closes like a safe door, and hides the shell from the visitor. It is
"good-bye." He receives exaggerated warning of the danger to his ears,
stuffs his fingers into them, and opens his mouth as instructed, hears a
loud but by no means deafening report, and sees a spit of flame near the
breech. Regulations of a severe character prevent his watching from an
aeroplane the delivery of the goods upon the customers opposite.

I have already described the method of locating enemy guns and so forth
by photography. Many of the men at this work are like dentists rather
than soldiers; they are busy in carefully lit rooms, they wear white
overalls, they have clean hands and laboratory manners. The only really
romantic figure in the whole of this process, the only figure that has
anything of the old soldierly swagger about him still, is the aviator.
And, as one friend remarked to me when I visited the work of the
British flying corps, "The real essential strength of this arm is the
organisation of its repairs. Here is one of the repair vans through
which our machine guns go. It is a motor workshop on wheels. But at any
time all this park, everything, can pack up and move forward like
Barnum and Bailey's Circus. The machine guns come through this shop in
rotation; they go out again, cleaned, repaired, made new again. Since we
got all that working we have heard nothing of a machine gun jamming in
any air fight at all."...

The rest of the career of the shell after it has left the gun one must
imagine chiefly from the incoming shell from the enemy. You see suddenly
a flying up of earth and stones and anything else that is movable in the
neighbourhood of the shell-burst, the instantaneous unfolding of a dark
cloud of dust and reddish smoke, which comes very quickly to a certain
size and then begins slowly to fray out and blow away. Then, after
seeing the cloud of the burst you hear the hiss of the shell's approach,