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.