or in command, the two lads
climbed into their air plane and started off.

The day was clear and bright, just the sort for aeroplane activity; and
it was evident there would be plenty of it, since, even as they began
climbing, Tom and Jack saw planes from their own aerodrome skirting
ahead of and behind them, while, in the distance and over German-held
territory, were Fokkers and Gothas with the iron cross conspicuously
painted on each.

Tom and Jack had been given a map of the front, their own and the German
lines being shown, and the probable location of the hidden Hun battery
marked. This they now studied as they started over the front, Jack being
in front, while Tom sat behind him, to work the swivel Lewis gun.

Their Spad machine was one that could be controlled from either seat, so
that if one rider was disabled the other could take charge. There
were two guns, one fixed and the other movable, and a good supply of
ammunition.

"Well, I guess there'll be some fighting to-day," observed Tom, as Jack
shut off the motor for a moment, to see if it would respond readily when
the throttle was opened again. "They're closing in from both sides."

And indeed the Allied planes were sailing forth to meet a squadron of
the enemy. But none of the Hun craft seemed to pay any attention to Tom
and Jack. Steadily they flew on until an exclamation from Jack caused
Tom to look down. He noted that they were over the German lines, and
headed for the probable location of the battery that had been such a
thorn in the side of the Allies.

CHAPTER XII. A PERFECT SHOT

The plane in which Tom and Jack had gone aloft to make observations
which, it was hoped, would result in the discovery of the hidden
battery, was a special machine. While very powerful and swift and
equipped for air-fighting, it was also one that had been used by one of
the French photographers and his pilot. The photographer, was a daring
man, and had, not long before, gone to his death in fighting three
Hun planes. But he had peculiar ideas regarding his car, and under his
orders it had been fitted with a glass floor in the two cockpits, or
what corresponded to them.

Thus he and his pilot could look down and observe the nature of the
enemy country over which they were traveling without having to lean
over, not always a safe act where anti-aircraft guns below are shooting
up shrapnel.

So as Torn and Jack flew on and on, over the enemy's first and
succ