Tom took the jump-off from the surface of the lake and from the ground. They made successful landings on both the water and the earth. After each flight there were adjustments to make and changes in the mechanism. Tom and his crew worked day and night upon the wonderful flying boat. At length Tom Swift was ready to make a longer flight in the winged boat. Until he had driven the _Winged Arrow_ for a considerable distance without descending and until he had made a successful landing in rough water and a good jump-off from the same, the young inventor would not be satisfied that he had accomplished what he had set out to do. He and Ned had forgotten the stranger who they believed had shown more than ordinary interest in the success or failure of the flying boat. And Mr. Swift had never mentioned that person to his son. Indeed, so deeply engaged was Tom Swift in his new seaplane that other interests literally faded out of his mind. Before the flight to the ocean which he had determined on, however, Tom spent an evening with Mary Nestor and her mother. At first Mrs. Nestor had heard so frequently from the invalid on his northern trip that she had lost much of her anxiety regarding Mr. Nestor’s health and safety. But after the steamship had landed him and Mr. Damon at Reykjavik and Mr. Nestor had written one letter, his family had not heard a word from him. “They were going into the interior—to Rosestone—the day following his letter,” Mary explained to Tom. “What could have become of them after that we cannot imagine. Mother is becoming much worried again.” “You don’t suppose that Iceland has postal communication as frequently as we have it here in the States, do you?” asked Tom. “It is sort of a barren land, I understand. They are all right. You’ll get a letter any day now.” “It has been a month,” Mrs. Nestor declared, shaking her head. Tom laughed cheerfully. “No use talking. I see I’ll have to provision this new plane of mine and take a trip in her to Iceland to look up that party.” “You could not go so far in the _Winged Arrow_, could you, Tom?” asked Mary. “I do not know why not. That is exactly what I built her for—long trips. She is able to carry provisions for a party of ten and enough gasoline to last for at least a flight of two thousand miles.” “Two thousand miles without coming down?” cried Mary. “About coming down, I don’t know. I expect her to clear a hundred miles an hour when put to it. Even if we don’t drive her more than fifty miles an hour, we could make a journey two thousand miles long in a little over a day and a half. “And if she proves sea-worthy—if we can bring her down and launch her into the air again from the surface of the ocean as easily as we do from Lake Carlopa—I would not be afraid of taking a trip to Iceland.”