The firing signal was hoisted to the peak.

"Are you ready, Mr. Ordnance Officer?"

"All ready, sir."

"Sound a long blast on the siren."

The weird voice of the siren shrieked its warning over the waters, while the prow of the battleship was rolling up a great white wave as the ship raced along at full speed.

"Fire!" came the quick word of command.

The ordnance officer pressed a button, his eyes on the target.

A dull, muffled explosion followed.

CHAPTER XVIII