The obvious action to take in such a position as that in which the 2nd Corps found themselves was to break contact with the enemy, to call for support from the 1st Corps, and to maintain the retreat as indefatigably as it had already been maintained in the preceding twenty-four hours.

But men have limits to their physical powers, which limits commonly appear sharply, not gradually, at the end of a great movement. The 1st Corps had been marching and fighting a day and a night, and that after a preceding whole day of retirement from before Mons. It was unable to execute a further effort. Further, the general in command of the 2nd Corps reported that the German pressure had advanced too far to permit of breaking contact in the face of such an attack.

It would have been of the utmost use if at this moment a large body of French cavalry—no less than three divisions—under General Sordet, could have intervened upon that critical moment, the morning of Wednesday, the 26th, to have covered the retirement of the 1st Corps. They were in the neighbourhood; the British commander had seen their commander in the course of the 25th, and had represented his need. Through some error or misfortune in the previous movement of this corps—such that its horses were incapable of further action through fatigue—it failed to appear upon the field in this all-important juncture, and General Sir Horace Smith-Dorrien was left facing overwhelming odds, which in artillery—the arm that was doing all the heavy work of that morning—were not less than four to one.

The fact that the retirement was at last made possible was due more than anything else to the handling of the British guns upon this day, and to the devotion with which the batteries sacrificed themselves to the covering of that movement; while the cavalry, as in the preceding two days, co-operated in forming a screen for the retreat.

It was about half-past three in the afternoon when the general in command of this exposed left flank judged it possible to break contact, and to give the order for falling back. The experiment—for it seems to have been no more secure than such a word suggests—was perilous in the extreme. It was not known whether the consequences of this fierce artillery duel against an enemy of four-fold superiority had been sufficient to forbid that enemy to make good the pursuit. Luckily, as the operation developed, it was apparent that the check inflicted upon such enormous odds by the British guns was sufficient for its purpose. The enemy had received losses that forbade him to move with the rapidity necessary to him if he was to decide the matter. He failed to press the retiring 2nd British Corps in any conclusive fashion: this 2nd Corps, the left wing, was saved; and with it the whole army, and perhaps the whole line.

The retreat of this body, which had thus covered all its comrades, continued under terrible conditions of strain (and after so heavy an action) right through the afternoon, and on hour after hour through the darkness; but though such an effort meant the loss of stragglers and of wounded, of guns whose teams had been destroyed, of material, and of all that accompanies a perilous retreat, one may justly say that well before midnight of that Wednesday, the 26th, the operation had proved successful and its purpose was accomplished.

Two more days of almost equal strain were, as we shall see, to be suffered by the whole army before it had reached a natural obstacle behind which it could draw breath (the river Oise), and might fairly be regarded as no longer in peril of destruction; but the breaking point that had come on that Wednesday, the 26th, had been successfully passed without disaster, and had been so passed, in the main, by virtue of the guns.

This critical day, upon which depended the fortunes certainly of the British contingent, and in some degree of all the "operative corner" of the French plan, turned in favour of the Allies, not only through the military excellence of the action which was broken off by Sir Horace Smith-Dorrien during the afternoon, but also through the vigour and tenacity of the retreat.

I must here beg the reader's leave for a short digression in connection with those two phrases—"in favour of," and "vigour." History in general treats a retirement, particularly a rapid retirement accompanied by heavy losses, as a disaster; and the conception that such a movement may seem to the military historian a success, and that the energy of its conduct is just as important as the energy of an assault, is unfamiliar to most students of civilian record. But I am writing here, though an elementary, yet a military history; and to the military historian a retreat may be just as much a factor in victory as an advance; while the energy and tenacity required for its carriage are, if anything, more important than the corresponding qualities required for an advance. And in the case of this critical day and a half, the Wednesday, August 26th, and the Wednesday and Thursday night, August 26th-27th, the preservation of the British forces, and to some extent of all that lay east of them, was made possible by the very fact that the retirement was prosecuted with the utmost rapidity and without a halt. Had the retreat been interrupted in the hope of making a stand, or in the hope of repose, the whole army would have gone.

Throughout the night, then, with heavy losses from stragglers, and in one case with the surrounding and annihilation by wounds and capture of nearly a whole battalion (the Gordons), the retreat of the 2nd Corps proceeded, and, in line with it, the retreat of the 1st Corps to the east.