ically safe from rifle fire, and soldiers intrenched on either
side of it add to its volume their own more accurate fire from their
rifles. Infantry in the open, though they were not subjected to the
fearful concentration of artillery fire, could not survive through a
mile of machine-gun and rifle-swept space. Successful advances
against anything but very inferior numbers badly armed become
impossible in any frontal attack in the open. Thus all modern
infantry operations must have more or less a siege character, as the
only practicable means of approach is by digging your way forward.
The spade has become almost as important a weapon as the rifle.

Impatience with digging, which was characteristic of the early days
of the American Civil War, and which has been generally resented by
all armies in the past, has now become second nature to every
soldier, because its value is brought home to him by the most
telling kind of lesson in experience--death. He puts earth between
himself and the enemy's fire as instinctively as one holds up his
hand to ward off a blow.

In trench fighting all that is exposed of a man firing is his head
and shoulders, which accounts for the high percentage of dead to
wounded in this war. In other wars it has been as one to five; while
in this war, on the western front, it has varied from as one to two
and three. If the trenches are brought extremely close together then
either side is safe from the other's artillery fire, because there
is as much danger of hitting your own trench as the enemy's with
your shells. A distance of 20 or 30 yards meant that at any time
either side could start in throwing bombs or grenades by hand across
that one definitely neutral country--the zone of death between the
trenches. Beyond that range up to the average range, trench mortars
which "lobbed" a charge of high explosive from trench to trench
could be used. Thus the war of machinery became a war of explosives.
Anything that could be dropped into the trench and burst might kill
or wound some of the enemy, which meant debit on their side of the
ledger in a war of attrition and exhaustion. The higher the angle of
flight the more likely the charge actually to fall into the narrow
ditch in the earth, instead of breaking its force against the wall,
which accounts for the superiority of the howitzer with its high
angle of flight and shorter range to the gun with its lower
trajectory and longer range.

Thus there can be