0,000
men on the steep eastern bank of the Ourcq and taking 150,000 troops
south across the Marne toward La Ferte Gaucher. He crossed the
Petit Morin and the Grand Morin, all unconscious that scores of
field glasses were trained upon his troops.

Probably believing that the British army had been hurried to the
aid of General Sarrail, General von Kluck advanced confidently.
Having concealment in view, the commanders of the French army and
the British army between them had left a wide gap between the two
armies. Through one of these apparently unguarded openings a strong
body of uhlan patrols advanced, riding southward until they reached
Nogent, south of Paris, and seemingly with the whole rich country
of central France laid wide open to a sharp and sudden attack.
Among the many strange features of this series of the battles of
the Marne this must certainly be reckoned as one. Though possessing
an unequaled military organization, though priding itself on its
cavalry scouts, though aided by aerial scouts, and though well
supplied with spies, yet the Allied armies, with the age-old device
of a forest, were able to cloak their movements from this perfectly
organized and powerful invading army. Much of the credit of this
may be assigned to the French and English aircraft, which kept
German scouting aircraft at a distance. But the Allied generals
were astounded at the result of their maneuver, which, as they
admitted afterward, was merely a military precautionary measure
against the discovery of artillery sites, and a device to keep
the enemy in general ignorance.

On Saturday, September 5, 1914, at the extreme north of the line
of the two armies facing each other across the Ourcq, an artillery
duel began. The offensive was taken by the French, and though in
itself it was not more striking than any of the artillery clashes
that had marked the previous month's fighting, it was significant,
for it marked the beginning of the battles of the Marne. The plans
of General Joffre were complete, but the actual point at which
the furious contest should begin was not yet determined. In the
northern Ourcq section, however, the realization by the French
that they were actually on the offensive at last, that the long
period of retreat was over, could not be restrained. The troops
were eager to get to work with the bayonet, and greatly aided by
their field artillery, in which mobility had been sacrificed to
power, they quickly cleared th