the squares. At 4.30 p.m. one of Bluecher's corps
was delivering the promised counter-attack against Napoleon's line of
communications. Soon after 9 p.m. Wellington and Bluecher met at La
Belle Alliance, Napoleon's headquarters before the battle, and the
pursuit was in full swing.

Opportunities for restoring the battle and for turning impending defeat
into a crushing victory are frequently offered during an engagement.
General Lee's thin lines at _Antietam_ or _Sharpsburg_ (September 17,
1862), slowly fed by men jaded by heavy marching, were sorely pressed,
but there was a lull in the Federal attack when Hooker's advance was
checked. Had General McClellan at that moment thrown in "his last man
and his last horse" in a vigorous reinforcing attack, _Antietam_ would
not have been a drawn battle, and Lee would not have retired at his
leisure into Virginia. Lee's great victory at _Chancellorsville_ (May
2-3, 1863), although marred by the accident which deprived him of
Stonewall Jackson, was a striking instance of the success of the
Defensive-Offensive system at the hands of a great commander, who
defeated 90,000 troops with less than half that number, by a containing
defence with 13,000 men and a decisive counter-stroke with the
remainder.

But while this combined system is regarded by most authorities as the
best, when circumstances warrant its adoption, it is the highest test
of generalship to seize the right moment to pass from the guard to the
thrust. This is the problem which confronted Marshal Foch, the
generalissimo of the Allied Forces, during the great {49} German
offensive movement on the Western Front in 1918. The defensive _role_
endured from March 21 until July 17, 1918, and although many local
counter-attacks were made along the whole battle front, the Allies did
not pass from the guard to the thrust until the decisive counter-stroke
was commenced in the _Second Battle of the Marne_ (July 18, 1918) on a
front of 27 miles from Fontenoy to Belleau, which drove the Germans
back across the Marne on July 20.

THE SECOND BATTLE OF THE MARNE (July 18, 1918).--The great German
offensive of March-June, 1918, was renewed on July 15, when the
artillery preparation opened shortly after midnight and troops were
poured across the Marne in small boats and over pontoon bridges. The
attack was not unexpected. Adequate reserves were ready and in place,
and a heavy counter-bombardment on the German troops in their p