To cover the detrainments of this fresh army in the district Clermont-Beauvais-Boix a cavalry corps and four territorial divisions were ordered to establish themselves on both banks of the Somme. In the wooded hills, however, which extend between the Oise and Lassigny the enemy displayed increasing activity. Nevertheless, the order still further to broaden the movement toward the left was maintained, while the territorial divisions were to move toward Bethune and Aubigny. The march to the sea went on. [Sidenote: Alternate reverse and success.] From the 21st to the 26th all our forces were engaged in the district Lassigny-Roye-Peronne, with alternations of reverse and success. It was the first act of the great struggle which was to spread as it went on. On the 26th the whole of the Sixth German Army was deployed against us. We retained all our positions, but we could do no more; consequently there was still the risk that the enemy, by means of a fresh afflux of forces, might succeed in turning us. Once more reinforcements, two army corps, were directed no longer on Beauvais, but toward Amiens. The front was then again to extend. A fresh army was constituted more to the north. From September 30 onward we could not but observe that the enemy, already strongly posted on the plateau of Thiepval, was continually slipping his forces from south to north, and everywhere confronting us with remarkable energy. [Sidenote: Cavalry operations.] Accordingly, on October 1 two cavalry corps were directed to make a leap forward and, operating on both flanks of the Scarpe, to put themselves in touch with the garrison of Dunkirk, which, on its side, had pushed forward as far as Douai. But on October 2 and 3 the bulk of our fresh army was very strongly attacked in the district of Arras and Lens. Confronting it were two corps of cavalry, the guards, four active army corps, and two reserve corps. A fresh army corps was immediately transported and detrained in the Lille district. But once more the attacks became more pressing, and on October 4 it was a question whether, in view of the enemy's activity both west of the Oise and south of the Somme, and also further to the north, a retreat would not have to be made. General Joffre resolutely put this hypothesis aside and ordered the offensive to be resumed with the reinforcements that had arrived. It was, however, clear that, despite the efforts of all, our front, extended to the sea as it was by a mere ribbon of troops, did not possess the solidity to enable it to resist with complete safety a German attack, the violence of which could well be foreseen. [Sidenote: Transport of the British Army.]