“I am sure we can build such a flying boat, father.”

“Humph! I wish I had your confidence, Tom,” chuckled Mr. Barton Swift, the old inventor.

His son laughed, too. “It isn’t confidence you lack,” he said. “It is just that you are too cautious to seem optimistic.”

“Have it your own way,” rejoined his father. “Just the same, a speed boat for the air, land, and sea that will do all you suggest is something to consider fearfully. Nothing to compare to it has ever yet been launched.”

“But it will be launched,” cried Tom Swift eagerly. “Somebody will put it into the air before we know it. Why not get ahead of the rest of the smart folks? Why not put out a flying boat that will make all their eyes bug out?”

“Even your slang gets ahead of me, Tom,” said his father mildly. “Just why do you wish to strain the optic nerves of your competitors?”

But Tom Swift only laughed. He knew just how young his father’s mind remained, even if he was a semi-invalid at times and his body was weakened by age and hard work.

“There is a bunch of rich men, I understand, who mean to build a flying boat to go hunting in up toward the Arctic Circle next summer. There are others that believe the mystery of the Antarctic can only be revealed through the use of such a craft. The interior of Africa, around Lake Tanganyika and the other great lakes can be properly explored only by the use of some such machine. Central South America can be reached more easily from the Amazon and its great branches than by any other means. Without a flying boat, how may one fly over the falls and escape the dangers of the rapids?”

“Good! Good!” exclaimed Mr. Barton Swift. “I see you have been thinking this thing out, at least. A great many people have excuses for what they want to do; but you, Tom, have a reason. What else?”

Tom Swift laughed again. He was a boyish fellow, in spite of all his experiences of the past few years; and a boy finds it difficult at most times to take older people into his confidence, especially about his dreams and hopes.

“I do not know that my suggestion should seem an impossibility,” Tom said, soberly. “See what the Swift Construction Company has done in the past. Of course, I am counting on your help, father, to carry such a thing to a successful conclusion.”

“You actually talk as though you had conceived a plan and would put it into effect, Tom!” cried his father.

“I don’t know but I have—and will,” said Tom, smiling once more. “At any rate, I have been revolving the scheme in my head for a long time. I admit it. A flying boat, as the storybook fellows write now, has ‘intrigued’ my interest. I’m coocoo about it, to use Ned Newton’s slang.”

“So you lay your knowledge of the argot to Ned?” laughed Mr. Swift. “But this flying boat?”

“A lot has been accomplished by other people. We would not be the first in the field, by any means. But I believe I have some ideas about such an invention that would put us ahead of everybody else. And that is the main thing.”

“The main thing, I should say, would be to have a working hypothesis of the idea in question,” observed Barton Swift dryly. “What would you build a flying boat for? To what particular use is it to be put? Therefore, in making plans for the boat, they must fit the needs of the craft as devised.

“In other words, Tom, what in the world do you want a flying boat for? You have your air scout, your aerial warship that you sold to the Government during the war, your air glider which as yet has not been equal