at I'd got to have a special day of it,
that's all," replied the other carelessly. "They wouldn't let me go
along with you chaps, and I had to do something to let the ugliness get
out; so I put it up to Fritz. And, say, I've had a glorious time, too."

He refused pointblank to tell them anything more at the time, so they
had to pick up all their information through other channels; but then it
was not so hard to do that, since nearly every working aviator had taken
note of Harry's remarkable work that morning.

Then came the afternoon.

Both Tom and Jack might have considered that time dragged, only for the
fact that they could pass the hours in a pleasant fashion. Tom managed
to get over to the field hospital to see his wounded friend, Fred
Lincoln. And, really, he did spend as much as ten minutes trying to
cheer that individual up, for Fred had lost an arm, and was feeling
blue over his future home-going to his young wife.

As for Jack, he haunted the Y. M. C. A. dugout and wrote letters home
until he could not think of another person who would want to be
remembered. It was a great day of rest to those hard-working air pilots,
though from the look on their faces when they were greeting the incoming
aviators one might have thought they rather envied them their latest
achievements.

Such is the force of habit.

At last came night, and the two air service boys thrilled with the
realization of what great things were apt to come to pass in their
experience before another dawn brought the grey into the eastern sky.

CHAPTER XV

OVER THE ENEMY'S LINES

IN all there were twenty planes starting out on that momentous
expedition to "strafe the Kaiser," as Jack called it. Half of these were
monster bombing machines of a late model, capable of carrying more of
the deadly explosives than had ever before been attempted.

The others were battle planes, guided by the most expert pilots, some of
whom were already famous aces. These were men whose names had become
household words over in America, heroes of the masses, whose pictures
always evoked storms of applause whenever shown on the screen in the
motion picture houses.

Tom owed the fact of his having been selected to guide one of the
bombers, instead of a fighting machine, to the fact that one man had
fallen sick, and was thus placed out of the running. In casting around
for an efficient substitute they had picked Tom.

The start was made an hour before midnig