"No, his machine caught fire. They got his petrol tank. It's all up with
him and La Garde. But we had our revenge. We sprayed the machine that
got them until there was nothing left of it. And I'm going out again
to-day in a Nieuport. They'll pay a price for Louis!"

CHAPTER XV

THE PICKED SQUADRON

"All ready, Jack?"

"Just a moment, Tom. I want to go over my struts and wires to make sure
everything is taut. I don't want any accidents."

"That's right. Got plenty of ammunition drums?"

"All I can carry. I've got some tracer bullets, too."

"That's good. Glad you reminded me of them. I must put in a stock. The
last time I went up I wasted a drum before I got my man."

Tracer bullets for aircraft guns, it might be observed, are balls of
fire which enable the pilot to see the course his machine gun bullets
are taking, so he may correct his fire.

"Well, how about you now?" asked Tom, as he added these useful supplies
to his ammunition.

"I guess we're ready to start," replied Jack.

They climbed into their machines, each pilot using a single-seat,
swift-flying craft, equipped with a Lewis machine gun. The squadron was
going out on patrol duty, and each pilot was to observe what he could
behind the German lines, and come back to report--that is if he did not
happen, as was too often the case, to be bagged by a German flier. The
small, swift machines did not carry the wireless outfit, and no reports
could be sent back to headquarters save those the pilot himself came in
with.

There was a rattle and a roar as the motors of the ten machines started,
and then over the ground they went, "taxi fashion," to get the necessary
speed to rise into the air. A moment later all went aloft, and were
headed toward the German lines.

Tom and Jack kept as close together as was safe, but it is dangerous for
two aeroplanes to approach too closely. If they do, and are not under
good control, there may be a suction created that will cause a
collision.

"Well, I hope I get one to-day," thought Tom, as he manipulated his "joy
stick," so as to send his plane up on a sharp slant. "I want to make
good, and then I'll have so much better chance to get after that German
gun." And the same thought was in Jack's mind.

The squadron was to remain aloft on a two-hour patrol, that is unless
something should occur to make it advisable to remain up longer. The
keen eyes of Tom and Jack, as well as those of their companions of th