CHAPTER XIII
A SECOND TEST
After his second shout of alarm Ned Newton remained quiet. After all, he did not lack either physical or moral courage. He had not entered into this test of the flying boat without knowing very well that something might go wrong and that a fatal disaster for all was possible.
How the mechanicians were affected, the inventor and Ned did not know just then. The members of the crew in the tail of the boat made no comment through the speaking tube. As for comments by anybody on the earth that might be watching the careening plane, Tom Swift had made no provision for receiving such a communication. There was radio on board the Winged Arrow, but it was not in use during this test.
Nor could any advice, even from Mr. Barton Swift, have aided the young inventor in this serious emergency. Something was wrong with the balance of the seaplane. Just what it was, Tom had not yet the first idea. He was as much puzzled as anybody else could have been.
The rolling of the huge structure continued. Had it not been put together with such care, the plane would never have withstood the second roll.
Ned, who had gained his feet and who clung to one of the hand-rails with which the compartment in the nose of the boat was furnished, now was silent. He watched his chum’s movements with great anxiety, but he did not interfere by either speech or act with Tom’s attempts to govern the craft.
The inventor watched the needles of the several indicators connected with the mechanism of the plane. Some of these gyrated crazily when the boat rolled. But there was an arrow on one dial that stood still.
This dial had nothing to do with the driving of the plane. At first it did not enter Tom Swift’s mind that this dial—or what it registered—was at all important to the flight of the seaplane.
It was the indicator which registered the amount of compressed air that filled the “skin” of the boat. This hollow between the outer and inner hull of the craft had to do with the balance and security of the plane when she had to be brought down into the sea in rough weather.
Tom’s experiments with the pigs’ bladders and the hollow bamboo had resulted in an attempt to overcome boisterous waves through the weight of compressed air between the two skins of the boat’s hull. How it was going to work when the Winged Arrow chanced to descend upon a rough sea, was yet to be proved.
He noted the unwavering needle on this particular indicator several times while the plane was rolling without getting from it any inspiration at all. Then, suddenly, he uttered a mighty shout, grabbed for the flexible speaking tube, and yelled to his chief mechanician:
“Brannigan! Start the pump! Get busy!”
“What pump, boss?” was the surprised query from the tail of the boat.
“Compressed air! Isn’t but one, Brannigan! Fill the skin!”
“All right, boss! Are you goin’ down?”
“Not if I can help it. I want to stay up,” answered Tom, and dropped the tube.
“What’s the idea?” demanded Ned, staring at him.
“I don’t quite know what the idea is myself, yet,” confessed the young inventor. “But something has got to be done, and I am willing to try—Here we go again!”
Once more the huge, groaning structure rolled. If it looked bad to those on the ground, consider how the crew of the Winged Arrow felt!
The usual kind of an equilibrator—that used in the government of most dirigible balloons and other flying craft—was a part of the Winged Arrow’s equipment, but in this strange case the instrument seemed to have no value at all. The great hull of the seaplane certainly did not balance.
Whether Tom drove the mechanism fast or slow, the rolling continued. No matter how strongly the structure was built, such wrenching must of necessity in time wreck the seaplane.
They were now a mile or more high in the air. If the plane fell apart at this altitude there would not be the smallest hope of escape for any of her crew. Tom had tried to descend, but she seemed to roll worse on a downward than on an upward slant.
“Brannigan! Make use of that pump!” Tom shouted through the tube.
“Aye, aye, sir!” came back the reply.
The finger on the dial had begun to move. The vacuum between the jackets of the hull began to fill with air. The plane regained an even keel again for a moment and Tom felt a tremor of the hull which he knew to be from the pressure of the air driven into the vacuum.
“What are you doing, Tom?” demanded Ned, putting his lips close to his friend’s ear.
“Trying a new one. Great Scott! Ned, if my suspicion is right, I have worked a scheme for balancing an object floating in air which as far as I know is an entirely new trick. I have invented something—perhaps—without the first idea that I was doing anything extraordinary.”
“Don’t care what it is,” replied Ned. “But if it is what is stopping the boat from rolling——”
“I believe it is! It is a new equilibrator! I believe it is going to work!”
“We’re sitting pretty now,” confessed Ned. “Don’t try any more tricks till we are down again.”
“Don’t fret.” Tom turned and spoke to Brannigan through the tube again. “Shut off! All right. Look out for yourselves back there. I am going to zoom.”
The Winged Arrow, once more on even keel, began to descend in a great spiral. Closer and closer she came to the earth. There was Lake Carlopa and the cove from which she had taken to the air. After a time the two friends in the bow of the plane could see the spectators on the shore.
Tom Swift had quite recovered from his disturbance of mind. He believed he had by chance discovered something that really was of great value in the management of this type of seaplane. He wanted to talk it over with his father and make other experiments before being sure that he had guessed right.
After all, experiments in natural science are the chief paths to invention. Tom thought that he might have hit upon one of those lucky discoveries that often aid in the establishment of worthwhile knowledge.
When the seaplane finally took the water, the air chamber had to be relieved of pressure before the hull floated at a proper depth. Mr. Barton Swift noted this at once and turned to see if the well dressed and talkative stranger had taken note of this fact.
The man had disappeared. A motor-car shooting away along the road to Shopton suggested the manner in which the stranger might have gone. It was plain that for some reason the man did not wish to meet the younger Swift at this time.
Tom’s father was so much interested in his son’s discovery regarding the compressed air chamber and its value as an equilibrator that he forgot to speak of the stranger and his evident interest in the new flying boat.
Indeed, all those closely connected with Tom’s experiments and with the success of the Winged Arrow, thought of little else for the next few days but the recurrent flights of the plane.
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.”
“Well, I just guess you won’t!” cried Mary. “That would be very perilous, Tom. Even if father and Mr. Damon were in trouble up there, you could scarcely help them by flying to them in a seaplane.”
Tom laughed too. The idea was odd enough. The use to which he expected to put the Winged Arrow was entirely practical.
That next morning they made the trial trip to the Atlantic. This test of the flying boat would be a real test. If she had to be brought down, either on land or sea, they would not be near headquarters and the mechanicians aboard the plane must be equal to all repairs that might be necessary.