there was a rushing, whizzing, throbbing noise in the air. a great body, like that of some immense bird, sailed along, casting a grotesque shadow on the ground below. an elderly man, who was seated on the porch of a large house, started to his feet in alarm.

"gracious goodness! what was that, mrs. baggert?" he called to a motherly-looking woman who stood in the doorway. "what happened?"

"nothing much, mr. swift," was the calm reply "i think that was tom and mr. sharp in their airship, that's all. i didn't see it, but the noise sounded like that of the red cloud."

"of course! to be sure!" exclaimed mr. barton swift, the well-known inventor, as he started down the path in order to get a good view of the air, unobstructed by the trees. "yes, there they are," he added. "that's the airship, but i didn't expect them back so soon. they must have made good time from shopton. i wonder if anything can be the matter that they hurried so?"

he gazed aloft toward where a queerly-shaped machine was circling about nearly five hundred feet in the air, for the craft, after swooping down close to the house, had ascended and was now hovering just above the line of breakers that marked the new jersey seacoast, where mr. swift had taken up a temporary residence.

"don't begin worrying, mr. swift," advised mrs. baggert, the housekeeper. "you've got too much to do, if you get that new boat done, to worry."

"that's so. i must not worry. but i wish tom and mr. sharp would land, for i want to talk to them."

as if the occupants of the airship had heard the words of the aged inventor, they headed their craft toward earth. the combined aeroplane and dirigible balloon, a most wonderful traveler of the air, swung around, and then, with the deflection rudders slanted downward, came on with a rush. when near the landing place, just at the side of the house, the motor was stopped, and the gas, with a hissing noise, rushed into the red aluminum container. this immediately made the ship more buoyant and it landed almost as gently as a feather.

no sooner had the wheels which formed the lower part of the craft touched the ground than there leaped from the cabin of the red cloud a young man.

"well, dad!" he exclaimed. "here we are again, safe and sound. made a record, too. touched ninety miles an hour at times—didn't we, mr. sharp?"

"that's what," agreed a tall, thin, dark-complexioned man, who followed tom swift more leisurely in his exit from the cabin. mr. sharp, a veteran aeronaut, stopped to fasten guy ropes from the airship to strong stakes driven into the ground.

"and we'd have done better, only we struck a hard wind against us about two miles up in the air, which delayed us," went on tom. "did you hear us coming, dad?"

"yes, and it startled him," put in mrs. baggert. "i guess he wasn't expecting you."

"oh, well, i shouldn't have been so alarmed, only i was thinking deeply about a certain change i am going to make in the submarine, tom. i was day-dreaming, i think, when your ship whizzed through the air. but tell me, did you find everything all right at shopton? no signs of any of those scoundrels of the happy harry gang having been around?" and mr. swift looked anxiously at his son.

"not a sign, dad," replied tom quickly. "everything was all right. we brought the things you wanted. they're in the airship. oh, but it was a fine trip. i'd like to take another right out to sea."

"not now, tom," said his father. "i want you to help me. and i need mr. sharp's help, too. get the things out of the car, and we'll go to the shop."

"first i think we'd better put the airship away," advised mr. sharp. "i don't just like the looks of the weather, and, besides, if we leave the ship exposed we'll be sure to have a crowd around sooner or later, and we don't want that."

"no, indeed," remarked the aged inventor hastily. "i don't want people prying around the submarine shed. by all means put the airship away, and then come into the shop."

in spite of its great size the aeroplane was easily wheeled along by tom and mr. sharp, for the gas in the container made it so buoyant that it barely touched the earth. a little more of the powerful vapor and the red cloud would have risen by itself. in a few minutes the wonderful craft, of which my readers have been told in detail in a previous volume, was safely housed in a large tent, which was securely fastened.

mr. sharp and tom, carrying some bundles which they had taken from the car, or cabin, of the craft, went toward a large shed, which adjoined the house that mr. swift had hired for the season at the seashore. they found the lad's father standing before a great shape, which loomed up dimly in the semi-darkness of the building. it was like an immense cylinder, pointed at either end, and here and there were openings, covered with thick glass, like immense, bulging eyes. from the number of tools and machinery all about the place, and from the appearance of the great cylinder itself, it was easy to see that it was only partly completed.

"well, how goes it, dad?" asked the youth, as he deposited his bundle on a bench. "do you think you can make it work?"

"i think so, tom. the positive and negative plates are giving me considerable trouble, though. but i guess we can solve the problem. did you bring me the galvanometer?"

"yes, and all the other things," and the young inventor proceeded to take the articles from the bundles he carried.

mr. swift looked them over carefully, while tom walked about examining the submarine, for such was the queer craft that was contained in the shed. he noted that some progress had been made on it since he had left the seacoast several days before to make a trip to shopton, in new york state, where the swift home was located, after some tools and apparatus that his father wanted to obtain from his workshop there.

"you and mr. jackson have put on several new plates," observed the lad after a pause.

"yes," admitted his father. "garret and i weren't idle, were we, garret?" and he nodded to the aged engineer, who had been in his employ for many years.

"no; and i guess we'll soon have her in the water, tom, now that you and mr. sharp are here to help us," replied garret jackson.

"we ought to have mr. damon here to bless the submarine and his liver and collar buttons a few times," put in mr. sharp, who brought in another bundle. he referred to an eccentric individual who had recently made an airship voyage with himself and tom, mr. damon's peculiarity being to use continually such expressions as: "bless my soul! bless my liver!"

"well, i'll be glad when we can make a trial trip," went on tom. "i've traveled pretty fast on land with my motorcycle, and we certainly have hummed through the air. now i want to see how it feels to scoot along under water."

"well, if everything goes well we'll be in position to make a trial trip inside of a month," remarked the aged inventor. "look here, mr. sharp, i made a change in the steering gear, which i'd like you and tom to consider."

the three walked around to the rear of the odd-looking structure, if an object shaped like a cigar can be said to have a front and rear, and the inventor, his son, and the aeronaut were soon deep in a discussion of the technicalities connected with under-water navigation.

a little later they went into the house, in response to a summons from the supper bell, vigorously rung by mrs. baggert. she was not fond of waiting with meals, and even the most serious problem of mechanics was, in her estimation, as nothing compared with having the soup get cold, or the possibility of not having the meat done to a turn.

the meal was interspersed with remarks about the recent airship flight of tom and mr. sharp, and discussions about the new submarine. this talk went on even after the table was cleared off and the three had adjourned to the sitting-room. there mr. swift brought out pencil and paper, and soon he and mr. sharp were engrossed in calculating the pressure per square inch of sea water at a depth of three miles.

"do you intend to go as deep as that?" asked tom, looking up from a paper he was reading.

"possibly," replied his father; and his son resumed his perusal of the sheet.

"now," went on the inventor to the aeronaut, "i have another plan. in addition to the positive and negative plates which will form our motive power, i am going to install forward and aft propellers, to use in case of accident."

"i say, dad! did you see this?" suddenly exclaimed tom, getting up from his chair, and holding his finger on a certain place in the page of the paper.

"did i see what?" asked mr. swift.

"why, this account of the sinking of the treasure ship."

"treasure ship? no. where?"

"listen," went on tom. "i'll read it: 'further advices from montevideo, uruguay, south america, state that all hope has been given up of recovering the steamship boldero, which foundered and went down off that coast in the recent gale. not only has all hope been abandoned of raising the vessel, but it is feared that no part of the three hundred thousand dollars in gold bullion which she carried will ever be recovered. expert divers who were taken to the scene of the wreck state that the depth of water, and the many currents existing there, due to a submerged shoal, preclude any possibility of getting at the hull. the bullion, it is believed, was to have been used to further the interests of a certain revolutionary faction, but it seems likely that they will have to look elsewhere for the sinews of war. besides the bullion the ship also carried several cases of rifles, it is stated, and other valuable cargo. the crew and what few passengers the boldero carried were, contrary to the first reports, all saved by taking to the boats. it appears that some of the ship's plates were sprung by the stress in which she labored in a storm, and she filled and sank gradually.' there! what do you think of that, dad?" cried tom as he finished.

"what do i think of it? why, i think it's too bad for the revolutionists, tom, of course."

"no; i mean about the treasure being still on board the ship. what about that?"

"well, it's likely to stay there, if the divers can't get at it. now, mr. sharp, about the propellers—"

"wait, dad!" cried tom earnestly.

"why, tom, what's the matter?" asked mr. swift in some surprise.

"how soon before we can finish our submarine?" went on tom, not answering the question.

"about a month. why?"

"why? dad, why can't we have a try for that treasure? it ought to be comparatively easy to find that sunken ship off the coast of uruguay. in our submarine we can get close up to it, and in the new diving suits you invented we can get at that gold bullion. three hundred thousand dollars! think of it, dad! three hundred thousand dollars! we could easily claim all of it, since the owners have abandoned it, but we would be satisfied with half. let's hurry up, finish the submarine, and have a try for it."

"but, tom, you forget that i am to enter my new ship in the trials for the prize offered by the united states government."

"how much is the prize if you win it?" asked tom.

"fifty thousand dollars."

"well, here's a chance to make three times that much at least, and maybe more. dad, let the government prize go, and try for the treasure. will you?"

tom looked eagerly at his father, his eyes shining with anticipation. mr. swift was not a quick thinker, but the idea his son had proposed made an impression on him. he reached out his hand for the paper in which the young inventor had seen the account of the sunken treasure. slowly he read it through. then he passed it to mr. sharp.

"what do you think of it?" he asked of the aeronaut.

"there's a possibility," remarked the balloonist "we might try for it. we can easily go three miles down, and it doesn't lie as deeply as that, if this account is true. yes, we might try for it. but we'd have to omit the government contests."

"will you, dad?" asked tom again.

mr. swift considered a moment longer.

"yes, tom, i will," he finally decided. "going after the treasure will be likely to afford us a better test of the submarine than would any government tests. we'll try to locate the sunken boldero."

"hurrah!" cried the lad, taking the paper from mr. sharp and waving it in the air. "that's the stuff! now for a search for the submarine treasure!"

该作者的其它作品

《tom swift and his airship》

《tom swift and the electronic hydrolung》