Retreat to the Aisne 191 long range of hills stretching from La Fere to Rheims, running straight across the front of the city and in the pathway of the invader. These hills are highest just back of Rheims, where they reach an elevation of nearly 1,000 feet. Just south of La Fere, at the other end near Noyon, so frequently mentioned in battle reports, the elevation is 600 feet. These hills are known indifferently as the Hills of Champagne and of the Ile-de-France. They are highest on the north and east where they rise abruptly from the plain, and fall down gradu- ally in the direction of Paris. Where the hills rise from the plains the French had erected a chain of forts stretching from La Fere to Rheims. This city was surrounded by a circle of forts, those to the west on the main range of hills, those on the east upon isolated foothills. In mili- tary volumes they are described as the Laon-La Fere-Rheims barrier, and they were intended to serve as a second line of defence in advance of Paris, to check the invader who had successfully forced the first line of fortresses at the frontier. In August they failed to serve this purpose be- cause the Germans turned them. Between La Fere and the English Channel, that is west of the Champagne Hills, there is a level plain, but from the highlands to the Channel the Sominc River runs through a valley which is marshy and serves as a military obstacle. Unfortunately for the French the Germans, having succeeded in concentrating an