Their own aerodrome lay only a few miles opposite.

By actual and repeated reconnaissance both from below and in the air,
this bluff was considered as deserted, or held at most by a very small
force. This was owing to its supposed isolation.

Evidently Erwin had just made a great discovery. At least he hoped so.

On he flew. His machine was hit in many places, principally the wings,
the tail and along the under side of the fuselage. Through this had
come the ball that nearly perforated the tank.

There was one more opening ahead and then the trench sank out of sight
near the base of the low bluff. Orry's hand closed over the first
grenade. He was really an expert bomb-thrower. At great risk he
dipped gradually until, when about at the point overhead he desired, he
threw two bombs in swift succession. Then-up, up rapidly. With all
the power of his engine he climbed, while two sharp explosions sounded
from below.

Had the lad looked down he would have seen the trench walls at the open
space crumble inward, while the mass of moving gray appeared to
disintegrate, to vanish for the time being.

But with the throwing of the bombs, Erwin had other work on hand.
Archie had broken loose again. One larger molded shot ripped through
the tail of the Bleriot, ricocheted obliquely and hit that same tank
again, but with more force. His head lowered, the lad saw what had
been done. More than that he saw what impended. The petrol was low.