“I’d just like to know who he is,” repeated Tom. “Anyway, I am going to ask you, Ned, to increase the special guards about the cove over there where the plane rests. I am not yet ready to give other people the benefit of my discoveries.”

“So Koku is not guard enough?” chuckled Ned Newton.

“He has to sleep once in a while. Besides, a well dressed man awes Koku a whole lot,” and Tom smiled. “And this chap you speak of could put it all over the innocent savage.”

They decided to have a special number of guards who should remain at the cove where the launching had taken place, at least, until the time of the try-out. And Tom and his men strained every effort to complete the flying boat and send it into the air as quickly as possible.

Tom kept three shifts a day at work. But only the most skilled of his men could be trusted on the job, so the crews were small. However, there was not an hour of the twenty-four save from Saturday evening until Monday morning when the hammers did not ring or the steam drills puff or the riveters clatter on the Winged Arrow.

That shore of Lake Carlopa became a very popular resort for sightseers during the ensuing fortnight. The newspapers had got hold of the idea that Tom Swift was about to reveal to the world another marvel, and the reporters would have annoyed the young inventor a good deal had it not been for Ned Newton.

Ned believed in a certain amount of publicity, and the stories he furnished the newspaper reporters, if not particularly scientific, were at least interesting. Tom Swift’s new flying boat was a first page leader for several days before the test day.

Tom was watchful for the reappearance of the man whose presence at the launching had disturbed him; but the French looking person did not again come to the cove. At least, Tom did not see the stranger. And as the hour approached when the Winged Arrow would be ready for her trial flight the young inventor gradually forgot all outside matters. He did not even go to the Nestor house to learn if the invalid and Mr. Damon had been heard from again. He began to sleep aboard the flying boat, as the cabin was practically finished.

This central portion of the pontoon, or boat, was arranged so as to utilize every inch of space. There were folding berths for eight. The cabin could be divided by a curtain if passengers of opposite sexes were included in any party. Meals for officers and passengers would be served here, too, the galley being directly aft.

In contradistinction to the ordinary sailing craft, the quarters of the crew of the Winged Arrow were in her tail, or after-part. These machinists would be furnished hammocks to sleep in. The prow of the boat, where the mechanism of the powerful searchlights was housed, was built of well-leaded glass so that an unobstructed view ahead and above, as well as below and on either side, could be obtained.