"Well, as I was saying, the spot that I picked out looked so little like water, that the Burlington railroad people—it was the Burlington that had asked me about it—called in Spearon, who really was the expert on the work. He's an expert all right. He promptly approved the site I had chosen, and told them to go down and they would strike good water at 3,000 feet. At first they laughed at the idea of any man being able to guess at the existence of water, 3,000 feet distant through solid rock, but they knew that Survey statements usually are to be depended on and they began. Some water was struck in an upper layer, but Spearon told them to go on. A dozen times the railroad was about to give up the project as useless, but, being urged, at last they agreed to go down the 3,000 feet, but not an inch further. At 2,920 feet they struck the sandstone, and boring on to 2,980 feet they struck water, and so, within twenty feet of the exact depth advised, they got a well flowing half a million gallons daily under a pressure of 75 pounds."

"A couple of hundred years ago, they would have burned you at the stake for a wizard," commented the boy.

"They would, son, sure enough. But people never stop to think how important this very water is. Why, it is by far the most valuable mineral in the United States!"

"More so than gold?"

"A thousand times! More than coal, too, which is vastly more valuable than gold. The coal's going to give out some day—by the way, remind me to tell you what the Survey's done on the coal question some time. I'd tell you now, but there's a man who got on at the last stop that I want to see," and with a nod, Field rambled to the other end of the car.

With stories and anecdotes of the Survey the time passed quickly, and Roger felt quite sorry the next day to find that they had arrived at their journey's end. At the depot, a small frame station, the rest of the members of the party awaited them, with a big lumbering farm wagon, but a pair of the finest horses Roger had ever seen. He won the heart of the teamster immediately by noticing them, and had the satisfaction of knowing that he had made a favorable impression on his future companions for the next few weeks by evincing a ready knowledge of the good points of a horse.

The drive that afternoon through the upper Minnesota country was Roger's first experience of a corduroy road, that abomination of highways, which consists merely of logs laid down horizontally across a trail and some dirt and sand sifted on top of them. In course of time, the dirt all seeps through between the interstices of the logs, and the latter arrange themselves in positions more picturesque than comfortable; which, being ridden over in a springless wagon at a good fast clip, is a more energetic "bump the bumps" than any amusement park has thought of inflicting on a suffering public.

Roger was thoroughly tired that night, though not for the world would he have shown it before his new-made friends; still he found much ado at supper to keep his eyes open and his head from nodding, when suddenly all his senses were galvanized into activity by the word "snipe."

"Boys, I promised Mr. Mitchon," Field was saying, "that we would have a snipe-shoot just as soon as we were able. Now, if we wait until we get right into the thick of the work, no one will want to knock off. Suppose we try a shoot to-night."

"Right you are," "Sure," "Just the thing;" a chorus of approval came from the members of the party and Roger was compelled to chime in with his assent, and, what was harder, to force an enthusiasm which, owing to his fatigue, he did not feel. Only one dissenting voice was heard, that of the farmer at whose house they were to put up for the night.

"There ain't no snipe round here," he said, "leastwise not this time of year."

"Yes there are, lots," answered Field, "I saw a big flight of them as we drove by that large slough a few miles out."

Roger thought it strange that the farmer should be mistaken about the bird season on his own farm, but surely people who could discover a flowing well 3,000 feet below the ground with nothing to show where it was, wouldn't be stopped for a few snipe. In fact, if any one had told the boy that the Survey had discovered the Fountain of Perpetual Youth or was making a detailed topographical map of Mars he would have accepted the statement without question or surprise.

The farmer's muttered objections being silenced by the united voices of the party, the plan of operations was outlined by Field.

"You see, Roger," he said, "as the youngest of the party you are always the guest of honor at the first few things the camp gets up, and so, as I promised, we'll let you have the best of the fun to-night. Remember, though, we expect you to get a big bag. It's a good dark night and you ought to be able to pick out a whole lot."

"But I don't see how you can work it at night," objected Roger. "Do you go out with torches, or how?"

"We'll show you how, when we get to that slough that I told you of. Bring that best gun of yours along, and we'll post you right where the birds will come."

There was a sense of strangeness about the whole affair which was puzzling to Roger, but he attributed it as much to his fatigue as to any other cause, and obediently fetched his gun out, saw that it was clean and in good order, and prepared to accompany the party. They borrowed a light rig from the farmer and started out. It was a little after nine o'clock when they left the house and fairly cold, while, as one of the men remarked, "It was as dark as the inside of an empty tar-barrel with the bung driven in."

They drove and drove for what seemed to Roger an interminable time, though he could not help wondering at the sudden twists and turns in the road, and several times, by the scraping of the underbrush against the body of the rig, he knew they were on no road at all. The undergrowth grew thicker and thicker and the ground more and more boggy, when, after they had been driving for at least two hours and Roger had fallen into a light doze, the horses were pulled up with a jerk.

"Here we are," said Field loudly. "Tumble out, boys."

The horses had been stopped at the very edge of an immense marsh, that looked almost like a lake in the dim light, but that its margin was fringed with reeds and bulrushes, and although it was so early in the year a scum was beginning to form. The place was not at all inviting, and Roger felt well satisfied that he was not there alone.

"Now, son," said Field, lighting a large lantern which was part of the camp outfit, "you stay right here and we will drive the horses away a little distance so that the possible noise of their moving about restlessly won't disturb the birds, and then we will circle the slough in both ways and drive the birds to you. You see, they won't rise at night, but keep to the ground, and if we start in opposite directions from the other side of the slough all the birds will come together right where you are. Then, when they find their escape cut off, they'll have to hit the water or else take wing."

"But it will be pretty hard to shoot them," protested Roger; "it's almost pitch-dark."

"They won't rise until they come into the circle of light shed by the lantern," said Field, "and then, if you're quick, you can get them as they rise. Now, remember, you've got to keep silent, or else, caught between two fires, they will scatter back from the water; we will be silent, too, so as not to scare them too much. Keep still, and don't shoot until the snipe begin to come into the light."

With this Field jumped into the rig, and a minute or two later Roger heard him stop the horses and speak loudly about tying them to a tree. A few moments later, he returned with one of the men.

"Harry and Jake have gone round to the south of the slough," he said, "and we will take the other side. Now remember, not a move until the birds begin to come. Good sport to you," and they were gone.

Roger sat patiently with his gun across his knees, waiting for the birds to come. He had been sitting perhaps for a quarter of an hour, when a very faint "Coo-ee" was heard and he stiffened to attention. The men, he thought, must be beginning to drive the birds from cover. The night wind was chill on the edge of the marsh, and Roger, expecting every minute that the birds would begin to come into the circle of light, dared not move. His left foot became numb, but he did not rise to his feet until the numbness became unendurable, and then, as softly and silently as he could, he stood up. The scene was even more lonely, viewed standing up. There was not a light to be seen, not a sound to be heard, save the hoarse croaking of the frogs and the booming of a bittern in the far distance.

The minutes passed into hours, until it became agony to refrain from sleep, but Roger felt that he would be forever disgraced in the eyes of his comrades if he were found asleep at his post on the very first occasion they had given him a trial of endurance, and he promised himself that he would stay awake, no matter what it cost him.

Then a faint mist began to wreathe upwards from the lake and took all sorts of fantastic shapes before the boy's tired eyes, and while, for a little time, it afforded him occupation to watch their curling gyrations, at the last this but added to the dreariness of the place. Once his eyes had closed and he dozed for a few seconds, when he was aroused, and not only aroused but startled, by the far-off howl of a wolf. Roger was no coward, and had all the boy's contempt for the coyote of the prairies, but he was woodsman enough to know that the coyote troubles timbered lands but little, and that the call was from the throat of the dreaded timber wolf.

What would not the boy have given for one of his rifles? But there he was at the edge of a slough, not even knowing in what direction he could retreat should flight prove necessary, with no weapon but a shotgun loaded with small bird-shot, and a timber wolf prowling near. Once, indeed he thought of shooting in order to attract attention, but the morbid fear of being thought timid and old-womanish restrained his hand from the trigger.

Again came the call, clear and unmistakable this time, and drawing nearer. All the wolf stories that he had read beside the fire at home rushed across his memory now—the Siberian wolves who chased across the steppes that traveler who saved his unworthy life by sacrificing to the beasts successively the three children intrusted to his care; the wolves who picked clean the bones of all the inhabitants in the Siberian village who refused to help escaping prisoners; the were-wolf, who, half-maiden and half-brute, lives on the blood of men; until, in spite of his courage, Roger found himself feeling far from at ease and deeply wishing that some of the others in the party were there to keep him company.

Again the wolf howled, a long-drawn-out howl with a little "yap" before it. Had Roger but known, he need have had no fear, for such is not the call of an angry or a hungry wolf, but merely the cry of the solitary hunter not running with the pack. A wolf after his prey does not howl, but gives a succession of short, sharp barks. Presently the boy received a sensation as of movement among the bushes to his right. He looked intently, but could see nothing. At one time, indeed, he thought he could discern two specks of light that might have been the eyes of the intruder, but knowing how easily the eyesight is deceived when it is being strained, and also having the good sense of not making matters worse by wounding a beast he feared he could not kill, Roger contented himself by keeping a lookout with every nerve strung. There was no longer any thought of the snipe, they had paled into insignificance before what appeared to be—although it was not—a real danger.

So Roger stood, watching the brush, the long night through, the little lamp shedding its pale gleam upon the ground at his feet and glimmering upon the waters of the lake, until in the east the first gray light of the false dawn began to appear. Gradually the light increased, and Roger with a sigh of relief took his eyes from the bush he had watched anxiously so long. As the day began to break and to disperse the slight mist, objects in the distance seemed to take shape, and Roger could hardly believe his eyes when he saw, but a few hundred yards away, the very house where he had supped the night before, and from which he had been taken a long two-hours' ride.

In a moment it all flashed on him, the old farmer's incredulity at the presence of snipe at that time of year, the readiness to put the newcomer in the place of honor, the unanimity of all the members of the party in falling in with the chief's suggestion, the folly of shooting anything on a pitch-black night, and he saw that he had been hoaxed. He was wet, incredibly weary and stiff from the strain, and Roger's first impulse was that of intense anger. As he would have phrased it himself, he was "good and mad." The boy soon reflected, however, that if this was a regular performance on the tenderfoot—which appeared probable from Mitchon in Washington having been in the game—a good deal depended on the way he took it. They would expect him to be angry or sulky. Well, he would disappoint them.

Just as he was about to walk into the barn, however, where he proposed to have a nap in the straw, who should meet him but Field and another of the men! They greeted him with a shout of laughter and satirical queries as to the number of snipe he had shot. Roger schooled himself to laugh in reply.

"That was one on me, all right," he said, "but this is only my second day. It's your turn now, but mine will come some other time."

The chief laughed appreciatively.

"That's the right way to take it, Roger," he said, "and now you'll know enough not to go shooting snipe any more at night, I reckon. But, lad, it's early yet, and we won't start for a couple of hours, so you just turn in and we'll call you when we are ready to go."

"I won't deny that I'll be glad of a nap," said Roger, yawning, "and I'm mighty glad that this part of my initiation is over with."

CHAPTER III
FOOLING A RESCUE PARTY

The work itself was not so hard to understand or to follow, but the difficulties of the nature of the ground made it appear to him almost insurmountable. Arising early in the morning, about half-past five o'clock, he found himself fully ready for breakfast, which was duly over by half-past six, when the work of making up the packs began. Each man in the party was supposed to carry a pack, all the properties of the camp being divided up into equal weights. The making up of these was a source of no small anxiety, as the division of weight made a lot of difference in the day's march. The load was so divided that it would rest upon the back, just below the neck, and to keep it in place a broad strap, called a "tump-strap" was passed across the forehead. If the strap was a little long, or the load adjusted so that it hung too far down, the effect was to jerk the neck back until it seemed that it would snap off, while if the load was too high up on the neck, in order to distribute the weight evenly the bearer would have to bend so far forward that he would be walking almost double.

Sometimes, though not often, the party was able to proceed straightaway without any ax-work, but more often all hands had to set to work, clearing away underbrush and second growth so that a clear distance might be secured for making a sight. At first it would seem that a swamp perforce must be level, and in such a case drainage would be extremely complex and difficult, but in the Chippewa swamps there is a heavy fall toward the Red Lake River, this fall, however, being interrupted by numerous small hog-backs and elevated stretches of ground which might almost be called islands.

"But, Mr. Field," said Roger to his chief, when this was explained to him, "if a drainage ditch were cut direct from the highest point of the marsh to the Red Lake River, would not all the water naturally flow into it, and so drain the swamp without all this elaborate surveying?"

"And how would you find the highest point or points of the marsh," said the other, smiling, "without a survey? You see, son, this swamp is like a continent on a small scale. It has its mountains and its valleys, its plateaus and its ravines, though these be measured in inches instead of hundreds of feet. Now, if this ground were rocky, all this drainage would make for itself a network of small streams and flow down to the river, but as the ground is naturally spongy the water has lain instead of running, and therefore has not cut any channels. Add to this the hundreds of thousands of years' deposit of rotting vegetation, and you see how impossible it is for the water to do what would naturally be expected, that is, find its own level."

"But it must flow down some time, surely," said the boy.

"The overplus does. In spring, that is to say in early spring, right after the snow melts, this whole swamp is a sheet of water, even worse than it is now, and the houses on the higher grounds are on islands, the farmers going to and from them with boats, but that soon runs off until it reaches the level of complete saturation, in other words, a bog as wet as it can hold. Now, what we have to do, is to trace this highest point or points, such as you spoke of, or, to speak more correctly, the succession of the lines of highest points, a very crooked series of lines, and find out their relation each to the other. This you see, will divide up the swamp into several drainage areas. Then each of these areas is to be surveyed to determine the line of drainage, the whole to be conformed to the main ditches that will flow to the river, and this intricate network of ditches must be kept at just the exact level of fall, so that it will flow unencumbered to the streams on either side of the swamp."

Roger whistled softly.

"That's why you've got to go over every foot of the country so carefully," he said.

"Of course. If it wasn't for the trees and brush, which prevent us seeing just where every little rise is, it would be comparatively easy, but unless we know the lie of the ground, we might plan a ditch just on the wrong side of a ridge of comparatively solid earth, which would divert the entire stream. Of course, there's a pretty good fall to the river, both the Mud River and the Red Lake River, but even so, an unobserved ridge of earth a few feet high, running along for a couple of miles would throw out the value of that particular ditch and create the cause for a new drainage area."

"I see," said the boy, "and I'm very glad you told me, Mr. Field, because it did look to me as though a lot of this exactness was unnecessary."

"We do nothing unnecessary on the Survey," came the prompt response. "No man knows better than we how much work there is yet to be done."

As the days went on Roger found himself becoming quite apt at the pack work, and, to his great delight, found his muscles hardening under the exercise so that the strain was not so great. Several times too, and this gave him great joy, the chief would send him out off the line of march, not more than fifty yards, with instructions to report on the nature of the ground. When about that distance, well within earshot, he was supposed to "Coo-ee" in order to find his way back to the party.

It chanced one afternoon, right after the short stop in the middle of the day, that Field sent Roger off, to the right of the party, in quite dense timber, and told him not to go further than twenty-five yards away. For twenty or thirty feet the boy hacked manfully through the underbrush, and then, to his delight, came across a smooth piece of marsh overlaid with water. Testing carefully every step he took, the lad found the bottom of it less like a morass than was the general character of the swamp, and he knew enough to realize that there must be firm ground on the other side. Knowing, moreover, that a piece of information such as this would be of great assistance he ventured to cross the stretch, and as he surmised, found a small hog-back on the further shore of the shallow lake. This ran parallel, so far as he could judge, with the route being taken by the members of the party, and Roger conceived the idea of following along this line, until it would be time for him to rejoin his friends. The wood was thick on the ridge, however, and Roger found that he was not making good time, so after going half a mile or so, he decided to strike across and meet the rest of the party.

When Roger turned, however, he found that he had ceased to be opposite the slough, and he plunged into a dense and palpitating quagmire, the kind against which he had been specifically warned, fairly firm on the surface, but which quivered like a jelly as far as he could see when he stepped upon it. None the less, it was the only way the boy knew to rejoin his comrades, so with considerable trepidation he stepped upon the edge. It held him, though with a sort of "give" that was most unpleasant. Another step he took, and this time the quag seemed to resent his intrusion; large black bubbles formed slowly and broke a few inches before his foot and the ground seemed to heave in front of him. The boy realized that he could go no further, but for daring and curiosity he took another step gingerly to see what would happen.

He learned! As the foot touched the ground it sank even with the little weight that he threw on it, almost to the depth of an inch, and with that slight pressure suddenly the suction of the marsh gripped him as though some foul fiend had him by the heel, and he threw all his weight back on his left foot in an endeavor to pull out the right. But this disturbed the balance of his poise, and the sudden weight on the one foot caused it to break through and the marsh had him by both feet. The pressure was so fearful that Roger knew shouting was useless, he would be deep under the quagmire before his comrades could even begin to find him.

But Field had not instructed Roger for nothing, and the lad was quick of thought. Instantly he threw his surveyor's rod down so that one end was on the comparatively dry ground whence he had stepped, the other by his feet, and with one supreme effort he threw himself flat upon the rod, though wrenching his ankle cruelly as he did so. This distribution of his weight over so much larger a plane surface prevented his further sinking, but the suction was still so great that he could not draw out his feet. Finally, by exerting all his strength he freed the one that was furthest out, and which had sunk but little, but he was held a prisoner by the other foot. Then an idea occurred to him. Taking his ax, he chopped the ground around his leg, and had the satisfaction of seeing water bubble up in its place. Little by little he loosened the suction of the bog until at last he was able to pull out his foot and crawl along the rod to the bank, where, trembling and exhausted, and suffering considerable pain from his wrenched ankle, he sat upon a projecting root to recover his breath and his somewhat shaken nerve.

This was Roger's first experience of the folly of attempting more than he had been told to do, before he was an old enough hand at the game to know the greatness of the risk. As soon as he had in part recovered himself, he shouted, according to agreement, expecting to hear immediately the return hail, which would tell him exactly where the party might be. But there was no answering cry! A little startled at the thought that he might have wandered out of hearing of the party, Roger waited a moment, then, making a megaphone of his hands, let out a stentorian howl, for all that he was worth. But the cry fell stifled in the dense branches and a muffled echo was the only response. Thinking that perhaps a whistle would sound further, he put his fingers in his mouth and whistled long and shrill, a note loud enough, it seemed to him, to be heard for miles; but for all the token of human answer, it might have been the crying of the curlew above the marsh.

By this time Roger was fully alive to the difficulties that confronted him. If he were out of reach of the party, and could not make himself heard, it would be very difficult to trace them, even if he crossed their trail; unless it were where they had been making a sight or where undergrowth had been cut, there would be no mark of their passage, as the soft ground speedily sucked in all trace of footsteps. A shot, he thought, would travel farther than the voice, and so, taking out his revolver, the boy fired three times in the air. He strained his ears eagerly, though fearing that no shot would answer, but when the minutes passed by he knew that he was lost and that he would have to find his way back to the party unaided.

But one thing remained to be done. He must retrace his steps, trusting to his new-born knowledge of woodsmanship to lead him aright, back to the place where he had gained the ridge of ground from the shallow lake, then cross that, if he could remember the direction, and he would be but twenty yards or so from the path the party must have traveled. He would be a couple of hours behind them, of course, but if he could strike their trail he was bound to overtake them some time that night. There was no other alternative, he must endeavor to find them, even at the risk of becoming still more enmeshed in the mazes of the swamp.

Limping back over the ridge of ground, his ankle growing sorer each step, Roger painfully wended his way to the little lake. He found the ridge, but in returning it appeared to divide into twain paths, and for a moment his heart sank within him; as luck would have it, however, he remembered seeing a tree that had been struck by lightning somewhere about where he then was, and he determined to go along each of the paths until he struck the tree. Taking the left hand, at random, he hobbled along for half an hour, but seeing no blighted tree, retraced his way and took the other path. Just as he was about to give up that route also, in despair, the sentinel tree on which he had been building loomed up before him. It was the first sure sign that he was on the right trail, and Roger let out a boyish whoop of delight. Suddenly he thought he heard an answering yell, and he called again, but there being no answer he felt that his ears had deceived him. Soon he came to the banks of the little shallow lake, and struck in to wade across.

This time, however, the luck which seemed to have deserted him so long, returned, for he found himself, in the course of a few steps, just at the place where the brushwood had been cut recently for the making of a sight, and the boy knew that he could not now be very far from the rest of the party. He followed the blazed trail as rapidly as his somewhat crippled condition would permit, shouting occasionally as he did so, when suddenly he heard voices. Stopping to make sure, and hearing speech quite distinctly, he hurried on, coming at last to a dense dark piece of the wood through which a path had been hewn with some difficulty. Another two minutes, he was assured, would bring him among his comrades, when he heard the voices again, and what they said made him pause.

"It's a good one on the boy," said one of the voices.

Roger knew that he was always spoken of in camp as "the boy," and he thought if they were planning some practical joke on him, like the "snipe shoot," over which they had never ceased to tease him, there could be nothing wrong in listening so that he could checkmate it.

"He must be quite near us, now," replied the other.

"Almost as near," said the first speaker, "as he was when he first thought that he was lost. That was an awful howl he gave, the second one we heard. It would make a fair sample for an Atlantic liner's foghorn."

Both men laughed, and the rich, easy voice of the chief of the party broke in.

"I'm not sorry the boy got a scare," he said; "he's all right, is the boy, but he thinks he knows it all. They all do, at first. I told him not to go thirty yards away, and one way and another he must have gone a mile. It's a good thing he paralleled us, or somebody would have had to go after him."

"I thought sure he'd find us right away when David called back," said the first speaker.

"Yes," replied Field, "I thought so, too. But he didn't, you see. Now let him learn how hard it is to find a party in these swamps and he'll know better next time. You've got the location of his last call, haven't you?"

"Sure!" said one of the men.

"Oh-ho!" thought Roger to himself. "So that's the reason I got no answer to my shouting and my shots. They're just waiting until I get in to guy me some more." He sat down on a root and thought for a few minutes. Then he grinned, and decided to bear the pain in his ankle a few moments longer. Striking off sharply from the trail that had been cut, he wormed his way up and on until he was almost opposite the party, and directly to the left; then, holding a bunch of grass over his mouth to give the muffled sound as of great distance, he gave a howl, putting into it as much anguish as he could manage.

As he expected he heard the sounds of work cease.

"The young idiot's wandered off the trail again," he heard David say to the chief.

"Well, get the direction," was the answer, with a tinge of annoyance this time, "and you two had better go after him. I made sure from his last hail that he was right by the camp."

Roger waggishly nodded his head in the direction of the speaker.

"I don't envy those two men their job," he said in an undertone, and, doubling on his tracks, he came back to the trail that had been blazed. Then circling round to the right, so as to be in the opposite direction from that which his searchers had taken, he quietly made his way past the working force and came to the spot where the cook was just making preparations for dinner. Unobserved, he crept quite close to the camp, and finding a convenient spruce with widely spreading branches, he climbed up some fifteen feet, where was a natural hammock in the boughs, and lay down, taking off the boot from his swollen foot and awaited what should come.

He had not long to wait. In less than half an hour the two men returned stating that they had found some signs of ax-work in the vicinity of the last hail, but that they had called and called and received no reply. The men spoke gravely and one of them said:

"I hope the youngster has not struck a quag!"

The leader gave an impatient exclamation.

"Well," he said, "it's our own fault if we have any trouble finding him, but he has been within a hundred yards of the camp all this time that he has been making such a fuss, and how he could be such an ass as to cross our trail and get on the other side of it without noticing, gets me."

Roger chuckled.

"You'll find it harder hunting for me than I did for you," he said to himself, "and perhaps the laugh won't be all on the one side."

He settled himself more comfortably in the tree and listened to Field giving instructions to the members of the party how they should separate and circle at an appointed distance, calling every few minutes as they did so.

In less than a quarter of an hour the camp was vacant except for the cook, who was still busy preparing the evening meal. That was the only part that was hard to Roger, for he had been through a good deal of excitement since lunch and not only was tired, but also very hungry. His foot was not hurting so much now that he was not stepping on it and with his boot off, although it had puffed up rapidly after the removal of the boot. But to be up in the branches of a tree, as hungry as a wolf, and to see the grub below, was almost more than boy nature could stand.

Presently the cook, having laid out a loaf of bread and a knuckle of ham, picked up his ax and went into the brush to get a little more dry wood, which was somewhat scarce about the camp. Roger slipped down from the tree and seized the bread and ham. Then in order that it might not be suspected who had done it, he scrabbled on the tin plate with some mud, and in the stiffer soil about—for that was the reason it had been chosen for a camp,—he made some tracks with the first, second, and third knuckles of his hand and the mark of his thumb knuckle behind. At a little distance the track looked almost like fox tracks. By stepping carefully on tufts of grass he kept the marks of his own feet from being seen, and then, with his booty, he returned to the tree.

He was hardly more than safely ensconced among the branches when the cook returned. He busied himself about the fire with the wood that he had brought, then chancing to look at the dish, he saw that the hambone and the bread had gone. The cook, whose language was that of a woodsman, consigned all four-footed thieves to perdition, and then bent down to examine the tracks. He looked at them carefully several times over, then:

"I sure would like to see that beast critter," he said, "fer that's the most plumb foolish tracks I ever set eyes on. It must be fox—but there ain't no foxes in this kind o' country, and, anyhow, the tracks don't mate."

This was true, for Roger had made the tracks, both on the nigh and the off sides with the fingers of his right hand. The cook, after muttering and grumbling to himself, got out from his store of provisions enough for the meal, and proceeded to cook the same, not without many returns to the mysterious tracks and comments more or less audible on creatures with feet like that who were so apt at thieving.

Presently two of the party came in, shaking their heads negatively to the cook's questioning gesture.

"Nary a sign," said one of the men, "he's lost a good and plenty."

"I ain't got much time to help," said the cook, "though I'll go out with you after supper. But this spot has got me locoed."

"How's that?" asked one.

The cook pointed to the tracks.

"I used to think I knew quite some about the swamps," he said, "I was born with an ax in my hand, pretty near, but I never yet saw any critter with tracks like them. An' what's more, I ain't never been informed that ham sandwiches form a reg'lar part of a fox's menoo!"

One of the men bent to examine the tracks, but the other said airily:

"I'm no Seton-Thompson on the tracks question. Wait till David comes, he's a regular nature-faker for you. Leave him alone and he'll tell a tale of seeing a fox do the honors at a ten-course dinner with squirrels popping the champagne corks."

The cook laughed, but awaited the verdict of his comrade, who, after a prolonged examination, straightened himself, and remarked soberly:

"That's got me! You say the hambone and the bread were clean gone?"

"Clean as a whistle! There was a lot of mud on the dish, and that was all."

"Put it up to David, or Field. Field will tell us all he knows, and what's more, will explain why he doesn't know the rest; but David will put up the best yarn."

A few minutes later the rest of the party dropped in and in turn expressed surprise and conjecture about the confusing marks upon the ground until all were back except David and the chief, and shortly David appeared.

"Where's Field?" one of the men asked.

"He stayed behind a minute or two for something. He said he'd be right along. No," he continued, in answer to a question, "we didn't see anything of the boy."

"Well, it's a good thing you're here, anyway," said the cook, "for we've been waiting for you to explain a mystery that's puzzled the whole camp. You're a woodsman, you know, and it's up to you to tell us."

"All right," said David with a confident swagger. "Trot out your mystery."

The cook led him to where the tracks were visible in the soil and related to him the theft of the hambone and the bread, concluding with:

"And what we want to know is—what kind of a critter made them tracks?"

David stooped down for a few seconds and looked at the marks on the ground, then turned around to the fellows grouped about him, and said in a tone of scorn:

"You don't know what that is?"

"No, what is it?" responded one of the men.

"Well, you're a pretty lot of lumberjacks not to know a swamp angel's work when you see one."

"Swamp angel?" queried the cook in amazement.

"Swamp angel, of course. Yes, why not? I suppose"—this in a tone of much condescension—"you have heard of a swamp angel?"

The cook grinned at him.

"You're a good one, David, all right," he said. "Go on, tell us about a swamp angel."

"Why, a swamp angel," said David, thinking rapidly, "is a cross between a flying squirrel and a flying fox——"

"With a strain of flying-fish thrown in. Go on, David," interrupted one of the men with a laugh.

"It lives only in the densest kind of swamps," went on David, ignoring the interruption, "and it is called an angel because it can fly so readily. Its chief characteristic is that it crosses its legs while walking, so that the off fore and hind leg track on the nigh side and the near ones on the off. That's what gives the tracks that peculiar look you noticed. Its usual food——"

"Is ham sandwiches," broke in the cook. "No, David, I guess the swamp angel yarn's a little strong. Here comes the chief; we'll see what he says about it."

As soon as Field arrived near the group of men, the cook started in to tell him about the theft of the food, but the chief stopped him.

"To Texas with the hambone," he said; "we've got no time to waste talking about trifles. It's up to us to find that boy without delay. I hold myself to blame in not getting after him sooner, but his last hail, it seemed to me, just before the one I sent you to find him on, was only a few yards from the camp. How, in so short a time, he could have got out of earshot, is a thing I don't understand. I only hope he hasn't put a bullet into himself somewhere with that pesky little gun of his while he was firing all those shots. Get busy at the grub, boys, because if we don't get him by the time it's dark, he may be out all night, and I don't want that."

"He can't be very far away, Mr. Field," said David.

"As long as he's out of reach, it doesn't much matter whether he's near or far. But he must be found, if it takes all night."

All through the supper the men discussed plans for the finding of the boy, but when Roger heard Field tell two of the men to start out and not return until midnight if they hadn't found the lad before then, he thought it was time to bring the jest to an end. He parted the branches over the chief's head and looked down.

Then, suddenly, the men gathered around the fire heard Roger's voice, saying in a smooth and sarcastic manner:

"I was never called an angel before, not even a swamp angel, though I'm pretty well up toward heaven in this tree. But this hambone is very dry eating, and I guess I'll come down for the butter and the mustard."

"You blithering idiot!" said Field, looking up angrily, though there was evidently a great relief in his voice, "get down out of that."

"Oh, very well!" said Roger with a grin, as he descended the branches of the tree. Then, coming into the circle, he added, "I thought I'd come down and help you eat that snipe that Mr. Field has just brought in!"

CHAPTER IV
IN THE GIANT TULE SWAMPS

Roger was growing weary of the Minnesota work because it was evident that it consisted of the same routine day after day, that it was unremittingly hard work, and that the sense of progress was slow in proportion to the labor involved. Then the mosquitoes were beginning to get troublesome, and worst of all, the "bulldog flies" began to make their presence felt. These large horse-flies, which madden cattle and drive horses to distraction, in certain parts of the marsh were ferocious and hungry enough to attack men. Roger found that he was popular with them and got many sharp nips, which, though in no sense dangerous, were irritating and painful.

"I don't want to seem ungrateful, Mr. Field," he said, when his chief broached the return of his former co-laborer to him, "and I'm not, but Mr. Mitchon seemed to think that I would only stay a few weeks here, for the sake of the experience and to get the hang of this kind of work. I think I have gained some knowledge of it, and," he laughed, "I can shoot snipe and teach swamp angels to steal ham sandwiches."

The chief smiled in response.

"You turned the tables on us very neatly that time, Roger," he said, "and you really had me badly worried, because, as you know yourself, these swamps are not a good place to get lost in. I reckon, from what you've told me, that if you had walked heedlessly on into that quag without trying to test it step by step, you would still be there, only at the bottom instead of the top."

"I really believe I would," answered the boy seriously.

"If you stick to the Survey," went on Field, "and come to be the head of a party, particularly in wild country, you will see how necessary it is to do just what you're told instead of trying to run the thing your own way. If you follow instructions and anything goes wrong, then the fault belongs to the head of the party, who is supposed to have enough judgment and experience to know what to do in an emergency. What could have been more simple than to go twenty or thirty yards farther away than you had been told, just as you did, for instance, and yet, if you had not been lucky, you would have disappeared forever in that quagmire and by your death spoiled our record."

"Have many lives been lost in Survey work?" asked Roger.

"In the nearly thirty years of the existence of the Geological Survey, as a separate branch of the Department of the Interior," replied Field, "during which time explorations of the most extreme peril have been undertaken, only one life has been lost. Really, when you come to consider how much of the work has been done in lands absolutely unknown, and that thousands of miles of territory have been covered wherein a white man had never before set his foot, this is nothing short of astounding."

"But if sickness should strike a camp?" queried the boy.

"Hard work, clean living, good judgment, and the open air, are worth all the drugs we know about and a whole lot more that we don't. Of course a small chest of certain radical remedies accompanies each party, with quinine and things like that, but it is seldom that it is opened."

"But how about accidents, Mr. Field?"

"Such as?"

"Breaking a leg by a fall, or something like that," the boy responded.

"I don't see what business any man on the Survey has to fall. That isn't what he's there for. He's there not to fall. Personally, I have never had any accidents which would need other than ordinary attention, nor have I had any with any members of my party. Then an injury would have to be pretty bad, any way, that couldn't wait until some kind of a doctor was reached, that is unless it was in the north of Alaska, or some place like that, and in such trips a little surgical case is sent along, and the chief would do as well as he could do with it."

"Then," said Roger with a short laugh, "I'm just as glad that I'm not at the bottom of the quag, for your sake as well as my own, for I should hate to be the one to spoil the Survey's record."

But while Roberts was expected in camp shortly, a couple more weeks rolled away before the party, completing its line through a very difficult piece of marsh, headed for one of the famous corduroy roads and made its way back to headquarters. There, with one of the farmer's children on his knee and the others grouped around him sat Roberts, occupied apparently in telling some interesting story or fairy tale. He put down the youngster and shouted as the party hove in sight.

The chief was delighted without question to see the newcomer, for while he had been greatly pleased with Roger, the boy could not be expected to be as valuable as an experienced man, and was not to be depended on to proceed in his work without instruction and supervision.

"I was looking for you a couple of weeks ago, Mr. Roberts," he said.

"I expected to be here earlier, Mr. Field," answered the other, "but Mr. Herold asked me to put in a few days in that Susquehanna flow-measurement business, and that put me back."

Roger looked inquiringly at his chief, who catching his look of question, said,

"Well, son?"

"I would like to ask," said the boy hesitatingly, "what that stream flow-measurement is for?"

Roberts looked up a little surprisedly, but a few words from Fields explained the situation, and the newcomer turned to Roger quite affably.

"Certainly, my boy, it's very simple," he said. "You see, all work on rivers, whether for the purpose of irrigation, flood control, or navigation, is dependent on the amount of water that flows through that river channel every year. A week of wet weather makes a vast difference to the amount of water the river is carrying, and a dry spell cuts it off."

"But don't springs and things keep the water about even?" queried the boy.

"No, indeed," answered his informant emphatically. "Why, the Tennessee River, which I worked on once, for three months never flowed more than 20,000 cubic feet per second, yet that same year, for fifteen days in the spring, it tore down with over 360,000 feet a second. In other words, in the spring it was as big as eighteen rivers its usual size."