In three days the British had not only gained the passages over the Aisne, but had won their way to the plateau. Both sides had fought with determination. The German commander knew that if he could not hold this position the whole contemplated strategy of throwing masses of reinforcements against the left flank of the Allied forces must collapse. He was well aware that if he failed, not only must his own force in all probability be destroyed, but the whole German line as far as Verdun must in all probability be crumpled up.
Not less was Sir John French aware that the future success of the Allied campaign hung upon obtaining a purchase on the German position which would force General von Kluck to employ his whole strength in holding on. It is easy, therefore, to infer how fierce had been this three days' struggle.
The Germans had put forth the greatest effort of which they were capable. But despite the natural advantage given them, first by the river front, and next by the rugged and broken ground in the many side valleys, they had been beaten. Henceforward the struggle was on less uneven terms. The fact had become manifest that without a strenuous counter-offensive the Germans could not hope to hold on.
This counter-offensive was attempted without delay.
Since the top of the plateau sloped from north to south, the positions held by the British were in general on lower ground than the trenches cut by the Germans, and it must have been something of a disagreeable surprise to the latter when on the morning of September 15, the heavy mists having lifted, they saw miles of earthworks, which had literally sprung up in the night. The rain and mist during the hours of darkness had made a night attack impossible, even if, after the eighteen hours' furious battle in the mists on the preceding day, they had had the stomach for it.
They had their surprise ready, however, as well. From well-hidden positions behind the woods on the top of the plateau they opened a violent bombardment of the British lines with their huge 8-inch and 11-inch howitzers, throwing the enormous shells, which fell with such terrific force as to bury themselves in the ground. Giving off in exploding dense clouds of black smoke, these shells blew away the earth on all sides of them in a rain of fragments of rock, masses of soil and stones, leaving the surface filled with holes wide and deep enough to be the burial place of several horses. This heavy ordnance was kept well beyond the range of the British guns, and employed for high-angle fire. So far as life was concerned, the shells caused relatively little loss. Their flight being visible—they looked not unlike tree-trunks hurled from across the hills—they could be dodged. On realising how little they were to be feared, the British troops nicknamed them "Black Marias," "Coalboxes," and "Jack Johnsons," and shouted jocular warnings. The idea of using these shells was to knock the British defence works to pieces. Some of these works, hastily thrown up, proved to be too slight, and had to be replaced by diggings, which became regular underground barracks.
At this time the British lines were in general more than a mile distant, on the average, from those of the enemy. They followed no symmetrical plan, but, adapted to the defensive features of the ground, were cut where there were at once the best shelters from attack and the best jumping-off places for offence. Describing them, the British military correspondent wrote:—
A striking feature of our line—to use the conventional term which so seldom expresses accurately the position taken up by an army—is that it consists really of a series of trenches not all placed alongside each other, but some more advanced than others, and many facing in different directions. At one place they run east and west, along one side of a valley; another, almost north and south, up some subsidiary valley; here they line the edge of wood, and there they are on the reverse slope of a hill, or possibly along a sunken road. And at different points both the German and British trenches jut out like promontories into what might be regarded as the opponent's territory.
While the British infantry had been entrenching, the artillery, with an equal energy, had hauled their guns up the steep roads, and in many cases up still steeper hillsides, and by the morning of September 15—another disagreeable surprise for the enemy—nearly 500 field pieces bristled from positions of vantage along the front. The reply to the German bombardment was a bombardment of the hostile trenches. The latter were crowded with men. If the German shells did a lot of injury to the landscape, the British shrapnel inflicted far heavier injury on the enemy's force. It swept the German trenches and field batteries with a regular hail of lead. Well-concealed though they to a great extent were, the German positions were not so well-concealed as the British positions. Both armies did their best to make themselves appear scarce, and beyond the deafening uproar of the guns belching from behind woods and undulations, there seemed at a distance few signs of life on either side. But, looked at from behind and within, the lines were very anthills of activity.
The bombardment went on until midnight. Then came a night battle of almost unexampled fury.