“And killing you,” clicked Mr. Farnum.

“Undoubtedly.  Yet seventy feet is as deep as one need go.  Fifty feet is far enough below the surface, for that matter.  And we have the splendid little ‘Pollard’ under such perfect control that we can drop to fifty feet below the surface, as shown by our submersion gauge, and keep just at that depth.”

“It’s all wonderful,” cried the boatbuilder.  “Jack, you are a genius at this work!”

“There are some rather big problems to be worked out, in connection with this new idea,” hinted Benson.

“What are the problems?”

“Well, in observing a stretch of water, for the position or approach of a hostile battleship, it might be necessary for the swimmer to go up several times.”

“Yes—?”

“That would call for a very considerable use of compressed air.”

“Naturally.”

“So, in the boat now building, Mr. Farnum, I think Mr. Pollard and yourself should provide for the carrying of greater quantities of compressed air.  For, when a submarine is below, you must always have reserve tanks of compressed air to be used in bringing the boat to the surface.  Of course, once on the surface, with the motor going, more compressed air can be quickly stored.”

“You’ve been doing some busy thinking, Jack,” spoke Mr. Farnum, approvingly.

“I haven’t been doing it all, sir,” was Benson’s quick reply.  “Hal and Eph have been talking it all over with me.”

“The Melvilles are very anxious to find out how you performed the seemingly wonderful feat of leaving the submerged boat and then returning to it.”

“Are you going to tell them, sir.”

“Not, at any rate, until I’ve taken more time to think about it.  Yet, you understand, Jack, I can’t be too offish with them.  They are able to control the investment of a good deal of money, and that money I am afraid we are going to need if we are to go as steeply as we’d like into the building of submarines.”

Jacob Farnum, it will be remembered, had married Grace Desmond, an heiress.  Her affairs were not yet fully settled through the probate court, but she would presently be entitled to about a half million dollars in her own right.  To many it would have seemed that, with a wife so rich, the inventor would not have to look far to find abundant capital.  Jacob Farnum, however, knew the hazards that surround even the best conducted business concerns, and he had determined that not a penny of his young wife’s fortune should be risked in his own ventures.  In other words, it was a point of honor with him not to take the slightest risk of involving his wife’s private fortune.

The following morning David Pollard was on hand, in response to a telegram from his friend.  Things were now about in shape for final discussion between Melville, the builder and the inventor.

In the private inner office of the shipyard the group of those most interested gathered.  Jacob Farnum seated himself beside his desk, Pollard taking a chair close by.  Lawyer Demarest, with a pile of impressive looking documents before him, sat at a large flat-top desk.  Melville, senior, and two business friends, sat a little apart, while Don Melville stood behind his father.