or de
Trouville was right, photography forms a valuable part of the new
warfare.

The photographing of the enemy positions is done in big, heavy machines,
carrying two men. They must fly comparatively low, and have not much
speed, though they are armed, and it takes considerable of an attack to
bring them down. But of course the pilot and his observer are in danger,
and, to protect them as much as possible, scout planes--the single-seat
Nieuports--are sent out in squadrons to hover about and give battle to
the German aircraft that come out to drive off the photographers.

"We'll undertake that," proceeded Major de Trouville. "I'll order the
big machine to get ready for an attempt to-morrow at locating the gun."

"Is it still shooting?" asked Jack.

"Yes, it has just been bombarding Paris; but I have no reports yet as to
the damage done."

"Aren't we doing anything at all?" asked Tom.

"Oh, yes, our batteries are keeping up a fire on the German lines along
the front behind which we think the gun is concealed, but what the
results are yet, we don't know."

"Well, let's hope for clear weather to-morrow," suggested Boughton.

The intervening time was occupied by the aviators in getting everything
in readiness. The machines were inspected, the automatic guns gone over,
and nothing left undone that could be thought of to give success.

The next day dawned clear and bright, and, as soon as it was light
enough to make successful photographs, the big machine set out, while
hovering above and to either side of it were several Nieuports. Tom and
Jack were each occupying one of these, ready to give battle to the Huns
above or below the clouds.

In order to distract the attention of the Germans as much as possible
from the direct front where the airships were to cross the lines, a
violent artillery fire was maintained on either flank. To this the
Germans replied, perhaps thinking an engagement was pending. And so,
amid the roar of big guns, the flying squadron got off.

"Now we'll see what luck we'll have," mused Tom, as he drove his machine
forward, being one of the large aerial "V" that had for its angle the
ponderous photographing bi-motored machine.

Over the German lines they flew, and then the Germans awoke to the
necessity of ignoring the fire on their flanks and began shooting at the
airships over their heads.

"This ought to bring out their pilots if they have any sporting blood,"
thought Jack.

And it did