own, and taxi around as well as we can
until we pick up Harry, or until he sees us. The machines will carry
three as well as two, and even if we have, by some mischance to go up
in singles, they'll carry double. But I figured on your being with me.
Harry knows enough of the game to be on the lookout when he hears the
bombs drop and sees the planes hovering over him, and he'll tip off the
others to be ready for a rescue.

"Of course I don't say we can get 'em all, and maybe something will
happen that we can't get Harry away. But I think we'll teach Fritz a
lesson, and I think we can break up the prison camp so some of the poor
fellows can get away. As I said, it's a desperate chance, but one we've
got to take."

"And I'm with you!" exclaimed Jack. "And now when does the big battle
take place?"

He was answered a moment later, for an orderly arrived with instructions
to the air service boys to report at their hangars at once.

There they were told something of the impending attack--the first public
mention of it, though more than one had guessed something unusual was in
the air from the tenseness of the last few days.

The attack was to start at dawn the next morning, preceded by an intense
artillery fire. It was to be the fiercest rain of shells since the
Americans had come to the front lines. Then the infantry, supported by
tanks and aeroplanes, would follow, going over in waves which it was
hoped would overwhelm the Germans.

That night was a tense one. Suppose the enemy had guessed, or a spy had
given word of the impending battle? Then success would be jeopardized.
But the night passed with only the usual exchange of shots and the
sending up of star shells over No Man's Land.

And so, as the hour of dawn approached, the tense and nervous feeling
grew. Tom and Jack, with their comrades in their hangars, were dressed
in their fur garments and ready. Their machines had received the last
touches from the hands of the mechanics, and each one was well equipped
with bombs and machine gun ammunition. Tom and Jack were to be allowed
to go up together in a big double bombing plane.

The night passed. The hour approached. Anxious eyes watched the hands of
watches slowly revolve.

Then suddenly, as if the very earth had been blasted away from beneath
them, the batteries of big guns belched forth fire, smoke and shell.

The great battle was on!

CHAPTER XXIV. SILENCING THE GERMAN GUNS

Engagements in the Wor