Monday, the 17th of August, Saarburg, the
most important railway junction between Strassburg and Metz, was in
French hands. Up to that date, though such comparatively small forces
were involved, the French had possessed a very decisive numerical
superiority. It was not destined to last, for there was moving down
from the north the now mobilized strength of Germany in this region;
and a blow struck against the French left, with no less than four
army corps, was speedily to decide the issue upon this subsidiary
front.

[Illustration: Sketch 66.]

This great force was based upon Metz, from which fortress the action
will presumably take its name in history. It stretched upon the 20th
of August from the north of Pont-a-Mousson to beyond Chateau Salins.
Before this overwhelming advance the French left rapidly retired. It
did not retire quickly enough, and one portion of the French force--it
is believed the 15th Division (that is, the first division of the 15th
Army Corps)--failed in its task of supporting the shock.

Details of the action are wholly lacking. We depend even for what may
be said at this date upon little more than rumour. The Germans claimed
a capture of ten batteries and of the equivalent of as many
battalions, and many colours. Upon the 21st the whole French left fell
back, carrying with them as a necessary consequence the centre in the
Vosges Mountains and the right upon the plains of Alsace. So rapid was
the retreat that upon the 22nd of August the Bavarians were at
Luneville, and marching on Nancy; the extreme right of the German line
had come within range of the forts north of Toul; and in those same
hours during which, on that same Saturday, the 22nd of August, the 5th
French Army in the north fell back at the news of Namur and lost the
Sambre, those forces on the borders of Alsace-Lorraine had lost all
the first advantages of their thrust into the lost provinces, had
suffered defeat in the first striking action of the war, and had put
Nancy in peril.

Nancy itself was saved. The French counter-offensive was organized on
the 23rd of August, at a moment when the German line lay from St. Die
northwards and westwards up to positions just in front of Nancy. It
was delivered about a week later. That counter-offensive which
ultimately saved Nancy belongs to the next volume, for it did not
develop its strength until after Sedan Day, and after the end of the
great sweep on Paris.

The situation, then, in t