“Important to me, or to you?” asked Jack, thoughtfully.

He had no intention of answering a much older man disrespectfully.  But there was about Herr Radberg the air of a man who expects his greatness to be recognized at a glance, and who demands obedience from common people as a right.  This sort of thing didn’t fit well with the American boy.

“Oh, it is important to you, and very much so,” urged the Professor, somewhat more anxiously.  “Besides,” added the German, with a now really engaging smile, “I have met your demand, Herr Benson, and have said ‘please.’”

“Then I suppose I’ll have to meet your demand,” nodded Jack, good-humoredly.  “Lead the way, sir.”

“Ach!  You may walk at my side,” permitted the German.

It all seemed a bit strange, but Captain Jack Benson had been through more strange experiences than had most Americans of twice or thrice his age.  Besides, as he walked beside Herr Professor Radberg Jack imagined that he had guessed at least an inkling of the other’s business.  The German had announced himself as a professor; probably, therefore, he was a scientist.  Being a scientist, the Professor had very likely invented, or nearly invented something intended for use in connection with submarine torpedo boats, and wanted to interest the concern by which the young submarine skipper was employed.  Though this guess was a reasonable one, it soon turned out to be the wrong one.  The Professor’s real reason for seeking this interview was one that was bound to take the submarine boy almost off his feet.

Readers of the preceding volumes in this series need no introduction to Captain Jack Benson, nor to his chums, Hal Hastings and Eph Somers.  Such readers recall, as told in “The Submarine Boys on Duty,” how Jack and Hal drifted into Dunhaven just at the right moment to fight for an opportunity to work themselves into the submarine boat building business.  How the boys helped build the first of the now famous Pollard submarines, and afterwards learned how to man her, was all told, together with all their strange adventures in their new life.

In the “The Submarine Boys’ Trial Trip” was related how Jack Benson solved the problem of leaving a submarine boat when it lay on the ocean’s bottom, and also the trick of entering that submerged boat again, after diving from the surface of the water.  The attempt of shrewd business men to secure control of the new submarine boat company was also described, together with the manner in which the submarine boys outwitted them.  Through a successful trial trip, and Captain Jack’s ingenious ways of arousing public interest, the government was forced to buy the “Pollard,” as the first of the submarines was named.

In “The Submarine Boys and the Middies” was narrated how the submarine boys secured the prize detail of going to the Naval Academy at Annapolis as temporary instructors in submarine boating.  Many startling adventures, and some humorous ones, were related in that volume.