The most advanced German batteries were placed in a pit, into which a telephone wire ran.

Evidently these guns, like the French, were fired by order from some distant point.

John longed to hurl a bomb at the pit, but the chances were ten to one that he would miss it, and he held to the ammunition depot, spread over a full acre, as his target.
Now the Germans saw them.

He knew it, as many of them looked up, and some began to fire at the _Arrow_, but the aeroplane was too high and swift for their bullets.
"Now!" said Lannes in sudden, sharp tones.
The aeroplane dipped with sickening velocity, but John steadied himself, and watching his chance he threw four bombs so fast that the fourth had left his hands before the first touched the ground.

An awful, rending explosion followed, and for a minute the _Arrow_ rocked violently, as if in a hurricane.