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 o