(3) To the north of Perthes, a comparatively tranquil region of uniform aspect, forming between the wooded hills of the Trou Bricot and those of the Butte du Mesnil a passage two miles wide, barred by several lines of trenches and ending at a series of heights--the Butte de Souain, Hills 195 and 201 and the Butte de Tahure, surmounted by the second German line.
(4) To the north of Mesnil, a very strong position, bastioned on the west by two twin heights (Mamelle Nord and Trapèze), on the east by the Butte du Mesnil. The German trenches form a powerful curtain between these two bastions, behind which a thickly wooded undulating region extends as far as Tahure.
(5) To the north of Beauséjour, a bare terrain easily traversable, with a gentle rise in the direction of Ripon to the farms of Maisons de Champagne.
(6) To the north of Massiges, hills numbered 191 and 199, describing on the map the figure of a hand, very strongly fortified and forming the eastern flank of the whole German line. This table-land slopes down gently in the direction of Ville-sur-Tourbe.
As to the German defenses, the French were intimately acquainted with every detail. They had maps showing every defensive work, trench, alley of communication, and clump of trees in the landscape. Each of these features had been given a special name or number preceded by a certain letter, according to the sector of attack wherein it was situated. These details had been laboriously collected by aviators and spies, and applied with minute precision.
On the morning of September 22, 1915, the French accelerated their long-sustained bombardment of the German positions with intense fury, continuing day and night without a break until the 25th. The direct object of this preparatory cannonade was to destroy the wire entanglements, bury the defenders in their dugouts, raze the trenches, smash the embrasures, and stop up the alleys of communication. The range included not only the first trench line, but also the supporting trench and the second position, though the last was so far distant as to make accurate observation difficult. The heavy long-range guns shelled the headquarters, the cantonments and the railroad stations. They speedily demolished the permanent way, thereby stopping all traffic in reenforcements, munitions and commissariat. From letters and notes afterwards found upon German prisoners who came out alive from that inferno, one may gather an approximate idea of what the bombardment was like: