with a great velocity -- no warning -- just whizz-bang; white smoke,
nearly always air bursts. The next size, probably 5 inch howitzers,
have a perceptible time of approach, an increasing whine,
and a great burst on the percussion -- dirt in all directions.
And even if a shell hit on the front of the canal bank,
and one were on the back of the bank, five, eight, or ten seconds later
one would hear a belated WHIRR, and curved pieces of shell would light --
probably parabolic curves or boomerangs. These shells have a great back kick;
from the field gun shrapnel we got nothing BEHIND the shell --
all the pieces go forward. From the howitzers, the danger is almost as great
behind as in front if they burst on percussion. Then the large shrapnel
-- air-burst -- have a double explosion, as if a giant shook a wet sail
for two flaps; first a dark green burst of smoke; then a lighter yellow burst
goes out from the centre, forwards. I do not understand the why of it.

Then the 10-inch shells: a deliberate whirring course --
a deafening explosion -- black smoke, and earth 70 or 80 feet in the air.
These always burst on percussion. The constant noise of our own guns
is really worse on the nerves than the shell; there is the deafening noise,
and the constant whirr of shells going overhead. The earth shakes
with every nearby gun and every close shell. I think I may safely enclose
a cross section of our position. The left is the front: a slope down
of 20 feet in 100 yards to the canal, a high row of trees on each bank,
then a short 40 yards slope up to the summit of the trench,
where the brain of the outfit was; then a telephone wired slope,
and on the sharp slope, the dugouts, including my own.
The nondescript affair on the low slope is the gun position,
behind it the men's shelter pits. Behind my dugout was a rapid small stream,
on its far bank a row of pollard willows, then 30 yards of field,
then a road with two parallel rows of high trees. Behind this again,