“Even keel, if you please,” again requested Commander Ennerling.

Jack began to flood, slowly, the water tanks, the “Pollard” sinking gradually.  With the young captain at one side of the gauge, Messrs. Farnum and Pollard took their posts at the other side, to watch the readings.

“How many feet down do you want to go?” asked young Benson, coolly.

“How far down do you dare to take the boat?” asked Mr. Farnum, almost hesitatingly.

“As far as you dare to let me,” replied Jack, with spirit.  “Watch the gauge, and tell me when to stop.”

“Jove, but you have a cool nerve, lad, if you back that up,” laughed lieutenant McCrea.

“Perhaps our young skipper is relying upon the caution of his employer,” suggested Commander Ennerling, smiling.

It is always a question of great importance just how far below the surface a submarine torpedo boat may go with safety.  The greater the depth the more enormous the pressure of the water.  At sufficient depth the water pressure is terrific enough to crush in the hull of the stoutest submarine.  At even less depth the pressure may easily start the plates so that the inrush of water will destroy all on board.

Yet Jack Benson’s proposition was to send the “Pollard” further and further below the surface, until owner or inventor should order him to stop.

All three of the Navy officers shot a look of admiration at the doughty young skipper.  Then, almost immediately, their faces resumed their usual expressions.  To the Navy officers this experience carried with it no dread.  The “Pollard” might prove, under severe test, wholly unfit to stand the pressure below surface.  Their death might be but a minute or two away, but with these Naval officers it was all in the line of duty.

It was not, with the members of the board, so much a matter of actual grit as of constant association with all forms of danger.

“We’re going pretty low,” muttered Mr. Farnum to himself, as he read the gauge.

“Can we stand much more depth?” wondered David Pollard, inwardly uneasy, though outwardly calm.  A moment later he told himself: 

“Jack Benson has never been as low as this before!”

“It won’t take much more of this to make further trial trips of no interest to us,” almost shivered Jacob Farnum.

Yet Jack, true to his word, allowed the “Pollard” to sink lower and lower.  He was waiting for the word—­or the bottom!

CHAPTER XIV

FOOLING THE NAVY, BUT ONLY ONCE

Commander Ennerling bent forward to read the submergence gauge.

“Jove, but you’ve really your nerve with you, Captain Benson,” he declared, simply.

“Confidence in the boat, sir,” Jack answered coolly.

Up in the conning tower, where he could observe the duplicate gauge, Eph Somers, though not easily frightened, was beginning to feel more than curious.