plateau from north to south throughout its entire length, and then as though there had been a general subsidence of the plain, giving rise to the clifflike formations known as Les Falaises de Champagne, at the foot of which runs the road from La Fère-Champenoise to Rheims.
The disposition and arrangement of the German forces is next to be considered. It can be assumed that their objective was Paris. It is also worthy of remembrance that the German tactical method has always favored the envelopment of the enemy's flanks rather than a frontal attack aiming to pierce the enemy's center, which latter was a favorite method of Napoleon I to reach decision.
The tactical method of envelopment demands great numerical superiority, and on account of the extreme extension of front necessitated is apt to become dangerous as perforce the center is left weak. Attempts to envelop, with which the observer is confronted again and again when considering the military movements of the Central Powers on the western battle front, were revealed on the morning of September 3, 1914, in the position occupied by the German forces, and, correspondingly, in the arrangement of the allied armies.