Tom Swift Among the Fire Fighters; Or, Battling with Flames from the Air (2024)

or

Battling with Flames from the Air

By

VICTOR APPLETON

CONTENTS

CHAPTER I

A BAD PLACE FOR A FIRE

"Impossible, Ned! It can't be as much as that!"

"Well, you can prove the additions yourself, Tom, on one of the addingmachines. I've been over 'em twice, and get the same result each time.There are the figures. They say figures don't lie, though it doesn'tfollow that the opposite is true, for those who do not stick closely tothe truth do, sometimes, figure. But there you have it; your financialstatement for the year," and Ned Newton, business manager for TomSwift, the talented young inventor, shoved a mass of papers across thetable to his friend and chum, as well as employer.

"It doesn't seem possible, Ned, that we have made as much as that thispast year. And this, as I understand it, doesn't include what was takenfrom the wreck of the Pandora?"

Tom Swift looked questioningly at Ned Newton, who shook his head inanswer.

"You really didn't get anything to speak of out of your underseasearch, Tom," replied the young financial manager, "so I didn't includeit. But there's enough without that."

"I should say so!" exclaimed Tom. "Whew!" he whistled, "I didn't thinkI was worth that much."

"Well, you've earned it, every cent, with the inventions of yourselfand your father."

"And I might add that we wouldn't have half we earn if it wasn't forthe shrewd way you look after us, Ned," said Tom, with a warm smile athis friend. "I appreciate the way you manage our affairs; for, though Ihave had some pretty good luck with my searchlight, wizard camera, wartank and other contraptions, I never would have been able to save anyof the money they brought in if it hadn't been for you."

"Well, that's what I'm here for," remarked Ned modestly.

"I appreciate that," began Tom Swift. "And I want to say, Ned—"

But Tom did not say what he had started to. He broke off suddenly, andseemed to be listening to some sound outside the room of his home wherehe and his financial and business manager were going over the year'sstatement and accounting.

Ned, too, in spite of the fact that he had been busy going overfigures, adding up long columns, checking statements, and giving theresults to Tom, had been aware, in the last five minutes, of anever-growing tumult in the street. At first it had been no more thanthe passage along the thoroughfare of an unusual number of pedestrians.Ned had accounted for it at first by the theory that some movingpicture theater had finished the first performance and the people werehurrying home.

But after he had finished his financial labors and had handed Tom thefirst of a series of statements to look over, the young financialexpert began to realize that there was no moving picture house nearTom's home. Consequently the passing throngs could not be accounted forin that way.

Yet the tumult of feet grew in the highway outside. Ned had begun towonder if there had been an attempted burglary, a fight, or somethinglike that, calling for police action, which had gathered an unusualthrong that warm, spring evening.

And then had come Tom's interruption of himself when he broke off inthe middle of a sentence to listen intently.

"What is it?" asked Ned.

"I thought I heard Rad or Koku moving around out there," murmured Tom."It may be that my father is not feeling well and wants to speak to meor that some one may have telephoned. I told them not to disturb mewhile you and I were going over the accounts. But if it is something ofimportance—"

Again Tom paused, for distinctly now in addition to the ever-increasingsounds in the streets could be heard a shuffling and talking in thehall just outside the door.

"G'wan 'way from heah now!" cried the voice of a colored man.

"It is Rad!" exclaimed Tom, meaning thereby Eradicate Sampson, an agedbut faithful colored servant. And then the voice of Rad, as he was mostoften called, went on with:

"G'wan 'way! I'll tell Massa Tom!"

"Me tell! Big thing! Best for big man tell!" broke in another voice; adeep, booming voice that could only proceed from a powerfully built man.

"Koku!" exclaimed Tom, with a half comical look at Ned. "He and Rad areat it again!"

Koku was a giant, literally, and he had attached himself to Tom whenthe latter had made one of many perilous trips. So eager were Eradicateand Koku to serve the young inventor that frequently there were more orless good-natured clashes between them to see who would have the honor.

The discussion and scuffle in the hall at length grew so insistent thatTom, fearing the aged colored man might accidentally be hurt by thegiant Koku, opened the door. There stood the two, each endeavoring topush away the other that the victor might, it appeared, knock on thedoor. Of course Rad was no match for Koku, but the giant, mindful ofhis great strength, was not using all of it.

"Here! what does this mean?" cried Tom, rather more sternly than hereally meant. He had to pretend to be stern at times with his oldcolored helper and the impulsive and powerful giant. "What are youcutting up for outside my door when I told you I must be quiet with Mr.Newton?"

"No can be quiet!" declared the giant. "Too much noise in street—bigcrowds—much big!"

He spoke an English of his own, did Koku.

"What are the crowds doing?" asked Ned. "I thought we'd been hearing anever increasing tumult, Tom," he said to the young inventor.

"Big crowds—'um go to see big—"

"Heah! Let me tell Massa Tom!" pleaded Rad. Poor Rad! He was gettingold and could not perform the services that once he had so readily andefficiently done. Now he was eager to help Tom in such small measure ascarrying him a message. So it was with a feeling of sadness that Tomheard the old man say again, pleadingly:

"Let me tell him, Koku! I know all 'bout it! Let me tell Massa Tom whutit am, an'—"

"Well, go ahead and tell me!" burst out Tom, with a good-natured laugh."Don't keep me in suspense. If there's anything going on—"

He did not finish the sentence. It was evident that something of momentwas going on, for the crowds in the street were now running instead ofwalking, and voices could be heard calling back and forth suchexclamations as:

"Where is it?"

"Must be a big one."

"And with this wind it'll be worse!"

Tom glanced at Ned and then at the two servants.

"Has anything happened?" asked the young inventor.

"Dey's a big fire, Massa Tom!" exploded Rad.

"Heap big blaze!" added Koku.

At the same time, out in the street high and clear, the cry rang out:

"Fire! Fire!"

"Is it any of our buildings?" exclaimed Tom, in his excitement catchinghold of the giant's arm.

"No, it's quite a way off, on de odder side of town," answered thecolored man. "But we t'ought we'd better come an' tell yo', an'—"

"Yes! Yes! I'm glad you did, Rad. It was perfectly right for you totell me! I wish you'd done it sooner, though! Come on, Ned! Let's go tothe blaze! We can finish looking over the figures another time. Is myfather all right, Rad?"

"Yes, suh, Massa Tom, he's done sleepin' good."

"Then don't disturb him. Mr. Newton and I will go to the fire. I'mglad it isn't here," and Tom looked from a side window out on manyshops that were not a great distance from the house; shops where he andhis father had perfected many inventions.

The buildings had grown up around the old Swift homestead, which, nowthat so much industry surrounded it, was not the most pleasant place tolive in. Tom and his father only made this their stopping place inwinter. In the summer they dwelt in a quiet cottage far removed fromthe scenes of their industry.

"We'll take the electric runabout, Ned," remarked Tom, as he caught upa hat from the rack, an example followed by his friend. Together theyoung inventor and the financial manager hurried out to the garage,where Tom soon had in operation a small electric automobile, that, morethan once, had proved its claim to being the "speediest car on theroad."

As they turned out of the driveway into the street they became aware ofgreat crowds making their way toward a glow of sinister red lightshowing in the eastern sky.

"Some blaze!" exclaimed Tom, as he turned on more power.

"You said it!" ejacul*ted Ned. "Must be a general alarm," he added, asthey caught the sound from the next street of additional apparatushurrying to the fire.

"Well, I'm glad it isn't on our side of town," remarked Tom, as helooked back at the peaceful gloom surrounding and covering his own homeand work buildings.

"Where do you reckon it is?" asked Ned, as they sped onward.

"Hard to say," remarked the young inventor, as he steered to one sideto pass a powerful imported automobile which, however, did not have thespeed of the electric runabout. "A fire at night is always deceiving asto direction. But we can locate it when we get to the top of the hill."

Shopton, the suburb of the town where Tom lived, was named so becauseof the many shops that had been erected by the industry of the younginventor and his father. In fact the town was named Shopton though oflate there had been an effort to change the name of the strictlyresidential section, which lay over the hill toward the river.

Tom's car shot up the slope with scarcely any slackening of speed, and,as he passed a group of men and boys running onward, Tom shouted:

"Where is it?"

"The fireworks factory!" was the answer.

"Fireworks factory!" cried Ned. "Bad place for a fire!"

"I should say so!" exclaimed Tom.

The chums had become gradually aware of the gale that was blowing, and,as they reached the summit of the hill and caught sight of the burningfactory, they saw the flames being swept far out from it and toward acollection of houses on the other side of a vacant lot that separatedthe fireworks industrial plant from the dwellings. As Tom Swiftglimpsed the fire, noted its proportions and the fierceness of theflames, and saw which way the wind was blowing them, he turned on thepower to the utmost.

"What are you doing, Tom?" yelled Ned.

"I'm going down there!" cried Tom. "That place is likely to explode anyminute!"

"Then why go closer?" gasped Ned, for his breath was almost taken awayby the speed of the car, and he had to hold his hat to keep it fromblowing away. "Why don't you play safe?"

"Don't you understand?" shouted Tom in his chum's ear. "The wind isblowing the fire right toward those houses! Mary Nestor lives in one ofthem!"

"Oh—Mary Nestor!" exclaimed Ned. Then he understood—Mary and Tom wereengaged to be married.

"They may be all right," Tom went on. "I can't be sure from thisdistance. Or they may be in danger. It's a bad fire and—"

His voice was blotted out in the roar of an explosion which seemed tohurl back the electric runabout and bring it to a momentary stop.

CHAPTER II

NO USE OF LIVING!

Only momentarily was Tom Swift halted in his progress toward the sceneof the blaze in the fireworks factory. To him, and to the chum who satbeside him on the seat of the electric runabout, it appeared that theblast had actually stopped the progress of the car. But perhaps thatwas more their imagination than anything else, for the machine swept ondown the hill, at the foot of which was the conflagration.

"That was a bad one, Ned!" gasped Tom, as he turned to one side to passan engine on its way to the scene of excitement.

"I should say so! Must have been somebody hurt in that blow-up!"

"I only hope it wasn't Mary or her folks!" murmured Tom. "The wind issweeping the fire right that way!"

"What are you going to do, Tom?" yelled his chum, as the businessmanager saw the young inventor heading directly for the blaze. "What'sthe idea?"

"To rescue Mary, if she's in danger!"

"I'm with you!" was Ned's quick response. "But you can't go any closer.The police are stretching the fire lines!"

"I guess they'll let me through!" said Tom grimly.

He slowed his car as he approached a place where an officer was drivingback the throng that sought to come closer to the blaze.

"Git back! Git back, I tell you!" stormed the policeman, pushingagainst the packed bodies of men and boys. "There'll be another blow-upin a minute or two, and a lot more of you killed!"

"Are there any killed?" asked Tom, stopping the car near the officer.

"I guess so—yes. And some of the houses are catching. Git back now!You, too, with that car! You'll have to back up!"

"I've got to go through!" replied Tom, with tightening lips. "I've gotto go through, Cassidy!" He knew the officer, and the latter nowseemed, for the first time, to recognize the young inventor.

"Oh, it's you, is it, Mr. Swift?" he exclaimed. "Well, go ahead. But becareful. 'Tis dangerous there—very dangerous, an'—"

His voice was lost in the roar of another explosion, not as loud orsevere as the first, but more plainly felt by Tom and Ned, for theywere nearer to it.

"Now will you git back!" cried Policeman Cassidy, and the crowd did,without further urging.

Tom started the runabout forward again.

"We've got to rescue Mary!" he said to Ned, who nodded.

In another moment the two young men were lost to sight in a swirl ofsmoke that swept across the street. And while they are thus temporarilyhidden may not this opportunity be taken of telling new readerssomething of the hero of this story?

The young inventor was introduced in the first volume of this series,called "Tom Swift and his Motor Cycle." It was Tom's first venture intothe realms of invention, after he had purchased from Mr. WakefieldDamon a speedy machine that tried to climb a tree with that excitablegentleman.

Tom, with the help of his father, an inventor of note, rebuilt themotor cycle adding many improvements, and it served Tom in good steadmore than once.

From then on the career of Tom Swift was steadily onward and upward.One new invention led to another from his second venture, a motor boat,through an airship and other marvels, and eventually to a submarine. Ineach of these vehicles of motion and travel Tom and his friends, NedNewton and Mr. Damon, had many adventures, detailed in the respectivevolumes.

His venture in proceeding to save Mary Nestor from possible danger inthe blaze of the fireworks factory was not the first time Tom hadrendered service to the Nestor family. There was that occasion on whichhe had sent his wireless message from Earthquake Island, as related inan earlier volume.

Space forbids the detailing of all that had happened to the younginventor up to the time of the opening of this story. Sufficient tosay that Tom's latest achievement had been the recovery of treasurefrom the depths of the ocean.

Tom Swift's activities in connection with his inventions had become sonumerous that the Swift Construction Company, of which Ned Newton wasfinancial manager and Mr. Damon one of the directors, had been formed.And when the rumor came that there was a chance to salvage some of theuntold wealth at the bottom of the sea, Tom was interested, as were hisfriends.

It was decided to search for the wreck of the Pandora, sunk in the WestIndies, and one of Tom's latest submarine craft was utilized for thispurpose.

Not to go into all the details, which are given in the last volume ofthis series, entitled "Tom Swift and His Undersea Search," suffice itto say that the venture was begun. Matters were complicated owing tothe fact that Mary Nestor's uncle, Barton Keith, was in trouble overthe loss of valuable papers proving his title to some oil lands. Marymentioned that a person, Dixwell Hardley, was the man who, it wassupposed, was trying to defraud her relative. And the complications maybe imagined when it is said that this same Hardley was the man who hadinterested Tom in the undersea search for the riches of the Pandora.

Tom had been at home some time now, and it was while going over hisaccounts with Ned, and, incidentally, planning new activities, that thecry of fire broke in on them.

"Whew, Tom, some heat there!" gasped Ned, lowering his arm from hisface, an action which had been necessitated by Tom's daring in drivingthe car close to the blazing fireworks factory.

"I should say so!" agreed Tom. "I can almost smell the rubber of mytires burning. But we're out of the worst of it."

"Lucky she didn't take the notion to blow up as we were passing,"grimly commented Ned. "Where are you aiming for now?"

"Mary's house. It's just beyond here. But we can't see it on account ofthe smoke."

A few seconds later they had passed through the black pall that wasslashed here and there with red slivers of flame, and, coming to a moreopen space, Ned and Tom cleared their eyes of smoke.

"I guess there's no immediate danger," remarked Tom, as he saw that thehome of Mary Nestor and the houses near her residence were, for thetime being, out of the path of the flames. The explosion had blown downpart of the blazing factory nearest the residential section, and theflames had less to feed on.

But the conflagration was still a fierce one. Not half the big factorywas yet consumed, and every now and then there would sound dull,booming reports, causing nervous screams from the women who were out infront of their homes, while the men would crouch down as though fearinga shower of fiery embers.

"Oh, Tom, I'm so glad you're here!" cried Mary, as the runabout drew upin front of her home. "Do you think it will be much worse?" and sheclutched his arm, as he got down to speak to her.

"I think the worst is over, as far as you people here are concerned,"the young inventor replied. "The wind has shifted a bit."

"And there are several engines near us, Tom," said Mr. Nestor, comingforward. "The firemen tell me they will play streams of water on theroofs and outsides of our houses if the flames start this way again."

"That ought to do the trick," said Tom, with a show of confidence."Anybody hurt around here?" he asked. "One of the policeman said heheard several were killed."

"They may have been—in the factory," said Mr. Nestor. "Of course ifthe fire and explosions had taken place in the daytime the loss of lifewould have been great. But most of the workers had left some timebefore the blaze was discovered. There are a few men on a night shift,though, and I shouldn't be surprised but what some of them hadsuffered."

"Too bad!" murmured the young inventor. "You're not worried about yourhome, are you, Mrs. Nestor?" he asked of Mary's mother.

"Oh, Tom, I certainly am!" she exclaimed. "I wanted to bring out ourthings, but Mr. Nestor said it wouldn't be of any use."

"Neither it would, if we've got to burn, but I don't believe wehave—now," said her husband. "That last explosion and the shift of thewind saved us. I appreciate your coming over, Tom," he went on. "Wemight have needed your help. It's queer there isn't some better, ormore effective, way of fighting a fire than just pouring on acomparatively insignificant bit of water," he added, as, from what wasnow a safe distance, they watched the firemen using many lines of hose.

"They do have chemical extinguishers," said Ned.

"Yes, for little baby blazes that have just started," went on Mr.Nestor. "But in all the progress of science there has not been muchadvance in fighting fires. We still do as they did a hundred yearsago—squirt water on it, and mighty little of it compared to the blaze.It would take a week to put this fire out by the water they are usingif it were not for the fact that the blaze eats itself up and hasnothing more to feed on."

"We'll have to get Tom to invent a new way of fighting fire," remarkedNed.

The young inventor was about to reply when several firemen, equippedwith smoke helmets which they adjusted as they ran, came running downthe street.

"What's the matter?" asked Tom of one whom he knew.

"Some men are trapped in a small shed back of the factory," was theanswer. "We just heard of it, and we're going in after them. Oh!Oh—my—my heart!" he gasped, and he sank to the sidewalk. Evidentlyhe was either overcome by the smoke and poisonous gases or by hisexertions.

Tom grasped the situation instantly. Taking the smoke helmet from theexhausted fire-fighter, the young inventor shouted:

"I'll fill your place! See if you can grab a hat, Ned, and come on!"

One of the other firemen had two helmets, and he offered Ned one.Pausing only long enough to see that Mr. Nestor and some others werelooking after the exhausted "smoke-eater," Ned raced on after Tom. Thetwo young men, following the firemen, made their way around the end ofthe factory to the smoke-filled yard in the rear. But for the helmets,which were like the gas masks of the Great War, they would not havebeen able to live.

One of the firemen pointed through the luridly-lighted smoke to a smallstructure near the main building. This was beginning to burn. Withquick blows of an axe the door was hewed down, and the rescue party,including Tom and Ned, made its way inside. In the light from theblaze, as it filtered through the windows, it could be seen that a manlay in a huddled heap on the floor.

By motions the leader of the rescue squad made it clear that the manwas to be carried out, and Tom helped with this while Ned, using anaxe, cleared away some debris to enable the door to be opened fully sothe men could pass out carrying their burden.

The man was taken to the Nestor yard and stretched out on the grass.Word was relayed to one of the ambulance doctors who were on the sceneattending to several injured firemen, and in a short time the man, who,it appeared, had been overcome by smoke, was revived.

"Well, that was a narrow squeak for you," said one of the firemen, gladto breathe without a mask on.

"Yes, it was touch and go," remarked the young doctor, who had usedheroic measures to bring the man back from the brink of the grave. "Butyou'll live now, all right."

The revived man looked dully about him. He seemed somewhat bewildered.

"Of what use to live?" he murmured. "You might as well have let me diein there. Life isn't worth living now," and he sank into a stupor,while Tom and the others looked wonderingly at one another.

CHAPTER III

TOM'S NEW IDEA

"What's the matter with him, Doctor?" asked Tom in a low voice of theyoung physician who had been working over the man. "Do you think he isworse hurt than appears? Is he dying, and is his mind wandering?"

"I don't believe so," answered the doctor. "At least I don't believethat he is dying, though his mind may be wandering. He isn'tinjured—at least not outwardly. Just temporarily overcome by smoke iswhat it looks like to me. But of course I haven't made a thoroughexamination."

"Hadn't we better get him into the house, Doctor?" asked Mr. Nestor,who stood with Tom, Ned and a group of men and boys about the inertform of the man lying on the grass. The rescued one was again seeminglyunconscious.

"The best medicine he can have is fresh air," the doctor replied. "He'sbetter off out here than in the house. Though if he doesn't revivepresently I will send him to the hospital."

The man did not appear to be so badly off but what he could hear, andat these words he opened his eyes again.

"I don't want to go to the hospital," he murmured. "I'll be all rightpresently, and can go home, though—Oh, well, what's the use?" he askedwearily, as though he had given up some fight. "I've lost everything."

"Well, you've got a deal of life left in you yet; and that's more thanyou could say of some who have come out of smaller fires than this,"said one of the firemen who, with Tom, had carried the man out of theshed. "Come on, we'd better be getting back," he said to his companion."The worst of it is over, but there'll be plenty to do yet."

"You said it!" commented the other grimly.

They went out of the Nestor yard, many of the crowd that had gatheredduring the rescue following. The doctor administered some morestimulant in the shape of aromatic spirits of ammonia to the man, who,after his momentary revival, had again lapsed into a state of stupor.

"Who is he?" asked Tom, as the physician knelt down beside the silentform.

"I don't know," said Mr. Nestor. "I know quite a number connected withthe fireworks factory, but this man is a stranger to me."

"I've seen him going into the main offices several times," remarkedMary, who was standing beside Tom. "He seemed to be one of the companyofficers."

"I don't believe so, Mary," stated her father. "I know most of thefireworks company officials, and I'm sure this man is not one of them.Poor fellow! He seems to be in a bad way."

"Mentally, as well as physically," put in Ned. "He acted as if sorrythat we had saved his life."

"Too bad," murmured Mary, and then a policeman, who had just come intothe yard to get the facts for his report, looked at the figure lying onthe grass, and said:

"I know him."

"You do?" cried Tom. "Who is he?"

"Name's Baxter, Josephus Baxter. He's a chemist, and he works in thefireworks factory here. Not as one of the hands, but in the experimentlaboratory. I've seen him there late at night lots of times. That's howI got acquainted with him. He was going in around two o'clock onemorning, and I stopped him, thinking he was a thief. He proved hisidentity, and I've passed the time of day with him many a time since."

"Where does he live?" asked Mr. Nestor.

"Down on Clay Street," and the officer mentioned the number. "He livesall alone, so he told me. He's some sort of an inventor, I guess. Atleast I judged so by his talk. Do you want an ambulance, Doctor?" heasked the physician.

"No, I think he's coming around all right," was the answer. "If we hadan auto we could send him home."

"I'll take him in the runabout," eagerly offered Tom. "But if he livesall alone will it be safe to leave him in his house?"

"He ought to be looked after, I suppose," the doctor stated. "He'll beall right in a day or so if no complications set in, but he'll be weakfor a while and need attention."

"Then I'll take him home with me!" announced Tom. "We have plenty ofroom, and Mrs. Baggert will feel right at home with some one to nurse.Bring the runabout here, will you please, Ned?"

As Ned darted off to run up the machine, the man opened his eyes again.For a moment he did not seem to know where he was or what had happened.Then, as he saw the lurid light of the flames which were now dying awayand realized his position, he sighed heavily and murmured:

"It's all over!"

"Oh, no, it isn't!" cheerfully exclaimed the doctor. "You will be allright in a few days."

"Myself, yes, maybe," said the man bitterly, and he managed to rise tohis feet. "But what of my future? It is all gone! The work of years islost."

"Burned in the fire?" asked Tom, wondering whether the man was a majorstockholder in the company. "Didn't you have any insurance? Though Isuppose you couldn't get much on a fireworks plant," he added, for heknew something of insurance matters in connection with his own business.

"Oh, it isn't the fire—that is directly," said the man, in the samebitter tones. "I've lost everything! The scoundrels stole them! AndI—Oh, never mind!" he cried. "What's the use of talking? I'm down andout! I might just as well have died in the fire!"

Tom was about to make some remark, but the doctor motioned to him torefrain, and then Ned came up with the runabout. At first JosephusBaxter, which was the name of the man who had been rescued, made someobjections to going to Tom's home. But when it was pointed out that hemight lapse into a stupor again from the effects of the smoke poisons,in which event he would have no one to minister to him at his lonelyhome, he consented to go to the residence of the young inventor.

"Though if I do lapse into unconsciousness you might as well let mekeep on sleeping until the end," said Mr. Baxter bitterly to Tom andNed, as they drove away from the scene of the fire with him.

"Oh, you'll feel better in the morning," cheerfully declared Ned.

The man did not answer, and the two chums did not feel much liketalking, for they were worn out and weary from their exertions at thefire. The factory had been pretty well consumed, though by strenuouslabors the blaze had not extended to adjoining structures. The home ofMary Nestor was saved, and for this Tom Swift was thankful.

Mrs. Baggert, the Swift's housekeeper, was indeed glad to have some oneto "fuss over," as Tom put it. She prepared a bed for Mr. Baxter, andin this the weary and ill man sank with a sigh of relief.

"Can I do anything for you?" asked Tom, as he was about to go out andclose the door.

"No—thank you," was the halting reply. "I guess nothing can be done.Field and Melling have me where they want me now—down and out."

"Do you mean Amos Field and Jason Melling of the fireworks firm?" askedTom, for the names were familiar to him in a business way.

"Yes, the—the scoundrels!" exclaimed Mr. Baxter, and from his voiceTom judged that he was growing stronger. "They pretended to be myfriends, giving me a shop in which to work and experiment, and when thetime came they took my secret formulae. I believe that is what theystarted the fire for—to conceal their crime!"

"You don't mean that!" cried Tom. "Deliberately to start a fire in afactory where there was powder and other explosives! That would be aterrible crime!"

"Field and Melling are capable of just such crimes as that!" saidJosephus Baxter, bitterly. "If they took my formulae they wouldn't stopat arson."

"Were your formulae for the manufacture of fireworks?" asked Tom.

"Not altogether," was the reply. "I had several formulae for valuablechemical combinations. They could be used in fireworks, and that is whyI could use the laboratory here. But the main use of my discoveries isin the dye industry. I would have been a millionaire soon, with therise of the American dye industry following the shutting out of theGermans after the war. But now, with my secret formulae gone, I am nobetter than a beggar!"

"Perhaps it will not be as bad as you think," said Tom, recognizing thefact that Mr. Baxter was in a nervous and excited state. "Matters maylook brighter in the morning."

"I don't see how they can," was the grim answer. "However, I appreciateall that you have done for me. But I fear my case is hopeless."

"I'll see you again in the morning," Tom said, trying to infuse somecheerfulness into his voice.

He found Ned waiting for him when he came downstairs.

"How is he?" asked the young business manager.

"In rather a bad way—mentally, at least," and Tom told of the lostformulae. "Do you know, Ned," he went on, "I have an idea!"

"You generally do have—lots of 'em!" Ned rejoined.

"But this is a new one," went on Tom. "You saw what trouble they hadthis evening to get a stream of water to the top stories of thatfactory, didn't you?"

"Yes, the pressure here isn't what it ought to be," Ned agreed. "Andsome of our engines are old-timers."

"Why is it necessary always to fight a fire with water?" Tom continued."There are plenty of chemicals that will put out a fire much quickerthan water."

"Of course," Ned answered. "There are plenty of chemical fireextinguishers on the market, too, Tom. If your idea is to invent a newhand grenade, stay off it! A lot of money has been lost that way."

"I wasn't thinking of a hand grenade," said Tom, as he drew some sheetsof paper across the table to him. "My idea is on a bigger scale.There's no reason, Ned, why a big fire in a tall building, like asky-scraper, shouldn't be fought from above, as well as from below. Nowif I had the right sort of chemicals I could—"

Tom paused in a listening attitude. There was the rush of feet and avoice cried:

"I'll get them! I'll get the scoundrels!"

CHAPTER IV

AN EXPERIMENT

"That can't be Koku and Rad in one of their periodic squabbles, canit?" asked Ned.

"No. It's probably Mr. Baxter," Tom answered. "The doctor said he mightget violent once or twice, until the effects of his shock wore off.There is some quieting medicine I can give him. I'll run up."

"Guess I'd better go along," remarked Ned. "Sounds as if you'd needhelp."

And it did appear so, for again the frenzied shouts sounded:

"I'll get 'em! I'll get the scoundrels who stole my secret formulaethat I worked over so many years! Come back now! Don't put the matchnear the powder!"

Tom and Ned hurried to the room where the unfortunate chemist had beenput to bed, to find him out in the hall, wrapped in a bedquilt, andwith Mrs. Baggert vainly trying to quiet him. Mr. Baxter stared at Tomand Ned without seeing them, for he was in a delirium of fever.

"Have you my formulae?" he asked. "I want them back!"

"You shall have them in the morning," replied Tom soothingly. "Liedown, and I'll bring them to you in the morning. And drink this," headded, holding out a glass of soothing mixture which the doctor hadordered in case the patient should become violent.

Josephus Baxter glared about with wild eyes, but between them Tom andMrs. Baggert managed to get him to drink the mixture.

"Bah! It's as bad as some of my chemicals!" spluttered the chemist, ashe handed back the glass. "You are sure you'll have my formulae in themorning?" he asked, as he turned to go back to his room.

"I'll do my best," declared Tom cheerfully. "Now please lie down."

Which, after some urging, Mr. Baxter consented to do. Eradicate wantedto lie down in the hall outside the excited chemist's door to guardagainst his emerging again, but Tom decided on Koku. The giant, thoughnot as intelligent as the colored man, was more efficient in anemergency because of his great strength. Eradicate was getting old,and there was a pathetic droop to his figure as he shuffled off whenKoku superseded him.

"Ah done guess Ah ain't wanted much mo'," muttered Rad sadly.

"Oh, yes, you are!" cried Tom, as, the excitement over, he walkeddownstairs with Ned. "I'm going to start something new, Rad, and I'llneed your help."

"Will yo', really, Massa Tom?" exclaimed faithful Rad, his facelighting up. "Dat's good! Is yo' goin' off after mo' diamonds, or up tode caves of ice?"

"Not quite that," answered the young inventor, recalling the stirringexperiences that had fallen to him when on those voyages. "I'm going towork around home, Rad, and I'll need your help."

"Anyt'ing yo' wants, Massa Tom! Anyt'ing yo' wants!" offered the nowdelighted Rad, and he went to bed much happier.

"Well, to resume where we left off," began Ned, when he and Tom wereonce more by themselves, "what's the game?"

"Oh, I don't know that it's much of a game," was the answer. "But Ijust have an idea that a big fire in a towering building can be foughtfrom above with chemicals, as well as from the ground with streams ofwater.

"Well, I guess it could be," Ned agreed. "But how are you going to getyour chemicals in at the top? Shoot 'em up through a hose? If you dothat you'll need a special kind of hose, for the chemicals will rotanything like rubber or canvas."

"I wasn't thinking of a hose," returned Tom. "What then?" asked theyoung financial manager.

"An airship!" Tom exclaimed with such sudden energy that Ned started."It just came to me!" explained the youthful inventor. "I waswondering how we could get the chemicals in from the top, and anairship is the solution. I can sail over the burning building and dropthe chemicals down. That will douse the blaze if my plans go right."

Ned was silent a moment, considering Tom's daring plan and project.Then, as it became clearer, the young banker cried:

"Blamed if I don't think that's just the thing, Tom! It ought to work,and, if it does, it will save a lot of lives, to say nothing ofproperty! A fire in a sky-scraper ought to be fought from above. Thenthe extinguisher element, whether chemicals or water, could be droppedwhere they'd do the most good. As it is now, with water, a lot of it iswasted. Some of it never reaches the heart of the fire, being splashedon the outside of the building. A lot more turns to steam before ithits the flames, and only a small percentage is really effective."

"That's my notion," Tom said.

"Then go ahead and do it!" urged his friend. "You have my permission!"

"Thanks," commented Tom dryly. "But there are several things to beworked out before we can start. I've got to devise some scheme forcarrying a sufficient quantity of chemicals, and invent some way ofreleasing them from an airship over the blaze. But that last part oughtto be easy, for I think I can alter my warfare bomb-dropping attachmentto serve the purpose.

"What I really need, however, is some new chemical combination thatwill quickly put a really big blaze out of business. There are anynumber of these chemicals, but most of them depend on the production ofcarbon dioxide. This is the product of some solution of a carbonate andsulphuric acid, and I suppose, eventually, I'll work out something onthat order. But I hope I may get something better."

"You haven't delved much into chemistry, have you?"

"No. And I wish now that I had. I see my limitations and realize myweakness. But I can brush up a little on my chemistry. As for themechanical part, that of dropping the extinguisher on the blaze, I'mnot worrying over that end."

"No," agreed Ned. "You have enough types of airships to be able toselect just the best one for the purpose. But, say, Tom!" he suddenlycried, "why not ask him to help you?"

"Who?"

"Mr. Baxter. He's a chemist. And though he says his formulae are aboutdyes and fireworks, maybe he can put you in the way of inventing achemical solution that will be death to fires."

"He might," Tom agreed. "But I think he'll be out of business for sometime. This shock—being overcome by smoke and his secret formulaehaving been stolen—seem to have affected his mind. I don't know that Icould depend on him."

"It's worth trying," declared Ned. "What do you suppose he means, Tom,saying that Field and Melling stole his formulae?"

"Haven't the least idea. I only know those fireworks firm membersslightly, if at all. I'm not sure I'd recognize them if I met them. Butthey are reputed to be wealthy, and I hardly think they would stoop tostealing some inventor's formulae.

"We inventors are a suspicious lot, Ned, as you probably have foundout," he added with a smile. "We imagine the rest of the world is outto cheat us, and I presume Josephus Baxter is no exception. Still,there may be some truth in his story. I'll give him all the help I can.But I'm going into the aerial fire-fighting game. I've been waiting forsomething new, and this may be it."

"You may count on me!" declared Ned. "And now, unless you're going tosit up all night and start studying chemistry, you'd better come tobed."

"That's right. Tomorrow is another day. I hope Mr. Baxter gets somerest. Sleep will improve him a lot, the doctor said."

"I know one friend of yours who will be glad to know that you are goingto start something," remarked Ned, as he and Tom started for theirrooms, for the young manager was staying with his friend for the night.

"Who?" Tom wanted to know.

"Mr. Wakefield Damon," was the answer. "He hasn't been over lately,Tom."

"No, he's been off on a little trip, blessing everything from hisbaggage check to his suspender buttons," laughed the young inventor, ashe recalled his eccentric acquaintance. "I shall be glad to see himagain."

"He'll be right over as soon as he learns what's in the wind,"predicted Ned.

The hopes that Mr. Baxter would be greatly improved in the morning weredoomed to disappointment. He was in no actual danger, the doctor said,but his recovery from the effects of the smoke he had breathed was notas rapid as desired or hoped for.

"He's suffering from some shock," said the physician, "and his mentalcondition is against him. He ought to be kept quiet, and if you can'thave him here, Mr. Swift, I can arrange to have him sent to a hospital."

"I wouldn't dream of it!" Tom exclaimed. "Let him stay here by allmeans. We have plenty of room, and Mrs. Baggert has been wishing forsome one to nurse. Now she has him."

So it was arranged that the chemist should remain at the Swift home,and he gave a languid assent when they spoke to him of the matter. Hereally was much more ill than seemed at first.

But as everything possible had been done, Tom decided to go ahead withthe new idea that had come to him—that of inventing an aerial chemicalfire-fighting machine.

"And if we get a chance, Ned, we'll try to get back those secretformulae Mr. Baxter claims to have lost," Tom declared. "I have heardsome stories about that fireworks firm, which make me believe there maybe something in Baxter's story."

"All right, Tom, I'm with you any time you need me," Ned promised.

The young inventor lost little time in beginning his operations. As hehad said, the chief need was a fire extinguishing chemical solution orpowder. Tom resolved to try the solution first, as it was easier tomake. With this end in view he proceeded to delve into old and newchemistry books. He also sought the advice of his father.

And one day, when Ned called, Tom electrified his chum with theexclamation:

"Well, I'm going to give it a try!"

"What?"

"My aerial chemical fire-fighting apparatus. Of course I only have thechemical yet. I haven't worked on the carrying apparatus nor decidedhow I will attach it to an airship. But I'm going up now with some ofmy new solution and drop it on a blaze from above."

"Where are you going to get the fire?" asked Ned. "You can't have asky-scraper blaze made to order, you know."

"No, but as this is only an experiment," Tom said, "a big bonfire willanswer the purpose. I'm having Koku and Rad make one now down in ourbig meadow. As soon as it gets hot enough and fierce enough, I'll sailover it in my small machine, drop the extinguisher on it, and see whathappens. Want to come?"

"Sure thing!" cried Ned. "And I hope the experiment is a success!"

"Thanks," murmured Tom. "I'm about ready to start. All I have to do isto take this tank up with me," and he pointed to one containing his newmixture. "Of course the arrangement for dumping it out of the aircraftis very crude," Tom said. "But I can work on that later."

Ned and he were busy putting the can of Tom's new chemical extinguisherin the airship when the door of the hangar was suddenly opened and avery much excited man entered crying:

"Fire! Fire! Bless my kitchen sink, your meadow's on fire, Tom Swift!It's blazing high! Fire! Fire!"

CHAPTER V

THE EXPLOSION

Tom and Ned were so startled by the entrance of the excited man withhis cry of "Fire!" that the young inventor nearly dropped the tank ofliquid extinguisher he was helping to hoist into the aeroplane. Then,as he caught sight of his visitor, Tom exclaimed:

"Hello, Mr. Damon! We were wondering whether you'd be along to witnessour first experiment."

"Experiment, Tom Swift! Experiment! Bless my Latin grammar! but you'dmuch better be calling out the fire department to play on that blazedown in your meadow. What is it—your barns or one of your new shops?"

"Neither one, Mr. Damon," laughed Ned. "It's only a blaze that Koku andRad started."

"And the fire department is here," added Tom.

"Where?" inquired the eccentric man.

"Here," and Tom pointed to his airship—one of the smaller craft—intowhich the tank of chemicals had been hoisted.

"Oh!" exclaimed Mr. Damon. "Something new, eh, Tom?" His eyes glistened.

"Yes. Fighting fires from the air. I got the idea after the fireworksfactory went up in smoke. Will you come along? There's plenty of room."

"I believe I will," assented Mr. Damon. It was not the first time, byany means, that he had gone aloft with Tom. "I happened to be comingover in my auto," he went on to explain, "when I happened to see thefire down in the meadow. I was afraid you didn't know about it."

"Oh, yes," replied Tom. "I had Rad and Koku light a big pile of packingboxes, to represent, as nearly as possible, on a small scale, a burningbuilding. I plan now to sail over it and drop the tins of chemicals.They are arranged to burst as they fall into the blaze, and I hope thecarbon dioxide set loose will blanket out the fire."

"Sounds interesting," commented Mr. Damon. "I'll go along."

The airship was wheeled out of the hangar and was soon ready for theflight. A big cloud of black vapor down in the meadow told Tom and Nedthat Koku and Eradicate had done their work well. The giant and thecolored man had poured oil over the wood to make a fierce blaze thatwould give Tom's new chemical combination a severe test.

A mechanic turned the propeller of the airship until there was anaccumulation of gas in the different cylinders. Then he stepped backwhile Tom threw on the switch. This was not one of the self-startingtypes, of which Tom possessed one or two.

"Contact!" cried Tom sharply, and the man stepped forward to give thebig blades a final turn that would start the motor. There was amuffled roar and then a steady staccato blending of explosions. Tomraced the motor while his men held the machine in place, and then,satisfied that all was well, the young inventor gave the word, and thecraft raced over the ground, to soar aloft a little later.

Tom, Ned and Mr. Damon could look down to the meadow where the bonfirewas blazing. A crowd had collected, but the heat of the blaze kept themat a good distance. Then, as many of the throng caught sight of theairship overhead, there was a new interest for them.

Tom had told Ned and Mr. Damon, before the trio had entered themachine, what he wanted them to do. This was to toss the chemicalsoverboard at the proper time. Of course in his perfected apparatus Tomhoped to have a device by which he could drop the fire extinguishingelements by a mere pressure of his finger or foot, as bombs werereleased from aircraft during the war. But this would serve for thetime being.

Nearer and nearer the blaze the airship approached until it was almostabove it. Tom had had some experience in bomb-dropping, and knew whento give the signal.

At last the signal came. Mr. Damon and Ned heaved over the side themetal containers of the powerful chemicals.

Down they went, unerring as an arrow, though on a slant, caused by theimpetus given them by the speed of the airship.

Tom and his friends leaned over the side of the machine to watch theeffect. They could see the chemicals strike the blaze, and it wasevident from the manner in which the fire died down that the containershad broken, as Tom intended they should to scatter their contents.

"Hurray!" cried Ned, forgetting that he could not be heard, for no headtelephones were used on this occasion and the roar of the motor woulddrown any human voice. "It's working, Tom!"

Truly the effect of the chemicals was seemingly to cause the fire to goout, but it was only a momentary dying down. Koku and Rad had made afierce, yet comparatively small, conflagration, and though for a timethe gas generated by Tom's mixture dampened the blaze, in a fewseconds—less than half a minute—the flames were shooting higher thanever.

Tom made a gesture of disappointment, and swung his craft around in asharp, banking turn. He had no more chemicals to drop, as he hadthought this supply would be sufficient. However, he had guessed badly.The fire burned on, doing no damage, of course, for that had beenthought of when it was started in the meadow.

"Something wrong!" declared the young inventor, when they were back atthe hangar, climbing out of the machine.

"What was it?" asked Ned.

"Didn't use the right kind of chemicals," Tom answered. "From the waythe flames shot up, you'd think I had poured oil on the blaze insteadof carbon dioxide."

"Bless my insurance policy, Tom!" cried Mr. Damon, "but I'd hate totrust to your apparatus if my house caught."

"Don't blame you," Tom assented. "But I'll do the trick yet! This isonly a starter!"

During the next two weeks the young inventor worked hard in hislaboratory, Mr. Swift sometimes helping him, but more often Koku andEradicate. Mr. Baxter had recovered sufficiently to leave the Swifthome. But though the chemist seemed well physically, his mind appearedto be brooding over his loss.

"If I could only get my secret formulae back!" he sighed, as he thankedTom for his kindness. "I'm sure Field and Melling have them. And Ibelieve they got them the night of the fireworks blaze; the scoundrels!"

"Well, if I can help you, please let me," begged Tom. And then hedismissed the matter from his mind in his anxiety to hit upon the rightchemical mixture for putting out fires from the air.

One afternoon, at the end of a week in which he had been busily andsteadily engaged on this work, Tom finally moved away from hislaboratory table with a sigh of relief, and, turning to Eradicate, whohad been helping him, exclaimed:

"Well, I think I have it now!"

"Good lan' ob massy, I hopes so!" exclaimed the colored man. "It sho'do smell bad enough, Massa Tom, to make any fire go an' run an' drownhisse'f! Whew-up! It's turrible stuff!"

"Yes, it isn't very pleasant," Tom agreed, with a smile. "Though I amgetting rather used to it. But when it's in a metal tube it won'tsmell, and I think it will put out any fire that ever started. We'llgive it a test now, Rad. Just take that flask of red stuff and pour itinto this one of yellow. I'll go out and light the bonfire, and we'llmake a small test."

Leaving Rad to mix some of the chemicals, a task the colored man hadoften done before, Tom went out into the yard near his laboratory tostart a blaze on which his new mixture could be tested.

He had not got far from the laboratory door when he felt a sudden jarand a rush of air, and then followed the dull boom of an explosion.Like an echo came the voice of Eradicate:

"Oh, Massa Tom, I'se blowed up! It done sploded right in mah face!"

CHAPTER VI

TOM IS WORRIED

Dropping what he had in his hands, Tom Swift raced back to thelaboratory where he had left Eradicate to mix the chemicals. Again thedespairing, frightened cry of the colored man rang out.

"I hope nothing serious has happened," was the thought that flashedthrough Tom's mind. "But I'm afraid it has. I should have mixed thosenew chemicals myself."

Koku, the giant, who was at work in another part of the shop yard,heard Rad's cry and came running up. As there was always more or lessjealousy between Eradicate and Koku, the latter now thought he had achance to crow over his rival, not, of course, understanding what hadhappened.

"Ho! Ho!" laughed Koku. "You much better hab me work, Master Tom. I nomake blunderstakes like dat black fellow! I never no make him!"

"I don't know whether Rad has made a mistake or not," murmured Tom."Come along, Koku, we may need your help. There has been an explosion."

"Yep, dat Rad he don't as know any more as to blow up de whole place!"chuckled Koku.

He thought he would have a chance to make fun of Eradicate, but neitherhe nor Tom realized how serious had been the happening. As the younginventor reached the laboratory, which he had left but a few secondsbefore, he saw the interior almost in ruins. All about were scatteredvarious pieces of apparatus, test tubes, alembics, retorts, flasks, andan electric furnace.

But what gave Tom more concern than anything else was the sight ofEradicate lying in the midst of broken glass on the floor. The coloredman was moaning and held his hands over his face, and the younginventor could see that the hands, which had labored so hard andfaithfully in his service, were cut and bleeding.

"Rad! Rad! what has happened?" cried Tom quickly.

"It sploded! It done sploded right in mah face!" moaned Eradicate."I—I can't see no mo', Massa Tom! I can't see to help yo' nevah nomo'!"

"Don't worry about that, Rad!" cried Tom, as cheerfully as possibleunder the circ*mstances. "We'll soon have you fixed up! Come in here,Koku, and help me carry Rad out!"

Though the fumes from the chemicals that had exploded were choking,causing both Tom and Koku to gasp for breath, they never hesitated. Inthey rushed and picked up the limp figure of the helpless colored man.

"Poor Rad!" murmured the giant Koku tenderly. "Him bad hurt! I carryhim, Master Tom! I take him bed, an' I go for doctor! I run likepainted pig!"

Probably Koku meant "greased pig," but Tom never thought of that. Allhis concern was for his faithful Eradicate.

"Me carry him, Master Tom!" cried Koku, all the petty jealousy of hisrival passing away now. "Me take care ob Rad. Him no see, me see forhim. Anybody hurt Rad now, got to hurt Koku first!"

It was a fine and generous spirit that the giant was showing, thoughTom had no time to speculate on it just then.

"We must get him into the house, Koku," said the young inventor. "Andtwo of us can carry him better than one. After we get him to a bed youcan go for the doctor, though I fancy the telephone can run evenquicker than you can, Koku."

"Whatever Master Tom say," returned the giant humbly, as he looked withpity at the suffering form of his rival—a rival no longer. It seemedthat Rad's working days were over.

Tenderly the aged colored man was laid on a lounge in the living room,Mr. Swift and Mrs. Baggert hovering over him.

"Where are you worst hurt, Rad?" asked Tom, with a view to getting aline on which physician would be the best one to summon.

"It's all in mah face, Massa Tom," moaned the colored man. "It's maheyes. Dat stuff done sploded right in 'em! I can't see—nevah no mo'!"

"Oh, I guess it isn't as bad as that," said Tom. But when he had aglimpse of the seared and wounded face of his faithful servant he couldnot repress a shudder.

A physician was summoned by telephone, and he arrived in his automobileat the same time that Mr. Damon reached Tom's house.

"Bless my bottle of arnica, Tom!" exclaimed the eccentric man, withsympathy in his voice. "What's this I hear? One of your men tells meold Eradicate is killed!"

"Not as bad as that, yet," replied Tom, as he came out, leaving thedoctor to make his first examination. "It was an explosion of my newaerial fire-fighting chemicals that I left Rad to mix for me. Ifanything serious results to him from this I'll drop the whole business!I'll never forgive myself!"

"It wasn't your fault, Tom. Perhaps he did something wrong," said Mr.Damon.

"Yes, it was my fault. I should not have let him take the chance with amixture I had tried only a few times. But we'll hope for the best. Howis he, Doctor?" Tom asked a little later when the physician came out onthe porch.

"He's doing as well as can be expected for the present," was theanswer. "I have given him a quieting mixture. His worst injury seems tobe to his face. His hands are cut by broken glass, but the hurts areonly superficial. I think we shall have to get an eye specialist tolook at him in a day or two."

"You mean that he—that he may go blind?" gasped Tom.

"Well, we'll not decide right away," replied the doctor, as cheerfullyas he could. "I should rather have the opinion of an oculist beforemaking that statement. It may be only temporary."

"That's bad enough!" muttered Tom. "Poor old Rad!"

"Me take care ob him," put in Koku, who had been humbly standing aroundwaiting to hear the news. "Me never be mad at dat black man no more!Him my best friend! I lub him like I did my brudder!"

"Thank you, Koku," said Tom, and his mind went back to the time when hehad escaped in his airship from the gigantic men, of whom Koku and hisbrother were two specimens. The brother had gone with a circus, andKoku, for several years, only saw him occasionally.

Everything possible was done for Eradicate, and the doctor said that itwould be several days, until after the burns from the explodingchemicals had partly healed, before the eye-doctor could make anexamination.

"Then we can only wait and hope," said Tom.

"And hope for the best!" advised Mr. Damon.

"I'll try," promised Tom. He went back to the laboratory with hiseccentric friend and with Ned, who had come over as soon as he heardthe news. Not much of an examination could be made, as the place was insuch ruins. But it was surmised that in combining the two chemicalmixtures a new one had been created, or at least one that Tom had notcounted on. This had exploded, blowing Eradicate down, flaring a sheetof flame up into his face, scattering broken glass about, and generallycreating havoc.

"I can't understand it," said Tom. "I was trying to make a fireextinguishing liquid, and it turned out to be a fire creator. I don'tsee what was wrong."

"One chemical might have been impure," suggested Ned.

"Yes," agreed Tom. "I'll check them over and try to find out where themistake happened."

"This place will have to be rebuilt," observed Ned. "It's in bad shape,Tom."

"I don't mind that in the least, if Rad doesn't lose his eyesight," wasthe answer of the young inventor, and his friends could see that he wasmuch worried, as well he might be.

In silence Tom Swift looked about the ruins of what had been a finechemical laboratory.

"It will take a month to get this back in shape," he said ruefully. "Iguess I shall have to postpone my experiments."

"Why not ask Mr. Baxter to help you?" suggested Ned.

"What can he do?" Tom wanted to know. "He hasn't any laboratory."

"He has a sort of one," Ned rejoined. "You know you told me to keeptrack of him and give him any help I could."

"Yes," Tom nodded.

"Well, the other day he came to me and said he had a chance to set up asmall laboratory in a vacant shop near the river. He needed a littlecapital and I lent it to him, as you told me to."

"Glad you did," returned Tom. "But do you suppose his plant is largeenough to enable me to work there until mine is in shape again?"

"It wouldn't do any harm to take a look," suggested Ned.

"I'll do it!" decided Tom, more hopefully than he had spoken since theaccident.

CHAPTER VII

A FORCED LANDING

Josephus Baxter seemed to have recovered some of his spirits after hisnarrow escape from death in the fireworks factory blaze. He greeted Tomand Ned with a smile as they entered the improvised laboratory he hadbeen able to set up in what had once been a factory for the making ofwooden ware, an industry that, for some reason, did not flourish inShopton.

"I'm glad to see you, Mr. Swift," said the chemist, who seemed to haveaged several years in the few weeks that had intervened since the fire."I want to thank you for giving me a chance to start over again."

"Oh, that's all right," said Tom easily. "We inventors ought to helpone another. Are you able to do anything here?"

"As much as possible without my secret formulae," was the answer. "If Ionly had those back from the rascals, Field and Melling, I would beable to go ahead faster. As it is, I am working in the dark. For someof the formulae were given to me by a Frenchman, and I had only onecopy. I kept that in the safe of the fireworks concern, and after thefire it could not be found."

"Was the safe destroyed?" asked Tom.

"No. But the doors were open, and much of what had been inside was inashes and cinders. Amos Field claimed that the explosion had blown openthe safe and burned a lot of their valuable fireworks formulae too."

"And you believe they have yours?" asked Ned.

"I'm sure of it!" was the fierce answer. "Those men are unprincipledrogues! They had been at me ever since I was foolish enough to tellthem about my formulae to get me to sell them a share. But I refused,for I knew the secret mixtures would make my fortune when I couldestablish a new dye industry. Field and Melling claimed they wanted theformulae for their fireworks, but that was only an excuse. The formulaewere not nearly so valuable for pyrotechnics as for dyes. The fireworksbusiness is not so good, either, since so many cities have voted for a'Sane Fourth of July.'"

"I can appreciate that," said Tom. "But what we called for, Mr. Baxter,is to find if you have room enough to let me do a little experimentinghere. I am working on a new kind of fire extinguisher, to be dropped ontall buildings from an airship."

"Sounds like a good idea," said the chemist, rather dreamily.

"Well, I have the airship, and I can see my way clear to perfecting adevice to drop the chemicals in metal tanks or bombs," went on Tom."But what bothers me is the chemical mixture that will put out firesbetter than the carbon dioxide mixtures now on the market."

"I haven't given that much study myself," said Mr. Baxter. "But you arewelcome to anything I have, Mr. Swift. The whole place, such as it is,will be at your disposal at any time. I intend to have it in bettershape soon, but I have to proceed slowly, as I lost nearly everything Iowned in that fire. If I could only get those formulae back!" he sighed.

"Perhaps you may recall the combinations," suggested Ned. "Or can't youget them from that Frenchman?"

"He is dead," answered the chemist. "Everything seems to be against me!"

"Well, it's always darkest just before daylight," said Tom. "So let ushope for the best. We both have had a bit of bad luck. But when I thinkof Rad, who may lose his eyesight, I can stand my losses smiling."

"Yes," agreed Mr. Baxter, "you have big assets when you have yourhealth and eyesight."

Three days later the eye specialist looked at Rad. Tom stood byanxiously and waited for the verdict. The doctor motioned to the younginventor to follow him out of the room, while Mrs. Baggert replaced thebandages on the colored man's eyes and Koku stood near him,sympathetically patting Rad on the back.

"Well?" asked Tom nervously, as he faced the physician.

"I am sorry, Mr. Swift, that I can not hold out much hope that your manwill ever regain his sight," was the answer.

Tom could not repress a gasp of pity.

"I do not say that the case is altogether hopeless," the doctor wenton; "but it would be wrong to encourage you to hope for much. I may beable to save partly the sight of one eye."

"Poor Rad!" murmured Tom. "This will break his heart."

"There is no need for telling him at once," Dr. Henderson said. "Itwill only make his recovery so much the slower. It will be weeks beforeI am able to operate, and, meanwhile, he should be kept as comfortableand cheerful as possible."

"We'll see to that," declared Tom. "Is he otherwise injured?"

"No, it is merely his eyesight that we have to fear for. And, as Isaid, that is not altogether hopeless, though it would not be honest tolet you look for much success. I shall see him from time to time untilhis eyes are ready to operate on."

Tom and his friends were forced to take such comfort as they could fromthis verdict, but no hint of their downcast feelings were made manifestto Eradicate.

"Whut de doctor man done say, Massa Tom?" asked Eradicate when theyoung inventor went back into the sick room.

"Oh, he talked a lot of big Latin words, Rad—bigger words than youused to use on your mule Boomerang," and Tom forced a laugh. "All hemeant was that you'd have to stay in bed a while and let Koku wait onyou."

"Huh! Am dat—dat big—dat big nice man heah now?" asked Rad, feelingaround with his bandaged hand; and a smile showed beneath the clothover his eyes.

"I here right upsidedown by you, Rad," said Koku, and his big handclasped the smaller one of the black man.

"Koku—yo'—yo' am mighty good to me," murmured Eradicate. "I reckon Ibeen cross to yo' sometimes, but I didn't mean nuffin' by it!"

"Huh! me an' you good friends now," said the giant. "Anybody what hurtmy Rad, I—I—bust 'im! Dat I do!" cried the big fellow.

"Come on," whispered Tom to Ned. "They'll get along all right togethernow."

But Eradicate caught the sound of his young employer's footsteps andcalled:

"Yo' goin', Massa Tom?"

"Yes, Rad. Is there anything you want?"

"No, Massa Tom. I jest wanted to ast if yo' done 'membered de time mahmule Boomerang got stuck in de road, an' yo' couldn't git past in yo'auto? Does yo' 'member dat?"

"Indeed I do!" laughed Tom, and Eradicate also chuckled at therecollection.

"That laugh will do him more good than medicine," declared the doctor,as he took his leave. "I'll come again, when I can make a more thoroughexamination," he added.

For Tom the following days, that lengthened into weeks, were anxiousones. There was a constant worry over Eradicate. Then, too, he washaving trouble with his latest invention—his aerial fire-fightingapparatus. It was not that Tom was financially dependent on thisinvention. He was wealthy enough for his needs from other patentedinventions he and his father owned.

But Tom Swift was a lad not easily satisfied. Once embarked on anenterprise, whether it was the creation of a gigantic searchlight, anelectric rifle, a photo telephone or a war tank, he never rested untilhe had brought it to a successful consummation.

But there was something about this chemical fire extinguishing mixturethat defied the young inventor's best efforts. Mixture after mixturewas tried and discarded. Tom wanted something better than the usualcarbonate and sulphuric combination, and he was not going to rest untilhe found it.

"I think you've struck a blind lead, Tom," said Ned, more than once.

"Well, I'm not going to give up," was the firm answer.

"Bless my shoe laces!" cried Mr. Damon, when he had called on Tom onceat the Baxter laboratory and had been driven out, holding his breath,because of the chemical fumes, "I should think you couldn't even starta fire with that around, Tom, much less need to put one out."

"Well, it doesn't seem to work," said the young inventor ruefully."Everything I do lately goes wrong."

"It is that way sometimes," said Mr. Baxter. "Suppose you let me studyover your formulae a bit, Mr. Swift. I haven't given much thought tofire extinguishers, but I may be able, for that very reason, toapproach the subject from a new angle. I'll lay aside my attempt to getback the lost formulae and help you."

"I wish you would!" exclaimed Tom eagerly. "My head is woozie fromthinking! Suppose I leave you to yourself for a time, Mr. Baxter? I'llgo for an airship ride."

"Yes, do," urged the chemist. "Sometimes a change of scene is ofbenefit. I'll see what I can do for you."

"Will you come along, Ned—Mr. Damon?" asked Tom, as he prepared toleave the improvised laboratory, the repairs on his own not yet havingbeen finished.

"Thank you, no," answered Ned. "I have some collections to make."

"And I promised my wife I'd take her riding, Tom," said the jolly,eccentric man. "Bless my umbrella! she'd never forgive me if I went offwith you. But I'll run you to your first stopping place, Ned, and youto your hangar, Tom."

His invitation was accepted, and, in due season, Tom was soaring aloftin one of his speedy cloud craft.

"Guess I'll drop down and get Mary Nestor," he decided, after ridingabout alone for a while and finding that the motor was running sweetlyand smoothly. "She hasn't been out lately."

Tom made a landing in a field not far from the home of the girl hehoped to marry some day, and walked over to her house.

"Go for a ride? I just guess. I will!" cried Mary, with sparkling eyes."Just wait until I get on my togs."

She had a leather suit, as had Tom, and they were soon in the machine,which, being equipped with a self-starter, did not need the services ofa mechanician to whirl the propellers.

"Oh, isn't it glorious!" said Mary, as she sat at Tom's side. Theywere in a little enclosed cabin of the craft—which carried justtwo—and, thus enclosed, they could speak by raising their voicessomewhat, for the noise of the motor was much muffled, due to one ofTom's inventions.

Other rides on other days followed this one, for Tom found more restand better refreshment after his hours of toil and study in these rideswith Mary than in any other way.

"I do love these rides, Tom!" the girl cried one day when the two weresoaring aloft. "And this one I really believe is better than any of therest. Though I always think that," she added, with a slight laugh.

"Glad you like it," Tom answered, and there was something in his voicethat caused Mary to look curiously at him.

"What's the matter, Tom?" she asked. "Has anything happened? Is Rad'scase hopeless?"

"Oh, no, not yet. Of course it isn't yet sure that he will ever seeagain, but, on the other hand, it isn't decided that he can't. It's afifty-fifty proposition."

"But what makes you so serious?"

"Was I?"

"I should say so! You haven't told me one funny thing that Mr. Damonhas said lately."

"Oh, haven't I? Well, let me see now," and he sent the machine up alittle. "Well, the other day he—"

Tom suddenly stopped speaking and began rapidly turning several valvewheels and levers.

"What—what's the matter?" gasped Mary, but she did not clutch his arm.She knew better than that.

"The motor has stopped," Tom answered, and the girl became aware of acessation of the subdued hum.

"Is it—does it mean danger?" she asked.

"Not necessarily so," Tom replied. "It means we have to make a forcedlanding, that's all. Sit tight! We're going down rather faster thanusual, Mary, but we'll come out of it all right!"'

CHAPTER VIII

STRANGE TALK

There was a rapid and sudden drop. Mary, sitting beside Tom Swift inthe speedy aeroplane, watched with fascinated eyes as he quicklyjuggled with levers and tried different valve wheels. The girl, throughher goggles, had a vision of a landscape shooting past with the speedof light. She glimpsed a brook, and, almost instantly, they had skimmedover it.

A jar, a nerve-racking tilt to one side, the creaking of wood and therattle of metal, a careening, and then the machine came to a stop, notexactly on a level keel, but at least right side up, in the midst of awide field.

Tom shut off the gas, cut his spark, and, raising his goggles, lookeddown at Mary at his side.

"Scared?" he asked, smiling.

"I was," she frankly admitted. "Is anything broken, Tom?"

"I hope not," answered the young inventor. "At least if it is, thedamage is on the under part. Nothing visible up here. But let me helpyou out. Looks as if we'd have to run for it."

"Run?" repeated Mary, while proving that she did not exactly need help,for she was getting out of her seat unaided. "Why? Is it going to catchfire?"

"No. But it's going to rain soon—and hard, too, if I'm any judge," Tomsaid. "I don't believe I'll take a chance trying to get the machinegoing again. We'll make for that farmhouse and stay there until afterthe storm. Looks as if we could get shelter there, and perhaps a bit toeat. I'm beginning to feel hungry."

"It is going to rain!" decided Mary, as Tom helped her down over theside of the fusilage. "It's good we are so near shelter."

Tom did not answer. He was making a hasty but accurate observation ofthe state of his aeroplane. The landing wheels had stood the shockwell, and nothing appeared to be broken.

"We came down rather harder than I wanted to," remarked Tom, as hecrawled out after his inspection of the machine. "Though I've madeworse forced landings than that."

"What caused it?" asked Mary, glancing up at the clouds, which weregetting blacker and blacker, and from which, now and then, vividflashes of lightning came while low mutterings of thunder rolled nearerand nearer. "Something seemed to be wrong with the carburetor," Tomanswered. "I won't try to monkey with it now. Let's hike for thatfarmhouse. We'll be lucky if we don't get drenched. Are you sure you'reall right, Mary?"

"Certainly, Tom. I can stand a worse shaking up than that. And youneedn't think I can't run, either!"

She proved this by hastening along at Tom's side. And there was need ofhaste, for soon after they left the stranded aeroplane the big dropsbegan to pelt down, and they reached the house just as the deluge came.

"I don't know this place, do you, Tom?" asked Mary, as they ran inthrough a gateway in a fence that surrounded the property. A pathseemed to lead all around the old, rambling house, and there was aporch with a side entrance door. This, being nearer, had been pickedout by the young inventor and his friend.

"No, I don't remember being here before," Tom answered. "But I'vepassed the place often enough with Ned and Mr. Damon. I guess theywon't refuse to let us sit on the porch, and they may be induced togive us a glass of milk and some sandwiches—that is, sell them to us."

He and Mary, a little breathless from their run, hastened up on theporch, slightly wet from the sudden outburst of rain. As Tom knocked onthe door there came a clap of thunder, following a burst of lightning,that caused Mary to put her hands over her ears.

"Guess they didn't hear that," observed Tom, as the echoes of the blastdied away. "I mean my knock. The thunder drowned it. I'll try again."

He took advantage of a lull in the thundering reverberations, andtapped smartly. The door was almost at once opened by an aged woman,who stared in some amazement at the young people. Then she said:

"Guests must go to the front door."

"Guests!" exclaimed Tom. "We aren't exactly guests. Of course we'd liketo be considered in that light. But we've had an accident—my aeroplanestopped and we'd like to stay here out of the storm, and perhaps getsomething to eat."

"That can be arranged—yes," said the old woman, who spoke with aforeign accent. "But you must go to the front door. This is theservant's entrance."

Mary was just thinking that they used considerable formality for casualwayfarers, when the situation dawned on Tom Swift.

"Is this a restaurant—an inn?" he asked.

"Yes," answered the old woman. "It is Meadow Inn. Please go to thefront door."

"All right," Tom agreed good-naturedly. "I'm glad we struck the place,anyhow."

The porch extended around three sides of the old, rambling house.Proceeding along the sheltered piazza, Tom and Mary soon foundthemselves at the front door. There the nature of the place was at oncemade plain, for on a board was lettered the words "Meadow Inn."

"I see what has happened," Tom remarked, as he opened the old-fashionedground glass door and ushered Mary in. "Some one has taken the oldfarmhouse and made it into a roadhouse—a wayside inn. I shouldn'tthink such a place would pay out here; but I'm mighty glad we struckit."

"Yes, indeed," agreed Mary.

The old farmhouse, one of the best of its day, had been transformedinto a roadhouse of the better class. On either side of the entrancehall were dining rooms, in which were set small tables, spread withsnowy cloths.

"In here, sir, if you please," said a white-aproned waiter, glidingforward to take Tom's leather coat and Mary's jacket of like material.The waiter ushered them into a room, in which at first there seemed tobe no other diners. Then, from behind a screen which was pulled arounda table in one corner, came the murmur of voices and the clatter ofcutlery on china, which told of some one at a meal there.

"Somebody is fond of seclusion," thought Tom, as he and Mary took theirplaces. And as he glanced over the bill of fare his ears caught themurmur of the voices of two men coming from behind the screen. Onevoice was low and rumbling, the other high-pitched and querulous.

"Talking business, probably," mused Tom. "What do you feel likeeating?" he asked Mary.

"I wasn't very hungry until I came in," she answered, with a smile."But it is so cozy and quaint here, and so clean and neat, that itreally gives one an appetite. Isn't it a delightful place, Tom? Did youknow it was here?"

"It is very nice. And as this is the first I have been here for a longwhile I didn't know, any more than you, that it had been made into aroadhouse. But what shall I order for you?"

"I should think you would have had enough experience by this time,"laughed Mary, for it was not the first occasion that she and Tom haddined out.

Thereupon he gave her order and his own, too, and they were soon eatingheartily of food that was in keeping with the appearance of the place.

"I must bring Ned and Mr. Damon here," said Tom. "They'll appreciatethe quaintness of this inn," for many of the quaint appointments of theold farmhouse had been retained, making it a charming resort for a meal.

"Mr. Damon will like it," said Mary. "Especially the big fireplace,"and she pointed to one on which burned a blaze of hickory wood. "He'llbless everything he sees."

"And cause the waiter to look at me as though I had brought in anescaped inmate from some sanitarium," laughed Tom. "No use talking, Mr.Damon is delightfully queer! Now what do you want for dessert?"

"Let me see the card," begged Mary. "I fancy some French pastry, ifthey have it."

Tom gazed idly but approvingly about as she scanned the list. Thesound of the rumbling and the higher-pitched voices had gone onthroughout the entire meal, and now, as comparative silence filled theroom, the clatter of knives and forks having ceased, Tom heard moreclearly what was being said behind the screen.

"Well, I tell you what it is," said the man whom Tom mentally dubbedMr. High. "We got out of that blaze mighty luckily!"

"Yes," agreed he of the rumbly voice, whom Tom thought of as Mr. Low,"it was a close shave. If it hadn't been for his chemicals, though,there would have been a cleaner sweep."

"Indeed there would! I never knew that any of them could act as fireextinguishers."

Tom seemed to stiffen at this, and his hearing became more acute.

"They aren't really fire extinguishers in the real sense of the word,"went on the other man behind the screen. "It must have been someaccidental combination of them. But in spite of that we put it all overJosephus Baxter in that fire!"

"What's this? What's this?" thought Tom, shooting a glance at Mary andnoting that apparently she had not heard what was said. "What strangetalk is this?"

CHAPTER IX

SUSPICIONS

"What's that?" exclaimed Mary Nestor, giving such a start as she satopposite Tom at the restaurant table that she dropped the bill of fareshe had been looking over.

A crash had resounded through the room, but it spoke well for the stateof Tom's nerves that he gave no indication that he had heard the noise.It was caused by a waiter when he dropped a plate, which was smashedinto pieces on the floor. The noise was startling enough to excuse Maryfor jumping in her chair, and it seemed to put an end to the strangetalk of "Mr. High" and "Mr. Low" back of the screen, for after thecrash of china only indistinct murmurs came from there. But Tom Swiftdid not cease to wonder at the import of the talk about chemicals,fire, and the mention of the name of Josephus Baxter.

"I think I'll try some of those Murolloas, as they call them, Tom,"announced Mary, having made her selection of the pastry. "And may Ihave another cup of tea?"

"Two if you like," answered the young inventor. "They say tea is goodfor the nerves, and you seem to need something, judging by the way youjumped when that plate fell."

"Oh, Tom, that isn't fair! After the way we had to come down in your'plane!" objected Mary.

"That's right!" he conceded. "I forgot about that. My fault, entirely!"

Mary smiled, and seemed to have regained her composure. Tom glanced ather anxiously, not because of what he thought might be the state of hernerves, but to see if she had sensed anything the two men behind thescreen had said. But the girl gave no indication that her mind had beenoccupied with anything more than the selection of her dessert.

"I wonder who they are, and what they meant by that talk," mused Tom,as the waiter served the Murolloas to him and Mary. "Poor Baxter! Itlooks as if he might have more enemies than the fireworks men heaccuses of having taken his valuable formulae. I must see him soon, andhave a talk with him. Yes, I must make a special point to see JosephusBaxter. But first I'd like to have a glimpse of these men."

Tom's wish in this respect was soon gratified, for before he and Maryhad finished their pastry and tea there was a scraping of chairs backof the sheltering screen, and the two men, "Mr. Low" and "Mr. High,"who had finished their meal, came forth.

Tom's judgment as to the statures of the men, based on the quality oftheir voices, was not exactly borne out. For it was the big man who hadthe high pitched, squeaky voice, and the little man who had the deep,rumbling tones.

They passed out, without more than a glance at Tom and his companion,but the young inventor peered at them sharply. As far as he could tellhe had seen neither of them before, though he had an idea of theiridentity.

Tom took the chance to make certain this conjecture when Mary left herseat, announcing that she was going to the ladies' parlor to arrangeher hair, which the run to escape from the rain had disarranged.

"Some storm," Tom observed to the waiter, who came up when the younginventor indicated that he wanted his check.

"Yes, sir, it came suddenly. Hope you didn't have to change a tire init, sir."

"No, my machine isn't that kind," replied Tom, as he handed out agenerous tip. "If I need a new tire I generally need a whole newoutfit."

"Oh, then—" Obviously the man was puzzled.

"We came in an aeroplane," Tom explained. "But we had to make a forcedlanding. Is there a garage near here? I may need some help gettingstarted."

"We accommodate a few cars in what was once the barn, and we have agood mechanic, sir. If you'd like to see him—"

"I would," interrupted Tom. "Tell the young lady to wait here for me.I'll see if I can get the Scud to work. If not, I'll have to telephoneto town for a taxi. Did those men who just left come in a car?" and henodded in the direction taken by the two who had dined behind thescreen.

"Yes, sir. And they had engine trouble, I believe. Our man fixed uptheir machine."

"Then he's the chap I want to see," thought Tom. "I'll have a talk withhim." He reasoned that he could get more about the identity of the twomysterious men from the mechanic than from the waiter. Nor was he wrongin this surmise.

"Oh, them two fellers!" exclaimed the mechanician, after he had agreedto go with Tom to where the airship Scud was stalled. "They come fromover Shopton way. They own a fireworks factory—or they did, before itburned."

"Are they Field and Melling?" asked Tom, trying not to let anyexcitement betray itself in his voice.

"That's the names they gave me," said the man. "Little man's Field. Hegave me his card. I'm going to get a job overhauling his car. Thereisn't enough work here to keep a man busy, and I told 'em I could do alittle on the outside. This place just started, and not many folks knowabout it yet."

"So I judge," Tom said. "Well, I'll be glad to have you give me a hand.I fancy the carburetor is out of order."

And this, when the young inventor and the mechanician from Meadow Innreached the stranded Scud, was found to be the case. The storm hadpassed, and Mary told Tom she would not mind waiting at the Inn untilhe found whether or not he could get his air craft in working order.

"There you are! That's the trouble!" exclaimed the mechanician, as hetook something out of the carburetor. "A bit of rubber washer chokedthe needle valve."

"Glad you found it," said Tom heartily. "Now I guess we can ride back."

While preparations were being made to test the Scud after thecarburetor had been reassembled, Tom's mind was busy with manythoughts, and chief among them were suspicions concerning Field andMelling.

"If their talk meant anything at all," reasoned the young inventor, "itmeant that there was some deal in which Josephus Baxter got the worstof it. 'Putting it over on him in the fire,' could only mean that. Ofcourse it isn't any of my business, in a way, but I don't think it isright to stand by and see a fellow inventor defrauded.

"Of course," mused Tom, while his helper put the finishing touches tothe carburetor, "it may have been a business deal in which one took asmany chances as the other. There are always two sides to every story.Baxter says they took his formulae, but he may have taken somethingfrom them to make it even. The only thing is that I'd trust Baxtersooner than I would those two fellows, and he certainly had a narrowsqueak at the fire.

"But I have my own troubles, I guess, trying to perfect thatfire-fighting chemical, and I haven't much time to bother with Fieldand Melling, unless they come my way."

"There, I reckon she'll work," said the mechanician, as he fastened thelast valve in the carburetor. "It was an easier job than I expected.Wasn't as much trouble as I had over their car those two fellers youwere speaking of—Field and Melling. They're rich guys!"

"Yes?" replied Tom, questioningly.

"Sure! They've started a big dye company."

"A dye company?" repeated the young inventor, all his suspicions comingback as he recalled that Baxter had said his formulae were morevaluable for dyes than for fireworks.

"Yes, they're trying to get the business that used to go to the Germansbefore the war," went on the man.

"Yes, the Germans used to have a monopoly of the dye industry," saidTom, hoping the man would talk on. He need not have worried. He was ofthe talkative type.

"Well, if these fellers have their way they'll make a million in dyes,"proceeded the mechanician, as he stepped down out of the airship."They've built a big plant, and they have offices in the LandmarkBuilding."

"Where's that?" asked Tom.

"Over in Newmarket," the man went on, naming the nearest large city toShopton. "The Landmark Building is a regular New York skyscraper.Haven't you seen it?"

"No," Tom answered, "I haven't. Been too busy, I guess. So Field andMelling have their offices there?"

"Yes, and a big plant on the outskirts for making dyes. They halfoffered me a job at the factory, but I thought I'd try this out first;I like it here."

"It is a nice place," agreed Tom. "Well, now let's see if she'll work,"and he nodded at the Scud.

It needed but a short test to demonstrate this and soon Tom went backto the Inn for Mary.

"Are you sure we shall not have to make another forced landing?" sheasked with a smile, a she took her place in the co*ckpit.

"You can't guarantee anything about an aeroplane," said Tom. "Buteverything is in our favor, and if we do have to come down I have abetter landing field than this." He glanced over the meadow near thewayside inn.

"I suppose I'll have to take a chance," said Mary.

However, neither of them need have worried, for the Scud tried,evidently, to redeem herself, and flew back to Shopton without a hitch.After making sure that his engine was running smoothly, Tom found hismind more at ease, and again he caught himself casting about to findsome basis for his suspicious thoughts regarding the two men who hadtalked behind the screen.

"What is their game?" Tom found himself asking himself over and overagain. "What did they 'put over' on poor Baxter?"

Tom had a chance to find out more about this, or at least start on thetrail sooner than he expected. For when he landed he saw Koku, thegiant, coming toward him with an appearance of excitement.

"Is Rad worse? Is there more trouble with his eyes?" asked the younginventor.

"No, him not much too bad," answered Koku. "I keep him good as I can.He sleep now, so I come out to swallow some fresh air. But man come tosee you—much mad man."

"Mad?" queried Tom.

"Well, what you say—angry," went on Koku. "Man what was in RomanSkycracker blaze."

"Oh, you mean Mr. Baxter, who was in the fireworks blaze," translatedTom. "Where is he, and what's the matter?"

CHAPTER X

ANOTHER ATTEMPT

Koku managed to make Tom understand that the dye inventor was in themain office of the Swift plant talking to Tom's father. The younginventor sent Mary home in his electric runabout in company with NedNewton, who, fortunately, happened along just then, and hurried to hisoffice.

"Oh, Tom, I'm glad you have arrived," said his father. "You rememberMr. Baxter, of course."

"I should hope so," Tom answered, extending his hand. He noticed thatthe man whom he had helped save from the fireworks blaze was under thestress of some excitement.

"I hope he hasn't been getting on dad's nerves," thought Tom, as hetook a seat. The elder Mr. Swift had been quite ill, and it was thoughtfor a time that he would have to give up helping Tom. But there hadbeen a turn for the better, and the aged inventor had again taken hisplace in the laboratory, though he was frail.

"What's the trouble now?" asked Tom. "At least I assume there has beensome trouble," he went on. "If I am wrong—"

"No, you are right, unfortunately," said Mr. Baxter gloomily. "Thetrouble is that everything I do is a failure. Up to a little while agoI thought I might succeed, in spite of Field and Melling's theft of theformulae from me. I made a purple dye the other day, and tested ittoday. It was a miserable failure, and it got on my nerves. I came tosee if you could help me."

"In what way?" asked Tom, wondering whether or not he had best tell Mr.Baxter what he had overheard at the Inn.

"Well, I need better laboratory facilities," the man went on. "I knowyou have been very kind to me, Mr. Swift, and it seems like animposition to ask for more. But I need a different lot of chemicals,and they cost money. I also need some different apparatus. You have itin your big laboratory. That wouldn't cost you anything. But of courseto go out and buy what I need—"

"Oh I guess we can stand that, can't we, Dad?" asked Tom, with a genialsmile. "You may have free access to our big laboratory, Mr. Baxter, andI'll see that you get what chemicals you need."

"Oh, thank you!" exclaimed the inventor. "Now I believe I shall succeedin spite of those rascals. Just think, Mr. Swift! They have started abig new dye factory."

"So I have heard," replied Tom.

"And I'm almost sure they're using the secret formulae they stole fromme!" exclaimed Mr. Baxter. "But I'll get the best of them yet! I'llinvent a better dye than they ever can, even if they use the secretsthe old Frenchman gave me. All I need is a better place to work and allthe chemicals at my disposal."

"Then we'll try to help you," offered Tom.

"And if I can do anything let me know," put in Mr. Swift. "I shall beglad to get in the harness again, Tom!" he added.

"Well, if you're so anxious to work, Dad, why not give me a hand withmy fire extinguisher chemical?" asked Tom. "I haven't been able to hiton the solution, somehow or other."

"Perhaps I may be able to give you a hint or two after I get settleddown," suggested Mr. Baxter.

"I shall be glad of any assistance you can give," replied Tom Swift."And now I'm going to start right in. Dad, you can make thearrangements for Mr. Baxter to use our big laboratory. And let him havecredit for any chemicals he needs. Have them put on my bill, for I ambuying a lot myself."

"I'll never forget this," said Mr. Baxter, and there were tears in hiseyes as he shook hands with Tom, who tried to make light of hisgenerous act.

Tom, after the wrecking of his laboratory, in which accident poorEradicate was injured, had built himself another—two others, in fact,after having shared Mr. Baxter's temporary one for a time. Tom put upthe most completely equipped laboratory that could be devised, and healso erected a smaller one for his own personal use, the main one beingat the disposal of his father and the various heads of the differentdepartments of the Shopton plant.

The little conference broke up, and Tom was on his way to his ownspecial private laboratory when there came the sound of some excitementin the corridor outside and Mr. Damon burst in.

"Bless my accident policy, Tom! what's this I hear?" he asked, all in afluster.

"I'm sure I don't know," answered the young inventor, with a smile."What about?"

"About you and Mary Nestor being killed!" burst out Mr. Damon. "Iheard you fell in the aeroplane and were both dashed to pieces!"

"If you can believe the evidence of your own eyes, I'm far from beingin that state," laughed Tom. "And as for Mary, she just left here withNed Newton."

"Thank goodness!" sighed Mr. Damon, sinking into a chair. "Bless myelevator! I rushed over as soon as I heard the news, and I was almostafraid to come in. I'm so glad it didn't happen!"

"No gladder than I," said Tom. "We had to make a forced landing, thatwas all," and he made as light of the incident as possible when he sawthe look of terror in his father's eyes.

"Some people in Waterford saw you going down," went on Mr. Damon, "andthey told me."

"It was a false alarm," replied Tom. "And now, Mr. Damon, if you wantto smell some perfumes come with me."

"Are you going into that line, Tom?" asked the eccentric man. "Blessmy handkerchief, my wife will be glad of that!"

"I mean I'm going to experiment some more with fire-extinguishingchemicals," laughed the young inventor. "If you want to—"

"Bless my gas mask, I should say not!" cried Mr. Damon. "I don't seehow you stand those odors, Tom Swift."

"Guess I'm used to 'em," was the answer. And then, leaving his fatherto entertain Mr. Damon and to make arrangements for Mr. Baxter's use ofthe main laboratory, he betook himself to his own private quarters.

The next week or so was a busy time for Tom; so busy, in fact, that hehad little chance to see Mr. Baxter. All he knew was that theunfortunate man was also laboring in his own line, and Tom wished himsuccess. He knew that if the man made any discoveries that would helpwith the fire-extinguishing fluid he would report, as he had promised.

"Well, Tom, how goes it?" asked Ned one day when he came over to callon his chum. "Are you ready to accept contracts for putting outskyscraper blazes in all big cities?"

"Not yet," was the answer. "But I'm going to make another attempt, Ned."

"You mean another experiment?"

"Yes, I have evolved a new combination of chemicals, using something ofthe carbonate idea as a basis. I found that I couldn't get away fromthat, much as I wanted to. But my application is entirely new, at leastI hope it will prove so."

"When are you going to try it?" asked Ned.

"Right away. All I have to do is to put the chemicals in the metaltank."

"Then I'd better get my leather suit on," remarked Ned, starting totake off his street coat. Tom kept for his chum a full outfit of flyinggarments, one suit being electrically heated.

"Oh, we aren't going up in any airship," Tom said.

"Why, I thought you were going to test your aerial fire fightingdingus!" exclaimed Ned.

"So I am. But I want to stay on the ground and watch the effect on theblaze as the tank bursts and scatters the chemical fluid."

"Then you want me, and perhaps Mr. Damon to take the stuff up in themachine? Excuse me. I don't believe I care to run an airship myself."

"No," went on Tom, "there isn't any question of an airship this time.No one is going up. Come on out into the yard and I'll show you."

Ned Newton followed his chum out into the big yard near one of theshops. Erected in it, and evidently a new structure, was a large woodenscaffold in square tower shape with a long overhanging arm and aplatform on the extremity. Beneath it was a pit dug in the earth, andin this pit, which was directly under the outstanding arm of the tower,was a pile of wood and shavings, oil-soaked.

"Oh, I see the game," remarked Ned. "You're going to drop the stufffrom this height instead of doing it from an airship."

"Yes," Tom answered. "There will be time enough to go on with theairship end of it after I get the right combination of chemicals. Andby having a metal container with the stuff in dropped from this framework, I can station myself as near the burning pit as I can get andwatch what happens."

"It's a good idea," decided Ned. "I wonder you didn't try that before."

"Mr. Baxter suggested it," replied Tom. "That helpful idea more thanpays me for what I have done for him. So now, if you're ready, I'd liketo have you watch with me and make some notes, one of us on one side ofthe pit, and one on the other. There are always two sides to a fire,the leeward and the windward, and I want to see how my chemicals act inboth positions."

"I'm with you," said Ned. "Who's going to drop the stuff—Koku?"

"No, he is a bit too heavy for the framework, which I had put up in ahurry. I'd have Rad do it, but he's out of the game."

"Poor old Rad!" murmured Ned. "Do you think he'll ever get better, Tom?"

"I don't know," sighed the young inventor. "All I can do is to hope. Heis very patient, and Koku is devoted to him. All their littlebickerings and squabbles seem to have been forgotten."

Tom called some of his workmen, some of them to start the blaze ofinflammable material in the pit, while one climbed up to the top of thetower of scantlings and made his way out on the extended arm, wherethere was a little platform for him to stand until it was time to dropthe chemicals.

"Light her up!" cried Tom Swift, and a match was thrown in among theoiled wood. In an instant a fierce blaze shot up, as hot, inproportion, as would come from any burning building.

For the second time Tom was about to make a test on a fairly largescale of his experimental extinguisher mixture.

"All ready up there?" he called to his helper perched high in the air.

"All ready!" came back the answer above the roar and crackle of theflames that made Tom and Ned step back.

Would success or failure attend the young inventor's project?

CHAPTER XI

THE BLAZING TREE

Tom Swift hesitated a moment before giving the final word that wouldsend the metal container of powerful chemicals down into the midst ofthe crackling flames. He wanted to make sure, in his own mind, that hehad done everything possible to insure the success of his undertaking.The young inventor never attempted the solution of any problem withoutgoing into it with his whole energy. So he wanted this experiment tosucceed.

He quickly reviewed, mentally, the composition of the chemicalcompound. He had made it as strong as possible, and he had spared nopains to insure a hot fire, so that the test would not be too simple.

"What's the matter, Tom?" asked Ned, as his chum appeared to hesitateabout giving the word that would send the chemicals hurtling down intothe fire.

"Nothing. I was just making sure I hadn't forgotten anything," Tomanswered. "I guess I haven't."

He paused a moment, looked up at his assistant on the overhanging armof the tower, glanced down at the flames, now at their height, and thensuddenly cried:

"Let her go!"

"Right!" came back the man's voice, and then a dark object, like abomb, was seen descending from the skeleton framework above the flames.

There was a scattering of the fire in the pit as the extinguisher bombfell among the blazing embers. Then followed a slight explosion whenthe bomb broke, as it was intended it should.

Tom and Ned leaned forward to peer through the pall of smoke whichswirled this way and that. Here was to come the real test of thedevice. Would the fumes of the liberated chemicals choke the fire, orwould it burn on in spite of them? That was the question to be settledfor Tom Swift.

Almost immediately he had his answer. For after a fierce burst of thetongues of fire following the fall of the bomb, there was a distinctdying down of the conflagration in the pit. Great clouds of smokearose, but the fire was quenched in a great measure, and as thefire-blanketing gas continued to be generated from the chemicalsliberated from the bomb, there was a further dying down of thecrackling fire.

"Tom, you've struck it!" yelled Ned in delight. "You have the rightcombination this time!"

Tom did not answer. He leaned forward and looked eagerly down into thepit. He was about to join with Ned in agreeing that he had, indeed,solved the problem, when, to his surprise, the flames started up again.

"What's this?" asked the young financial manager. "Are you going tohave a second test, Tom?"

"Not that I know of," was the puzzled answer. "I don't exactlyunderstand this myself, Ned. By all calculations this fire ought tohave died a natural death, but now it is breaking out again. I thinkwhat must have happened is that a quantity of the oil they poured oncollected in a pool and didn't get all the effects of the chemicalsfrom the bomb. Then the oil started to blaze."

"What can you do about it?" Ned wanted to know.

"Oh, I've got another bomb up there," and Tom pointed to his helper whowas still perched on the overhanging arm. "I was prepared for some suchemergency as this. Drop the other one!" Tom yelled, and again a darkobject fell, bursting in the pit and again liberating the gas that wassupposed to choke any fire.

The flames that had started up for the second time instantly died down,and Ned, leaning over the edge of the pit, cried:

"Hurray, Tom! That does the business!" But the young inventor shook hishead. "I'm not quite satisfied," he remarked. "It didn't work quicklyenough. What I want is a chemical combination that will choke the fireoff first shot."

"Well, you pretty nearly have it," observed Ned.

"Yes. But 'good enough' isn't what I want," Tom said. "I've got to workon that chemical compound again. I think I know where I can improve it."

"Well, if I were a fire, and I had this happen to me," remarked Ned,laughing and pointing to the heap of blackened embers in the pit, "Ishould feel very much discouraged."

"But not enough," declared Tom. "I want the fire to be out more quicklythan this one was. I think I can improve that chemical compound, andI'm going to do it."

"All right! Come on down!" he called to his helper, who was stillperched on the overhanging arm. "We won't do any more today."

"What is your next move?" asked Ned, as Tom started for his small,private laboratory.

"Oh, I'm going to fiddle around among those sweet-smelling chemicals,"answered the young inventor.

"Bless my vest buttons! then I'm not coming in, exclaimed a voice whichcould proceed from none other than Mr. Damon. And he it proved to be.He had driven over from Waterford in his automobile and had arrivedjust as the fire test was concluded.

"Oh, come on in!" called Tom. "You can visit with dad, and Eradicatewill be glad to see you."

"Poor Rad! How is he?" asked Mr. Damon, walking along with Tom and Ned.

"No change," was the sad answer of the young inventor, for he feltresponsible for the mishap to the colored man. "They can't operate onhis eyes yet."

"And when they do will he be able to see?" asked Mr. Damon.

"That is what we are all hoping," answered Tom with a sigh. "But do goin to see him, Mr. Damon. It will cheer him up."

"I will," promised the eccentric man. "At any rate I'll not venturenear your perfume shop, Tom Swift!"

"And I don't see that I can be of any service," added Ned, "so I'm offto my work."

"All right," assented Tom. "I've got several new schemes to try. Someof them ought to work."

Tom Swift was very busy for the next few days—so busy, in fact, thateven Mary saw little of him. He was closeted with Mr. Baxter more thanonce, and that individual seemed to lose some of his bitter feelingsover the loss of his formulae as he found he could be of service to theyoung inventor. For he was of service in suggesting new ways ofcombining fire-fighting chemicals, gained by his association with thefireworks concern.

"And that's about all the benefit I derived from being with thosescoundrels, Field and Melling," said Mr. Baxter gloomily.

"You still think they took your dye formulae?" asked Tom.

"I'm positive of it, but I can't prove anything. They threatened to getthe best of me when I would not sell them, for a ridiculously low sum,an interest in the secrets. And I believe they did get the best of meduring that fire."

"I believe the same!" exclaimed Tom.

"How is that? What do you know? Can you help me prove anything againstthem?" eagerly asked the chemist.

"Well, I don't know," answered Tom slowly. "I'll tell you what I heard."

Thereupon he related the conversation he had overheard while with Maryat the wayside inn. The eyes of Josephus Baxter gleamed as he listenedto this recital.

"So that was their game!" he cried, as he smote the table with hisfist, thereby nearly upsetting a test tube of acid, which Tom caughtjust in time. "I knew something crooked was going on, and they thoughtI'd be so badly overcome in the fire that I wouldn't know, or wouldn'tremember, what happened."

"What did happen?" asked Tom. "All I know is that you were overcome inthe laboratory room."

"It's too long a story to tell in detail now," said Mr. Baxter. "Butthe main facts are that through misrepresentations I was induced toassociate myself with Field and Melling. They had a good factory forthe making of fireworks, and some of the chemicals used in thatindustry also enter into the manufacture of the kind of dyes I have inmind to make. So I associated myself with them, they agreeing to let meuse their laboratory.

"One night they came to see me as I was working there over my formulae.They pretended to have discovered something in an expired patent thatnullified what I had. I did not believe this to be so, and I broughtout my formulae to compare with theirs—or what they said they had. Thenext thing I remember was that the fire broke out and my formulaedisappeared. Then I was overcome, and I did not care what happened tome, for, having lost the valuable dye formulae, I did not think lifeworth living.

"Perhaps I was foolish," said Mr. Baxter, "but I had tried so manythings and failed, and I counted so much on these formulae that itseemed as if the bottom dropped out of everything when I lost them."

"I know," said Tom sympathetically. "I've been in the same boat myself.But are you sure they took the papers which meant so much to you?"

"I don't see who else could," answered the chemist. "The papers were ina tin box on the table in the room where I was overcome by fire gases,or where, perhaps, they drugged me. I am not clear on this point. Andafterward the tin box could not be found. There wasn't enough fire inthat room to have melted it."

"No," agreed Tom, "it was mostly smoke in there, and smoke won't melttin. Nor did I see any box on the table when we carried you out."

"Then the only other surmise is that Field and Melling got away with myformulae during the excitement and when I was half unconscious," Wenton Mr. Baxter bitterly. "But you can see how foolish I would be toaccuse them in court. I haven't a bit of proof."

"Not much, for a fact," agreed Tom. "Well, with what I heard and whatyou tell me, perhaps we can work up a case against them later. I'll goover it with Ned. He has a better head for business than I."

"Yes, we inventors need some business brains; or at least the time togive to business problems," agreed the chemist. "But enough of mytroubles. Let's get at this chemical compound of yours."

Tom and Mr. Baxter spent many days and nights perfecting thefire-extinguisher chemical, and, after repeated tests, Tom felt that hewas nearer his goal.

One afternoon Ned called, and Tom invited him to go for a ride in asmall but speedy aeroplane.

"Anything special on?" asked the young manager.

"In a way, yes," Tom answered. "I'm having a firm in Newmarket make mesome different containers, and they have promised me samples today. Ithought I'd take a fly over and get them. I have the chemical compoundall but perfected now, and I want to give it another test."

"All right, I'm with you," assented Ned. "Newmarket," he addedmusingly. "Isn't that where Field and Melling are now?"

"Yes. They have a factory on the outskirts of the place, and theiroffices are in the Landmark Building. But we aren't going to see them,though we may call on them later, when you have that case better workedup." For Ned's services had been enlisted to aid Mr. Baxter.

"I shall need a little more time," remarked Ned. "But I think we can atleast bluff them into playing into our hands. I have a report to hearfrom a private detective I have hired."

"I hope we can do something to aid Baxter," remarked Tom. "He has doneme good service in this chemical fire extinguisher matter."

A little later Tom and Ned were speeding through the air on their wayto Newmarket. The rapid flier was making good time at not a greatheight when Ned, leaning forward, appeared to be gazing at something inthe near distance.

"What's the matter?" asked Tom, for he had his silencer on this craftand it was possible for the occupants to converse. "Do you hear one ofthe cylinders missing, Ned?"

"No. But what's that smoke down there?" and Ned pointed. "It looks likea fire!"

"It is a fire!" exclaimed Tom, as he took an observation. "Not a bigone, but a fire, just the same. If only—"

He did not finish what he started to say, but changed the direction ofhis air craft and headed directly toward a pall of smoke about a mileaway.

In a few seconds they were near enough to make out the character of theblaze.

"Look, Tom!" cried Ned. "It's an immense tree on fire!"

"A tree!" exclaimed Tom, half incredulously, for he was leaning forwardto look at one of the aeroplane gages and did not have a clear view ofwhat Ned was looking at.

"Yes, as sure as Mr. Damon would bless something if he were here! It'sa tree on fire up near the top!"

"That's strange!" murmured Tom. "But it may give me just the chanceI've been looking for."

Ned wondered at this remark on the part of his chum as the airship drewnearer the blazing monarch in the patch of woods over which they werethen hovering.

CHAPTER XII

TOM IS LONESOME

"This is certainly the strangest sight I ever saw," remarked Ned, as heand his chum flew nearer and nearer to the smoking and blazing tree."Is the world turning upside down, Tom, when fires start in thisfashion?"

"I fancy it can easily be explained," answered the young inventor."We'll go into that later. Here, Ned, grab hold of that tin can on thefloor and take out the screw plug."

"What's the idea?"

"I want you to drop it as nearly as you can right into the midst of thetree that's on fire."

"Oh, I get your drift! Well, you can count on me."

Ned picked up from the floor of their aeroplane a metal can similar tothose Tom used to hold oil or perhaps spare gasoline when he wasexperimenting on airship speed. The opening was closed with a screwplug, with wings to afford an easier grip. As Ned unscrewed this hisnostrils were greeted by an odor that made him gasp.

"Don't mind a little thing like that," cried Tom. "Drop it down, Ned!Drop it down! We're going to be right over the tree in another secondor two!"

Ned leaned over the side of the craft and had a good view of thestrange sight. The tree that was on fire was a dead oak of great size,dwarfing the other trees in the grove in which it stood. In common withother oaks this one still retained many of its dried leaves, though itwas devoid, or almost devoid, of life. Ned noticed in the branches manyirregularly shaped objects, and it appeared to be these that were onfire, blazing fiercely.

"It looks as though some one had tied bundles of sticks in the tree andset them on fire," Ned thought as he poised the opened tin of theevil-smelling compound on the edge of the aeroplane's co*ckpit.

"Let her go, Ned!" cried Tom. "You'll be too late in another second!"

Ned raised himself in his seat and threw, rather than let fall, the canstraight for the blazing tree. Like a bomb it shot toward earth, andNed and Tom, looking down, could see it strike a limb and break open,the rupture of the can letting loose the liquid contained in it.

And then, before the eyes of Tom and Ned, the fire seemed to die out asa picture melts away on a moving picture screen. The smoke rolled awayin a ball-like cloud, and the flames ceased to crackle and roar.

"Well, for the love of molasses! what happened, Tom?" cried Ned, as theyoung inventor guided his craft about in a big circle to come backagain over the tree. He wanted to make sure that the fire was out.

It was!

"What sent that blaze to the happy hunting grounds?" asked Ned.

"My new aerial extinguisher," answered Tom, with justifiable pride inhis voice. "This fire happened in the nick of time for me, Ned. I had atin of my new combination in the car, not with any intention of usingit, though. I intended to pour it in the new containers I am havingmade in Newmarket to see if it would corrode them, a thing I wish toavoid.

"But when I saw that tree on fire I couldn't resist the temptation touse my very latest combination of chemicals. It is so recent that Ihaven't actually tried it on a blaze yet, though I had figured out intheory that it ought to work. And it did, Ned! It worked!"

"Well, I should say so!" agreed his chum. "That blaze was doused forfair. The test could not have been better. But what in the name of avolunteer fire department set that tree to blazing, Tom?"

"I'll tell you in a moment. I want to make some notes before I forget.That combination seems to be just of the right strength. It did thetrick. Here, take the wheel and hold her steady while I jot down somememoranda before they get away from me."

Ned was capable of managing an airship, especially under Tom's watchfuleye, and as this craft was one with dual controls there was nodifficulty in shifting from one steersman to the other.

So while Ned guided, now and then gazing down at the tree from whichsome smoke still arose, though the fire was all out, Tom made thenecessary scientific notes for future amplification.

"And now," observed Ned, as his chum resumed the wheel, "suppose youenlighten me on how that tree came to be on fire—if you didn't set ityourself."

"No, I didn't do that," Tom said, with a laugh. "And I only have atheory as to the cause of the blaze. But suppose we go down and take alook. There's a good field around this grove, and we can get a finetake off. I'll have to go back to Shopton anyhow, to get some more ofthe chemical."

So the aeroplane made a landing, and then the mystery was explained.The dead oak, to which some of its last year's foliage still clung, wasthe abiding place of thousands of crows that had built their nests init. There were hundreds of the big nests, made of dried sticks, mostly,and these made an ideal fuel for the fire.

"But where are the crows, and what started the fire?" asked Ned.

"I fancy the birds flew away as soon as they saw their homes on fire,"said Tom. "Or they may not have been at home. Flocks of crows often goto some distant feeding ground for the day, returning at night. I fancythat is what happened here.

"As for the cause of the blaze, I believe it was set by somemischievous boys, who saw a good chance to have some fun withoutthought of doing any real damage. For the dead tree was of no value,and I imagine the farmers would be glad to see the flock of crowsdispersed. Some boys probably climbed up and set fire to one of thenests, and then, when they saw the whole lot going, they becamefrightened and ran away."

And Tom's theory was, eventually, proved to be true. Somelads, wandering afield, had set fire to the crows' nests and then,frightened as they saw a bigger blaze than they intended, ran away.

Tom and Ned did not remain to see what the returning crows might thinkabout the destruction of their homes, provided they saw fit to return,but, starting the aeroplane, were again on their way.

Tom had lingered long enough to make sure that his latest combinationof chemicals had been just what was needed. He felt sure that by usinga larger quantity, no fire, however fierce, could continue to blaze.

"But I want to give it a good trial, Ned, as we did from the tower,"said Tom. "Though I don't believe there'll be a fizzle this time."

It did not take long for Tom to secure another supply of the newchemical. He then went with it to the firm in Newmarket that was makinghis containers, or "bombs" as he called them.

On his return he consulted with Mr. Baxter as to the ingredients of thefluid that had put out the blaze in the tree.

"I believe you have at last hit on the right combination," said thechemist. "You are on the road to success, Tom. I wish I could say thesame of myself."

"Perhaps your formulae may come back to you as suddenly as theydisappeared, or as quickly as I discovered that I had the right thingto put out the fire," said Tom hopefully.

Busy days followed for the young inventor. Now that he was convinced hehad at last evolved the right mixture of chemicals, he prepared to makea test on a larger scale than merely a blazing tree.

"I'll try it with a fire in the pit," he said to his chum.

Preparations were made, and the day before Tom was to carry out hisplans he received a letter.

"What's the matter? Bad news?" asked Ned, as he saw his friend's facechange after reading the epistle.

"Nothing much. Only Mary is going away, and I had expected her to be atthe test," Tom answered.

"Going away?" echoed Ned. "For long?"

"Oh, no, only for a couple of weeks. She is going to visit an uncle andaunt in Newmarket, or just outside of that city. Another uncle, BartonKeith, has offices in the Landmark Building, I believe."

"Landmark Building," murmured Ned. "Isn't that where Field and Mellinghang out?"

"Yes. But don't mention Mary's uncle in connection with them," laughedTom. "He wouldn't like it."

"I should say not!"

Ned well remembered Mary's uncle, who had been associated with Tom inrecovering the treasure in the undersea search.

"Well, if she can't be here, she can't," said Tom, as philosophicallyas possible. "I'd better run over and bid her goodbye."

This Tom did, though Ned noticed that his chum acted as though lonesomeon his return.

"But when he gets to work testing his new chemical he'll be all right,"decided Ned.

CHAPTER XIII

A SUCCESSFUL TEST

"It took you long enough," Ned remarked as Tom entered the main officeof the plant, having been to see Mary off on her trip to Newmarket.This was following his call of the night before to learn moreparticulars of her unexpected visit.

"Yes, I didn't plan to be gone so long," apologized Tom. "But I thoughtwhile I was there I might as well go all the way with her."

"And did you?"

"Yes. In the electric runabout. I wanted to come back and get theairship, but she said she wanted to look nice when she met herrelatives, and as yet airship travel is a bit mussy. Though when I getmy cabined cruiser of the clouds I'll guarantee not to ruffle a curl ofthe daintiest girl!"

"Getting poetical in your old age!" laughed Ned. "Well, here is thatstatement you said you wanted me to get ready. Want to go over it now?"

"No, I guess not, as long as you know it's all right. I'm going tostart right in and get ready for a bang-up test."

"Of what—your new aerial fire fighting apparatus?"

"Yes. Mr. Baxter and I are going to make up a lot of the chemicalcompound that—we discovered through using it on the blazing tree—willbest do the trick. Then I'm going to try it on a pit fire, and afterthat on a big blaze with an airship."

"Let me know when you do," begged Ned. "I want to see you do it."

"I'll send you word," promised the young inventor.

Then he began several days and nights of hard work. And he was glad tohave the chance to occupy himself, for, though Tom professed not to bemuch affected by the departure of Mary Nestor, he really was verylonesome.

"How is her uncle, Barton Keith, by the way?" asked Ned, when he calledon his chum one day, to find him reading a letter which needed but halfan eye to tell was from Mary.

"About as usual," was the answer. "He sends word by Mary that he'll beglad to see us any time we want to call. He has some nice offices inthe Landmark Building."

"Those papers proving his right to the oil land, which you recoveredfrom the sunken ship for him, must have made his fortune."

"Well, yes—that and other things," agreed Tom. "Say, we had someexciting times on that undersea search, didn't we?"

"Did you call on Mr. Keith when you went to Newmarket with Mary?" Nedwanted to know, for he and Tom had taken quite a liking to MissNestor's uncle.

"No, I didn't get a chance. Besides, I wanted to keep away from theLandmark Building."

"Why?"

"Oh, I might run into Field and Melling, and I don't want to see themuntil I can accuse them, and prove it, of having taken Mr. Baxter's dyeformulae."

"Oh, yes, they're in the same building with Mr. Keith, aren't they? Whydo they call it the Landmark? Though I suppose the answer is obvious."

"Yes," assented Tom. "It's a big building—the tallest ever erected inthat city, and a fine structure. Though while they were about it Idon't see why they didn't make it fireproof."

"Didn't they?" asked Ned, in surprise. "Then the insurance rates mustbe unusually high, for the companies are beginning to realize how firedepartments, even in big cities, are hampered in fighting blazes abovethe tenth or twelfth stories."

"Yes, it was a mistake not to have the Landmark Building fireproof,"admitted Tom. "And Mr. Keith says the owners are beginning to realizethat now. It is what is called the 'slow burning' construction."

"Insurance companies don't go much on that," declared Ned, who was in aposition to know. "Well, let us hope it never catches fire."

These were busy days for the young inventor. He laid aside all hisother activities in order to perfect the plans for manufacturing hisnew chemical fire extinguisher on a large scale. For Tom realized thatwhile a small quantity of chemicals in a compound might act in acertain way on one occasion, if the bulk should happen to be increasedthe experimenter could not always count on invariably the same results.

There appeared to be at times a change engendered when a large quantityof chemicals were mixed which was not manifest in a small andexperimental batch.

So Tom wanted to mix up a big tank of his new chemical compound and seeif it would work in large quantities as well as it did with the smallamount Ned had dropped on the blazing tree.

To this end Tom worked at night, as well as by day, and finally heannounced to Ned and Mr. Damon, who called one evening, that hebelieved he had everything in readiness for an exhaustive test the nextday.

"There's the stuff!" exclaimed Tom, not a little proudly, as he wavedhis hand toward an immense carboy in the main shop. "That's what I hopewill do the trick. Just take a—"

"Hold on! Stop! That's enough! Bless my hair brush!" cried Mr. Damon,holding up a protesting hand. "If you take that cork out, Tom Swift,you and I will cease to be friends!"

"I wasn't going to open it," laughed the young inventor. "It has aworse odor and seems to choke you more in a big quantity than whenthere's only a little. I was just going to shake the carboy to let yourealize how full it was."

"We'll take your word for it!" laughed Ned. "Now about your test. Howare you going to work it?"

"There are to be two tests," answered Tom. "The first, and the smaller,will be in the pit, as before, only this time we shall have what, Ibelieve, will be the successful combination of chemicals to drop on it.

"The second test will be the main one. In that I plan to have an oldbarn which I have bought set ablaze. Then Ned and I will sail over itin the airship and drop chemicals on it. The barn will be filled withempty boxes and barrels, to make as hot a fire as possible. You areinvited to accompany us, Mr. Damon."

"Will there be any smell?" asked the eccentric man, who seemed to havea dislike for anything that was not as agreeable as perfume.

"No, the chemicals will be sealed in containers, which will be droppedfrom my airship as bombs were dropped in the war," said Tom.

"On those conditions I'll go along," agreed Mr. Damon. "But bless mywedding certificate, Tom! don't tell my wife. She thinks I'm crazyenough now, associating with you and flying occasionally. If shethought I would help you battle with flames from the air she'd likelynever speak to me again."

"I'll not tell," promised Tom, laughing.

Preparations for the test went on rapidly. In the morning a fire was tobe started in the same pit where the experiment had partly failedbefore.

From the platform over the blazing hole some of the new combination ofchemicals was to be dropped. If it acted with success, as Tom believedit would, he proposed to go on with the more important test in theafternoon.

To this end he had purchased from a farmer the right to set on fire anold ramshackle barn, standing in the midst of a field about three milesoutside of Shopton. The barn was on an untilled farm, the house havingbeen destroyed some years before, and it was not near any otherstructures, so that, even in a high wind, no damage would result.

Tom had filled the barn with inflammable material, and was going tospare no effort to have the test as exhaustive as possible.

The time came for the preliminary trial, and there were a few anxiousmoments after the oil-soaked boards and boxes in the pit were setablaze.

"Let her go!" cried Tom to his man on the elevated platform, and downfell the container of chemicals. It had no sooner struck and burst,letting loose a mass of flame-choking vapor, than the fire died out.

"You've struck it, Tom! You've struck it!" cried Ned.

"It begins to look so," agreed the young inventor. "But I'll not callmyself out of the woods until this afternoon. Though we can consider ita success so far."

Quite a throng was on hand when the old barn was set ablaze. Tom andNed and Mr. Damon were there with the airship which had been especiallyfitted to carry the bombs filled with the extinguisher.

In order to insure a quick, hot blaze the barn was fired on all foursides at once by Tom's men. When it was seen to be a veritable ragingfurnace of fire, Tom and his two friends took their places in theairship and rapidly mounted upward.

Necessarily they had to circle off away from the blaze to get to thenecessary height, but Tom soon brought the airship around again andheaded for the black pall of smoke which marked the place of theblazing barn.

"We'll all three send down bombs at the same time," Tom told hisfriends, as they darted forward. "When I give the word press thelevers, and the chemical containers will drop. Then we'll hope for thebest."

Higher mounted the flames, and more fiercely raged the fire. The heatof it penetrated even aloft, where Tom and his friends were scuddingalong in the airship.

"Now!" cried Tom, as his craft hovered for an instant in a favorableposition for dropping the bombs. The young inventor, Mr. Damon, and NedNewton pressed the levers. Looking over the sides of the craft, theysaw three dark objects dropping into the midst of the burning barn.

CHAPTER XIV

OUT OF THE CLOUDS

Almost as though some giant hand had dropped an immense cloak over thefire in the barn, so did the blaze die down instantly after Tom Swift'sextinguishing liquid had been dropped into the seething caldron offlame. For a moment there was even no smoke, but as the embers remainedhot and glowing for a time, though the flames themselves were quenched,a rolling vapor cloud began to ascend shortly after the first cessationof the fire. But this only lasted a little while.

"You've turned the trick, Tom!" cried Ned, leaning far over to look atwhat was left of the barn and its contents.

"Bless my insurance policy, I should say so!" exclaimed Mr. Damon. "Itwas certainly neat work, Tom!"

"It does look as if I'd struck the right combination," admitted Tom,and he felt justifiable pride in his achievement.

"Look so! Why, hang it all, man, it is so!" declared Ned. "That firewent out as if sent for by a special delivery telegram to give ahurry-up performance in another locality. Look, there's hardly anysmoke even!"

This was so, as the three occupants of the rapidly moving airship couldsee when Tom circled back to pass again over the almost destroyedstructure. He had waited until it was almost consumed before droppinghis chemicals, as he wished to make the test hard and conclusive. Nowthe fire was out except for a few small spots spouting up here andthere, away from the center of the blaze.

"Yes, I guess she doesn't need a second dose," observed Tom, when hesaw how effective had been his treatment of the fire. "I had anadditional batch of chemicals on hand, in case they were needed," headded, and he tapped some unused bombs at his feet.

"I call this a pretty satisfactory test," declared Ned. "If you want toform a stock company, Tom, and put your aerial fire-fighting apparatuson the market, I'll guarantee to underwrite the securities."

"Hardly that yet," said Tom, with a laugh. "Now that I have my chemicalcombination perfected, or practically so, I've got to rig up an airshipthat will be especially adapted for fighting fires in sky-scrapers."

"What more do you want than this?" asked Ned, as his chum prepared todescend in the speedy machine.

"I want a little better bomb-releasing device, for one thing. Thisworked all right. But I want one that is more nearly automatic. Then Iam going to put on a searchlight, so I can see where I am heading atnight."

"Not your great big one!" cried Ned, recalling the immense electriclantern that had so aided in capturing the Canadian smugglers.

"No. But one patterned after that." Tom answered.

"Bless my candlestick!" exclaimed Mr. Damon, "what do you want with asearchlight at a fire, Tom? Isn't there light enough at a blaze,anyhow?"

"No," answered the young inventor, as he made his usual skillfullanding. "You know all the big city fire departments have searchlightsnow for night work and where there is thick smoke. It may be that someday, in fighting a sky-scraper blaze from the clouds at night, I'llhave need of more illumination than comes from the flames themselves."

"Well, you ought to know. You've made a study of it," said Mr. Damon,as he and Ned alighted with Tom, the latter receiving congratulationsfrom a number of his friends, including members of the Shopton firedepartment who were present to witness the test.

"Mighty clever piece of work, Tom Swift!" declared a deputy chief. "Ofcourse we won't have much use for any such apparatus here in Shopton,as we haven't any big buildings. But in New York, Chicago, Pittsburghand other cities—why, it will be just what they need, to my way ofthinking."

"And he needn't go so far from home," said Mr. Damon. "There is onetall building over in Newmarket—the Landmark. I happen to own a littlestock in the corporation that put that up, along with other buildings,and I'm going to have them adopt Tom Swift's aerial fire-fightingapparatus."

"Thank you. But you don't need to go to that trouble," asserted Tom."My idea isn't to have every sky-scraper equipped with an airshipextinguisher."

"No? What then?" asked Mr. Damon.

"Well, I think there ought to be one, or perhaps two, in a big citylike New York," Tom answered. "Perhaps one outfit would be enough, forit isn't likely that there would be two big fires in the tall buildingsection at the same time, and an airship could easily cover thedistance between two widely separated blazes. But if I can perfectthis machine so it will be available for fires out of the reach ofapparatus on the ground, I'll be satisfied."

"You'll do it, Tom, don't worry about that!" declared the deputy chief."I never saw a slicker piece of work than this!"

And that was the verdict of all who had witnessed the performance.

With the successful completion of this exacting test and the knowledgethat he had perfected the major part of his aerialfire-extinguisher—the chemical combination—Tom Swift was now able todevote his attention to the "frills" as Ned called them. That is, hecould work out a scheme for attaching a searchlight to his airship andmake better arrangements for a one-man control in releasing thechemical containers into the heart of a big blaze.

Tom Swift owned several airships, and he finally selected one of nottoo great size, but very powerful, that would hold three and, ifnecessary, four persons. This was rebuilt to enable a considerablequantity of the fire-extinguishing liquid to be stored in the underpart of the somewhat limited co*ckpit.

This much done, and while his men were making up a quantity of theextinguisher, using the secret formula, and storing it in suitablecontainers, Tom began attaching a searchlight to his "cloudfire-engine," as Koku called it.

The giant was aching to be with Tom and help in the new work, but Kokuwas faithful to the blinded Eradicate, and remained almost constantlywith the old colored man.

It was touching to see the two together, the giant trying, in his kind,but imperfect way, to anticipate the wishes of the other, with whom hehad so often disputed and quarreled in days past. Now all that wasforgotten, and Koku gave up being with Tom to wait on Eradicate.

While the colored man was, in fact, unable to see, following theaccident when Tom was experimenting with the fire extinguisher, it washoped that sight might be restored to one eye after an operation. Thisoperation had to be postponed until the eyes and wounds in the facewere sufficiently healed.

Meanwhile Rad suffered as patiently as possible, and Koku shared hisloneliness in the sick room. Tom came to see Rad as often as he could,and did everything possible to make his aged servant's lot happier. ButRad wanted to be up and about, and it was pathetic to hear him askabout the little tasks he had been wont to perform in the past.

Rad was delighted to hear of Tom's success with the new apparatus,after having been told how quickly the barn fire was put out.

"Yo'—yo' jest wait twell I gits up, Massa Tom," said Rad. "Den Ah'llhelp make all de contraptions on de airship."

"All right, Rad, there'll be plenty for you to do when the time comes,"said the inventor. And he could not help a feeling of sadness as heleft the colored man's room.

"I wonder if he is doomed to be blind the rest of his life," thoughtTom. "I hope not, for if he does it will be my fault for letting himtry to mix those chemicals."

But, hoping for the best, Tom plunged into the work ahead of him. Hedid not want to offer his aerial fire extinguisher to any large cityuntil he had perfected it, and he was now laboring to that end.

One day, in midsummer, after weary days of toil, Tom took Ned out for aride in the machine which had been fitted up to carry a large supply ofthe chemical mixture, a small but powerful searchlight, and other new"wrinkles" as Tom called them, not going into details.

"Any special object in view?" asked Ned, as Tom headed across country."Are you going to put out any more tree fires?"

"No, I haven't that in mind," was the answer. "Though of course if wecome across a blaze, except a brush fire, I may put it out. I have thebombs here," and Tom indicated the releasing lever.

"What I want to try now is the stability of this with all I have onboard," he resumed. "If she is able to travel along, and behave as wellas she did before I made the changes, I'll know she is going to be allright. I don't expect to put out any fires this trip."

In testing the ship of the air Tom sent her up to a good height,heading out over the open country and toward a lake on the shores ofwhich were a number of summer resorts. It was now the middle of theseason, and many campers, cottagers and hotel folk were scattered aboutthe wooded shore of the pretty and attractive body of water.

Tom and Ned had a glimpse of the lake, dotted with many motor boats andother craft, as the airship ascended until it was above the clouds.Then, for a time, nothing could be seen by the occupants but masses offeathery vapor.

"She's working all right," decided Tom, when he found that he couldperform his usual aerial feats with his craft, laden as she was withapparatus, as well as he had been able to do before she was soburdened. "Guess we might as well go down, Ned. There isn't much moreto do, as far as I can see."

Down out of the heights they swept at a rapid pace. A few moments laterthey had burst through the film of clouds and once more the lake wasbelow them in clear view.

Suddenly Ned pointed to something on the water and cried:

"Look, Tom! Look! A motor boat in some kind of trouble! She's sinking!"

CHAPTER XV

COALS OF FIRE

Tom Swift saw the craft almost as soon as did his chum. It was rather alarge-sized motor boat, quite some distance out from shore, and therewas no other craft near it at this time. From the quick, first view Tomand Ned had of it, they decided that a party of excursionists were on apleasure trip.

But that an accident had happened, and that trouble, if not, indeed,danger, was imminent, was at once apparent to the young inventor andthe other occupant of the swiftly moving airship.

For as Tom shut off his motor, to volplane down, thus reducing allnoise on his craft, they could dimly hear the shouts and calls forhelp, coming from the water craft below them.

"Help! Help!" came the impassioned appeals, floating up to Tom and Ned.

"We're coming!" Tom answered, though it is doubtful if his voice washeard. Sound does not seem to carry downward as well as upward, andthough Tom's craft was making scarcely any noise, save that caused bythe rush of wind through the struts and wires, there was so muchconfusion on the motor boat, to say nothing of the engine which wasgoing, that Tom's encouraging call must have been unheard.

"What are you going to do, Tom?" asked Ned, "You can't land on thewater!"

"I know it; worse luck! If I only had the hydroplane, now, we couldmake a thrilling rescue—land right beside the other boat and take 'emall off. But, as it is, I'll have to land as near as I can and then wewill look for a boat to go out to them in."

Ned saw, now, what Tom's object was. On one shore of the lake was alarge, level field, suitable for a landing place for the craft of theair. At least it looked to be a suitable place, but Tom would beobliged to take a chance on that. This field sloped down to the beachof the lake, and as Ned and his chum came nearer to earth they couldsee several boats on shore, though no persons were near them. Had therebeen, probably they would have gone to the rescue.

Tom cast a rapid look across the sheet of water, to make sure hisservices were really needed. The motor boat was lower in the lake now,and was, undoubtedly, sinking. And no other craft was near enough torender help. Though distant whistles, seeming to come from approachingcraft, told of help on the way.

"Hold fast, Ned!" cried Tom, as they neared the earth. "We may bump!"

But Tom Swift was too skillful a pilot to cause his craft to sustainmuch of a crash. He made an almost perfect "three point landing," andthere would have been no unusual shaking, except for the fact that thefield was a bit bumpy, and the craft more heavily laden than usual.

"Good work, Tom!" cried Ned, as the Lucifer slackened her speed, theyoung inventor having sent her around in a half circle so that she nowfaced the lake. Then Tom and Ned climbed from the co*ckpit, throwing offgoggles and helmets as they ran to the shore where there were severalrowboats moored.

"And a little old-fashioned naphtha launch! By all that's lucky!" criedTom. "I didn't think they made these any more. If she only works now!"

There was a little dock at this point on the lake, and the boatsappeared to be held at it for hire. But no one was in charge, and Tomand Ned made free with what they found. They considered they had thisright in the emergency.

The naphtha launch was chained and padlocked to the dock, but using anoar Tom burst the chain.

"Get one of the rowboats and fasten it to the back of the launch!" Tomdirected Ned. "I don't believe this craft will hold them all," and henodded toward those aboard the sinking boat—for it was only tooplainly sinking now.

"All right!" voiced Ned. "I'm with you. Can you get that engine towork?"

"She's humming now," announced Tom, as he turned on the naphtha, andthrew in a blazing match to ignite it, this act saving his hand.Naphtha engines are a trifle treacherous.

A few moments later, though not as quickly as a gasoline craft couldhave been gotten under way, Tom was steering the small launch out andaway from the dock, and toward the craft whence came the faint callsfor help. Behind them Tom and Ned towed a large rowboat.

Tom speeded the naphtha craft to its limit, and, fortunately for thosein danger, it was a fast boat. In less time than they had thoughtpossible, the young inventor and his chum were near the boat that wasnow low in the water—so low, in fact, that her rail was all but awash.

"Oh, take us out! Save us!" screamed some of the girls.

"Take it easy now," advised Tom, approaching with care. "We've got roomfor you all. Ned, get back in the rowboat and bring that alongside—onthe other side. We'll take you all in," he added.

"Girls first!" called Ned sternly, as he saw one young fellow about toscramble into the naphtha boat.

"Sure, girls first!" agreed the skipper of the disabled craft. "Hit asubmerged log," he explained to Tom, as the work of rescue proceeded."Stove a hole in the bow, but we stuffed coats and things in, and madeit a slow leak. Kept the engine going as long as we could, but Ithought no one would ever come! Lucky you happened to see us from upthere!"

"Yes," assented Tom shortly. He and Ned were too busy to talk much, asthey were aiding in getting some hysterical girls and young women intothe two sound craft. And when the last of the picnic party had beentaken off, the boat with a hole in it gave a sudden lurch, there was agurgling, bubbling sound, and she sank quickly.

Tom and Ned had anticipated this, however, and had their craft well outof the way of the suction.

"You'll all have to sit quiet," Tom warned his passengers as he tookNed's boat, with her load, in tow. "I've got about all the law allowsme to carry," he added grimly.

"Oh, what ever would we have done without you?" half sobbed one girl.

"I guess you could have managed to swim ashore," Tom answered, notwanting to make too much of his effort.

Then more rescue boats came up, but those in the naphtha craft, andNed's smaller one, refused to be transferred, and remained with ourfriends until safely landed at the dock.

Receiving the half-hysterical thanks of the party, and leaving them toexplain matters to the owner of the borrowed boats, Ned and Tom wentback to the Lucifer, and were soon aloft again.

"Pretty slick act, Tom," remarked Ned.

"Oh, it's all in the day's work," was the answer. He had all butperfected his big fire-extinguishing aeroplane, and was contemplatingmeans by which he could give a demonstration to the fire department ofsome big city, when Mr. Baxter asked to see Tom one day. There was alook on the face of the chemist that caused Tom to exclaim with a gooddeal of concern:

"What's the matter?"

"Only the same old trouble," was the discouraged answer. "I can't geton the track of my lost secret formulae. If I had Field and Mellinghere now I—I'd—"

He did not finish his threat, but the look on his face was enough toshow his righteous anger.

"I wish we could do something to those fellows!" exclaimed Tomenergetically. "If we only had some direct evidence against them!"

"I've got evidence enough—in my own mind!" declared Mr. Baxter.

"Unfortunately that doesn't do in law," returned Tom. "But now that Ihave this airship firefighter craft so nearly finished, I can devotemore time to your troubles, Mr. Baxter."

"Oh, I don't want you bothered over my troubles," said the chemist."You have enough of your own. But I'm at my wit's end what to do next."

"If it is money matters," began Tom.

"It's partly that, yes," said the other, in a low voice. "If I hadthose dye formulae, I'd be a rich man."

"Well, let me help you temporarily," begged Tom. And the upshot of thetalk was that he engaged Mr. Baxter to do certain research work in theSwift laboratories until such time as the chemist could perfect certainother inventions on which he was working.

In return for his kindness to a fellow laborer, Tom received from Mr.Baxter some valuable hints about fire-extinguishing chemicals, onehint, alone, serving to bring about a curious situation.

It was several days after the accident to the motor boat from which theyoung inventor and Ned Newton had rescued the party of pleasure seekersthat Tom was visited by Mr. Damon, who drove over in his car.

"Have you anything special to do, Tom?" asked the eccentric man. "Ifyou haven't I wish you'd take a ride with me. Not for mere pleasure!Bless my excursion ticket, don't think that, Tom!" cried his friendquickly.

"I know better than to ask you out for a pleasure jaunt. But I havebecome interested in a certain candy-making machine that a man over inNewmarket is anxious to sell me a share in, and I'd like to get youropinion. Can you run over?"

"Yes," Tom answered. "As it happens I am going to Newmarket myself."

"Oh, I forgot about Mary Nestor being there!" laughed Mr. Damon. "Slydog, Tom! Sly dog!" and he nudged the youth in the ribs.

"It isn't altogether Mary. Though I am going to see her," Tom admitted."It has to do with a little apparatus I am getting up. I can captureseveral birds in the same auto, so I'll go along."

This pleased Mr. Damon, and he and Tom were soon speeding over theroad. It was just outside Newmarket that they saw an automobile stalledat the foot of a hill which they topped. It needed but a glance to showthat there was serious trouble. As Mr. Damon's car went down the slopetwo men could be seen leaping from the other machine. And, as they didso, flames burst out of the rear of the stalled machine.

"Fire! Fire!" cried Mr. Damon, rather needlessly it would seem, as anyone could see the blaze.

"Another chance!" exclaimed Tom, reaching down between his feet for awrapped object he had placed in Mr. Damon's car. "It's Field andMelling!" he cried. "The two men who boasted of having put it over onMr. Baxter. Their car is blazing. Here's where I get a chance to heapcoals of fire on their heads!"

CHAPTER XVI

VIOLENT THREATS

Tom Swift's companion in the automobile was sufficiently acquaintedwith this old expression to understand readily what it meant. And as hedirected his car as close as was safe to the blazing car, Mr. Damonasked:

"Are you going to put out that fire for them, Tom?"

"I'm going to try," was the grim answer.

The young inventor was rapidly taking out of wrapping paper a metalcylinder with a short nozzle on one end and a handle on the other. Itwas, obviously, a hand fire extinguisher of a type familiar to all.

"Wait Tom, I'll slow up a little more," said Mr. Damon, as he appliedthe brakes with more force. "Bless my court plaster! don't jump andinjure yourself."

But Tom Swift was sufficiently agile to leap from the automobile whenit was still making good speed. He did not want Mr. Damon to approachtoo close to the burning car, for there might be an explosion. At thesame time, he rather discounted the risk to himself, for he ran rightin, while the two men, who had leaped from the blazing machine, hurriedto a safe distance.

Tom held in readiness a small hand extinguisher. It was one he hadconstructed from an old one found in the shop, but it contained some ofhis own chemicals, the original solution having been used at some timeor other. It was the intention of the young inventor to put on themarket a house-size extinguisher after he had disposed of his bigairship invention.

"Look out there! The gasoline tank may go up!" cried Field, the smallman with the big voice.

Tom did not answer, but ran in as close as was necessary and began toplay a small stream from his hand extinguisher on the blazing car. Hewas thus able to direct the white, frothy chemical better than when hehad shot it from the airship, and in a few seconds only some wisps ofcurling smoke remained to tell of the presence of the fire. Theautomobile was badly charred, but the damage was not past redemption.

"Bless my check book! you did the trick, Tom," cried Mr. Damon, as healighted and came up to congratulate his companion.

"Yes. But this wasn't much," Tom said. "I didn't use half the charge.Short circuit?" he asked Field and Melling who were now returning,having seen that the danger was passed.

"I—I guess so," replied Melling, in his squeaky voice. "We—we aremuch obliged to you."

"No thanks necessary," said Tom, a bit shortly, as he turned to go backwith Mr. Damon to their car. "It's what any one would do under likecirc*mstances."

"Only you did it very effectively," observed Field.

Tom was wondering if they knew who he was and of his association withJosephus Baxter. He did not believe the men recognized him as theperson who had been at the Meadow Inn one day with Mary. They hadhardly glanced at him then, he thought.

"That's a mighty powerful extinguisher you have there, young man," saidMelling. "May I ask the make of it? We ought to carry one like it onour car," he told his companion.

"It is the Swift Aerial Fire Extinguisher," said Tom gravely, with aglance at Mr. Damon.

"The Swift—Tom Swift?" exclaimed Melling. "Do you mean—"

"I am Tom Swift," put in the young inventor quickly. "And this is oneof my inventions. I might add," he said slowly, looking first Mellingand then Field full in the face, "that I was aided in perfecting thechemical extinguisher by Josephus Baxter."

The effect on the two men, whom Tom believed were scoundrels, wasmarked.

"Baxter!" cried Field.

"Is he associated with you?" demanded Melling.

"Not officially," Tom answered, delighted at the chance to "rub it in,"as he expressed it later. "I have been helping him, and he has beenhelping me since he lost his dye formulae in—in your fire!"

"Does he say he lost them in the fire of our factory?" demanded Fieldaggressively.

"He believes he did," asserted Tom. "I helped carry him out of thelaboratory of your place when he was almost dead from suffocation. Heremembers that he had the formulae then, but since has been unable tofind them."

"He'd better be careful how he accuses us!" blustered Field, in his bigvoice.

"We could have the law on him for that!" squeaked the bigger Melling.

"He hasn't accused you," said Tom easily. "He only says the formulaedisappeared during the fire in your place, and he is just wondering,that is all—just wondering!"

"Well, he—we, I—that is, we haven't anything from Baxter that wedidn't pay for," declared Field. "And if he goes about saying suchthings he'd better be careful. I am going—"

But he suddenly became silent as his companion's elbow nudged him. Andthen Melling took up the talk, saying:

"We're much obliged to you, Mr. Swift, for putting out the fire in ourcar. But for you it would have been destroyed. And if you ever want tosell the extinguisher process of yours, you'll find us in the market.We are going into the dye business on a large scale, and we can alwaysuse new chemical combinations."

"My extinguisher is not for sale," said Tom dryly. "Come on, Mr. Damon.We can take you into town, I suppose," Tom went on, looking at hiseccentric friend for confirmation, and finding it in a nod. "But Idoubt if we could tow you, as we are in a hurry, and—"

"Oh, thank you, we'll look over our machine before we leave it," saidMelling. "It may be that we can get it to go."

Tom doubted this, after a look at the charred section, but he easilyunderstood the dislike of the men, upon whose heads he had heaped coalsof fire, to ride with him and Mr. Damon.

So Field and Melling were left standing in the road near their strandedcar, which, but for Tom Swift's prompt action, would have been only aheap of ruins.

Tom first visited the man who had a candy machine, in which the ownerwanted to interest Mr. Damon. After seeing a demonstration and givinghis opinion, he attended to his own affairs, in which his handextinguisher played a part. Then he called on Mary Nestor at herrelative's home.

"Oh, but it's good to see you again, Tom!" cried Mary, after the firstgreeting. "What have you been doing, and what's all that white stuff onyour coat?"

"Fire extinguisher chemical," Tom answered, and he related what hadhappened.

"What's the matter with your aunt, Mary? She seems worried aboutsomething," he said, after the aunt with whom Mary was staying had comein, greeted Tom briefly, and gone out again.

"Oh, she and Uncle Jasper are worried over money matters, I believe,"Mary said. "Uncle Jasper invested heavily in the Landmark Buildinghere, and now, I understand, it is discovered that it was put up inviolation of the building laws—something about not being fire-proof.Uncle Jasper is likely to lose considerable money.

"It isn't that it will make him so very poor," Mary went on. "ButUncle Barton Keith—you remember you went on the undersea search withhim—Uncle Barton warned Uncle Jasper not to go into the LandmarkBuilding scheme."

"And Uncle Jasper did, I take it," said Tom.

"Yes. And now he's sorry, for not only may he lose money, but UncleBarton will laugh at him, and Uncle Jasper hates that worse than losinga lot. But tell me about yourself, Tom. What have you been doing? Andis Eradicate going to get better?"

"I hope so," Tom said. "As for me—"

But he was interrupted by loud voices in the hall. He recognized thetones of Mary's Uncle Jasper saying:

"They're scoundrels, that's what they are! Just plain scoundrels! WhenI accuse them of swindling me and others in that Landmark Building dealthey have the nerve to ask me to invest money in some secret dyeformulae they claim will revolutionize the industry! Bah! They'rescoundrels, that's what they are—Field and Melling are scoundrels, andI'm going to have them arrested!"

CHAPTER XVII

A TOWN BLAZE

Mary's uncle, Jasper Blake, always an impetuous man, opened the door soquickly that Tom, who was standing near it talking to Mary, barely hadtime to move aside.

"Oh, Tom, excuse me! Didn't see you!" bruskly went on Mr. Blake. "Butthis thing has gotten on my nerves and I guess I'm a bit wrought up.

"There isn't any guessing about it, Uncle Jasper," said Mary, with alaugh and a look at Tom to warn him not to tell her relative that hehad just befriended Field and Melling. "For," as Mary said to Tomlater, "he would positively rave at you."

Tom was wise enough to realize this, and so, after some laughingreference to the effect that he would have to wear protective armor ifhe stood near doors when Mary's uncle opened them so suddenly, theconversation became general.

"I hope you never get roped in as I have been," said Mr. Blake, as hesat down. "Those scoundrels, Field and Melling, would rob a baby of hisfirst tooth if they had the chance!"

"No, I am not likely to have anything to do with them; though I havemet them," and Tom gave Mary a glance. "But did I hear you say they areembarking on a dye enterprise?" he asked. "I couldn't help overhearingwhat you said in the hall," he explained.

"That's the story they tell," said Uncle Jasper. "I was foolish enoughto invest in the Landmark Building, and now I'm likely to lose it allin a lawsuit."

"I mentioned it," said Mary.

"And that isn't the worst," went on Mr. Blake. "But Barton—that's yourfriend of the submarine—will give me the laugh, for he was asked toinvest in the same building, and didn't."

"Oh, maybe it will all turn out right," said Tom consolingly. "Myfriend Mr. Damon has a little stock in the same structure."

"Nothing those two scoundrels have anything to do with will turn outright," declared Mary's uncle. "And to think of their nerve when theyask me to go in with them on a dye scheme!"

"That's what interests me," said Tom.

"Well, take my advice and don't become interested to the extent ofinvesting any money," warned Mr. Blake. "I'm not going to."

"I didn't mean that way," said Tom. "But I happen to be acquainted withan expert dye maker who lost some secret formulae during a fire inField and Melling's factory."

"You don't say so!" cried Mr. Blake. "Tom Swift, there's somethingwrong here! Let you and me talk this over. I begin to see how I may beable to take a peep through the hole in the grindstone," a colloquialexpression which was as well understood by Tom as were some of Mr.Damon's blessing remarks.

"If you're going to talk business I think I'll excuse myself," saidMary.

"Don't go," urged Tom, but she said to him that she would see himbefore he left, and then she went out, leaving her uncle and the younginventor busily engaged in talking.

But though Mr. Blake had certain suspicions regarding Field andMelling, and though Tom Swift, too, believed they had something to dowith the disappearance of Baxter's secret formulae, it was anothermatter to prove anything.

Impetuous as he often was, Mr. Blake was for calling in the police atonce, and having the two men arrested. But Tom counseled delay.

"Wait until we get more evidence against them," he urged.

"But they may skip out!" objected Mary's uncle.

"They won't with that Landmark Building on their hands," said the younginventor.

"Their hands! Huh! They'll take precious good care that the trouble andresponsibility of it are on other people's hands before they go,"declared Mr. Blake. "However, I suppose you're right. Barton Keith setsa deal by your opinion since that undersea search, and while I don'talways agree with him, I do in this case. Especially since he is likelyto have the laugh on me."

"Oh, I wouldn't count everything lost in that building deal," said Tom."A way may be found out of the trouble yet. But I must be getting back.Dr. Henderson was to give a report today on the condition ofEradicate's eyes, and I want to be there."

"Mary was saying something about your faithful old retainer being introuble," said Mr. Blake. "I'm sorry to hear about it."

"We are all sorry for poor Rad," replied Tom slowly. "I only hope hegets his sight back. His last days will be very sad if he doesn't."

Tom found Mary waiting for him after he had left her uncle, and, aftera short talk with her, he made ready to ride back with Mr. Damon, who,after having attended to several other matters, was now outside in hiscar.

"When are you coming home, Mary?" Tom asked.

"In a week or two," she answered. "I'll send word when I'm ready andyou can come and get me."

"Delighted!" declared Tom. "Don't forget!" During the ride home theyoung inventor was unusually silent, so much so that Mr. Damon finallyexclaimed:

"Bless my phonograph, Tom Swift! but what is the matter? Has Marybroken the engagement?"

"Oh, no, nothing like that," was the answer. "Only I'm wondering aboutEradicate, and—other matters."

Other matters had to do with what Mary's uncle had told Tom about theinterest manifested by Field and Melling in some dye industry.

Tom's forebodings regarding his colored helper were nearly borne out,for Dr. Henderson gloomily shook his head when asked for the verdict.

"It's too early to say for a certainty," replied the medical man, "butI am not as hopeful as I was, Tom, I'm sorry to say."

"I'm sorry to hear it," returned Tom. "Is there anything we can do—anyhospital to which we can send him for special treatment?"

"No, he is doing as well as he can be expected to right here. Besides,he has his friends around him, and the companionship of that giant ofyours, absurd as it may seem, is really a tonic to Eradicate. I neversaw such devotion on the part of any one."

"Koku has certainly changed," said Tom. "He and Rad used always to bequarreling. But I guess that is all over," and Tom sighed.

"Oh, I wouldn't say that," declared the medical man. "I haven't givenup, though there are some symptoms I do not like. However, I am goingto wait a week and then make another test."

Tom knew that the week would be an anxious one for him, but, as itdeveloped, he had so much to do in the next few days that, for the timebeing, he rather forgot about Eradicate.

Field and Melling, he heard incidentally, had their machine towed to agarage for repairs, but beyond that no word came from the two men.Josephus Baxter remained at work over his dye formulae in one of Tom'slaboratories, but the young inventor did not see much of thediscouraged old man.

Tom did not tell of the encounter with Field and Melling and ofextinguishing the fire in their car, for he knew it would only exciteMr. Baxter, and do no good.

It was within a few days of the time when Tom was to call in acommittee of fire insurance experts to give them a demonstration of theefficiency of his aerial fire-fighting machine. He was putting thefinishing touches to his craft and its extinguishing-dropping deviceswhen he received a call from Mr. Baxter.

"Well, how goes it?" asked Tom, trying to infuse some cheer into hisvoice.

"Not very well," was the answer. "I've tried, in every way I know, toget on the track of the missing methods perfected by that Frenchman,but I can't. I'd be a millionaire now, if I had that dye information."

"Do you really think they have them—actually have the formulae?" askedTom.

"I certainly do. And the reason I believe so is that I was over at achemical supply factory the other day when an order came in for aquantity of a very rare chemical."

"What has that to do with it?" asked Tom.

"This chemical is an ingredient called for by one of the dye formulaethat were stolen from me. I never heard of its being used for anythingelse. I at once became suspicious. I learned that this chemical hadbeen ordered sent to Field and Melling in their new offices in theLandmark Building."

"Maybe they intend to use it in making a new kind of fireworks,"suggested Tom.

Mr. Baxter shook his head.

"That chemical never would work in a skyrocket or Roman candle," hesaid. "I'm sure they're trying to cheat me out of my dye formulae. If Icould only prove it!"

"That's the trouble," agreed Tom. "But I'll give you all the help Ican. And, come to think of it, I believe you might interest Mr. Blake.He has no love for Field and Melling, and he has several keen lawyerson his staff. I believe it would be a good thing for you to talk to Mr.Blake."

"Please give me a letter of introduction to him," begged Mr. Baxter."What I need is legal talent and capital to fight these scoundrels. Mr.Blake may supply both."

"He may," agreed Tom. "I'll fix it so you can meet him. But what do youthink of this combination, Mr. Baxter? It is my very latest solutionfor putting out fires. I'm loading an airship up with some of the bombcontainers now, and—"

Tom's further remarks were interrupted by the noise of shouting andtumult in the street, and a moment later yells could be heard of:

"Fire! Fire! Fire!"

"Another blaze!" exclaimed Mr. Baxter, raising the shades which hadbeen drawn, since night had fallen.

"And not far away," said Tom, as he caught the reflection of a redgleam in the sky.

There was a ring at the front doorbell, and almost at once Ned Newton'svoice called:

"Tom! Tom Swift! There's quite a fire in town! Don't you want to tryyour new apparatus on it?"

"The very chance!" exclaimed the young inventor. "Come on, Mr. Baxter.There's room in the airship for you and Ned. I want you to see how mychemical works!"

Without waiting for a reply from the chemist, Tom caught him by thehand and led him toward the side door that gave egress to the yardwhere one of the airships was housed. Tom caught sight of Ned, who washastening toward him.

"Big fire, Tom!" said the young manager again. "Fierce one!"

"I'm going to try to put it out!" Tom answered. "Want to come?"

"Sure thing!" answered Ned.

CHAPTER XVIII

FINISHING TOUCHES

Tom Swift and Ned Newton were so accustomed to acting quickly and inemergencies that it did not take them long to run out the airship,which Tom had in readiness, not especially for this emergency, but todemonstrate his new apparatus to a committee of fire underwriters whomhe had invited to call in a few days.

"Take this, if you will, Mr. Baxter!" cried Tom, giving the chemist ametal container. "It's a little different combination from theextinguisher I already have in the machine. Maybe I'll get a chance totry it."

"You're going to have all the chance you want, Tom, by the looks ofthat blaze," commented Ned Newton.

"It does look like quite a fire," observed Tom, as he gazed up at thesky, where the reflection was turning to a brighter red.

Outside in the streets near the Swift house and shops could be heardthe rattle of fire apparatus, the patter of running feet, and manyshouts from excited men and boys.

"Any idea what it is, Ned?" asked Tom, as he motioned to Mr. Baxter toclimb into the aircraft.

"Some one said it was the new Normal School. But that's farther to thenorth," was Ned's answer. "By the way the blaze has increased since Ifirst saw it, I'd take it to be the lumberyard."

"That would make a monster blaze!" observed Tom. "I don't believe I'llhave chemicals enough for that," and he looked at the rather smallsupply in his craft. "However, I haven't time to get any more. Besides,they'll have the regular department on the job, and this isn't askyscraper, anyhow."

"No, we'll have to go to New York or Newmarket for one of those,"observed Ned. "All ready, Tom?"

"All ready," said the young inventor, as Ned took his place beside Mr.Baxter.

"What's the matter, Tom?" asked the voice of Mr. Swift, as he came outinto the yard, having been attracted by the flashing lights and thenoise of the aircraft motor, as Tom gave it a preliminary test.

"There's a fire in town," Tom answered. "I'm going to see if they needmy services."

"Guess there isn't any question about that," said his business manager.

Tom's father, who was suffering the infirmities of age, was in thehabit of retiring early, and he had dozed off in his chair directlyafter supper, to be awakened by the shouting and confusion about theplace.

"Take care of yourself, my boy!" he advised, as there came a moment ofsilence before the throttle of the aircraft was opened to send it onits upward journey. "Don't take too many risks."

"I won't," Tom promised. "We'll be back soon."

Then came the roar of the motor as Tom cut out the muffler to gainspeed and, a moment later, he and his two friends were sailing aloftwith a load of fire-extinguishing chemicals.

Up and up rose the aircraft. It was not the first time Mr. Baxter hadenjoyed the sensation, but he was not enough of a veteran to be immuneto the thrills nor to be altogether void of fear. And it was his firstnight trip. Still he gave few evidences of nervousness.

"These she is!" cried Ned, for when the exhaust from the motor was sentthrough the new muffler Tom had attached it was possible to talk aboardthe Lucifer. The young manager pointed down toward the earth, overwhich the craft was then skimming, though at no great height.

"It is the lumberyard!" exclaimed Mr. Baxter presently.

"It sure is," assented Tom. "I know I haven't enough stuff to cover asbig a blaze as that, but I'll do my best. Fortunately there is no windto speak of," he added, as he guided the craft in the direction of thefire.

"What has that to do with it—I mean as far as the working of yourchemical extinguisher is concerned?" asked Mr. Baxter. "Can't you dropthe bomb containers accurately in a wind?"

"Well, the wind has to be allowed for in dropping anything from anaeroplane," Tom answered. "And, naturally, it does spoil your aim to anextent. But the reason I'm glad there is no wind to speak of is thatthe chemical blanket I hope to spread over the fire won't be so quicklyblown away."

"Oh, I see," said Mr. Baxter. "Well, I'm glad that you will be able tohave a successful test of your invention."

"The regular land apparatus is on hand," observed Ned, for they werenow so near the fire that they could look down and, in the reflectionfrom the blaze, could see engines, hose-wagons and hook and laddertrucks arriving and deploying to different places of advantage, fromwhich to fight the lumberyard fire that was now a roaring furnace offlames.

"No skyscraper work needed here," observed Tom. "But it will give me achance to use the latest combination I worked out. I'll try that first.Are you ready with it, Mr. Baxter?"

"Yes," was the answer.

The young inventor, not heeding the cries of wonder that arose frombelow and paying no attention to the uplifted hands and arms pointingto him, steered his craft to a corner of the yard where there was asmall isolated fire in a pile of boards. It was Tom's idea to try hisnew chemical first on this spot to watch the effect. Then he would turnloose all his other containers of the chemical mixture that had provedso effective in other tests.

Attention of those who had gathered to look at the fire was aboutevenly divided between the efforts of the regular department and thepending action by Tom Swift. The latter was not long in turning loosehis latest sensation.

"Let it go!" he cried to Mr. Baxter, and down into the seething caldronof flame dropped a thin sheet-iron container of powerful chemicals.Leaning over the co*ckpit of the aircraft, the occupants watched theeffect. There was a slight explosion heard, even above the roar of theflames, and the tongues of fire in the section where Tom's extinguisherhad fallen died down.

"Good work!" cried Ned.

"No!" answered Tom, shaking his head. "I was a little afraid of this.Not enough carbon dioxide in this mixture. I'll stick to the one Ifound most effective." For the flames, after momentarily dying down,burst out again in the spot where he had dropped the bomb.

Tom wheeled the airship in a sharp, banking turn, and headed for theheart of the fire in the lumberyard. It was clearly getting beyond thecontrol of the regular department.

"How about you, Ned?" called Tom, for he had given his chum charge ofdropping the regular bombs containing a large quantity of theextinguisher Tom had practically adopted.

"All ready," was the answer.

"Let 'em go!" came the command, and down shot the dark, sphericalobjects. They burst as they hit the ground or the piles of blazinglumber, and at once the powerful gases generated by the mixture ofseveral different chemicals were released.

Again the three in the airship leaned eagerly over the side of theco*ckpit to watch the effect. It was almost magical in its action.

The bombs had been dropped into the very fiercest heart of the fire,and it was only an instant before their action was made manifest.

"This will do the trick!" cried Ned. "I'm certain it will."

"I didn't have much fear that it wouldn't," said Tom. "But I hoped theother would be better, for it is a much cheaper mixture to make, andthat will count when you come to sell it to big cities."

"But the fire is certainly dying down," declared Mr. Baxter.

And this was true. As container after container of the bomb type fellin different parts of the burning lumberyard, while Tom coursed aboveit, the flames began to be smothered in various sections.

And from the watching crowds, as well as from the hard-working membersof the Shopton fire department, came cheers of delight andencouragement as they saw the work of Tom Swift's aerial fire-fightingmachine.

For he had, most completely, subdued what threatened to be a greatfire, and when the last of his bombs had been dropped, so effective wasthe blanket of fire-dampening gases spread around that the flames justnaturally expired, as it were.

As Tom had said, the absence of wind was in his favor, for thegenerated gases remained just where they were wanted, directly over thefire like an extinguishing blanket, and were not blown aside as wouldotherwise have been the case.

And, by the peculiar manner in which his chemicals were mixed, Tom hadmade them practically harmless for human beings to breathe. Though thefire-killing gases were unpleasant, there was no danger to life inthem, and while several of the firemen made wry faces, and one or twowere slightly ill from being too close to the chemicals, no one wasseriously inconvenienced.

"Well, I guess that's all," said Tom, when the final bomb had beendropped. "That was the last of them, wasn't it, Ned?"

"Yes, but you don't need any more. The fire's out—or what isn't can beeasily handled by the hose lines."

"Good!" cried Tom. "But, all the same, I wish I had been able to makethe first mixture work."

"Perhaps I can help you with that," suggested Mr. Baxter.

And the following day, after Tom had received the thanks of the townofficials and of the fire department for his work in subduing thelumberyard blaze, the young inventor called Josephus Baxter inconsultation.

"I feel that I need your help," said the young inventor. "You have beenat this chemical study longer than I, and I am willing to pay you wellfor your work. Of course I can't make up to you the loss of your dyeformulae. But while you are waiting for something to turn up in regardto them, you may be glad to assist me."

"I will, and without pay," said the chemist.

But Tom would not hear of that, and together he and Mr. Baxter setabout putting the finishing touches to Tom's latest invention.

CHAPTER XIX

ON THE TRAIL

"There, Tom Swift, it ought to work now!"

Josephus Baxter held up a large laboratory test tube, in which seethedand bubbled some strange mixture, turning from green to purple, then tored, and next to a white, milky mixture.

"Do you think you've hit on the right combination?" asked the younginventor, whose latest idea, the plan of fighting fires in skyscrapersfrom an airship as a vantage point, was taking up all his spare moments.

"I'm positive of it," said Mr. Baxter. "I've dabbled in chemicals longenough to be certain of this, even if I can't get on the track of themissing dye formulae."

"That certainly is too bad," declared Tom. "I wish I could help you asmuch as you have helped me."

"Oh, you have helped me a lot," said the chemist. "You have given me aplace to work, much better than the laboratory I had in the oldfireworks factory of Field and Melling. And you have paid me, more thanliberally, for what little I have done for you."

"You've done a lot for me," declared Tom. "If it had not been for yourhelp this chemical compound would not be nearly as satisfactory as itis, nor as cheap to manufacture, which is a big item."

"Oh, you were on the right track," said Mr. Baxter. "You would havestumbled on it yourself in a short time, I believe. But I will say, TomSwift, that, between us, we have made a compound that is absolutelyfatal to fires. Even a small quantity of it, dropped in the heart of alarge blaze, will stop combustion."

"And that's what I want," declared Tom. "I think I shall go ahead now,and proceed with the manufacture of the stuff on a large scale."

"And what do you propose doing with it?" asked Mr. Baxter.

"I'm going to sell the patent and the idea that goes with it to as manylarge cities as I can," Tom answered. "I'll even manufacture theairships that are needed to carry the stuff over the tops of blazingskyscrapers, dropping it down. I'll supply complete aerialfire-fighting plants."

"And I think you'll do a good business," said the chemist.

It was the conclusion of the final tests of an improved chemicalmixture, and the reaction that had taken place in the test tube was theend of the experiment. Success was now again on the side of Tom Swift.

But when that has been said there remains the fact that it was just theother way with the unfortunate Mr. Baxter.

Try as he had, he could not succeed in getting the right chemicalcombination to perfect the dye process imparted to him by his lateFrench friend. With the disappearance of the secret formulae went thegood luck of Josephus Baxter.

He had worked hard, taking advantage of Tom's generosity, to bring backto his memory the proper manner of mixing certain ingredients, so thatpermanent dyes of wondrous beauty in coloring would be evolved. But itwas all in vain.

"I know who have those formulae," declared the chemist again and again."It is those scoundrels, Field and Melling. And they are planning tobuild up their own dye business with what is mine by right!"

And though Tom, also, believed this, there was no way of proving it.

As the young inventor had said, he was now ready to put his own latestinvention on the market. After many tests, aided in some by Mr. Baxter,a form of liquid fire extinguisher had been made that was superior toany known, and much cheaper to manufacture. Veteran members of firedepartments in and about Shopton told Tom so. All that remained was todemonstrate that it would be as effective on a large scale as it was ona small one, and big cities, it was agreed, must, of necessity, add itto their equipment.

"Well, I think I'll give orders to start the works going," said Tom, atthe conclusion of the final test. "I have all the ingredients on handnow, and all that remains is to combine them. My airship is all ready,with the bomb-dropping device."

"And I wish you all sorts of luck," said Mr. Baxter. "Now I am going tohave another go at my troubles. I have just thought of a possible newway of combining two of the chemicals I need to use. It may be I shallhave success."

"I hope so," murmured Tom. He was about to leave the room when Koku,the giant, entered, with a letter in his hand. The big man showed somesigns of agitation, and Tom was at once apprehensive about Eradicate.

"Is Rad—has anything happened—shall I get the doctor?"

"Oh, Rad, him all right," answered Koku. "That is him not see yet, butmebby soon. Only I have to chase boy, an' he make faces at me—boybring this," and the giant held out the envelope.

"Oh!" exclaimed Tom, and he understood now. Messenger boys frequentlycame to Tom's house or to the shops, and they took delight in pokingfun at Koku on account of his size, which made him slow in gettingabout. The boys delighted to have him chase them, and something likethis had evidently just taken place, accounting for Koku's agitation.

"This is for you, Mr. Baxter, not for me," said Tom, as he read thename on the envelope.

"For me!" exclaimed the chemist. "Who could be writing to me? It's abig firm of dye manufacturers," he went on, as he caught a glimpse ofthe superscription in the upper left hand corner.

Quickly he read the contents of the epistle, and a moment later he gavea joyful cry.

"I'm on the trail! On the trail of those scoundrels at last!" exclaimedJosephus Baxter. "This gives me just the evidence I needed! Now I'llhave them where I want them!"

CHAPTER XX

A HEAVY LOAD

Josephus Baxter was so excited by the receipt of the letter which Kokudelivered to him that for some seconds Tom Swift could get nothing outof him except the statement:

"I'm on their trail! Now I'm on their trail!"

"What do you mean?" Tom insisted. "Whose trail? What's it all about?"

"It's about Field and Melling! That's who it's about!" exclaimed Mr.Baxter, with a smothered exclamation. "Look, Tom Swift, this letter isaddressed to me from one of the biggest dye firms in the world—a firmthat is always looking for something new!"

"But if you haven't anything new to give them, of what use is it?" Tomasked, for he knew that the chemist had said his process, stolen, as heclaimed, by Field and Melling, was his only new project.

"But I will have something new when I get those secret formulae awayfrom those scoundrels!" declared Mr. Baxter.

"Yes, but how are you going to do it, when you can't even prove thatthey have them?" asked Tom.

"Ah, that's the point! Now I think I can prove it," declared Mr.Baxter. "Look, Tom Swift! This letter is addressed to me in care ofField and Melling at the office I used to have in their fireworksfactory."

"The office from which you were rescued nearly dead," Tom added.

"Exactly. The place where you saved me from a terrible death. Well, ifyou will notice, this letter was written only two days ago. And it isthe first mail I have received as having been forwarded from thataddress since the fire. I know other mail must have come for me,though."

"What became of it?" asked Tom.

"Those scoundrels confiscated it!" declared the chemist. "But, in somemanner, perhaps through the error of a new clerk, this letter wasremailed to me here, and now I have it. It is of the utmost importance!"

"In what way?" asked Tom.

"Why, it is directed to me, outside and in, and it makes an inquiryabout the very dyes of the lost secret formulae, one dye in particular."

"I don't quite understand yet," said Tom.

"Well, it's this way," went on Mr. Baxter. "I had, in the office ofField and Melling, all the papers telling exactly how to make the dyes.After the fire, in which I was rendered unconscious, those papersdisappeared.

"The only way in which any one could make the dyes in question was byfollowing the formulae given in those papers. And now here is a letter,addressed to me from a big firm, asking my prices on a certain dye,which can only be made by the process bequeathed to me by theFrenchman."

"Which means what?" asked Tom.

"It means that Field and Melling must have been writing to this firm ontheir own hook, offering to sell them some of this dye. But, in someway, my name must have appeared on the letter or papers sent on by thescoundrels, and this big firm replies to me direct, instead of to Fieldand Melling! Even then I would not have benefited if they hadconfiscated this letter as I am sure, they have done in the case ofothers. But, by some slip, I get this.

"And it proves, Tom Swift, that Field and Melling are in possession ofmy dye formulae, and that they have tried to dispose of some of the dyeto this firm. Not knowing anything of this, the firm replies to me. Sonow I have direct evidence—just what I wanted—and I can get on thetrail of the scoundrels who have cheated me of my rights."

Tom looked at the letter which, it appeared, had been left with Koku bya special delivery boy from the post office. It was an inquiry aboutcertain dyes, and was addressed to Mr. Baxter in care of Field andMelling, the former fireworks firm, which now had started a big dyeplant, with offices in the Landmark Building in Newmarket.

"It does look as though you might get at them through this," Tom said,as he handed back the letter. "But I'm afraid you'll have to getfurther evidence before you could convict them in a court oflaw—you'll have to show that they actually have possession of yourformulae."

"That's what I wish I could do," said the chemist, somewhat wistfully.His first enthusiasm had been lessened.

"I'll help you all I can," offered Tom. And events were soon totranspire by which the young inventor was to render help to the chemistin a most sensational manner.

"Just now," Tom went on, "I must arrange about getting a large supplyof these chemicals made, and then plan for a test in some big city."

"Yes, you have done enough for me," said Mr. Baxter. "But I think now,with this letter as evidence, we'll be able to make a start."

"I agree with you," Tom said. "Why don't you go over to see Mr. Damon?He's a good business man, and perhaps he can advise you. You mightalso call on that lawyer who does work for Mr. Keith and Mr. Blake. Andthat reminds me I must call Mary Nestor up and find out when she iscoming home. I promised to fetch her in one of the airships."

"I will go and see Mr. Damon," decided Mr. Baxter. "He always givesgood advice."

"Even if he does bless everything he sees!" laughed Tom. "But if you'regoing to see him I'll run you over. I'm going to Waterfield."

"Thanks, I'll be glad to go with you," said the chemist.

Mr. Damon was glad to see his friends, and, when he had listened to thelatest developments, he exclaimed with unusual emphasis:

"Bless my law books, Mr. Baxter! but I do believe you're on the righttrail at last. Come in, and we'll talk this over."

So Tom left them, traveling on to a distant city where he arranged fora large supply of the chemicals he would need in his extinguisher.

For several days Tom was so busy that he had little time to devote toMr. Baxter, or even to see him. He learned, however, that the chemistand Mr. Damon were in frequent consultation, and the young inventorhoped something would come of it.

Tom's own plans were going well. He had let several large cities knowthat he had something new in the way of a fire-fighting machine, and hereceived several offers to demonstrate it.

He closed with one of these, some distance off, and agreed to fly overin his aircraft and extinguish a fire which was to be started in an oldbuilding which had been condemned, and was to be destroyed. This was ina city some four hundred miles away and when Ned Newton called on himone afternoon he found Tom busily engaged in loading his sky-craft witha heavy cargo of the newest liquid extinguisher.

"You aren't taking any chances, are you, Tom?" asked Ned.

"What do you mean?"

"I mean you seem to have enough of the liquid 'fire-discourager' todouse any blaze that was ever started."

"No use sending a boy on a man's errand," said Tom. "I'm counting onyou to go with me, Ned—you and Mr. Baxter. We leave this afternoon forDenton."

"I'll be with you. Couldn't pass up a chance like that. But here comesKoku, and it looks as if he had something on his mind."

The giant did, indeed, seem to be laboring under the stress of someemotion.

"Oh, Master Tom!" the big man exclaimed when he had got the attentionof the young inventor. "Rad—he—he—"

"Has anything happened?" asked Tom, quickly. "No, not yet. But dat pillman—he say by tomorrow he know if Rad ever will see sunshine more!"

"Oh, the doctor says he'll be able to decide about Rad's eyesighttomorrow, does he?"

"Yes. What so pill man say," repeated Koku.

"Um," mused Tom, "I wish I were going to be here, but I don't see how Ican. I must give this test." But it was with a sinking heart as hethought of poor Eradicate that the young inventor proceeded to pileinto his airship the largest and heaviest load of chemicals it had evercarried.

CHAPTER XXI

THE LIGHT IN THE SKY

"Well, what do you say, Tom?" asked Ned, in a low voice.

"She's all right as far as I can see, though she may stagger a bit atthe take off."

"It's a pretty heavy load," agreed the young manager, as he and TomSwift walked about the big fire-fighting airship Lucifer, which hadbeen rolled outside the hangar. "But still I think she'll take it,especially since you've tuned up the motor so it's at least twenty percent. more powerful than it was."

"Perhaps you'd better leave me out," suggested Mr. Baxter, who had beenhelping the boys. "I'm not a feather weight, you know."

"I need you with us," said Tom. "I want your expert opinion on theeffect the new chemicals have on the flames."

"Well, I'd like to come," admitted the chemist, "for it will be avaluable experience for me. But I don't want an accident up in the air."

"Trust Tom Swift for that!" cried Ned. "If he says his aircraft will dothe trick, it positively will."

"How about leaving me out?" asked Mr. Damon. "I'm not an expert inanything, as far as I know."

"You are in keeping us cheerful. And we may need you to bless things ifthere's a slip-up anywhere," laughed Tom, for Mr. Damon had beeninvited to be one of the party.

"I don't so much mind a slip-up," said Mr. Damon, "as I do a slip down.That's where it hurts! However, I'll take a chance with you, Tom Swift.It won't be the first one—and I guess it won't be the last."

The work of getting the big airship ready for what was to be aconclusive test of her fire-fighting abilities from the cloudsproceeded rapidly. As has been related, Tom had perfected, with thehelp of Mr. Baxter, a combination of chemicals which was effective inputting out a fire when dropped into the blaze from above. Quantitiesof this combination had been stored in metal containers which Tom hadat first styled "bombs," but which he now called "aerial grenades."

The manner of dropping the grenades was, on the whole, similar to themanner in which bombs were dropped from airships during the Great War,but Tom had made several improvements in this plan.

These improvements had to do with the releasing of the bombs, or, inthis case, grenades. It is not easy to drop or throw something from aswiftly moving airship so that it will hit an object on the ground.During the war aviators had to train for some time before becoming evenapproximately accurate.

Tom Swift decided that to leave this matter to chance or to the eye ofthe occupant of an airship was too indefinite. Accordingly he inventeda machine, something like a range-finder for big guns. With this it wasa comparatively easy matter to drop a grenade at almost any designatedplace.

To accomplish this it was necessary to take into consideration thespeed of the airship, its height above the ground, the velocity of thewind, the weight of the grenades, and other things of this sort. But byan intricate mathematical process Tom solved the problem, so that itwas only necessary to set certain pointers and levers along a sliderule in the co*ckpit of the craft. Then when the releasing catch waspressed, the grenades would drop down just about where they were mostneeded.

"I think everything is ready," said Tom, when he had taken a last lookover his craft, making sure that all the chemical grenades were inplace. "If you will be ready, gentlemen, we will take our places andstart in about half an hour," he added. "I want to say goodbye to myfather, and cheer up Rad—if I can."

"The doctor will know tomorrow, will he?" asked Mr. Damon.

"Yes. And I'm sorry I will not be here to listen to the report," saidTom. "Though I am almost afraid to receive it," he added in a lowvoice. "I shall blame myself if Rad is to go through the remainder ofhis life blind."

"It couldn't be helped," said Ned. "We'll hope for the best."

"Yes," agreed Tom, "that's all we can do—hope for the best. By theway," he went on, turning to Mr. Baxter, "are you any nearer fasteningthe guilt on those two rascals, Field and Melling?"

"Bless my prosecuting attorney, no!" exclaimed Mr. Damon. "Those arethe slickest scoundrels I ever tackled! They're like a flea. Once youthink you have them where you want them, and they're on the other sideof the table, skipping around."

"I've about given up," said Mr. Baxter, in discouraged tones. "I guessmy dye formulae are gone forever."

"Don't say that!" exclaimed Tom. "Once I get this fire matter off myhands, I'm going to tackle the problem myself. We'll either make thosefellows sorry they ever meddled in this matter, or we'll get up a newcombination of dyes that will put them out of business!"

"Bless my Easter eggs, I'm glad to hear you talk that way!" cried Mr.Damon.

"Well, Rad, I'll expect to see you up and around when I get back," saidTom to his old servant, as he stepped into the sick room to say goodbye.

"Oh, is yo' goin', Massa Tom?" asked the colored man, turning hisbandaged head in the direction of the beloved voice.

"Yes. I'm going to try out a new scheme of mine—the fire extinguisher,you know."

"De same one whut fizzed up, an'—an' busted me in de eyes, Massa Tom?"

"Yes, Rad, I'm sorry to say, it's the same one."

"Oh, shucks now, Massa Tom! whut's use worryin'?" laughed Rad. "I suahwill be all right when yo' gits back. De doctor man—de 'pill man' datgiant calls him—says I'll suah be better."

"Of course you will," declared Tom, but his heart sank when he saw Mrs.Baggert remove the bandages and he caught sight of Rad's burned faceand the eyes that had to be kept closed if ever they were again to lookon the sunshine and flowers. "And when I come back, Rad, I'll stage alittle fire for your benefit, and show you how quickly I can put itout."

"Ha! dat's whut I wants to see, Massa Tom, I suah does like to seefires!" chuckled Eradicate. "Mah ole mule, Boomerang—does yo' 'memberhim, Massa Tom?"

"Of course, Rad!"

"Well, Boomerang he liked fires, too. Liked 'em so much I jest couldn'tgit him past 'em lots ob times I But run 'long, Massa Tom. Yo' ain'tgot no time to waste on an ole culled man whut's seen his best days.Yas-sir, I reckon I'se seen mah best days," and the smile died from thehonest, black face.

"Oh, don't talk like that!" cried Tom, as cheerfully as he could."You've got a lot of work in you yet, Rad. Hasn't he, Koku?" and theyoung inventor appealed to the giant, who seldom left the side of hisformer enemy.

"Rad good man—him an' me do lots work—next week mebby," said Koku,smiling very broadly.

"That's the way to talk!" exclaimed Tom, and he laughed a little thoughhis heart was far from light.

And then, having seen to the final details, he took his place in thebig airship with Ned, Mr. Damon and Josephus Baxter. The craft carriedthe largest possible load of fire extinguishing chemicals.

As Tom had feared, the Lucifer staggered a bit in "taking off" latethat afternoon when the start was made for the distant city of Denton,where the first real test was to be made under the supervision andcriticism of the fire department. But once the craft was aloft she rodeon a level keel.

"I guess we're all right," Tom said. But to make certain he circledseveral times over his own landing field, that a good place to comedown might be assured if something unforeseen developed.

However, all went well, and then the course was straightened for thedistant city.

"We'll go right over Newmarket, sha'n't we, Tom?" asked Ned, as thespeed of the Lucifer increased.

"Yes. And I wish I had time to stop and see Mary, but I haven't. It'sgetting dark fast, and we ought to arrive at our destination early inthe morning. The test has been set by the committee for ten o'clock."

They settled themselves comfortably in the big craft for a long nighttrip, and Mr. Damon was just going to bless something or other when hepointed off into the distance.

"Look, Tom!" cried the eccentric man. "See that light in the sky!"

"Seems to be a fire," observed Ned.

"It is a fire!" shouted Mr. Baxter. "And it's in Newmarket, if I'm anyjudge."

Tom Swift did not answer, but he shoved forward the gasolene lever ofhis controls, and the Lucifer shot ahead through the air while the red,angry glow deepened in the evening sky.

CHAPTER XXII

TRAPPED

While Tom Swift was loading the Lucifer for her trip and the fireextinguishing test to occur the next morning, quite a different scenewas taking place in the home of Jasper Blake, the uncle of Mary Nestor,where she had gone to spend a few weeks.

"Well, are you all ready, Mary?" asked her aunt, and it was about thesame time that Ned Newton asked that same question of Tom Swift. OnlyTom was in Shopton, and Mary was in Newmarket, and Tom was setting offon an air voyage, while Mary was only preparing to take a car downtownto do some shopping.

"Yes, Aunt, I'm all ready," Mary answered. "But I may be a bit lategetting home."

"Why?" asked Mrs. Blake.

"I promised Uncle Barton I'd stop and call on him at his office," Maryreplied. "He has something he wants me to take home to mother when I gotomorrow."

"I shall be sorry to see you go back," said Mrs. Blake. "But I imaginethere will be those in Shopton who will be glad to see you return,Mary."

"Yes, mother wrote that she and dad were getting a bit lonesome," thegirl casually replied, as she adjusted her veil.

"Yes, and some one else. Ah, Mary, you are a very lucky girl!" laughedher aunt, while Mary turned aside so she would not see her own blushesin the mirror.

"I thought Tom was going to call and take you home in his airship,Mary," went on her relative.

"So he is, I believe, on his way back from a city where he is going tobe tomorrow making a big fire test. I am to wait for him until tomorrowafternoon. But now I really must go shopping, or all the bargains willbe taken. Is there any word you want to send to Uncle Barton?"

"No," answered Mrs. Blake. "Though you might tell him to stop pokingfun at your Uncle Jasper for having invested money in the LandmarkBuilding. It's getting on your Uncle Jasper's nerves," she added.

"Uncle Barton never can give up a joke, once he thinks he has one,"said Mary. "But I'll tell him to stop pestering Uncle Jasper."

"Please do," urged Mary's aunt, and then the girl left.

Mary's uncle, Barton Keith, with whom Tom Swift had been associatedduring the undersea search, had offices in the Landmark Building, buthis home was in an adjoining suburb.

The girl was pleased with the results of her shopping, and at the closeof the afternoon she stopped at the Landmark Building and was soonbeing shot up in the elevator to the floor where Barton Keith had hisoffices.

Though Mr. Keith had refrained from investing in the Landmark Buildingand though he laughed at Mary's Uncle Jasper for having done so, thisdid not prevent him from having a suite of offices in the big structurewhich, as we already know, was owned in large part by Field and Melling.

"Ah, Mary! Come in!" exclaimed Mr. Keith, welcoming Tom Swift'ssweetheart. "It is so late I was afraid you weren't coming, and I wasabout to close the office and go home."

"You must blame the bargain sales for my delay," laughed Mary. "I hopeI haven't kept you waiting."

"No, I still had a few things to do. One was to write a letter to yourUncle Jasper, telling him I had heard of another fire trap that wasopen to investors."

"Oh, and that reminds me I must tell you not to push Uncle Jasper toofar!" warned Mary.

"Ha! Ha!" laughed Uncle Barton. "He made fun of me for going on theundersea search with Tom Swift. But I made good on that, and that'smore than he can say about his Landmark Building deal!"

"But don't exasperate him too much!" begged Mary. "By the way, what arethey doing to this building? I see the stairways and some of theelevator shafts all littered with building material."

"They are trying to make it fireproof," answered her uncle. "It'srather late to try that now, but they've got either to do it or stand abig increase in insurance rates. I'm glad I'm out of it. But now, Mary,take an easy chair until I finish some work, and then I'll walk outwith you."

Mary took a seat near one of the front windows, whence she could lookdown into the now fast-darkening streets. She could see the suppercrowds hurrying home, and out in the corridor of the big skyscrapercould be heard the banging of elevator doors as the office tenants, oneafter another, left for the day.

Suddenly there was more commotion than usual, followed by the sound ofbroken glass. Then came a cry of:

"Fire! Fire!"

Mary sprang to her feet with a gasp of alarm, and her uncle rushed pasther to the door leading into the hall outside his offices. As he openedthe door a cloud of smoke rushed toward him and Mary, causing them tochoke and gasp.

Mr. Keith closed the door a moment, and when he opened it again thesmoke in the hall seemed less dense.

"It probably is only a slight blaze among some of the material theworkmen are using," he said. "Come, Mary, we'll get out."

Pausing only to swing shut the door of his heavy safe and to stuff somevaluable papers into his pocket, Mr. Keith advanced and, taking Mary bythe arm, led her into the hall. The smoke was increasing again, anddistant shouts and cries could be heard, mingled with the breaking ofglass.

Mr. Keith rang the elevator buzzer several times, but when no car cameup the shaft in response to his summons he turned to his niece and said:

"We'll try the stairs. It's only ten stories down, and going down isn'tanything like coming up."

"Oh, indeed I can walk!" said Mary. "Let's hurry out!"

They turned toward the stairway, which wound around the elevatorshafts, but such a cloud of hot, stifling smoke rolled up that it sentthem back, choking and gasping for breath.

And then, as they stood there, up the elevator shafts, which wereveritable chimneys, came more hot smoke, mingled with sparks of fire.

"Trapped!" gasped Mr. Keith, and he pulled Mary back toward his officesto get away from the choking, stifling smoke. "We're trapped!"

CHAPTER XXIII

TO THE RESCUE

"Uncle! Uncle Barton!" faltered Mary, as she clung to Mr. Keith. "Can'twe get down the stairs?"

"I'm afraid not, Mary," he answered, and he closed the door of hisoffice to keep out the smoke that was ever increasing.

"And won't the elevators come for us?"

"They don't seem able to get up," was his reply. "Probably the firestarted in the bottom of the shafts, and they act just like flues,drawing up the flames and smoke."

"Then we must try the fire escapes!" exclaimed Mary, and she startedtoward the front window, pulling her uncle across the room after her.

"Mary, there aren't—aren't any fire escapes!" he said hoarsely.

"No fire escapes!" The girl turned paler than before.

"No, not an escape as far as I know. You see, this was thought to be afireproof building at first and small attention was given to escapes.Then the law stepped in and the owners were ordered to put up regularescapes. They have started the work, but just now the old escapes havebeen torn down and the new ones are not yet in place."

"Oh, but Uncle Barton! can't we do something?" cried Mary. "There mustbe some way out! Let's try the elevators again, or the stairs!"

Before Mr. Keith could stop her Mary had opened the door into the hall.To the agreeable surprise of her uncle there seemed to be less smokenow.

"We may have a chance!" he cried, and he rushed out. "Hurry!"

Frantically he pushed the button that summoned the elevators. Downbelow, in the elevator shafts, could be heard the roar and crackle offlames.

"Let's try the stairs!" suggested Mary. "They seem to be free now."

She started down the staircase which went in square turns about thebattery of elevators, and her uncle followed. But they had not morethan reached the first landing when a roll of black, choking smoke,mingled with sparks of fire, surged into their faces.

"Back, Mary! Back!" cried Mr. Keith, and he dragged the impetuous girlwith him to their own corridor, and back into his offices which, forthe time being, were comparatively free from the choking vapor.

"We must try the windows, Uncle Barton! We must!" cried Mary. "Surelythere is some way down—maybe by dropping from ledge to ledge!"

Her uncle shook his head. Then he opened the window and looked out. Ashe did so there arose from the streets below the cries of many voices,mingled with the various sounds of fire apparatus—the whistles ofengines, the clang of gongs, and the puffing of steamers.

"The firemen are here! They'll save us!" cried Mary, as she heard thenoises in the street below. "We can leap into the life nets."

"There isn't a life net made, nor men who could retain it, to hold up aperson jumping from the tenth story," said her uncle. "Our only chanceis to wait for them to subdue the fire."

"Isn't there a back way down, Uncle Barton?" "No, Mary!" He closed thewindow for, open as it was, the draft created served to suck smoke intothe office, and Mary was coughing.

Uncle and niece faced each other. Trapped indeed they were, unless thefire, which was now raging all through the building, with the stairsand elevator shafts as a center, could be subdued. That the city firedepartment was doing its best was not to be doubted.

"We can only wait—and hope," said Mr. Keith solemnly.

Mary gave a gasp. Her uncle thought she was going to burst into tears,but she bravely conquered herself and faced him with what was meant tobe a smile. But it is difficult to smile with quivering lips, and Marysoon gave up the attempt.

Mr. Keith went over to the water cooler—one of those inverted largeglass bottles—and looked to see how much water it contained.

"It's nearly full," he said.

"What good will it do?" asked Mary. "This fire is beyond a little waterlike that."

"Yes, but it will serve to keep our handkerchiefs wet so we can breathethrough them if the smoke gets too thick," was his reply.

"It begins to look as if we'd need to try that soon," said Mary, andshe pointed to thick smoke curling in under the door.

"Yes," agreed her uncle. "It's getting worse." Hardly had he spokenwhen there came a rush of feet in the corridor outside his office door.Then a voice exclaimed:

"We're trapped! We can't get down either the stairs or the elevators!"

"It can't be possible!" said another voice. "Something must be done!Help! Help! Take us out of here!"

"Foolish cowards!" murmured Mr. Keith, and then the door of his officewas violently opened and two men rushed in. They were strangers to Maryand her uncle.

"Isn't there any way out of this fire trap?" cried one of the men. "Arethere any fire escapes at your windows?"

"None," said Mr. Keith.

"This is all your fault, Melling!" cried the smaller of the two men,whose voice, in loudness and depth of pitch, was out of all proportionto his size. "All your fault! I told you we should have those new fireescapes!"

"And you were the one, Field, who objected to the cost of fire escapeswhen you found what the charge would be," retorted the other. "You saidwe didn't need to waste that money, if the building was fire-proof."

"But it isn't, Melling! It isn't!" yelled the other.

"We're finding that out too late!" came the retort. "But I'm not goingto die here like a rat in a trap!" And he raised the window and leanedout and yelled, "Help! Help! Help!"

"Don't do that," said Mr. Keith, coming over to close the casem*nt."They can't hear you down below, and opening the window will only fillthis place with smoke. Are you Field and Melling?"

"Yes, of the Consolidated Dye Company," was the answer from the bigman. "We are also part owners of this building, but I wish we weren't."

"It is a pretty poor specimen of a modern building," said Mr. Keith."You have offices here, haven't you?" he went on. "I remember to haveseen your names on the directory."

"We're on the floor above," was the answer from Field. "We were in arear room, going over some accounts, and we didn't know anything waswrong until we smelled smoke. We tried to get down, and managed tocome, by way of the stairs, as far as this floor," he explained quickly.

"You can't go any farther," said Mr. Keith. "All there is to do is towait for the firemen."

"Suppose they never come?" whined Melling. "Oh, they'll come!" assertedMary's uncle, but he spoke more to quiet her alarm than because hereally believed it, for the Landmark Building was a seething furnace offlame centering in and about the elevator shafts and stairs.

Meanwhile Tom and his companions in the airship had seen the red glowin the evening sky, and in another minute the young inventor had turnedhis craft more directly toward it.

"It surely is in Newmarket," said Mr. Damon. "Right in the center ofthe city, too. There's one big building there—the Landmark."

"Looks as if that was afire," said Ned quickly. "Hasn't some relativeof Mary's an office there, Tom?"

"Yes. Mr. Keith. And her other uncle, Jasper Blake, is also interestedin the building. It's the Landmark all right!" cried Tom, as his craftrose higher and advanced nearer the blaze.

"What are you going to do?" yelled Mr. Damon, as he saw the younginventor head directly toward a spouting mushroom of flame, whichshowed that the fire had broken through the roof. "What are you goingto do?"

"Go to the rescue!" answered Tom Swift. "I couldn't ask a betteropportunity to try my new extinguisher! Sit tight, every one!"

CHAPTER XXIV

A STRANGE DISCOVERY

Once it became evident to the occupants of the airship what Tom Swift'splans were, they all prepared to help him. Previous to the trip certainduties had been assigned to each one, duties which were to be exercisedwhen Tom gave the exhibition of his new aerial fire-fighting apparatusat the set fire before the fire department of Denton.

This preparation now stood the young inventor in good stead, for therewas no confusion aboard the Lucifer when she winged her way toward theburning Landmark Building, where the flames were continually spoutinghigher and higher as they rushed through the roof, directly above thestairway well and elevator shafts.

So far the flames had confined themselves to this central part of thebig structure, but it was only a question of time when they wouldspread out on all sides, licking up the remainder of the pile. And, forthe most part, the firemen on the ground were at a great disadvantage.

They had run in lines as near as they could get to the center of theblaze, and had also attached hose to the standpipes inside thebuilding. But this last effort was wasted, as developed later, forthere was no one in the building to direct the nozzle ends of the hoseattached to the standpipes on the different floors. Also the fierceheat fairly melted the pipes themselves in the vicinity of the elevatorshafts, and there was no automatic sprinkling system in the building.

This was the situation, then, when Tom in his airship loaded withfire-extinguishing chemicals headed for the blaze. And this, also, wasthe desperate situation that confronted Mary Nestor and her uncle,Barton Keith, as well as Amos Field and Jason Melling. Thoseunscrupulous and cowardly men were in a veritable panic of fear, whichcontrasted strangely with the calm, resigned attitude of Mary and heruncle.

"We must get out! Some one must save us!" yelled Field.

"Jump from the window!" cried Melling.

"No, I can't permit that!" declared Mr. Keith, standing in their path."It would be sure death! As it is, there may be a chance."

"A chance? How?" asked Field. "Listen to that!"

Through the closed door of Mr. Keith's office could be heard the roarand crackle of flames, while the very air was now stifling and hot,filled with acrid smoke.

"We can only wait," said Mr. Keith, and he wet Mary's handkerchief inthe water and handed it to her to bind over her face.

"Is everything all right, Ned?" called Tom, as he turned on a littlemore power, so that the Lucifer lunged ahead toward the great pillar offire that now reddened the sky for miles around.

"All ready," was the answer. "You only have to give the word when youwant us to let go."

"Let go!" cried Mr. Damon. "Bless my umbrella, Tom! We don't have tojump out, do we?"

"He means to let go the extinguisher grenades," said Mr. Baxter. "Shallwe let them all go at once, Tom?" asked the chemist.

"No, drop half when I shoot over the first time. We'll see what effectthey have, and then come back with the rest."

"That's the idea!" cried Ned. "Well, give us the word when you'reready, Tom."

"I will," was the answer of the young inventor, and with keen eyes hebegan to set the automatic gages so those in charge of the grenadeswould be able to drop them most effectively.

The flames were mounting higher and higher above the ill-fated LandmarkBuilding. It was a "land-mark" now, for miles around—a fearsome mark,indeed.

"I hope every one is out of the place," said Ned, as the airshipapproached nearer and the fierceness of the fire was more manifest.

"Bless my thermometer, you're right!" exclaimed Mr. Damon. "I don't seehow any one could live in that furnace."

Seen from above it appeared that the fire was engulfing the wholebuilding, while, as a matter of fact, only the central portion was yetblazing. But it was only a question of time when the remainder wouldignite.

And it was to this fact—that the fire was rushing up the stairway andelevator shafts as up a chimney—that Mary and her uncle, as well asField and Melling, owed their temporary safety.

Had Tom known that the girl he loved was in such direful danger, it isdoubtful if his hand would have been as steady as it was on throttleand steering wheel. But not a muscle or nerve quivered. To Tom it wasbut carrying out a prearranged task. He was going to extinguish a greatblaze, or attempt to do so, by means of his aerial fire-fightingapparatus. And his previous tests had given him confidence in hisdevice. His one regret was that the fire department of the city thatwas contemplating the purchase of certain rights in his invention couldnot witness what he was about to do.

"But they'll hear of it," declared Ned, when Tom voiced this idea tohis chum.

Nearer and nearer to the up-spouting column of flames the airshipwinged her way. Tense and alert, Tom sat at the wheel guiding his craftwith her load of fire-defying chemicals. Behind him were Ned, Mr. Damonand Mr. Baxter, ready to drop the grenades at the word.

"Getting close, Tom!" called Ned, as they could all feel the heat ofthe conflagration in the Landmark Building, which now seemed doomed.

"You'll not dare cross it too low down, will you?"

"No, I'll have to keep pretty well up," was the answer. "There's acurrent of air over that fire which might turn us turtle."

Heat creates a draft, sucking in colder air from below, and making anupward-rushing column which, in the case of a big blaze, is verypowerful. Tom knew he had to avoid this.

It was now almost time to act. In another few seconds they would besailing directly into the path of the up-spouting flames. Realizingthat to do this at too low an elevation would result in disaster, Tomsent his craft upward at a sharp angle. Then he turned to call to hiscompanions.

"Be ready when I give the word!"

"All set and ready!" answered Ned, and the others signified theirattention to the command that soon was to be given.

Having attained what he considered a sufficient elevation, Tom headedthe Lucifer straight toward the up-spouting column of fire and smoke.If ever his craft of the air was to justify her name it was now!

Straight and true as an arrow she headed for the fiery pillar! Hotterand hotter grew the air! The darkness of the night was lighted by theawful fire, which rendered objects in the street clear and distinct.But Tom and his friends had little time for such observation.

"Get ready!" cried the young inventor, as he felt a rush of heat acrosshis face, partly protected, as it was, by great goggles.

"All ready!" shouted Ned.

"Let go!" cried Tom, and with a click of springs the fire extinguishersdropped from the bottom of the Lucifer into the very heart of theflames in the Landmark Building.

There was a blast as from a furnace seventy times heated, a choking andgasping for breath on the part of the occupants of the airship, ashriveling, as it seemed, of the naked flesh, and then, when itappeared that all of them must be engulfed in the great heat, theairship passed out of the zone of fire.

A rush of cool air followed, reviving them all, and then, when out ofthe swirls of smoke, Ned, looking back, cried:

"Good work, Tom! Good work!"

"Did we hit it?" cried the young inventor. "She's half gone!" declaredMr. Baxter. "Can you give her the rest of the load?"

"I'm going to try!" declared Tom.

"Bless my bank balance!" shouted Mr. Damon, "are we going through thatawful furnace again?"

"It will not be so bad this time," observed Ned. "The fire is half outnow. Tom's stuff did the trick!"

Indeed it was evident, as Tom sent the Lucifer around in a sharp turn,that the fire had been largely smothered by the gas that now lay overit like a wet blanket. But there was still some fire spouting up.

"Give her all we have!" yelled Tom, as, once more, he prepared to crossthe zone of fire.

"Right," sang out Ned.

Once more the Lucifer swept over the burning building. Down shot theremaining grenades, falling into the mass of flames and bursting,though the reports could not be heard because of the tumult in thestreets below. For the firemen and spectators had seen the sudden dyingdown of the fire, they had caught sight of a shadowy shape in thenight, hovering over the blazing building, and they wondered what itall meant.

"How is it?" asked Tom, as he guided the craft back to get a view ofhis work.

"That settles it!" answered Ned. "There isn't fire enough now to broila beefsteak!"

This was not exactly true, for the blaze was not entirely subdued. Butthe flames had all been killed off in the higher parts of the LandmarkBuilding, and what remained could easily be dealt with by the firemenon the ground. They proceeded to make short work of the remainder ofthe conflagration, the while wondering who had so effectively aidedthem from the clouds.

"Well," observed Tom, as he saw how effectively he had smothered thegreat fire, "it's of no use to go on now. I haven't an ounce ofchemical left on board. I can't give the demonstration that I plannedfor tomorrow."

"You've given a better demonstration here than you ever could have inthe other city," declared Mr. Baxter. "I fancy this will be all thetest needed, Tom Swift!"

"Perhaps. I hope so. But we may as well land and see from the groundthe effect of our work. I'd also like to inquire if any one was hurt.Let's go down."

It was rather ticklish work, making a landing in the midst of apopulous city, and at night. But as it happened, there had been anumber of buildings razed in the vicinity of the Landmark structure,and there was a large, vacant level space. Also several of the city'sfire department searchlights were focused around the burning structure,and when it became evident that an airship was going to land—though asyet none guessed whose it was—the searchlights were turned on thevacant spot and Tom was able to make a good landing, his own powerfulsearchlight giving effective aid.

"What did you do that put out the fire?" demanded the chief of theNewmarket department, as he rushed up with a crowd of others when Tomand his friends alighted.

"I dropped a few grenades down that chimney," modestly answered theyoung inventor.

"A few grenades! Say, you must have turned a whole river of themloose!" cried the delighted chief. "It doused the fire quicker than Iever saw one put out in all my life!"

"I'm glad I was successful," said Tom. "But was any one in thebuilding?"

"Yes, a few," answered a policeman, who was trying to keep the crowdback from the airship. "They're bringing them out now."

"Killed?" gasped Tom.

"No. But some of them are badly hurt," the officer answered. "Therewas one young lady and a man named Barton Keith—"

"Barton Keith!" shouted Tom, springing forward. "Was he—Who was theyoung lady? I—I—"

But at that moment there was a stir in the crowd about the building, inwhich only a little fire flow remained, and through the throng came adisheveled and smoke-blackened young lady and a man whose clothing wasalso greatly disarrayed.

"Mary!" cried the young inventor.

"Tom!" gasped Mary Nestor. "How did you get here?"

"I came to put out the fire," was the answer, and Tom cooled down nowthat he saw Mary was unharmed. "How did you happen to be in thebuilding?"

"I was in Uncle Barton's office when the fire broke out," answeredMary, "and we were trapped. We had to stay there, with two men from thefloor above."

"Yes, and if they had stayed with us they wouldn't have been hurt,"said Mr. Keith. "But, as it was, they rushed out and tried to get downthe stairs. They were caught in the draft and badly burned, I believe.They are bringing them out now."

Two stretchers, on which lay inert forms, were borne through the nowsilent crowd by firemen and police officers, and taken to waitingambulances.

"That's Field and Melling," said Mr. Keith to Tom. "They had officesjust above me, and they were trapped, as were Mary and I. They actedlike big cowards, too, though I hope they're not badly hurt. We stayedinside my office, and we were just giving up the hope of rescue whenthe fire seemed suddenly to die down."

"I should say it was sudden!" cried the enthusiastic local chief. "Itwas the chemicals from this young man's airship that did the trick!"

"Oh, Tom, was it your new machine?" asked Mary.

"Yes," was the answer. "I was on my way to give a test tomorrow inDenton when I saw this fire. I didn't know you were in it, though,Mary."

"Oh, but I'm glad you came," she said. "It was just—awful!" and sheclung to Tom's arm, trembling.

When Field and Melling, whose rash conduct had caused them to beseverely but not fatally burned, had been taken to a hospital and thefire was declared to be practically out, Tom made arrangements to leavehis airship in the city field all night.

"And you and your friends can come to Uncle Jasper's house," said Mary.

"Of course!" said Uncle Jasper himself, who had arrived on the scene,attracted to the fire by the news that his niece and Mr. Keith were indanger. "Lots of room! Come along! We'll celebrate your rescue."

So the crew of the fire-fighting Lucifer went with Mary, while thefiremen, after again thanking Tom most enthusiastically, kept onplaying, as a precaution, their streams of water on the still hotbuilding.

Only the central portion of the structure, the stairs and elevatorshafts, were burned away. The strong upward draft had kept the firefrom spreading much to either side.

"It certainly was a fierce blaze, and I'm glad my chemicals took suchprompt effect," said Tom. "I shall not fear any test after this."

It was the day following the night of excitement, and Tom and hisfriends, at the invitation of the fire department of Newmarket, wereinspecting what was left of the Landmark Building—and there wasconsiderable left—though access to the upper floors was to be had onlyby ladders, down which Mary and her uncle, Barton Keith, had beencarried.

"Here are my offices," said Mr. Keith, who accompanied Tom, Ned, Mr.Damon and Mr. Baxter, as he ushered them into his suite of rooms.

"Bless my fountain pen! nothing is burned here," cried the eccentricman.

"No, the flames just shot upward," explained the fire chief, who wasleading the party. "But I think those chemicals of yours would havebeen just as effective, Mr. Swift, if the fire had mushroomed out more."

"It was hot enough as it was," answered Tom, with a grim laugh.

"Bless my thermometer, too hot—too hot by far!" exclaimed Tom Swift'seccentric friend, and to this Ned nodded an amused agreement.

An exclamation from Mr. Baxter attracted the attention of all in Mr.Keith's office. The chemist picked up from the floor a bundle of papers.

"Here is a bundle of documents that some one has dropped, Mr. Keith,"he said. "I guess you forgot to put it in your safe.Why—why—no—they aren't yours! They're mine. Here are my missing dyeformulae! The secret papers I've been searching for so long! The onesI thought Field and Melling had!" cried Mr. Baxter. "How—how did theyget here?" and, wonderingly, he looked at the bundle of papers he haddiscovered in such a strange manner.

CHAPTER XXV

THE LIGHT OF DAY

"What's that? Your dye formulae here in my office?" cried Mr. Keith,for he had heard something of the chemist's loss, though he did notdirectly associate Field and Melling with it.

"That's what this is! The very papers, containing all the rare secrets,for which I have been so at a loss!" cried the delighted old man. "NowI can give to the world the dyes for which it has long been waiting!Oh, Tom Swift, you did more than you knew when you put out this fire!"and he hugged the bundle of smoke-smelling papers to his breast.

"But how did they get here?" asked the young inventor. "I know thatField and Melling had offices in this building. They were starting anew dye concern, and, though Mr. Baxter and I suspected them of havingstolen his secret, we couldn't prove it."

"But we can now!" cried Mr. Baxter. "Though I don't know that I'llbother even to accuse them, as long as I have back my previous papers.I see how it happened. They had the formulae in their office. Theyrushed out with the documents, and, when they found they couldn't getpast this floor, they went into Mr. Keith's office. There, in theirexcitement, they dropped the papers, and you put the fire out just intime, Tom, or they'd have been burned beyond hope of saving. You havegiven me back something almost as valuable as life, Tom Swift!"

"I'm glad I could render you that service," said the young inventor."And I had no idea, when I dropped the chemicals, that I was savingsomeone even more valuable than your secret formulae," and they allknew he referred to Mary Nestor.

An examination of the papers found on Mr. Keith's office floor showedthat not one of the dye secrets was missing. Thus Mr. Baxter came intopossession of his own again, and when Field and Melling weresufficiently recovered they were charged with the theft of the papers.The charge was proved, and, in addition, other accusations were broughtagainst them which insured their remainder in jail for a considerableperiod.

As Mr. Baxter had suspected, Field and Melling had, indeed, robbed himof his dye formulae papers. They learned that he possessed them, andthey invited him to a night conference with the purpose of robbing him.The fire in their factory was an accident, of which they took advantageto make it appear that the chemist lost his papers in the blaze. Butthey had taken them, and though they did not mean to leave poor Baxterto his fate, that would have been the result of their selfish actionhad not Tom and Ned come to the rescue. And it was of this "puttingover" that Field and Melling had boasted, the time Tom overheard theirtalk at Meadow Inn.

As Mr. Baxter guessed, the letter delivered to him at Tom's place wasone that the two scoundrels would have retained, as they had otherslike it, if they had seen it. But a new clerk forwarded it, and theevidence it contained helped to convict Field and Melling.

As for the Landmark Building, while badly damaged, it would have beenworse burned but for Tom's prompt action. And though he was more thanglad that he had been on hand, he rather regretted that he could notgive the test for which he had set out.

Eventually the building was made more nearly fire-proof and thefire-escapes were rebuilt, and Mr. Blake did not lose his money, as hehad feared, though Barton Keith said it was more owing to Tom Swift'sgood luck than to Mr. Blake's management.

But, as it developed, nothing could have been more opportune than Tom'saction, for word of his quenching a bigger blaze than he would have hadto encounter in the official test reached the Denton fire department.As a result there was a conference, and, after only a nominal showingof his apparatus, it was adopted by a unanimous vote.

But this occurred some time afterward, for, following his rescue ofMary Nestor and her uncle and the saving of the lives of Field andMelling, as well as others in the building, by his prompt smothering ofthe fire, Tom returned to Shopton.

He and his companions went in the Lucifer, minus, now, the big load ofchemicals, and on landing near the hangar Tom was surprised to see Kokuthe giant running toward him. The big man showed every symptom of greatexcitement as he cried:

"Oh, Master Tom! He see the light ob day! he see the light ob day now!Oh, so glad! So glad!"

"Who sees the light of day?" asked the young inventor.

"Black Rad! Eradicate! Him eyes all better now! Pill man take offcloth. Rad—he see light ob day!"

"Oh, I'm so glad! So thankful!" cried Tom. "How I've wished for this!Is it really true, Koku?"

"Sure true! Pill man say Rad see K O now." The giant, doubtless, meant"O K," but Tom understood. And it was true, as he learned more directlya little later.

When Tom entered the room where Rad had been kept in the dark eversince the explosion, the colored man looked at his master with seeingeyes, though the apartment was still but dimly lighted.

"I's all right ag'in now, Massa Tom!" cried Rad. "See fine! I's allready to make more smellin' stuff to put out fires!"

"You won't have to, Rad!" cried Tom joyfully. "My chemical extinguisheris completed, and you did your share in making it a success. But Inever would have felt like claiming credit for it if you had been—hadbeen left in the dark."

"No mo' dark, Massa Tom!" said Eradicate. "I kin see now as good aseber, an' yo'-all won't hab to 'pend on dat lazy good-fo'-nuffincocoanut!" and he chuckled as he looked at the giant.

"Huh! Lazy!" retorted the big man. "I show you—black coon!"

"By golly!" laughed Rad. "Him an' me good friends now, Massa Tom. NeberI fuss wif Koku any mo'! He suah was good to me when I had to stay inde dark!"

Of course it would be too much to hope that Koku and Eradicate neveragain quarreled, but for a long time their warm friendship was a thingat which to marvel, considering the past.

"Well, I guess this settles it," said Tom to Ned one day, after goingover the day's mail.

"Settles what, Tom?"

"My aerial fire-fighting apparatus. Here's word from the National FireUnderwriters Association that they have adopted it, and there will be abig reduction of rates in all cities where it is a part of the firedepartment equipment. It's been as great a success as Mr. Baxter's newdye."

"Yes, and he has had wonderful success with that. But what are yougoing to do now, Tom? What new line of endeavor are you going to aimat?"

Tom arose and reached for his hat.

"I am now going," he said, with a grin, "to see somebody on privatebusiness."

"You are going to see Mary Nestor!" broke out Ned.

"I am," said Tom.

And he did.

THE TOM SWIFT SERIES

By VICTOR APPLETON

Uniform Style of Binding. Individual Colored Wrappers. Every VolumeComplete in Itself.

Every boy possesses some form of inventive genius. Tom Swift is abright, ingenious boy and his inventions and adventures make the mostinteresting kind of reading.

TOM SWIFT AND HIS MOTOR CYCLE
TOM SWIFT AND HIS MOTOR BOAT
TOM SWIFT AND HIS AIRSHIP
TOM SWIFT AND HIS SUBMARINE BOAT
TOM SWIFT AND HIS ELECTRIC RUNABOUT
TOM SWIFT AND HIS WIRELESS MESSAGE
TOM SWIFT AMONG THE DIAMOND MAKERS
TOM SWIFT IN THE CAVES OF ICE
TOM SWIFT AND HIS SKY RACER
TOM SWIFT AND HIS ELECTRIC RIFLE
TOM SWIFT IN THE CITY OF GOLD
TOM SWIFT AND HIS AIR GLIDER
TOM SWIFT IN CAPTIVITY
TOM SWIFT AND HIS WIZARD CAMERA
TOM SWIFT AND HIS GREAT SEARCHLIGHT
TOM SWIFT AND HIS GIANT CANNON
TOM SWIFT AND HIS PHOTO TELEPHONE
TOM SWIFT AND HIS AERIAL WARSHIP
TOM SWIFT AND HIS BIG TUNNEL
TOM SWIFT IN THE LAND OF WONDERS
TOM SWIFT AND HIS WAR TANK
TOM SWIFT AND HIS AIR SCOUT
TOM SWIFT AND HIS UNDERSEA SEARCH
TOM SWIFT AMONG THE FIRE FIGHTERS
TOM SWIFT AND HIS ELECTRIC LOCOMOTIVE
TOM SWIFT AND HIS FLYING BOAT
TOM SWIFT AND HIS GREAT OIL GUSHER
TOM SWIFT AND HIS CHEST OF SECRETS
TOM SWIFT AND HIS AIRLINE EXPRESS

THE DON STURDY SERIES

By VICTOR APPLETON

Individual Colored Wrappers and Text Illustrations by WALTER S. ROGERSEvery Volume Complete in Itself.

In company with his uncles, one a mighty hunter and the other a notedscientist, Don Sturdy travels far and wide, gaining much usefulknowledge and meeting many thrilling adventures.

DON STURDY ON THE DESERT OF MYSTERY;

An engrossing tale of the Sahara Desert, of encounters with wildanimals and crafty Arabs.

DON STURDY WITH THE BIG SNAKE HUNTERS;

Don's uncle, the hunter, took an order for some of the biggest snakesto be found in South America—to be delivered alive!

DON STURDY IN THE TOMBS OF GOLD;

A fascinating tale of exploration and adventure in the Valley of Kingsin Egypt.

DON STURDY ACROSS THE NORTH POLE;

A great polar blizzard nearly wrecks the airship of the explorers.

DON STURDY IN THE LAND OF VOLCANOES;

An absorbing tale of adventures among the volcanoes of Alaska.

DON STURDY IN THE PORT OF LOST SHIPS;

This story is just full of exciting and fearful experiences on the sea.

DON STURDY AMONG THE GORILLAS;

A thrilling story of adventure in darkest Africa. Don is carried over amighty waterfall into the heart of gorilla land.

THE RADIO BOYS SERIES (Trademark Registered)

By ALLEN CHAPMAN

Author of the "Railroad Series," Etc.

Individual Colored Wrappers. Illustrated. Every Volume Complete initself.

A new series for boys giving full details of radio work, both insending and receiving—telling how small and large amateur sets can bemade and operated, and how some boys got a lot of fun and adventure outof what they did. Each volume from first to last is so thoroughlyfascinating, so strictly up-to-date and accurate, we feel sure all ladswill peruse them with great delight.

Each volume has a Foreword by Jack Binns, the well-known radio expert.

THE RADIO BOYS' FIRST WIRELESS
THE RADIO BOYS AT OCEAN POINT
THE RADIO BOYS AT THE SENDING STATION
THE RADIO BOYS AT MOUNTAIN PASS
THE RADIO BOYS TRAILING A VOICE
THE RADIO BOYS WITH THE FOREST RANGERS
THE RADIO BOYS WITH THE ICEBERG PATROL
THE RADIO BOYS WITH THE FLOOD FIGHTERS
THE RADIO BOYS ON SIGNAL ISLAND
THE RADIO BOYS IN GOLD VALLEY

THE RAILROAD SERIES

By ALLEN CHAPMAN

Author of the "Radio Boys," Etc.

Uniform Style of Binding, illustrated. Every Volume Complete in Itself.

In this line of books there is revealed the whole workings of a greatAmerican railroad system. There are adventures in abundance—railroadwrecks, dashes through forest fires, the pursuit of a "wildcat"locomotive, the disappearance of a pay car with a large sum of money onboard—but there is much more than this—the intense rivalry amongrailroads and railroad men, the working out of running schedules, thegetting through "on time" in spite of all obstacles, and themanipulation of railroad securities by evil men who wish to rule orruin.

RALPH OF THE ROUND HOUSE;
Or, Bound to Become a Railroad Man.

RALPH IN THE SWITCH TOWER;
Or, Clearing the Track.

RALPH ON THE ENGINE;
Or, The Young Fireman of the Limited Mail.

RALPH ON THE OVERLAND EXPRESS;
Or, The Trials and Triumphs of a Young Engineer.

RALPH, THE TRAIN DISPATCHER;
Or, the Mystery of the Pay Car.

RALPH ON THE ARMY TRAIN;
Or, The Young Railroader's Most Daring Exploit.

RALPH ON THE MIDNIGHT FLYER;
Or, The Wreck at Shadow Valley.

RALPH AND THE MISSING MAIL POUCH;
Or, The Stolen Government Bonds.

THE RIDDLE CLUB BOOKS
By ALICE DALE HARDY

Individual Colored Wrappers. Attractively Illustrated. Every VolumeComplete in Itself.

Here is as ingenious a series of books for little folks as has everappeared since "Alice in Wonderland." The idea of the Riddle books is alittle group of children—three girls and three boys decide to form ariddle club. Each book is full of the adventures and doings of thesesix youngsters, but as an added attraction each book is filled with alot of the best riddles you ever heard.

THE RIDDLE CLUB AT HOME

An absorbing tale that all boys and girls will enjoy reading. How themembers of the club fixed up a clubroom in the Larue barn, and howthey, later on, helped solve a most mysterious happening, and how oneof the members won a valuable prize, is told in a manner to pleaseevery young reader.

THE RIDDLE CLUB IN CAMP

The club members went into camp on the edge of a beautiful lake. Herethey had rousing good times swimming, boating and around the campfire.They fell in with a mysterious old man known as The Hermit of TriangleIsland. Nobody knew his real name or where he came from until thepropounding of a riddle solved these perplexing questions.

THE RIDDLE CLUB THROUGH THE HOLIDAYS

This volume takes in a great number of winter sports, including skatingand sledding and the building of a huge snowman. It also gives theparticulars of how the club treasurer lost the dues entrusted to hiscare and what the melting of the great snowman revealed.

THE RIDDLE CLUB AT SUNRISE BEACH

This volume tells how the club journeyed to the seashore and how theynot only kept up their riddles but likewise had good times on the sandand on the water. Once they got lost in a fog and are marooned on anisland. Here they made a discovery that greatly pleased the folks athome.