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
