“Humph!  Let him be talked about,” returned Don, with a lowering scowl.  “I suppose he’s pretty conceited to-day, but it won’t be long before I’ll have it fixed so that his pride shall go down lower than ever the ‘Pollard’ could sink.”

“Will you use our submarine boat to do it?” inquired the elder Melville, with a meaning smile.

CHAPTER VIII

FARNUM STOCK GOES UP

“Got time to look at something, Mr. Pollard?” asked Captain Jack, two days later.

The captain and crew of the submarine had entered the outer office.  In his hands Jack carried a small wooden box.  Hal and Eph looked delightfully mysterious.

“Time to look at something?” repeated the inventor, with a laugh.  “I seem to have plenty of time for almost anything these days.”

There being none of the office employees about at the moment, Benson led the way to one of the desks, opened the box and took out a complicated-looking little model.

“You know, Mr. Pollard,” murmured Jack, while the other two boys drew close, “although we have hit upon the way for some of a submarine’s crew to escape when the boat is at the bottom, or in deep water, it always needs at least one of the crew to remain behind to close the rear port of the torpedo tube and to operate the compressed air a little.  So, valuable though our trick may be, it really means that, in case of serious accident, one member of the crew would have to remain behind in order to help the next to last to get away.  So, in case of accident, there would always be one member of the crew who would have to be left behind to die.  That’s the thing we fellows have been working on, and here’s the result.  At least, it’s the best we can do with it.”

“What’s the idea?” inquired the inventor, examining the small model curiously.

“Why,” laughed Jack Benson, good-humoredly, “it’s an automatic device, set to a time principle, for closing the after port of the torpedo tube and letting off some compressed air.  By means of this automatic device the last fellow could let himself out safely.  That’s the theory, you see; but we’re new inventors, and so there’s some flaw in the device.  It will take a skilled mind like yours to see where the fault lies.”

Jack explained volubly, while David Pollard looked over the model that the trio of young geniuses had put together.  Then Benson drew from an inner pocket, and spread out, some carefully made mechanical drawings that made his idea plainer.  Jack was not a trained draughtsman, but he had a great natural talent in that direction.

“Why, you have a splendid idea here,” cried the inventor, presently.

“It doesn’t quite work, though,” said Hal, ruefully.

“Lot’s of inventions don’t, unfortunately,” winced David Pollard.  “I know something about that, for a big percentage of my inventions have turned out to have more flaws than good points.  But this is really ingenious, boys.  Who has had the big share in this get-up?”