r toward winning the first battle of the Marne. It was the
truck transportation system of the French along the famous "Sacred Road"
back of the battle line at Verdun that kept inviolate the motto of the
heroic town, "They Shall Not Pass." Motor trucks that brought American
reserves in a khaki flood won the second battle of the Marne. It was
automobile transportation that enabled Haig to send the British
Canadians and Australians in full cry after the retreating Germans when
the backbone of the German resistance was broken before Lens, Cambrai,
and Ostend.

America's railway transportation system in France was one of the marvels
of the war. Stretching from the sector of seacoast set apart for America
by the French Government, it radiated far into the interior, delivering
men, munitions and food in a steady stream. American engineers worked
with their brothers-in-arms with the Allies to construct an
inter-weaving system of wide-gauge and narrow-gauge roads that served to
victual and munition the entire front and further serve to deliver at
top speed whole army corps. It was this network of strategic railways
that enabled the French to send an avalanche clad in horizon-blue to the
relief of Amiens when Hindenburg made his final tremendous effort of
1918.

In its essentials, military effort in the great conflict may be roughly
divided into
Open warfare,
Trench warfare,
Crater warfare.

The first battle of the Marne was almost wholly open warfare; so also
were the battles of the Masurian Lakes, Allenstein, and Dunajec in the
eastern theater of war, and most of the warfare on the Italian front
between the Piave River and Gorizia.

In this variety of battle, airplanes and observation balloons play a
prominent part. Once the enemy is driven out of its trenches, the
message is flashed by wireless to the artillery and slaughter at long
range begins. If there have been no intrenchments, as was the case in
the first battle of the Marne, massed artillery send a plunging fire
into the columns moving in open order and prepare the way for machine
gunners and infantry to finish the rout.

In previous wars, cavalry played a heroic role in open warfare; only
rarely has it been possible to use cavalry in the Great War. The Germans
sent a screen of Uhlans before its advancing hordes into Belgium and
Northern France in 1914. The Uhlans also were in the van in the Russian
invasion, but with these exceptions, German cavalry was a