THE BOY SCOUTS OF THE FLYING SQUADRON by Scout Master Robert Shaler



CONTENTS

CHAPTERS I. The Two Wolf Patrol Boys II. A Camp Supper III. The Mysterious Explosion IV. Reading a "Sign" by Torchlight V. The "Fool-Proof" Aeroplane VI. A Red Letter Day in the Woods VII. Bud's Meteor VIII. Uncle Sam's Flying Squadron IX. Friends in Khaki X. Up in a War Monoplane XI. Good-By to the Foreign Spies XII. Home Again



CHAPTER I

THE TWO WOLF PATROL BOYS

"I want to own up that I'm pretty nearly all in and done for!"

"Same here, Bud. The going was tough over that frozen side of old Stormberg mountain. Then we are carrying such loads into the bargain."

"For one, I'm glad we are nearly there, Hugh."

"Yes, another steady pull and we ought to strike the shanty. We aimed to get to it by nightfall, you remember, Bud."

"Yes, and after eating such a big Thanksgiving dinner, we've been pretty spry to accomplish all we have. Why, I haven't had a pull anything like this since we broke camp last summer up at Pioneer Lake!"

"And we never could have done it only for the lift we got from Farmer Badgely, going home from market. That put us some miles on the way. If you've rested enough, Bud, perhaps we would better be on the move again. The sun is getting close to the diving line, you notice."

"Here goes, then!"

With these words Bud Morgan, first-class scout and one of the leading boys in the Wolf Patrol, inserted his arms in the loops of the pack he was handling, and managed to heave it on to his sturdy back.

His companion did likewise, for each of them was "toting" much more than the customary amount of luggage that a scout on the hike would carry with him.

This comrade was an agile chap, about the same weight as Bud, but with a wide-awake expression on his face that let everybody know in the start that he was one of those born leaders who forge to the front through circumstances often beyond their control.

Hugh Hardin was not only leader of the Wolf Patrol. Sometimes he had been deputized to act in place of the regular scout master of the troop, when Lieutenant Denmead and Assistant Rawson chanced to be called away and could not serve. So well had Hugh carried out his task on such occasions, it was generally accepted as a foregone conclusion that in case the latter officer resigned, as he had lately given hints of doing, Hugh would be elected in his stead. There might be a few boys in the troop, now consisting of four patrols, who would prefer to see Alec Sands, leader of the Otters, placed in that elevated position, but his popularity was confined to his particular chums, while that of Hugh embraced members of every patrol.

On this day, Hugh and Bud had started from home immediately after partaking of a glorious Thanksgiving feast. As all preparations had been made for this trip up into the wilderness many miles above the home town, it was evident that they had a particular object in view; which, in fact, was the case.

Bud Morgan was rather given to conjuring up new and sometimes startling inventions. These he usually tried upon some of his mates and not always in a fashion to add to their peace of mind, either. On more than one occasion in the past they had been suddenly confronted by some innovation that for the moment rather demoralized the valiant wearers of the scout khaki.

Bud had not been very successful in his wonderful inventions. They were apt to disappoint him in the severe testing out. Theory might be all very well, but when it came to practice there was generally a screw loose in his figuring that could not be tightened; and, in consequence, trouble often perched on Bud's shoulders.

During the late summer and early autumn he had been working on some idea that seemed to have taken hold of his mind to a greater extent than any previous effort had ever done. His chums knew of it, but no one had been able to coax Bud to let them share his confidence.

When the time came that Bud could not contain his secret any longer, he had gone to the leader of his patrol and confessed. At the same time he managed to interest Hugh to such an extent that the other promised to go off with him during the few days of grace granted by the school authorities around "turkey-eating time" in late November, so as to give his new invention at least a fair trial.

And this was why they had started so soon after the annual big dinner, which fact in itself spoke volumes for the grit and determination of the two lads. Few boys would have been in condition to walk three miles during the balance of the day.

They knew one fellow at least, Billy Worth, also a Wolf scout, who was so fond of eating that doubtless at this very moment he was stretched out at full length on the sofa in his den at home, trying to figure how ever he could partake of supper after disposing of such a stupendous amount of turkey and fixings.

In the previous stories of this series, the reader who may have been fortunate enough to peruse them has come to know both Hugh and Bud pretty well. They have been followed through many adventures calculated to prove their worth as scouts, and, taken on the whole, it will be admitted that in most cases the boys carried off the honors. In the Wolf patrol, as well as among the Otters, Hawks, and Foxes, there were other lads who were also animated by the same sort of progressive spirit, and who never allowed an opportunity to improve their minds or to broaden their knowledge of Nature escape them.

After taking up their heavy burdens again, Hugh and his comrade walked on for some time through the woods. The leaves were well off the trees, though the oaks still held their brown mantle, being the very last to shed their summer coat. It had frozen quite hard for several nights previous, and some of the town boys had cherished vague hopes that there might be ice for the Thanksgiving holidays, a custom that used to prevail years before, according to the accounts given by their parents. As yet, however, only a covering an inch or so thick had settled on the ponds, and of course the running river showed no signs of congealing, so that skating would have to be postponed to a later date.

Around the two scouts there lay a complete wilderness of trees. Had they searched high and low it is doubtful whether they could have found a more lonely spot within twenty miles of home.

Stormberg Mountain, on which many of their previous adventures had taken place, reared its peak on the right; and Rainbow Lake was within two miles of their present location. In selecting this place for their little outing, Bud had probably figured that the chances of their being disturbed or spied upon by any of the curious town boys would be very slight. And, like all modest inventors, Bud was very shy about showing off until he could be certain that he had actually something worth talking about to display.

The sun had seemed to hesitate upon the horizon, but now it took a sudden dip below the earth's rim, and Bud exclaimed:

"Say, did you see the sun just slide out of sight then, as though he was ashamed to leave us in the dark? This place has all grown up since I was here last, so I hope we'll get to the shack before night really sets in."

"We will all right, Bud, so don't worry any," laughed Hugh, whose aim it seemed to be to take things as philosophically as possible, especially when they could not be changed. "Right now I'm beginning to recognize some familiar things around us. There is that chestnut that has thrown out three young suckers. When it gets big, it will make a land-mark worth talking about. I noticed it the last time I was through these woods."

"Yes, like as not," grumbled Bud, who was very tired, "if the old chestnut bug that's killing all the trees in the next county doesn't get up here next year and put the kibosh on our fine nut trees for keeps. Oh! look at that rabbit spin out of that brush pile! He's on the jump, let me tell you! Hugh, I'm beginning to recognize some things around here, too, that I remember must have been close to the shack. There's the meadow clearing that I had in my mind when choosing to come away up here to try out my latest wonder. Yes, and as sure as anything, I can hear the singing of that little waterfall just below the big spring."

"It seems to tell me that I'm thirsty enough to stop and get a drink before going on. The shack lies just back of that screen of trees and bushes, anyway," Hugh remarked, as he turned slightly aside and headed directly toward the quarter from whence that melodious song arose.

Apparently Bud was of the same mind, for he instantly followed suit. In another minute both scouts had deposited their packs on the hard ground and were kneeling at the rim of the little basin where the clear water, bubbling up from the sand, ran away in a busy stream that as yet had not felt the chilling hand of Jack Frost.

Each boy produced a collapsible metal cup with which he could dip into the sparkling spring. This is a much better way than bending down and sucking in great quantities of water, without knowing what impurities may be swallowed. Some scouts on their tramps even carry a small filtering stone such as is used in the army, and this is considered a wise precaution by thoughtful scout masters.

"Well, that tastes pretty fine," remarked Bud, after he had drunk his fill and carefully replaced his cup in its receptacle; "and now to get under cover. I reckon the very first thing we ought to attend to is getting a supply of wood indoors, so as to make the old shanty feel comfortable. I never think of a camp without seeing a camp fire as the best thing in it. It is that that binds scouts together more than any other part of the outdoor game, I think. Does it strike you that way, too, Hugh?"

"Yes, I came to that conclusion," replied the leader of the Wolf patrol, "after watching how anxious the boys always were to get plenty of fuel ready long before night came. Then you know a fire stands for grub time, too, and that always appeals to scouts who have done lots of things during the day to tire themselves out."

"That's so, I've had heaps of fun just watching Billy Worth's eyes dance while he hauled firewood into camp. With every armful he seemed to be saying, 'There, that's going to help cook our supper to-night! And we're going to have fried onions, and potatoes and ham omelette!' I had half a notion to ask Billy to come along with us on this trip, but somehow I hated to think of the fun he'd poke at me in case my wonderful invention turned out to be a fizzle, like so many of them have in the past. I knew you wouldn't give me away, Hugh, if that happened,—-and if I lived to tell the tale! Well, I hope I can get my pack on my back again for the last hundred feet; but it comes harder every time. Thanks awfully for the poke, Hugh; it did the business. Now I'm in harness and ready to go on."

The two weary scouts staggered more or less as they started to push through the last barrier of trees and brush. They knew that they would speedily discover the long deserted shack there among the second growth thicket of young trees. Indeed, it was hardly half a minute later when Bud came to a sudden halt, at the same time saying in a hoarse whisper:

"Hugh, look there, will you? There's a light in the shanty! What do you think of the meanness of that? After we've come all the way up here just to keep to ourselves, then to find somebody camping on the ground! Shucks! It makes me feel as if it was a bad omen, and right in the start, too!"



CHAPTER II

A CAMP SUPPER

The two boys stood there looking for a full minute. Hugh had discovered the presence of a light in the cabin about the same time that Bud mentioned the fact. It could be seen shining through the aperture that had once been used as a window. There was no glass in this now, and a heavy shutter, hung on rusty hinges, gave the only means of keeping out the cold air, though this had not been closed by the unknown party within.

"Whoever can it be?" muttered the disgusted Bud, doubtless begrudging that long tramp from the road where the friendly farmer had dropped them.

"Perhaps some one who's thinking of using the old shanty as headquarters while trapping this season," Hugh replied. "You know Ralph Kenyon used to take quite a lot of pelts around this region before he joined the scouts and changed his mind about that sort of thing."

"Then you don't think it could be a hobo?" queried Bud with a relieved vein in his voice.

"Well, tramps nearly always stick close to the railroads, you know," the other observed with the air of one who had made it a point to take note of such happenings; "and besides, what hobo would think of wandering away up here so far from a base of supplies? But we can settle all that easy enough, Bud."

"By going on and breaking in on him, you mean?" questioned the other eagerly.

"Yes, though perhaps first of all we'd do well to creep up and take a look in at that opening. A scout should be sure of his ground before he takes a leap. It isn't always so easy to go back again."

"All right, Hugh, let's start right in and have a squint at him. Seems to me I get a whiff of cooking, don't you?"

"Yes, I noticed that, Bud; and also that he's got a fire burning in there. You can see it flicker, and that wouldn't happen if the light came from a lantern, or even from a torch."

"Smells good, too. That fellow knows how to cook, whoever he is," remarked the other scout, sniffing eagerly at the air as he spoke. Hours had passed since dinner-time and they had had a hard tramp.

They advanced quickly though cautiously. Their hearts were beating faster than usual, perhaps because they had been carrying heavy loads. Then again there was a chance that the moment's excitement had considerable to do with the quickening of their pulses.

Arriving alongside the wall of the lonely cabin that had been built many years before by a man who meant to start a farm up in this region, the boys hastened to glue their eyes to the opening.

What they saw astonished them and at the same time relieved their feelings. There was but a single occupant of the cabin, and he a boy about their own age, also dressed in the khaki uniform of a scout. He was busily engaged in cooking some supper, and apparently did not suspect the presence of any one near by.

"Why, it's Ralph Kenyon!" gasped Bud. "Whatever can he be doing all by himself up here?"

Hugh could give a guess. He knew that in times past the young chap in question had made it a practice to trap the little wild animals that might still be found in the woods and swamps of that region, for the sake of the money he could get for their fine furry pelts. This was before he joined the scouts, which was soon after valuable ore had been discovered on the Kenyon farm and a strip of land sold to the railroad, these transactions placing the family on a secure financial foundation.

Evidently as the cold weather came on, Ralph had been tempted to wander over to his old stamping-grounds, not to set traps as of yore or shoot any of the timid woods' animals for the sake of their warm coats, but just to revive old recollections.

He had evidently fetched his double-barrel shotgun along with him, since it stood in a corner; and he was evidently cooking a brace of fat quail which he must have managed to knock down on his trip up here.

From the way he cocked his head just then it seemed as though Ralph must have thought he had heard some strange sound. Perhaps Bud had spoken louder than he had meant to do. But then there was no need of further holding back. Ralph was a member of the same troop as themselves, and while perhaps Bud would have preferred not increasing the number of witnesses to his own triumph or rank failure, he saw that it could not be helped. And Bud was one of those who can make the best of a bad bargain. Besides, Ralph was a good fellow, and generally well liked by his companions.

Instead of calling out and telling the boy inside the shack that a couple of weary wayfarers had arrived and meant to join him, Hugh saw fit to give the recognized signal of the Wolves: "How-oo-oo!" twice repeated.

Then as Ralph sprang to the door to take away the prop with which he had secured it, Hugh and Bud pushed into the interior of the cabin.

Ralph stared at them but seemed decidedly pleased, for he instantly thrust out his hand in friendly greeting.

"Well, well, who'd think you would drop in on me as if you came from the skies?" he was saying as he worked Hugh's arm like a milkman's pump handle. "You see, I've been coming out here for several years every Thanksgiving afternoon to set my first traps of the season; and while I don't expect ever to do it again, I just couldn't keep from spending one night in the woods to revive old recollections. But I'm tickled to death at the idea of having company, for it does get mighty lonesome sometimes. Whatever are you doing up here, Hugh and Bud?"

So, as Hugh waited for his companion to explain, Bud began to tell how he had been up to his old tricks again and believed that he had invented something that was going to be a stunning success; also, that he had coaxed accommodating Hugh to go off with him in order to try it out in secret.

"Of course, since we find you in possession of the shanty where we meant to put up for one or two nights," Bud continued, with a grin, "why, I'll have to let you share my secret tomorrow when we start to try it out. Till then don't ask questions and I'll tell you no lies. And I want to inform you right now that what you're cooking for supper sets my nerves on edge, it smells so good."

"That's lucky," remarked Ralph, "for I have just four more fat juicy quail on hand. I made a double shot into a covey that got up in the brush. If you fellows say the word, I'll start right away to get them ready for the pan."

"You'll do nothing of the kind," chuckled Hugh, who, like Bud, had deposited his burden in a corner, "we're only too glad of a chance to help pluck a few feathers ourselves. It's enough that you make us a present of what you meant probably to take home to your mother."

"Oh! I can get others later on," observed Ralph, as he pointed to the little heap of brown and black feathers which marked the spot where the unused birds lay. "You see, she's not feeling very well, my mother, I mean, and somehow quail on toast always appeals to her. But while you're working there, let me make more coffee. Have you got cups and such things along in your packs, boys?"

"We have," declared the overjoyed Bud; "and this bird is just prime; never saw a fatter one, I declare. Say, Hugh, we didn't expect such a bully treat as this, did we, when we aimed to get here in time to cook supper?"

Preparations progressed rapidly. As Ralph had already stowed away quite a large quantity of wood for use during the night, that labor was spared the two late arrivals, which fact pleased Bud very much. He could work as hard as the next one when interested in what he was doing, but gathering fuel had never appealed to him in the same way it did to Billy Worth, who was all the time figuring out what splendid things the wood could be used to cook.

As the three boys sat around eating the evening meal, they chatted in a lively manner. Hugh told how he and Bud had had a fine lift by means of the farmer's wagon, and then continued:

"I suppose you started this morning, and on that account missed your Thanksgiving turkey, Ralph? But you said your mother was not feeling well; and so perhaps the feast has been postponed at your house to a more convenient time?"

"Just what it has," replied the other. "You see my married sisters are expected home on Saturday night, and so mother decided to let the big dinner go until Sunday, when we'll all be together again. I just took a snack to munch on at noon, and brought some things to cook. I got here two hours back, and had plenty of time to fix things as I wanted them for my one night out."

"Perhaps you'll make it two, if we decide to stay that long, eh, Ralph?" asked Bud, who was feeling much more warmly toward the other since partaking of the delicious quail. "You see, we've got plenty of rations along for three, and you'd be as welcome to share with us as a shower in June."

"I'll see about that to-morrow afternoon, Bud," replied the other. "But before I forget it, I want to tell you boys about a couple of queer men I happened to see while coming through the woods not more than a mile or so away from here."

"P'raps timber prospectors" suggested Hugh; "I've known of such men to come up in this region trying to spy out new fields for operating their destructive saw-mills. Somehow I hate to see the forest wiped out that way. A tree takes some hundreds of years to mature, and then it goes down in a heap, to be sawed up into boards. It seems like a shame to me every time I think of how the timber is disappearing. I believe in the work of the Forest Reserve Board. It's high time this country began to think of keeping what it's got before everything is lost. But tell us about these men that you saw. They were not tramps, Ralph?"

"Oh, no, they were dressed too well for that," replied the other quickly. "I happened to sight them in time to duck behind a tree, and they never once suspected that anybody was near. One was a tall, thin man, a German, I thought, while the other was dark and short,—-fact is, I took him for a Chinese, a Japanese or a Korean from the color of his skin and his black bristling hair."

"That sounds interesting, anyway!" commented Bud. Then he added with a little amused laugh, "P'raps they've heard in some mysterious way, Hugh, how a celebrated young inventor named Bud Morgan means to try out his latest wonderful stunt, and they hope to steal the concrete result of his budding genius. But go on, Ralph. What did they do that looked suspicious?"

"Oh! their every action struck me as queer," Ralph continued. "You see they talked in a low voice, put their heads close together, looked all around as if they were afraid some one might be watching them, and then moved off, always turning to the right and to the left. You know when valuable iron ore was discovered on our farm, for a long time afterward strange men came prowling around there. It struck me these fellows might be looking for something like that."

"Perhaps they're really civil engineers, meaning to run a line across here in order to straighten the railroad and save time on through trains," Hugh suggested, leaning back after finishing his meal.

"That might account for it," Ralph admitted, "though they acted mighty strange to me. I never let out a peep till they'd disappeared from sight; and even then I thought it best to change my line of advance for fear that I might stumble on the precious pair again. Really now, I'd give a cooky to know just who and what they are, and why they've come away up here where only charcoal burners can be met as a rule."

Bud had opened his mouth to make some remark, sighing to think how he was utterly unable to eat another bite, when there was a sudden vivid flash as of lightning without that startled all the scouts; and immediately following came a tremendous roar similar to a clap of nearby thunder!



CHAPTER III

THE MYSTERIOUS EXPLOSION

"Wow! that was a stunner all right!" exclaimed Bud. "Why, honest, I could feel the ground shake under me when that thunder clap came! And as I happened to be looking over there where the opening lies, the flash nearly blinded me."

"Lightning and thunder in November is something you don't often meet," was the comment of Ralph, turning a perplexed face toward Hugh, as though depending on the leader of the Wolf patrol to solve the puzzle.

Without saying a word, Hugh jumped to his feet and went outside to take a look around. He came back almost immediately, and his face told them that his investigation instead of clearing up the mystery had only added to it.

"What did you find out, Hugh?" questioned Bud.

"Not a single cloud to be seen in all the sky!" said the other impressively.

"Whew! that seems queer, doesn't it?" faltered Bud.

"And it must be almost down to freezing, into the bargain," added the patrol leader. "I've seen lightning before, in February even, but always during a thaw. Fact is, boys, I can't believe that it was either lightning or thunder we saw and heard."

"But, Hugh, what could it have been then?" demanded Ralph.

"If we were nearer the granite quarries, I'd say they had set off an extra big blast. You know we sometimes hear a faraway boom over home. Sound travels many miles when there's a sub-strata of rock like a ledge to act as a conductor."

"Yes, but then I understood work had stopped there for the season the Saturday before Thanksgiving," volunteered Bud. "Still, they may be doing some blasting, just to keep things moving as long as the snow holds off. If that was a blast of dynamite, it must have been a stunner to make the earth quiver so much."

Hugh made no reply. Plainly he was deeply impressed with the mysterious nature of the unannounced explosion. And when once Hugh started to find out what things meant, he seldom let the matter drop until he had accomplished his purpose.

Bud also went to the door and looked out, his curiosity having been duly aroused. Hence he did not hear Ralph make a significant admission.

"Now that I come to think of it," the other remarked, "for the last two nights I can remember hearing a distant, dull sound that I thought was a heavy blast off in this quarter. I chanced to be outdoors each night about ten o'clock. It's come much earlier this time, it seems; but, anyhow, that is getting to be a regular nightly performance I wonder if they are working over in the granite quarries? I'm something of a sticker when anything bothers me like this, and for three cents I'd take a turn over that way to-morrow just to satisfy my mind."

"I was wondering whether those two men you saw could have had anything to do with that queer crash and flash?" suggested Hugh slowly.

"Ginger! I wonder now!" exclaimed Ralph, who apparently had not thought to connect the pair of strangers with the mysterious goings-on. "But they didn't seem to have anything along with them at that time. I remember seeing the taller man take something out of his pocket and examine it, Hugh; and at the time it struck me the shiny object looked mighty like one of these modern automatic pistols."

Hugh shook his head as though, try as he would, as yet he could see no way of solving the puzzle. Just then Bud came back, having fixed the door the same way he had found it, with the loose board used as a prop to keep it in position.

"Just as you said, Hugh," he announced, "it's clear as a bell, with a young moon hanging low in the western sky and the stars shining like all get-out. No siree, thunder never yet was heard on a night like this. So I guess it must have been a blast. They do say dynamite shakes the ground a heap more than powder, because its force is always directed downward. If you put a cartridge on top of a big rock and fire it, the boulder is shattered to pieces. Powder you've got to put underneath every time."

"Correct, Bud, you go up to the head of the class," laughed Hugh.

"I wanted to ask Ralph if when he used to camp around here last winter he ever knew the air to be clear enough to hear the noise of the mill over at town?"

"Why, it's a good many miles away," returned Ralph, "and I don't know that I ever did hear what you say. But what makes you ask that, Bud?"

"Oh! the atmosphere must be doing its prettiest then, to-night," came the answer. "While I was standing just outside the door I could hear the plain rattle of the machinery, though it died away quick enough. I understand that business is so good that they're running a night shift at the mills. And sounds can be heard a long way off after sunset, can't they, Hugh?"

"That's all as true as anything, Bud, though if you'd asked me my opinion before you spoke, I would have said it was foolish to think we could hear the mills so far away as this, no matter how clear the frosty air might be."

"Well, that may be," remarked the other boy doggedly; "but I did hear machinery pounding away at a right merry pace, give you my word on that. I even stepped out further and looked around, but there wasn't a thing in sight, only the stars shining up there and the little horned moon dropping down close to the horizon."

"We came up here thinking we'd be all alone and could do what we'd planned without being interrupted," observed Hugh, "but seems as though we've dropped on the queerest sort of a mystery the very first thing. And as scouts always stand to investigate what they don't understand, I reckon we'll have our hands full prying into this thing."

"But don't let it make my affairs take second place, Hugh," pleaded Bud. "What if some fellow does happen to be using up explosives by the cartload, that oughtn't to interfere with the trying out of the little invention which the brain of a Morgan has conjured up, and which, if successful, will be a blessing to science, as well as to aviators in particular."

Ralph pricked up his ears at hearing these last few words. No doubt they set him to wondering what Bud had invented now; but the latter did not take the time or trouble to let him into the secret, so Ralph just had to possess his soul in patience.

"You needn't think that I'll let anything drag me away from the first object of our trip up here, Bud," soothed the patrol leader, who knew how deeply in earnest his chum was. "But it may be that we'll find the time to look into this other business, too. If more shocks come that are as bad as that one was, we're not apt to get much sleep to-night, boys."

"Then here's hoping they'll stay away," wished Bud. "Why, a few more shocks like that would start all my joints loose, I do believe! Could that have been a meteor bursting, do you think, Hugh?"

"Well, that's a new idea," admitted the other, "and one that didn't come to me, I'll own up. A meteor can fall at any old time, day or night, though we only see them shooting after dark sets in. When one of these fragments of fused metal and slag does rush toward the earth and bury itself in the ground, it makes just such a brilliant flash. Some say there is a fearful crash when it strikes. Stranger things have happened, I take it, Bud, than to believe that was a falling meteor of a pretty good size."

"But don't shooting stars generally fall in the summer time, Hugh?" questioned Bud.

It had become a habit with most of the scouts to ask the Wolf leader any and all sorts of questions, as though he might be looked upon as a walking encyclopedia or dictionary; and it kept Hugh pretty busy accumulating information in order to be well posted for these constant demands on his time and patience.

"Yes, I believe the earth does pass through the greatest showers of meteors in August, but then there are lots of them loose at any time. I've read of some remarkable ones being dug out of the earth in various places. If this should prove to be a big meteor and we could find where it struck, it would be a feather in the caps of the scouts. Some old professor would be hustling up this way as soon as we let them know at Yale or Harvard."

"Then we'll try to find where it struck!" declared Ralph.

"It would be as bad as hunting for a needle in a haystack in all this big wilderness," ventured Bud; "though there'd be no harm in our trying,—-that is, if I'm in any shape to go with you after I've had my little innings."

Again did Ralph wear a puzzled frown as he heard Bud make this significant remark. He must have wondered more than ever what it could possibly be that the other had conceived this time. On other occasions his efforts, while ambitious, had ended in smoke, and the rest of the boys often quizzed poor Bud most unmercifully on account of his shortcomings. But then, all great inventors must make a beginning. It is not expected that genius can take the saddle at one bound. Persistence counts more in such cases than anything else.

The fellow who has faith in himself is apt to get there in the end, no matter what grievous disappointments waylay him on his course; that is, if he really amounts to more than a flash in the pan. Bud sometimes comforted himself with reflections along this order. He was not easily cast down, and that counted for a good deal.

The three scouts sat in the shack crosslegged, like so many Turks, and chatted busily as time passed on. Ralph was easily induced to speak of his various experiences when he used to trap in this same neighborhood during past winters. He had run across a number of strange things that were well worth telling; and Hugh especially showed the keenest kind of interest in all he had to say.

Bud, like most promising candidates among those destined to become truly great, had a habit of forgetting that there were others present besides himself. He would fall into a reflective mood and knit his brow as though wrestling with grave problems, upon the solving of which the fate of nations depended.

Ralph knew all about the habits of foxes, mink, otter, weasels, muskrats, raccoons, 'possums and divers other small fur-bearing animals such as give up their warm coats for the purpose of keeping ladies' hands and necks comfortable during wintry blasts. He had had many amusing experiences with some of them, and as the scout patrol leader never wearied of learning interesting facts at first hand, Ralph was kept busy talking and answering questions, until considerable time had slipped by and there was Bud yawning as though threatening to dislocate his jaws.

"Guess we'd better be thinking of bunking down for the night," suggested Hugh. "Did you fetch a blanket along with you, Ralph?"

"Well, I'm too old a hand to be caught napping in the woods without thinking of the night that is coming," replied the other, laughing at the same time. "Over in the corner you'll see the bully red blanket that's hugged me tight on many a cold night when I was tending my line of traps. I feel that it is like an old friend when I get it tucked around me, and you'd think I was an Esquimo lying there, or one of those mummies they get out of Mexican catacombs."

"That's all right," Hugh declared; "I thought you were too sensible to come up here and spend a night at this time of year without something to keep you from freezing. Why, even on a summer night that starts in hot, it's apt to feel chilly along about three in the morning. I've seen the time when I'd have given a heap to have my blanket along; and the only thing I could do was to get up and start the fire booming again."

The three boys started to pick out the best spots for making their beds, each one being governed by some idea of his own. It was lucky they did not all think alike, or they must have drawn straws for first choice.

Hugh was carefully laying his blanket down so that he could crawl into it as if it were a bag, after he had taken his shoes and some of his outer clothing off, when he felt a gentle tug at his sleeve.

"Hugh!" said a soft voice in a whisper.

"What is it, Ralph?" questioned the other, going right along with what he was doing in order not to show that there was anything amiss.

"Don't act as if I was saying anything out of the common, Hugh," said the other; "but first chance you get, peep out of the tail of your eye at the broken window, and you'll find that we're being watched!"



CHAPTER IV

READING A "SIGN" BY TORCHLIGHT

Of course it gave the leader of the Wolf patrol a thrill when he heard this low warning from Ralph. You never would have known it, though, from any uneasy movement on his part.

He knew that the boy who had spent so much of his time in the woods, trapping the cunning little furry inhabitants in seasons gone by, would not alarm him needlessly. And so, watching his chance, Hugh managed to shoot a glance toward the opening without betraying the fact that he was particularly interested in that quarter.

As he did so, he was just in time to see a face vanish from view. In fact, he barely caught a fleeting glimpse of it, and yet Hugh felt perfectly sure that he had not alarmed the watcher in any way.

The cause of the unknown party's sudden withdrawal was speedily made plain. Bud seemed to be gasping, and immediately whispered hoarsely:

"Great guns! did you see that, fellows? As sure as my name's Bud Morgan there was a man peeking in at the window there! Honest Injun, there was!"

Undoubtedly the unknown visitor must have discovered Bud staring straight at him, and thought it high time to disappear.

"Yes, we both saw him, Bud," said Hugh, rather disappointed that, after all, the fellow had been chased away before they could find out his identity or what he wanted, prowling around in such a suspicious way.

"Who in the dickens was it?" exclaimed Bud, evidently growing angry now that his astonishment had worn away. "The nerve of him, poking his nose in where it isn't wanted! Why don't we get a move on and chase after him? Ralph, remember that you've got your scatter-gun handy. Don't forget to take that, will you?"

"Did you recognize that face, Ralph?" asked the practical scout leader, turning to the young trapper of the past.

"I think—-yes, I'm nearly dead sure it was one of the two men I saw acting in such a suspicious way this afternoon," came the answer.

"Which one, would you say?" continued Hugh.

"The taller one," came from Ralph without hesitation. "I think you said he looked a little like the German type, wasn't that about it, Ralph?"

"Yes, that was what I believed at the time I saw him," replied the other.

He had already stepped over and picked up his gun. There was a gleam in his eyes that told of a spirit aroused. Ralph had become a scout and was to the best of his ability trying to live up to the duties of one belonging to the organization; but of course there were times when the old spirit would come to the surface. The present occasion was one of these moments.

"Let's go outside and look around," Hugh suggested.

"Bully idea!" muttered the impatient Bud; and having no gun to grasp, he made a lunge for the stout stick which Ralph had been using as a sort of poker when the fire needed attention.

Hugh did something still more practical. He stooped down and calmly selected a certain blazing brand from the fire. This was of such a nature that when properly handled it could be made to serve as a pretty fair torch.

When Bud saw what the patrol leader was doing, he grunted and nodded his head as though comprehending things. Bud always could "see through a mill-stone that had a hole in it," as he was accustomed to say; in so many words, he was quick to grasp things after some smarter fellow had blazed the way. A "hint was as good as a nod" to Bud.

"Fine thing, Hugh!" he commented admiringly. He realized how valuable such a light might prove under the circumstances.

Ralph removed the piece of board that served to hold the door shut, and boldly led the way outside. The others pressed closely at his heels, Hugh holding the spluttering torch above his head and Bud gripping his club with the full intention of using it should the occasion warrant such action.

All was dark and still without. The night wind moaned in the branches of the trees where the leaves had fallen, or rustled the brown foliage of the oaks; but they could see no hostile form.

"Oh! he skipped out, all right, sure he did!" declared Bud, with something like a sneer in his voice. "He knew I had glimpsed him, and he didn't have the nerve to hold over and meet us face to face. Wonder if it would make him run any faster if you banged away a couple of times with your gun, Ralph?"

The idea did not seem to appeal to Ralph, however, for he made not the slightest effort to act upon it. Standing there, he stared around at the gloomy woods and waited to see what Hugh would so.

The latter had also taken a fair survey of the singular picture as seen by the weird light of the torch. Presently he stepped forward and turned the corner of the shack. Ralph followed him closely, while Bud, still holding his cudgel in an aggressive manner, posted himself at the corner, where he could not only watch what the other fellows did but at the same time keep an eye on the door. He did not mean to leave the way open for anybody to sneak into the shack while their attention was directed elsewhere,—-not if he knew his duty, and he believed he did.

Now Hugh, being an experienced scout, first of all thought to make sure that they had really been spied upon. This he knew could be readily ascertained by examining the ground under the opening called a window. Men can hardly stand on ordinary soil without leaving some sort of impression there. And those boys who have spent many a vacation in the woods, studying Indian tactics as applied to the life of a scout, know how to read such signs almost as easily as they might the printed page of a book.

Bending down therefore at the suspected spot, Hugh quickly pointed out the imprint of feet to Ralph.

"That proves it!" exclaimed the other as he flung a hasty glance over his shoulder, apparently half suspecting that the object of their conversation might suddenly burst upon his vision.

"Yes, it's easy to see he was standing here after creeping on his hands and knees," Hugh remarked, still studying the marks. "And he's wearing a pretty fine pair of modern shoes into the bargain; which shows that the men you saw were not tramps. At the same time, Ralph, I can't believe they were timber-cruisers, either, looking for new belts of forest that could be bought up. Whenever I've seen one of those men, he wore laced hunting shoes that came half way to the knee, so as to protect his legs against snake-bites and thorns while pushing through the scrub. No, this man has rather a dainty foot, and it strikes me as mighty queer he should be wandering around here."

"What are we going to do next?" asked Ralph, looking as though he stood ready to carry out any suggestion Hugh might make, even to chasing around and trying to follow the trail of the fleeing spy.

"Nothing, that I can see," answered Hugh; "and so let's go in again. We can talk it over better there than out here, you know."

Two minutes later and they were once more indoors. Seated before the fire, they canvassed the matter thoroughly. From every angle they tried to penetrate the mystery, but it seemed to baffle them.

"I had an experience once that makes me sort of think they may be keepers from some asylum looking for an escaped lunatic," Hugh finally remarked; "though if that were the case, they'd be apt to wear some sort of gray uniform, and you didn't say anything about that, Ralph."

"Yes," added the other, quickly, "but if that's what they were, why should they act so queer? Wouldn't two such men want to scrape an acquaintance with us scouts, so as to get a few pointers? I don't think that covers the bill, Hugh."

"And I didn't, either, when I spoke of it," the patrol leader said, as he smiled and nodded his head. "But perhaps Bud may set us right. I can see from the look on his face that he has a brilliant idea."

"Oh, shucks! I don't know how brilliant it is," the party mentioned hastened to remark, "but you're welcome to my thought. Suppose there happened to be some desperate men hiding up here in these woods, say counterfeiters, for instance? I've heard that such fellows always try to pick a lonely place to do their work in. Well, the Government always sends out smart men belonging to the Secret Service to round these chaps up. I was speculating on whether those two strangers Ralph saw mightn't be detectives. I reckon they looked as if they wanted to detect, all right; and let me tell you, p'raps we're under the ban of suspicion right now."

Bud ended his remarks in a rather awed voice, but neither of the others seemed to be at all worried. Indeed, Hugh chuckled as though amused.

"It may be that you've guessed the right answer, Bud," he said, "but all the same I don't believe it. There's something deeper about those men than that. And unless I miss my guess, we'll find in the end, if we learn anything at all, that they've got some sort of connection with that queer flash and crash that gave us such a scare earlier in the night."

Bud stared at Hugh on hearing this.

"Whee! do you really think so, Hugh?" he muttered, as though trying to grasp what all this might stand for, and yet hardly able to comprehend its full significance.

After all their talk, however, they were really no nearer a solution of the matter in the end than when they started to discuss it. Hugh said they would have to wait and see what turned up next, before settling on any one explanation and both the other scouts agreed with him.

So they finally prepared to lie down and get what sleep was possible, which under the conditions could hardly be expected to amount to a great deal.

Their blankets were folded in such fashion as to give them the best results. This wrinkle they had learned in the field of practical experience, than which there is no better guide. Theory is all very well, but the book-taught scout has a great many ideas to change when he gets out into the open, with the stars shining down on him from the blue vault of heaven and the voices of Nature surrounding him on every side, instead of the bare ceiling and walls of his bedroom at home.

That night certainly dragged along fearfully. Every now and then one of the boys would turn over and grunt, or else raise his head to look around him at the flickering light of the fire on the walls of the lonely woods' shack.

As many as six times did Hugh crawl out from the warm folds of his blanket to replenish the fire, for the night air was chill; and after one has slept, his body is apt to feel cold, as the heart beats less rapidly, and the blood circulates with more difficulty.

But thank goodness, these things must all have an end, and Bud heaved a sigh of profound thanksgiving when finally he saw signs of dawn appear through the open window.

"Day's coming on, and we're all on deck with nothing gone wrong!" he observed loud enough for the others to hear him. This chanced to be one of Bud's ways of informing his chums that he thought it high time they turned out for "reveille."

As there was no use in trying to sleep any longer with the anxious Bud on deck, since this was to be looked upon as his particular day, Hugh and Ralph followed the other's example, and were soon hustling out to wash in water that nearly froze their fingers it was so cold.

The sun was nearing the horizon, and from all indications it promised to be just such a day as the one before had proved; which fact delighted Bud immensely.

"Because," he explained after giving an exhibition of a Highland Fling to allow some of his pent-up enthusiasm to escape, "this is the day a Morgan is going to win fame or else make the grandest foozle you ever saw."



CHAPTER V

THE "FOOL-PROOF" AEROPLANE

"That was a good breakfast, all right, but I'm glad it's over," Bud remarked some time later.

Ralph, of course, did not exactly understand what this meant, but Hugh knew. He was in the confidence of the young inventor far enough to appreciate his eagerness to be at work. He knew what had brought Bud all the way up to this lonely spot, in order that none of the town boys might spy upon him while trying out his latest wonderful invention.

Truth to tell, Bud had taken a most intense interest in aviation of late. Everything that bore upon the subject fascinated the boy, and he dreamed of making the name of Morgan famous through some remarkable invention connected with the work of the daring airmen.

He had confessed to Hugh in strict confidence that he had managed to fashion a little model aeroplane that he believed to be uncapsizable. Many more mature minds than that of Bud Morgan had been wrestling with this important question for years, because it was pretty generally understood that when this condition had been really attained, the sport of aviation would advance with great bounds. Make navigating the upper air currents practically safe, and thousands would take up flying just as they had the driving of automobiles when the road racers had been perfected as they are to-day.

The huge packages which the two scouts had staggered under during their weary hike from the road where the accommodating farmer had dropped them, really contained the said model. It was not of very large size, and the little engine which was to drive it really weighed as much as the rest of the thing; but Bud declared that it would answer all his purposes, and prove whether he had been wasting his time and spending money uselessly of late or not.

Once the breakfast had been disposed of, Bud was trembling with eagerness to get started. He could not understand why the others should delay so, when time was slipping away.

Presently they left the cabin, closing the door behind them. All of the blankets, as well as their food supplies, had been left inside, and they did not want any wandering wild animal like a 'coon or a fox to make way with the latter during their absence at the proving grounds. It was this same caution that urged Hugh to cover up the aperture through which they had obtained fresh air during the night just past, and which went by the name of a window.

The open field which Bud had once before mentioned as the very place for the trial spins with his aeroplane model was not very far distant. The man who had originally started to make a farm away up here had diligently cut down trees for a space of several acres. He had also grubbed the ground so thoroughly that it had remained clear all these years, save for an annual crop of grass, now withered and dead.

"If we can help any, Bud, just tell us what to do," Hugh said to the inventor, after the three boys had come to a halt on the border of this open space.

"That's the kind of talk I like to hear, Hugh," the other replied, looking up with a smile on his anxious face. "Just wait till I get these covers off, and then you'll see what I've been doing all these months when some of the fellows were kidding me on being a regular old book worm and not wanting to come out and play even football with them. It was the hardest kind of work, but if she even goes a little, I'll think it wasn't time wasted. All I want is encouragement; I've got the bull-dog grit to carry it on all right."

"I reckon you have, Bud," was the only comment Hugh made; and he ought to know, because Bud was a member of the Wolf patrol and the leader had watched him work many a time as though there were no such word as "fail" in his lexicon.

So Bud busied himself in undoing stout cords and opening both bundles. When Hugh saw the nature of the load he had been packing up the side of Stormberg Mountain, he shook his head and laughed.

"What did you think I was, Bud, a mule, or a Chinese porter used to carrying as much as half a ton on his back?" he demanded. "Why, that engine would have given me a bad scare if I'd seen it beforehand. And I toted that all the way up here from the road, did I? Well, anyway, I've earned the right to boast after this. A motor is no light load, I don't care how small it may be. Don't you agree with me, Ralph?"

Ralph was chuckling to himself, seemingly much amused.

"I should say yes," he replied; "and I don't wonder you complained of feeling a touch of pain in the muscles of your back last night, Hugh. But really the load Bud took himself was larger and just about as heavy as yours, you see."

"Oh! he gave me my choice. I saw it was six of one and half a dozen of the other, so I took the smaller one. I reckon I'll be ready to tackle a house next time, after having a motor on my back."

Bud set to work assembling the various parts of his model. In some respects it was rather a crude imitation of a monoplane, but for practical purposes no doubt it would answer just as well as the most elegant model. What Bud wanted to find out most of all was whether he had been working on the right principle. If that turned out to be correct he could afford to have a better model made; then he could take up the idea with some of those capitalists who were interested in building airships of all kinds.

For once Bud was supreme. He gave his orders and the others obeyed. Even Hugh, accustomed to being the leader, willingly assumed the air of a novice, though Bud knew very well that the other had studied the subject of aviation very thoroughly and was competent to advise in a pinch.

By slow degrees Bud managed to get his planes adjusted and the tiny motor installed. Hugh, in a quiet and unostentatious way, often assisted him to overcome some difficulty that arose; so that Bud declared he did not know how he could have managed without the other's help in tightening wire stays and installing the motor.

At last the work seemed to have been accomplished. Bud said he could fix the rudder of the model so that when once it was in the air, it would continue to make revolutions for a certain time. He declared it would actually fly around the field slowly until the measured stock of gasoline had been exhausted, when of course it would drop to the ground as the engine ceased to work.

"You see I expect to manage by means of this cord," he explained. "I'll chase along below, and every once in so often try to upset the thing by giving a savage jerk. Then you'll discover whether my device is going to work. If it does half way decently in this clumsy model, it'll pay to install it on a real aeroplane and either go up myself or else have an air pilot do it for me. But say, let me tell you right now that I'm shivering all over as if I had the ague! 'Cause why? In half an hour or so I'm going to know whether I'm IT, or else a lunkhead that ought to be smothered before his fool notions get him into a peck of trouble."

"Oh! I wouldn't put it that way, Bud," advised Hugh. "You mustn't call yourself hard names, even if this invention fails to work. They say Edison has lots of rank failures that the public never hears about; only his brilliant successes become known. Suppose this scheme doesn't do all that you expect it to, why, perhaps you'll see where it falls short and be able to remedy the fault. If you have faith in yourself, it's going to turn out all right every time. Try seventy times seven, and never give up as long as life lasts."

"Nil desperandum!" quoted Ralph; "or, as we Americans have it, 'if at first you don't succeed, try, try again!'"

"You just bet I will, fellows," said Bud firmly; "and now let's make the first trial spin."

He had elevated the model so that it would start in the air without the necessity of leaving the ground. This was a minor matter, and only intended to hurry things along.

When the little motor got to work there was an immediate movement of the rough miniature monoplane.

"Hurrah! there she goes!" cried Ralph, really excited when he saw the object of Bud's recent labors actually moving through space, sustained by the extended pair of planes.

Hugh, too, felt a thrill of delight. He was very fond of Bud, and anything that promised to repay the other scout for his weeks of arduous labor pleased the leader of the Wolf patrol more than he could express in words.

Bud was about the busiest boy any one had ever known. To run along and keep, up with that hurrying model, hanging on to the long stout cord, was no easy task. The rudder had certainly been fixed properly to insure a circuit of the field; but as the ground was very rough in places, Bud had great difficulty in keeping from falling many times. This was partly on account of the fact that he had to fasten his eyes on the scurrying monoplane model pretty much all the time, and could therefore not pay much attention to where he was going, or see the traps lying in the way of his feet.

He stuck to his task heroically, with grim determination to see it through to the bitter end. Every once in a while he would give the cord a savage jerk. In this way he managed to make the little flier take sudden lurches; but in every instance the model instantly resumed its upright position as soon as the pull was past. It reminded Hugh of prank-loving swimmers attempting to sink a boat built with air chambers, which would bob to the surface triumphantly every time.

So far as one could tell from watching these rather clumsy operations on the part of the inventor, his apparatus for steadying an aeroplane was surely showing signs of being a success. It consisted of a small iron bar weighing an ounce or so, which was hung as a pendulum from an arm projecting from under the operator's seat. This pendulum was so delicately set that it seemed to respond to the slightest deviation of the aeroplane from the horizontal.

As the excited inventor explained to his chums, after he had allowed the craft to come to earth again, not without some little damage which precluded another flight that day, it was a very simple thing after all. If the craft was thrown from its balance in any way, the movement of this pendulum would cause two little valves to open. This would make the compression from the engine force a piston back and forth, which communicated with the warping levers and automatically accomplished what had up to that time, Bud went on to say, been done by the hand of the busy aviator. Thus a mechanical balancer had been arranged, so that the pilot need never bother himself as to whether a stiff gale were blowing or not, since practically nothing could upset his craft.

"It looks to me as if you had a good idea there, Bud," said Hugh; "and unless somebody's been ahead of you in the field, it ought to make you famous as an inventor. Perhaps when you try it again to-morrow, after mending your planes, you'll discover a few ways in which it can be improved. Never believe anything is perfect the first time. And now, shall we gather it up again and carry it to the cabin?"

"You're awfully kind, Hugh!" declared the happy Bud, whose face was rosy from his recent tremendous exertions and from the glow of satisfied ambition. "I am convinced that I haven't been wasting my time, even if I'm only harrowing in a field some other fellow may have plowed before me."

They managed to get the miniature aeroplane over to the shack, though it was no light burden, taken all in all. Bud, however, was feeling so pleased that he could have done the work of an ox himself. There is nothing like satisfaction to bring out unsuspected powers in a boy; and just then Bud believed he could have carried as great a load as any Turkish hamel or porter.

Leaving the queer looking contrivance outside the door, Bud hurried in as though something that he had suddenly thought of was bothering him. A minute later he burst into view again, a row of wrinkles across his forehead and words of alarm sounding from his lips.

"I can't find it anywhere," he lamented, "and I'm dead sure I left it there on the pile of blankets. Hugh, somebody's been in the shack while we were away, and cribbed the plan for my aeroplane stability device!"



CHAPTER VI

A RED LETTER DAY IN THE WOODS

Both Hugh and Ralph looked serious when their comrade made this announcement.

"That's a tough deal on you, old fellow!" said the latter, feeling that it must mean considerable to Bud to have his idea stolen just when it was giving promise of being a signal success.

"Sure you left them there on the pile of blankets, are you?" asked ever practical Hugh.

"That's right, he did," Ralph volunteered. "I remember seeing some papers there when I went out, and I was the last to leave, you know. And you say that they've clean disappeared, have they, Bud?"

"Come on in and see if either of you have sharper eyes than I seem to have," the other scout demanded.

Accepting the invitation, Hugh and Ralph bustled about for several minutes, hunting all through the interior of the shack, but without any success.

"Nothing here, that's sure," admitted the patrol leader. "It was careless of you to leave your precious plan behind when you went to try the model out."

Bud scratched his tousled head as though endeavoring to collect his wits.

"Let me see," he started to say, slowly; "don't blame me if I'm all mixed up over this business. I've waited so long for this time to come that I'm sure rattled, that's what's the matter. What did I lay down here? Some parts of the plans for the model, that goes without saying; but seems like I've got a paper in my pocket right now. Let's see, I honestly believe that it's the key to the invention. Just what it is, boys; and without this, nobody'd ever know what all those markings on the other papers were meant for."

"Then it's all right, after all?" asked Hugh, smiling again when he saw that suggestive grin on his comrade's face.

"It seems that I can make an aeroplane fool proof, when all the time the fool killer ought to get hold of me," Bud confessed contritely. "It was certainly careless of me to leave any part of my precious papers floating around, and only good luck has saved me from being left high and dry. But perhaps those fellows will think they've got hold of some remarkable design. They might crack their brains trying to make it out, and then not learn a single thing. When a fellow laughs last, he's going to laugh best, believe me."

"Well, next time be more careful, that's all," advised Ralph. "You can't always count on being so lucky. An inventor ought to keep his secrets locked up, and not let them lie around loose. You'll find that there are plenty of sly thieves ready to steal ideas, as well as money and jewels. An idea that's worth a fortune can be cribbed a heap easier than the coin itself."

"Only a part of the morning's gone," announced Hugh. "How shall we put in the rest of the day?"

"Oh! I'll be pretty busy making repairs to my model," Bud replied. "You two fellows can find plenty to interest you both. Only don't roam too far afield in looking up interesting things. With that mysterious pair hanging out around here, I won't feel any too easy in my mind. My idea may be worth a cool million, you know."

While Bud was working diligently, the other two amused themselves first of all by closely examining the ground just before the door of the cabin.

"Here you can see several imprints of that fine pair of shoes," Ralph said almost immediately; "and that makes it look as though the man who wore them really did slip inside while we were away. Chances are, he wonders what boys wearing khaki suits like the regular soldiers of the army are up here for. You agree with me, don't you, Hugh?"

"It looks that way," admitted the other. "Here you see one of the impressions has stopped short only a few inches from the door, as if the man stood here listening before stepping in, after carefully removing the piece of rope we fixed to hold the door shut from the outside."

"But how do you know that that impression wasn't made twenty-four hours ago?" asked Bud, who was sitting cross-legged close by and listening to their talk, even while he worked at his broken wing tip.

"Nothing could be easier," replied Hugh. "Here's the foot mark I purposely made when I came out of the cabin last, and you can see that he stepped into the same place. That tells us he was here afterward. Get that, don't you, Bud?"

"I'd be a donkey if I didn't, and not worthy of being called a scout," the other boy remarked with scathing emphasis. "Fact is, if my mind wasn't so much wrapped up with this aeroplane stability device, I couldn't have missed seeing that little trick myself if I'd looked the ground over; because that happens to be one of the first things I ever learned about tracking and trailing."

"Even if the sneak didn't get anything worth while," Ralph continued indignantly, "the fact that they seem to be hanging out around here seems to tell that they must have a good reason for it all. The more I get to thinking about it, the less I feel like saying we'd better let the thing alone because it doesn't concern us. When things come to such a pass that unknown persons even sneak into your cabin in your absence and steal what they believe to be valuable papers, it's high time to take a hand in the business. And if while we're wandering around here we happen to run across those two men, I'll feel like asking what they mean by poking their noses into Bud's private business."

"Hear! hear!" said Bud, pretending to clap his hands; "that's the sort of a chum to stack up with. Ralph's the kind to stick to a fellow through thick and thin. And please inform that taller walking mystery for me, Ralph, that I feel like telling him to his face that he's a thief. Will, too, if ever I get half a chance."

Pretty soon Hugh and Ralph changed the subject of conversation and wandered off together, talking earnestly about the habits of muskrats and mink and otter. It was pretty late in the year to do much in the way of tracking, but Ralph knew several places along a nearby stream where he had often caught mink that were using the burrows; and he was anxious to show his friend certain things in connection with the habits of the sleek animals, the skins of which were always in such good demand for furs.

They had a joyous time together, because both were animated by the same sort of desire to know all that could be learned of wild animal life. Hugh's scout education had given him a pretty good insight into these things; but he knew the relative value of book learning and practical experience, and never let an opportunity to see for himself slip past.

At no time did they wander far afield. And as certain signals had been arranged with Bud, whereby he could summon them to his assistance in case there was any symptom of impending trouble, there did not seem to be any need of worry.

Once in so often they would walk back to the near vicinity of the shack; and on discovering Bud there, busily engaged in mending his disabled aeroplane model, they considered that they could saunter off again to investigate further into the secrets of wood and swamp, the latter now half frozen over in the cold late November atmosphere.

That was a day Hugh Hardin would long remember. He picked up a stack of practical information on topics that had always interested him greatly. Ralph was the best kind of a chum with whom to be wandering through the forest. He knew many things in connection with these subjects and was always ready to impart information to others, as well as to demonstrate what he was discussing.

At noontime they cooked dinner. Bud was not nearly through his repairs, though he declared that he was making satisfactory progress and would have the model in as good shape as ever long before evening set in.

"To-morrow we'll have another and convincing test!" he declared positively, with something of the air of a conqueror about him. Hugh noticed this with a smile, though he thought there was some excuse for Bud's displaying a disposition to "crow."

All of the boys showed that they had their appetites along with them on this trip, to judge by the rapid way in which the great heap of splendid flapjacks made by Ralph disappeared, until only the empty platter remained. But then, they were up here to enjoy themselves, and what better way could they find of doing this than by feasting on real camp cooking?

During the afternoon, Ralph and Hugh spent some more of their time in making discoveries. The former young trapper had a host of reminiscences to fall back on, now that he was located close to the scenes of many of his previous excursions in search of fur and feather.

"See that tree lying there chopped down?" he asked Hugh, as they came upon a pretty fairsized specimen of the forest monarch, which, after being put to the ax, had broken many limbs off when it crashed down. "Well, I did that little job all by myself. Want to know why?"

"I might give a guess, as I see traces of old honeycomb around here. I'll warrant you discovered a hive of bees in this tree and meant to get gallons and gallons of their fine stores. How about that, Ralph?"

"You struck the right nail on the head," laughed the other, "just as I felt certain you would when I saw you look around that way. Yes, I felt amply repaid for all my work after cutting through the tree, because two years ago times were a bit hard with the Kenyons, and all that nice honey proved a treat in our family circle, you'd better believe."

"How did you find the honey tree,—-by tracking the bees up the usual way?" Hugh asked.

"That was how I did it," Ralph replied. "I once saw a regular bee hunter do the stunt, and so I knew how; and it worked right well, too. I started out with a little honey and coaxed a wandering bee to fill himself up. Then with a pair of old opera glasses, I watched his flight just as far as I could see him. Going over to that point, I repeated the experiment. After doing it for about six times I saw my loaded bee rise, and make for this tree. Then, as it was a warm noon, I discovered a swarm of young bees trying their wings away up in the air, and I knew I had located the tree hive. It is an easy job, once you get on to it, Hugh."

"Some time I'd like to come out with you and try for another hive," observed the other scout. "But it's too late this year, because, unless a very warm day happens to come along, the bees will stick close to their hives."

In this sort of fashion the afternoon did not hang heavy on the hands of the two boys. It never does with scouts who are alive to their opportunities along the line of investigation. Time passed so quickly and pleasantly that, almost before either of them suspected it, the sun started to go down. And about the same moment they heard Bud giving the Wolf signal, not in a fashion to indicate any pressing necessity for their presence at the shack, but just to tell them he was getting lonely and that they had better come home.

They found that Bud had started supper, being in a joyous frame of mind because of the glittering prospects for success in connection with his new invention. Bud was a novice in the business. He would doubtless learn in due time how many bitter disappointments attend the fortunes of all those who spend their waking hours in trying to conjure up startling innovations.

After the evening meal had been enjoyed to its limit and everything cooked by Bud had vanished, the three chums again sat around and talked on all sorts of interesting subjects.

Bud, however, seemed to be uneasy. Perhaps it was on account of his anxiety to have the morrow come, when he could improve on the trial of his model aeroplane. Then again it might have been that the attempted larceny of his precious plan wore upon his mind.

Be that as it may, every little while he would go to the door and step outside.

It might have been the fourth time he did this that he thrust his head inside again and called to the others to join him.

"That clatter of machinery is hanging around again, Hugh!" he said, excitedly. "Perhaps you'll be able to tell me whatever it means, and if we could really hear the working of the mills all these miles away!"



CHAPTER VII

BUD'S METEOR

Both scouts hurried out to join Bud. They found him standing there with his head cocked on one side, apparently listening as hard as he could.

Indeed it did not require any especial gift of hearing to catch the strange noises spoken of by the ambitious inventor. They seemed to be close at hand and constantly growing louder all the time. Just as Bud had declared, the racket was undoubtedly caused by some sort of machinery.

Hugh immediately made an important discovery. It rather startled him, too, as well it might, for he had not been dreaming of anything so unusual.

"Why, it's in the air!" he exclaimed involuntarily.

"Sure it is," agreed the excited Bud; "in the air and everywhere else. Seems to me I might be listening to a dozen shuttles working with a rush."

"But I mean that it comes from above our heads!" Hugh quickly added; at which both the others gasped in wonder, though realizing that what the patrol leader had said was actually true.

"Whatever can it mean?" stammered Bud.

"Say, do you know it makes me think of something I heard over at Bellville during county fair week!" burst out Ralph.

"Meaning an aeroplane?" declared Hugh.

"Just what it was, Hugh," returned Ralph. "But what would a flier be doing away up here, going around and around in the dark of night?"

"I don't know, and that's all I can say," replied the other; "but perhaps we may be able to find out. There it comes again, swinging around in a circle. If we all look sharp, we may be able to glimpse something up against the sky."

"My stars! An aeroplane!" Bud was muttering to himself, as he hastened to follow his companions away from the door in order to have a better range of observation. "Of all the things that we could meet up here, an aeroplane! And me just pining away with yearning to see one in action! Oh! don't I hope it turns out that way, though? Do you see it yet, boys? When you do, please put me wise, won't you?"

All of them were straining their eyes to make a discovery, and as it was possible to follow the course of the swiftly circling though as yet unseen object by listening to the rattle of its engine or propeller, they kept their attention directed to one particular quarter.

"Oh! I think I can see it now!" cried Bud excitedly.

"Yes, we all do," added Ralph.

They continued to stare up at the moving object, which, as seen in that uncertain light, looked not unlike a monstrous bat with extended wings. The sound of the busily working machinery grew louder constantly. No wonder Bud had been so perplexed when he heard all this, though more faintly, on the previous night and asked whether it could be possible to catch the sound of the mills many miles away.

As the three scouts continued to stand there gaping at the dimly seen flier, a sudden terrific crash and vivid flash almost stunned them. Indeed, Bud crumpled up and might have fallen to the ground, only that he came in contact with Hugh and received the support of his firm footing.

The very ground shivered under them. It seemed as though some subterranean mine must have been exploded, causing the rockribbed earth to quiver in a sickening fashion.

When they dared look up again, the queer bat-like object had vanished entirely from sight. Voices were heard, however, close at hand. They told of more or less excitement; and coming with them was the sound of one or more persons pushing recklessly through the thickets that grew in many places as a second growth.

Presently even these noises died away and a dead silence reigned. By then, Bud managed to regain possession of his voice.

"Oh, another terrible meteor! Why, we must be right in the middle of a shower of shooting stars! And let me tell you, that one hit the earth not a great way off, too! I'm going to take a look in the morning and see if I can find it. They say that college professors often pay big sums for being set on the track of these meteors that bury themselves in the ground. What if she had dropped right down on top of this shanty, boys? I'm glad we got off as well as we did, aren't you, Hugh?"

Hugh did not answer. Evidently he was thinking deeply at that particular moment. There was indeed plenty to concern him in connection with the mysterious aeroplane that nightly circled the region, always accompanied by that strange explosion.

"Seems to me I can smell something queer like burnt powder," Bud presently remarked. "Do meteors explode when they hit the earth, Hugh?" And would they send out a rank odor like that?"

"I don't happen to be up in the doings of meteors, Bud," answered the other, "but I should think it might be something like that. We'll all take a look after breakfast, and see what we can find. Perhaps it may surprise us. This seems to be a general all-around surprise party for the lot of us. We were taken aback to find Ralph here in the old shack; he had his surprise when he watched those two men carry on so queerly; then we had the shock last night of hearing thunder and seeing lightning when the sky was clear; after that, the fellow looking in at the window startled us. You were a little surprised your self, I reckon, Bud, at your success in trying out your stability device as applied to aeroplanes. And now comes the discovery that one of the air craft is skimming around here nightly, doing some stunt that we can't understand yet."

"We ought to call this Camp Surprise, then," announced Ralph.

"That's what," echoed Bud.

"Now let us go in again," suggested Hugh. "It seems as if the fireworks might be all over for this particular night. Even the aeroplane has gone off where none of us can hear the motor working any longer."

"Perhaps she dropped to the ground," remarked Bud. "There might be another open place not far away, like the old field where we tried out my little model this morning. And say, doesn't it strike you as funny that just one solitary meteor should take a notion to explode each night?"

No one answered this question, though Bud was too busy pondering on the run of strange events that had fallen to their share of late to notice the lack of interest his comrades seemed to take in the matter.

Once inside, they again sat around talking. It was Ralph this time who gave utterance to a certain fact that had been in his mind, which interested both his chums as soon as they heard it.

"I don't know," he started to say soberly, "whether either of you happened to notice it, but there seemed to be something foreign about the voices we heard after the big noise. Not a single word could I understand, either, and yet they seemed to be pretty near by."

"I didn't happen to notice that, Ralph," Hugh observed seriously; "but if the men who spoke were your mysterious friends of the other day, one thing is sure—-they weren't the ones who sat in that speeding monoplane."

"Eh? How do you know that?" queried Bud, becoming deeply interested.

"Well, in the first place," suggested Ralph, not waiting for Hugh's reply, "the sound of voices came from the same level as our own location. I'm dead sure of that fact. Then again we could hear the swish of brush, and I even caught the sound of men crashing through thickets and falling over logs."

"Yes," added Hugh, "and it struck me that they were in something like a blue fright, as though the nearness of that explosion had given them a bad scare. Only a sudden panic could make men rush through thickets as recklessly as they were going."

"Everybody may not like meteors to drop all around 'em," Bud muttered; "and I can't blame the fellows much, either. I came near being knocked flat on my back, myself, when that one let go with a bang. My ears are ringing yet, and I'm afraid I'll go deaf if I have to hear much more of that sort of cannonading."

Although they continued to sit up for some little time and talk, Hugh did not see fit to mention certain suspicions that had taken root in his own mind. He believed he was on the track of the truth, but until he had a little more positive evidence he hesitated to speak out boldly.

They finally settled down and tried to sleep. Bud seemed to find little difficulty in forgetting all his troubles and triumphs, for his heavy breathing quickly announced that he was dead to the world. With the other two it was a more protracted task, and possibly they turned over as many as half a dozen times before surrendering drowsily to the god of slumber.

There was no further trouble during the balance of that night, the second they had spent in the old shack. Saturday morning dawned with a clear sky, and it looked as though the day might be a repetition of the two previous ones. This gratified the scouts very much, for no matter how seasoned a camper may be, the weather has considerable to do with his enjoyment. If rain continues to pour down, there is very little pleasure to be found in spending hours or days under canvas or the leaking roof of a cabin, wishing in vain for a break in the weeping clouds. And so the three lads expressed themselves as contented when they broke out from the shelter of the shack on that morning and found the conditions so favorable.

Bud hoped to make another try with his model before noon, since they expected to be on the move shortly afterward. There was a long hike before them ere they could expect to reach the road leading home, where possibly a wagon might be hired to help get them into town again.

One thing pleased them, and this was the fact that for the most part the return journey would be down-grade. In consequence they expected to make the distance separating them from the road in about half the time it had taken in coming.

Bud hurried through the morning meal. Indeed, Ralph even joked him on his seeming lack of appetite; for as a rule Bud was a good feeder and came second only to Billy Worth, long recognized as champion in the troop.

"Well, you see," Bud explained, "there are a whole lot of important things I mean to do to-day, and the sooner I get busy the better chance I'll have to go through the list. First thing of all is to take a little tramp around toward the west of the camp, to see if I can stumble on the place where that last old shooting star struck us. I'm going to look sharp for a hole, because it seems to me such a big lump of iron and other ore would smash into our earth at a pretty lively clip."

"Hold on a minute and let's start fair!" called out Ralph. "We're just as anxious as you are to make some sort of discovery, eh, Hugh?"

"Some sort, yes," the patrol leader admitted, with a queer little smile that Bud noticed, but could not understand just then.

So the three boys started to comb the immediate vicinity of the shack, spreading out in something like a fan formation. They took to the west, because all of them seemed to be of one opinion: that the dreadful crash had come from that particular quarter.

Now and then one of them would call out or give the Wolf signal, just to inform the others where he happened to be. In this manner some ten minutes went by and Hugh was thinking that the explosion must have been much further away than any of them had suspected at the time, when Bud was heard giving tongue.

Bud, when excited, always broke loose and allowed himself free rein.

"Come this way, boys!" he was shouting gleefully. "I've run the old meteor to earth. My stars! what a terrible hole she did make! Must be as big as a house!"



CHAPTER VIII

UNCLE SAM'S FLYING SQUADRON

"How—-oo—-ooo!"

Ralph gave the long-drawn cry of the timber wolf as he hurried in the direction of Bud's shouts. Hugh speedily joined him, coming from some side quarter, and the pair were soon closing in on the other scout.

They found Bud clinging to a shattered sapling and staring down into a gaping aperture that looked big enough for the excavation of a church cellar. All around were evidences of a most tremendous explosion or upheaval, some trees being actually shattered and others leaning over as though ready to fall.

"Talk to me about your meteors," burst out the wondering Bud as he saw the others coming along, "I hope to goodness one of them never drops down on our roof at home. Just looky here what it did to the poor old earth! That sky traveler's as big as the parsonage, I should think."

Hugh turned to Ralph.

"No doubt about what happened now, is there?" he asked.

"Well, I should say not," came the answer, as Ralph stared down into the hole.

"Must be some new sort of explosive they're experimenting with," added the patrol leader seriously; "and to look at that gap you'd believe it beats dynamite all hollow. Drop a bomb made of that stuff on a fort, and goodby to the whole business."

"W—-what's that?" exclaimed the wondering Bud. "Do you mean to tell me that it wasn't a meteor that made all that racket the last two nights?"

"So far as I know," Hugh told him, "when a meteor drops down, it buries itself in the earth and gradually cools off, for it's been made almost red-hot by passing so swiftly through space. But it doesn't, as a rule, burst and tear a horrible slash in the ground like this."

"Then what made it, Hugh?" asked the other, evidently puzzled.

"A dropped bomb!"

"A bomb, you say? Oh, Hugh, that was why the old aeroplane kept circling all around, wasn't it? They were picking out some place to make a big hole! Whee! No wonder then they came up here to this lonely place to try things out. A farmer'd be apt to kick like a steer if he waked up some fine morning and found holes like this in his garden or field. It's good we didn't happen to be standing here when they dropped the bomb, as you call it."

"I had an idea of something like this last night," Hugh said; "but thought best not to mention it until I could see my way clearer. But now the last doubt has gone, and I know the truth."

"But Hugh, who could it be trying out this awful explosive, and wanting to do it where no curious eyes could watch the operation?"

"I don't know that, Bud, but we can guess. It must be either some company in the market with explosives, or else the Government itself trying to see how the Flying Squadron, as they call their aerial arm of the service, could work in time of actual war."

"Say, if they could drop bombs like that just, where they wanted," remarked Bud admiringly, "I'd pity the enemy, whether Japanese or German or anything else. Just think of a great big bat circling around in the darkness of night, sending down a searchlight, maybe, to pick out the right spot, and then, bang! Good-by to your old fort or battleship! It would be all over before you could wink twice. And let me tell you, fellows, we've got the bully boys in the army to do this same stunt, if anybody on earth can!"

"Thank you for the compliment, my boy!"

A quiet voice said this, and the three scouts looked up hastily to discover that a man clad in a faded suit of khaki was standing close by, watching them with an expression of amusement on his clear-cut face.

There was something about his make-up that instantly convinced Hugh of his connection with the aviation corps of the Government service. This, then, would seem to prove that it was the army engaged in making these secret experiments with the new explosive, perhaps from a war aeroplane that may have been given over into the charge of the Flying Corps for trial.

Hugh immediately advanced toward the officer and gave the regular salute, as every scout is taught to do when he meets one who is above him in rank. To his delight, the other acknowledged the salute immediately.

"We are Boy Scouts belonging to a town some miles away from here," Hugh started to explain.

"And what are you doing here?" inquired the officer pleasantly.

"We came up to watch one of my chums experiment with a device he believes he has discovered," replied Hugh. "For the last two nights we have been puzzled to understand what that terrible roar and flash meant. At first, we thought a meteor had fallen; but when it came again last night and we saw the aeroplane swinging around up there in the sky, I began to believe there was some connection between them. And now that we've found this hole in the ground, I know it shows where your bomb struck, Lieutenant."

"Yes, that is what happened," remarked the officer. "I came here this morning to take notes, so that I could make a full report of our practice. We have not thought it necessary to make use of our searchlight so far when dropping a bomb; but now that we know others besides ourselves are up here, we must be more careful. Perhaps I would hesitate to say all this to most people whom I happened to meet by accident, but I know what Boy Scouts are and how devoted they have always proved to patriotic motives. I'm positively certain that nothing could tempt one of you lads to betray any confidence I placed in you."

"Thank you, sir," said Hugh, flushing with keen pleasure at hearing such words of praise from an army officer. "And perhaps you may not know that there are others up here who seem to be deeply interested in all that you are doing."

"What is that, my boy?" exclaimed the other, showing sudden interest.

"Why, by chance my friend here, Ralph Kenyon, who has trapped all through this section in years gone by, saw two men talking and acting in a strange way. They've been spying on us, too, while we've occupied the old shack close by. They even crept in while we were off yesterday, to steal some plans of an aeroplane improvement which this other scout, Bud Morgan, had carelessly left there."

"Two men, you say," the officer commented, knitting his brows with sudden suspicion and uneasiness. "Could you tell whether they seemed to look like natives or foreigners, son and he wheeled so as to face Ralph as he asked this.

"I had an idea that one looked like a Japanese and the other a German," the boy answered promptly.

At this, the army man rubbed his chin and seemed to consider.

"I've taken you into my confidence so far already, boys," he observed presently, "that I suppose I might as well go right along and tell you everything. We are up here, representing the Flying Squadron of the army, to experiment with a new war aeroplane much more powerful than anything before devised; also to ascertain whether there is any truth in the wild claims put forth by the inventor of the latest explosive, that his discovery must make war so horrible that nations would be compelled to keep the peace after this. And, judging from what that one small bomb did here, I fancy he was not mistaken in his estimate. We could destroy the largest battleship afloat as easy as to snap our fingers. Of course there are secret agents of numerous Great Powers constantly floating around in Washington, trying to learn what Uncle Sam has up his sleeve in the way of new inventions calculated to destroy the enemy in time of war. And we have feared all along that one or more of these spies may have gotten on our track. I'm very much gratified with what you have told me, for now we know what to expect, and can avoid taking any unnecessary risk."

"Would these foreign spies dare attempt to ruin your war aeroplane, or try to blow you all up with some of your own explosive?" asked Ralph.

"I wouldn't put it past them," replied the other. "They are playing a desperate game, you understand, and have their orders from the home Governments to keep us from forging ahead too fast. But I haven't introduced myself as yet. I am Lieutenant Fosdick, and I have had some little experience in army aviation."

"I wonder if you can be the same Lieutenant Fosdick I've heard so much about from our Scout Master, a retired army officer named Lieutenant Denmead?" Hugh ventured to say eagerly.

"Well, this is a pleasure to be sure!" remarked the other smilingly. "To be sure I know Denmead. I saw a great deal of him several years ago. And so he is spending his spare time in teaching the young idea how to shoot, but with the arms of peace rather than those of bloody war? He was always crazy over boys, and must be a cracking good Scout Master, because he knows so much of Western life among the Indians. He was with Miles in the Sioux War long ago, as you may know. But what was this you said about one of your mates inventing something in connection with the management of aeroplanes? That would seem to be right in my line, and if he has no serious objections, I'd like to hear about it."

At that, Bud turned fiery red, but with pleasure more than embarrassment. It was a crowning triumph in his career to find himself an object of interest in the eyes of so famous an aviator as Lieutenant Fosdick, of whom he remembered reading quite frequently as the most fearless air pilot in the Flying Squadron of Uncle Sam.

Encouraged by the winning smile on the bronzed face of the army officer, Bud only too gladly started to explain what his hopes were.

"I'd like to see this wonderful little model of yours in action, son," the experienced air pilot remarked afterwards. "Suppose all of you come over to our headquarters, which happen to be not more than half a mile away from here. We have a fine open spot where we can ascend and alight with ease, day or night. You will be welcome, I assure you. We have a dozen men there besides those connected with the war aviation corps, simply to guard against any spies giving us trouble. If you can go now, I'd be pleased to wait for you, so as to pass you through the lines."

"How long will it take you to get your little machine dismantled, so we can handle it, Bud?" asked Hugh.

"Oh! I can do it in a jiffy, because, you see, it's fixed for taking apart," the inventor of the party hastened to declare.

So Lieutenant Fosdick accompanied them to the shack. While Bud busied himself with his model, Ralph and Hugh chatted with the army officer. He asked more questions concerning Bud and the idea he had been trying out.

"It would seem as though your friend might have a touch of genius about him somewhere," the aviator said with a smile, "though I'm afraid that he's too late with that wonderful stability device, because it is very similar to one the Wright Brothers got out some time ago. That's the way it often happens, and many a man has studied some clever thing out only to find that he has been anticipated by some earlier inventor. But say nothing about this for the present. Your friend surely deserves to have a little glory out of the game before the blow falls. And I shall be curious to see how he manages with this model of his, for it looks good to me."

Evidently Bud had found favor with the army man. Even though doomed to disappointment with regard to his wonderful invention, the boy might derive satisfaction in knowing that his work had not been entirely in vain.

When half an hour had passed, Bud declared everything in readiness for the change of base; and soon the boys were accompanying the skilled aviator through the woods headed for the camp of the Flying Squadron.



CHAPTER IX

FRIENDS IN KHAKI

While they were pushing laboriously onward through the woods, overcoming all manner of obstacles, Lieutenant Fosdick gave the scouts a pleasant surprise.

"One reason why I asked you to visit our camp," he remarked, "was because I fancied all of you might be glad of a chance to take a spin aloft in an aeroplane. You may like that, if it happens that you've never enjoyed the experience up to now."

Hugh immediately turned to the army man and expressed his pleasure.

"I've often hoped to have a chance to go up," he said, "but hardly thought it would happen so soon. And we'll all be only too glad to accept your invitation."

"I should say so," added Ralph.

Bud did not say a single word, and turning to ascertain why, the officer found a smile of the "kind that won't come off" spreading all the way across his face. It was evident that Bud was too happy for words. He had long dreamed of spinning through the upper currents in one of those bustling airships that are becoming more common every day; but, like Hugh, he had not expected the golden opportunity to be sprung upon him so soon.

As they walked along, the officer once more started to question them regarding the two strange men who seemed to be hanging about without any known business to keep them up in this unsettled region.

"I think you said that one of them looked in through the window of your shack night before last, and then fled when you let him see that he had been discovered?" he remarked to Hugh.

"Yes, and we made sure that he had been there by examining the soil under the window. It is a part of a scout's education, you know, sir, looking for signs. We found them, too, marks of a long narrow shoe, that told us the man could never be a hobo but must be a gentleman. After they had rummaged through our cabin while we were away, we found the same marks before the door, and indenting tracks of our own, so that proved just when the fellows must have been around."

The army officer nodded his head and laughed softly.

"I understand what you mean, son," he remarked, "and it quite tickles me to know how clever our boys are getting under the influence of this new scout movement. It is bound to wake up most lads and set them to thinking for themselves, years before they would have been aroused under the old way. And I must say I'm heartily in sympathy with the work of the association. It's the finest thing that ever happened for the boys of America. If I had sons, they should everyone of them join one of your troops as soon as they were old enough."

"We forgot to tell you, sir, about hearing those two men rushing through the dense woods and thickets just after the explosion last night. They seemed to act as if more or less frightened; and I guessed that they may have had a narrow escape from being struck by your bomb."

At that, the other burst into a laugh.

"That is a rich joke," he declared. "Possibly in the excitement of the moment, after being knocked down by the shock, they may have suspected that we knew of their presence and were trying to encompass their destruction. But I am glad it happened that way. Perhaps they may have more respect for Uncle Sam's Flying Squadron after this, and fight shy of running their heads into trouble. I'll have the guards at the camp doubled at night time, and any straggler will be apt to find it pretty warm around there: I'd advise all persons who have no business at our headquarters to give the camp a wide berth, or something not down on the bills might happen, to their surprise and consternation as well."

"If you haven't run across these men, sir," Hugh remarked, "of course you could hardly say who they might be."

"I can give a pretty good guess, though," came the prompt reply. "We have been dogged by a pair of spies on former occasions, the one a short Jap, and the other, much taller, undoubtedly a German. Both of them happen to be famous aviators in their own countries, which was doubtless why they were sent out to discover what the Flying Squadron was doing up here in secret."

"I suppose their main objects would be to learn the composition of this latest thing in explosives, and to take note of your war aeroplane, so as to steal the improvements," Hugh went on to say, being desirous of learning all he could while the other was in this communicative frame of mind.