Shaping his course by the chart which Captain Jack had given him, Frank kept the course accurately. The speed of the vessel was maintained at five knots, in accordance with Captain Jack's calculations. As Frank's watch showed half past eleven, he felt that the time to exercise the greatest caution had come.
The lad turned the wheel over to Williams and took the latter's place at the periscope. Directly he was able to make out the coast line, and even at this distance he felt certain that he could make out a long row of buildings in the background. The submarine was, of course, still too far away for possible vessels, which would lie low on the water, to be within the lad's range of vision.
"Where are the mines?" the lad asked Williams.
"Foot of the ladder, sir," was the reply.
"Fuses attached?"
"Yes, sir, and anchors, too, sir."
"Good! Of course, we'll have to come to the surface to let them go."
"Of course, sir."
"Then be ready when I give the word. I can't pick up any submarines at this distance, but they may all be upon the surface as well as resting beneath the water."
"I'm ready, sir."