guarded in two dimensions, and that it is always possible for an
airman to penetrate far into enemy country. They do not see their own
pilots on their long raids into German territory. Furthermore, while
the outward journey is often accomplished easily enough, the return
home is a different matter. Telephones are busy from the moment the
lines are crossed, and a hostile patrol, to say nothing of a lone
_avion_, will be fortunate if it returns safely.

But infantrymen are to be forgiven readily for their outbursts against
the aviation service. They have far more than their share of danger
and death while in the trenches. To have their brief periods of rest
behind the lines broken into by enemy aircraft--who would blame them
for complaining? And they are often generous enough with their praise.

On this occasion there was no bombing. The German remained at a great
height and quickly turned northward again.

Dunham and Miller came to meet us. We had all four been in the schools
together, they preceding us on active service only a couple of months.
Seeing them after this lapse of time, I was conscious of a change.
They were keen about life at the front, but they talked of their
experiences in a way which gave one a feeling of tension, a tautness
of muscles, a kind of ache in the throat. It set me to thinking of a
conversation I had had with an old French pilot, several months
before. It came apropos of nothing. Perhaps he thought that I was
sizing him up, wondering how he could be content with an instructor's
job while the war is in progress. He said: "I've had five hundred
hours over the lines. You don't know what that means, not yet. I'm no
good any more. It's strain. Let me give you some advice. Save your
nervous energy. You will need all you have and more. Above everything
else, don't think at the front. The best pilot is the best machine."

Dunham was talking about patrols.

"Two a day of two hours each. Occasionally you will have six hours'
flying, but almost never more than that."

"What about voluntary patrols?" Drew asked. "I don't suppose there is
any objection, is there?"

Miller pounded Dunham on the back, singing, "_Hi-doo-dedoo-dum-di_.
What did I tell you! Do I win?" Then he explained. "We asked the same
question when we came out, and every other new pilot before us. This
voluntary patrol business is a kind of standing joke. You think, now,
that four hours a day over the lines is a light programme. Fo