struck; but with all that racket going on around
of course no ordinary human voice could have been heard.

He could see that it had not been a successful attempt, for the bomb
struck the ground at some little distance away from the terminus of the
structure spanning the river. However, it did considerable damage where
it fell, and created no end of alarm among those who were near by.

As yet the Air Service Boys had not been engaged with any of the hostile
planes, though most of the other Yankee pilots seemed to be having their
hands full in meeting and repelling fierce attacks.

Both kept in readiness for work should their turn come, Tom manipulating
the plane, and Jack working the rapid-fire gun which he had learned to
handle so cleverly.

Strangely enough, Jack, as he looked, was reminded of a vast circus which
he had once attended, and where tumblers, athletes, and trained animals
were all performing in three rings at the same time. He had found it
utterly impossible to watch everything that went on, and remembered
complaining lustily afterwards in consequence.

Now there were some eleven rings in all, besides what was taking place
thousands of feet below, where the bombs had started to burst, tearing
great gaps in the ground close to the bridge, and causing the water
itself to gush upward like spouting geysers.

Lower still dropped the venturesome pilots guiding the destinies of the
four huge bombers. What chances they were taking, bent only on succeeding
in the important task to which they had been assigned!

Jack knew he would never forget that dreadful crisis, no matter if he
were allowed to live to the age of Methuselah; such an impression did it
make upon his mind.

But their turn came at length, for in the dim light two big Gothas were
discovered swinging in toward them as though bent on bringing about the
destruction of the Yankee battleplane.

Jack forgot about what was taking place below, since all of his
energies must now be directed toward beating off this double attack.
It had come to the point of self-preservation. The Hun airmen were
playing a prearranged game of hunting in couples. While one made a
feint at attacking, the other expected to take advantage of an
exposure and inflict a fatal blow that would send the American
aeroplane whirling to death.

Jack saw when the nearest plane opened fire. The spitting flame told him
this, for it darted out like the fiery tongue of a serpent. He als