“All right!” the command came from Mr. Lockyer. His voice shook as he uttered it. He caught his breath sharply.

The foreman echoed the word in stentorian tones.

“Let her go, boys!”

Boom!

The supreme moment had come.

The hammer fell upon that last wedge. A sharp quiver ran through the steel structure of the diving boat. It was the first stirring of life within her frame.

“She’s off!”

Old Tom Marlin, forgetful of discipline, had uttered the sharp cry. It had been wrung from him by the tension of the moment as the submarine began to move.

Crash!

The bottle smashed across the prow. Its contents gushed sparkling and bubbling down her gray sides. Then, in a clear, girlish voice, came the words so fraught with meaning to the inventor. There was not a quiver in the girl’s voice, though her eyes were strangely bright as she exclaimed: