the shells exploding several miles away with a sound of
jarring thunder claps.

In addition to the ambulances there was a constant stream of outgoing
traffic of other kinds: dispatch riders on motor cycles, feeling their
way cautiously along the side of the road; ammunition supply and
battalion transport wagons, the horses rearing and plunging in the
darkness. We approached a crossroad and halted to make way for some
batteries of field pieces moving to new positions. They went by on a
slippery cobbled road, the horses at a dead gallop. In the red
lightenings of heavy-gun fire they looked like a series of splendid
sculptured groups.

We moved on and halted, moved on again, stumbled into ditches to get out
of the way of headquarters cars and motor lorries, jumped up and pushed
on. Every step through the thick mud was taken with an effort. We
frequently lost touch with the troops ahead of us and would have to march
at the double in order to catch up. I was fast getting into that
despondent, despairing frame of mind which often follows great physical
weariness, when I remembered a bit of wisdom out of a book by William
James which I had read several years before. He had said, in effect, that
men have layers of energy, reserves of nervous force, which they are
rarely called upon to use, but which are, nevertheless, assets of great
value in times of strain. I had occasion to test the truth of this
statement during that night march, and at intervals later, when I felt
that I had reached the end of my resources of strength. And I found it to
be practical wisdom which stood me in good stead on more than one
occasion.

We halted to wait for our trench guides at the village of Vermelles,
about three miles back of our lines. The men lay down thankfully in the
mud and many were soon asleep despite the terrific noise. Our batteries,
concealed in the ruins of houses, were keeping up a steady fire and the
German guns were replying almost as hotly. The weird flashes lit up the
shattered walls with a fascinating, bizarre effect. By their light, I saw
men lying with their heads thrown back over their pack-sacks, their
rifles leaning across their bodies; others standing in attitudes of
suspended animation. The noise was deafening. One was thrown entirely
upon his own resources for comfort and companionship, for it was
impossible to converse. While we were waiting for the order to move, a
homeless dog put his cold nose into my hand. I p