"And do you think you can put something like that on your guns,
so the recoil will be taken up?" Ned wanted to know.

"I think so," spoke Tom. "I'm going to work on it right away,
and we'll soon see how it will turn out It's mighty lucky you
thought of that, for I sure was up against it, as the boys say."

"It just seemed to come to me," spoke Ned, "seeing how easily
the door closed."

"If the thing works I'll give you due credit for it," promised
Tom. "Now, I've got to figure out how much force a modified
hydrostatic valve check like that will take up, and how much
recoil my biggest gun will have."

"Then you're going to put several guns on the Mars?" asked Ned.

"Yes, four quick-firers, at least, two on each side, and
heavier guns at the bow and stern, to throw explosive shells in a
horizontal or upward direction. For a downward direction we won't
need any guns, we can simply drop the bombs, or shells, from a
release clutch."

"Drop them on other air craft?" Ned wanted to know.

"Well, if it's necessary, yes. Though I guess there won't be
much chance of doing that to a rival aeroplane or dirigible. But
in flying over cities or forts, explosive bombs can be dropped
very nicely. For use in attacking other air craft I am going to
depend on my lateral fire, from the guns mounted on either beam,