“Why, yes; that will be mighty important—­if we go under the German flag.”

“If you go?” repeated the Professor.  “Why, that is all settled!”

“Then I must have missed something, by not watching you closely enough,” murmured Jack.  “I shall have to sit up straighter and keep my eyes wider open.  When was it all settled, sir?”

“Why, did you not tell me—­”

“Haven’t had a blessed chance to tell you anything,” replied Jack, looking astonished.  “You’ve been doing all the telling.”

“But you’ll go with me, of course, to Washington?” uttered Radberg, looking much taken aback.

“I doubt it,” muttered young Benson, shaking his head.  “In fact, sir, I may as well tell you that it’s waste of our time to carry this line of talk any further.”

“Ach!  You are cunning,” smiled Professor Radberg, no longer nonplussed.  “That is as it should be, too, for you are a clever young man, Herr Benson.”

“A thousand thanks,” murmured Captain Jack.

“But, instead of talk,” pursued the German, “you wish to see some money.  Quite right!  I should, were I in your place, Herr Benson.  Well, then—­ach!  Look at this.”

Thrusting a fat hand down deep in a trousers pocket, Herr Professor Radberg brought up into view a big roll of money.  He held this up so that the submarine boy could feast his eyes on it.  Jack looked, composedly.

“Did you ever see anything like this—­you, who are such a young boy?” smiled the German, teasingly.

“I—­I don’t know, really,” responded Jack, thoughtfully, thrusting a hand down into his own trousers pocket.  Young Benson brought up into the light a very comfortable looking handful of banknotes, rolled and surrounded by a broad elastic band.  “Let’s measure the two, Professor, and see how they compare.”

“Ach!” muttered the German, regarding Jack’s money with some displeasure.  “Where did you get all that?”

“Oh, now, Professor!” cried the young submarine captain, reproachfully.  “I didn’t ask you where you got yours!”

“Ach!  This is all so much foolishness!” cried the German Professor, returning his money to his pocket.

“That’s what I think, too,” agreed Jack, following suit.  “It’s what our English cousins call ‘bad form,’ to go to comparing piles of money.”

“Now, sit down, Herr Benson, and I will tell you what a very handsome sum of money, and what excellent wages, the German government will pay you to enter our imperial naval service.”

“How much money is there in Germany?” interrupted the submarine boy, thoughtfully.

“How much, in all Germany?” demanded the Professor.  “Nein!  How should I know?”

“You expect me, of course, to turn my back on this country for good, to tell you Germans whatever I may know about submarine secrets, to drill with your navy, and be prepared to fight in your navy if war comes?”