"Torpedoes all right?"
"Yes, sir. I just examined them ten minutes ago."
"Guess there are no other precautions we can take," said Frank. "Be ready to grab a couple of mines and follow me on deck when I give the word." Frank turned and summoned one of the pirate crew, a negro, who answered to the name of Jefferson.
"Jefferson, take the wheel," he said.
Jefferson did so, grinning.
"Slow to two knots, Williams," ordered Frank.
Williams signaled the engine room and the pace of the submarine slowed down until the vessel was barely moving through the water.
Frank glanced at his watch. It was 12 o'clock.
"Fifteen minutes in which to lay the mines," he said to himself. "They must explode at 12:30—"
At 12:10 the submarine emerged from the depth and floated calmly upon the surface of what appeared to be an artificial harbor. Frank and Williams, leaving Jefferson at the wheel and ordering the engines stopped, sprang on deck, carrying two small packages each. These, bound in little tin boxes, were the deadly mines.