their navy.

Tom and Jack had displayed considerable ability in carrying out their
work, and could no longer be regarded as novices. Each of them had for
some time been anticipating promotion, and hoped to return home with the
rank of lieutenant at least.

They had been entrusted with a number of especially dangerous missions,
and had met with considerable success in putting these through. Like most
other ambitious young fliers, they hoped soon to merit the title of
"ace," when they could point to at least six proven victories over rival
pilots, with that number of planes sent down in combat.

On the present occasion they had sallied out "looking for trouble," as
Jack put it; which, in so many words, meant daring any Hun flier to meet
them and engage in a duel among the clouds.

Other planes they could see cruising toward the northwest, and also
flying in an easterly direction; but as a rule these bore signs of being
Allies' machines, and in all probability had Yankee pilots manning them.

Apparently the Hun airmen were otherwise employed. They seemed to prefer
venturing out after nightfall, gathering in force, and often taking a
strange satisfaction in bombing some Red Cross hospital, where frequently
their own wounded were being treated alongside the American doughboys.

During the weeks that the Americans were battling in the great Argonne
Forest the two Air Service Boys had contributed to the best of their
ability to each daily drive. Again and again had they taken part in such
dangerous work as fell to the portion of the aviators. Their activities