In fact, that joke of Jack’s was heard of in the halls of Congress later on.  The significant fact of it all was that, while the “Pollard” had been manoeuvred for the successful perpetration of the joke, neither of the other two submarines with the fleet was “handy” enough to be used in quite such a neat trick.

When a United States rear-admiral entertains guests at luncheon aboard his flagship, the affair is a stately one.  When our three friends appeared at table there were several naval officers in attendance.

“I have been laughing a good deal to-day, Captain Benson, over the joke sprung on us last night,” was Admiral Bentley’s greeting.  “It was cleverly carried out, and with a great deal of skill in seamanship as well.”

“It wasn’t intended, sir, to be so much a joke as a demonstration of what our boat can accomplish,” Jack replied, modestly.

“I haven’t lost sight of the practical side of the affair, I assure you,” rejoined the admiral.  “But I am afraid I have wounded one heart—­McCrea’s.”

“Then I am very sorry,” replied Jack, quickly.  “I had hoped he would feel as much like laughing as anyone.”

“Mr. McCrea might feel more like laughing, if it weren’t for the fact that his brother officers insist on doing his laughing for him,” chuckled the admiral.

The talk now turned upon the “Pollard’s” construction, which the inventor explained, while Jacob Farnum threw in a few words now and then.  Captain Jack had the good taste to remain silent during this discussion.  Admiral Bentley asked many questions, appeared deeply interested, and promised to make a thorough trip of inspection aboard the submarine.

“The time may come, of course,” said the admiral, musingly, “when a flag officer will have to make his headquarters aboard such a little craft, for the day may not be far distant when battleships will be too cumbrous and too costly to be risked any more at sea when a nation is engaged in war.”

“That’s our captain’s view of the possibilities,” nodded Mr. Farnum.

“It will be a sad blow to some of us old salts,” laughed the admiral.  “It isn’t likely to strike me, of course.  I shall be retired, and done with the service, before the big battleship becomes as useless in war as a ferryboat.  But you, Captain Benson, will very likely live to see the day when the battleships will be sold for freight steamers.  By the way, my young friend, what is your age?  Sixteen.  Why, you are young enough to enter Annapolis.  With your bent for things naval, why don’t you try to interest your home Congressman in appointing you as a cadet?”

“If the battleship is to go, sir,” replied the youngster, “or even if the submarine is to become a vastly more important craft, it seems to me that I shall be seizing the biggest chance by staying right with Mr. Farnum and Mr. Pollard.  The greatest naval man of the future may be the all-around submarine expert.”