It was a bushmaster which started the Quest of the Emerald—and only a possible bushmaster at that. One May evening in Cornwall, Big Jim Donegan, the lumber-king, sat in the misty moonlight with his slippered feet on the rail of the veranda of the great house in which he lived alone. He was puffing away at a corn-cob pipe as placidly as if he did not have more millions than Cornwall has hills—which is saying something, for Cornwall has twenty-seven of the latter. Along the gravel walk, which wound its way for nearly half a mile to the entrance of the estate, came the sound of a dragging footstep. A moment later, from out of the shadows stepped a man over six feet in height, a little stooped, and who wore a shiny frock-coat surmounted by a somewhat battered silk hat. The stranger had a long, clean-shaven, lantern-jawed face. His nose jutted out like a huge beak, a magnificent, domineering nose, which, however, did not seem in accord with his abstracted blue eyes and his precise voice.

"What do you want?" snapped Big Jim, bringing his feet to the floor with alarming suddenness.

The stranger blinked at him mildly for a moment with a gaze that seemed to be cataloguing the speaker.

"This is Mr. James Donegan," he finally stated.

"How do you know?" demanded the lumber-king.

"You have all the characteristics of a magnate," returned the other, calmly, "energy, confidence, bad temper, worse manners, and—"

"Whoa!" shouted Big Jim, whose bark was worse than his bite and who always respected people who stood up to him. "Never mind any more statistics. Who are you!"

"My name is Ditson," responded the other, sitting down without invitation in the most comfortable chair in sight. "Professor Amandus Ditson. I am connected with the Smithsonian National Museum."

"Well," returned Mr. Donegan, stiffening, "I don't intend to subscribe any money to the Smithsonian Museum or any other museum, so there's no use of your asking me."

"I had no intention of asking you for anything," returned Professor Ditson, severely. "I had understood that you were a collector of gems, and I came to place at your disposal certain information in regard to the finest emeralds probably now in existence. I too am a collector," he went on abstractedly.

"Humph!" grunted Big Jim. "What do you collect?" he inquired, regarding his visitor shrewdly.

"Bushmasters," responded Professor Ditson, simply.

"Come again," returned Big Jim, much puzzled, "I don't quite get you. What are bushmasters?"

"The bushmaster," announced Professor Ditson, with more animation than he had yet shown, "is the largest, the rarest and the deadliest of South American serpents. It attains a length of over twelve feet and has fangs an inch and a half long. You will hardly believe me," he went on, tapping Mr. Donegan's knee with a long, bony forefinger, "but there is not a single living specimen in captivity at present, even in our largest cities."

The lumber-king regarded the scientist with undisguised astonishment.

"Professor Amandus Ditson," he announced solemnly, "so far as I'm concerned, there can continue to be a lack of bushmasters not only in our great cities, but everywhere else. Snakes of any kind are absolutely nothing in my young life."

"Tut! tut!" responded the professor, reprovingly. "I think that I could convince you that you are wrong in your unfortunate aversion to reptiles."

"No you couldn't," returned Big Jim, positively, "not if you were to lecture all the rest of the year."

"Well," responded Professor Ditson soothingly, "suppose we discuss your hobby, which I understand is precious stones."

"Now you're talking," returned the other, enthusiastically, "I suppose I've about the finest collection of gems in this country, and in some lines perhaps the best on earth. Take pearls, for instance," he boasted. "Why, Professor Ditson, some boys right here in Cornwall helped me get the finest examples of pink and blue pearls that there are in any collection. When it comes to emeralds, there are half a dozen collectors who beat me out. What's all this dope you have about them, anyway?"

"Last year," replied the other, "I was in Peru at a time when they were repairing one of the oldest cathedrals in that country. A native workman, knowing that I was interested in rarities of all kinds, brought me an old manuscript, which turned out to be a map and a description of the celebrated Lake of Eldorado."

"That's the name of one of those dream places," interrupted Mr. Donegan, impatiently. "I've no time to listen to dreams."

Professor Ditson was much incensed.

"Sir," he returned austerely, "I deal in facts, not in dreams. I have traveled one thousand miles to see you, but if you can not speak more civilly, I shall be compelled to terminate this interview and go to some one with better manners and more sense."

"Just what I was going to suggest," murmured Big Jim, taken aback, but much pleased by the professor's independence. "So long, however, as you've beat me to it, go on. I'll hear you out anyway."

Professor Ditson stared at him sternly.

"For nearly four hundred years," he began at last, "there have been legends of a sacred lake somewhere in Bolivia or Peru. Once a year, before the Spanish conquest, the chief of the Incas, the dominant race of Peru, covered with gold-dust, would be ferried out to the center of this lake. There he would throw into the lake the best emerald that had been found in their mines during the year and then leap in himself. At the same time the other members of the tribe would stand on the shores with their backs to the lake and throw into the water over their shoulders emeralds and gold ornaments."

"Why on earth did they do that?" exclaimed the old collector.

"As an offering to the Spirit of the Lake," returned the professor. "The Spaniards, when they heard the story, named the lake, Eldorado—The Lake of the Golden Man. As the centuries went by, the location was lost—until I found it again."

There was a long pause, which was broken at last by the lumber-king.

"Have you any proof that this story of yours is true?" he inquired sarcastically.

For answer, the scientist fished a dingy bag from his pocket and shook out on the table a circlet of soft, pale gold in which gleamed three green stones.

"I found this ten feet from the shore," he said simply.

The lumber-king gasped as he studied the stones with an expert eye.

"Professor Ditson," he admitted at last, "you're all right and I'm all wrong. That's South American gold. I know it by the color. African gold is the deepest, and South American the palest. Those stones are emeralds," he went on; "flawed ones, to be sure, but of the right color. The common emerald from the Ural Mountains is grass-green," lectured Mr. Donegan, fairly started on his hobby. "A few emeralds are gray-green. Those come from the old mines of the Pharaohs along the coast of the Red Sea. They are found on mummies and in the ruins of Pompeii and along the beach in front of Alexandria, where treasure-ships have been wrecked."

Professor Ditson yawned rudely.

"Once in a blue moon," went on the old collector, earnestly, "a real spring-green emerald with a velvety luster, like these stones, turns up. We call 'em 'treasure emeralds,'" he continued, while Professor Ditson shifted uneasily in his chair. "Most of them are in Spanish collections, and they are supposed to be part of the loot that Cortez and Pizarro brought back to Spain when they conquered Mexico and Peru. How large did these old Peruvian emeralds run?" he inquired suddenly.

He had to repeat this question before Professor Ditson, who had been dozing lightly, roused himself.

"Ah yes, quite so, very interesting, I'm sure," responded that scientist, confusedly. "As to the size of South American emeralds," he went on, rubbing his eyes, "the Spanish record shows that Pizarro sent back to Spain several which were as large as pigeon eggs, and there is a native tradition that the last Inca threw into Eldorado an oval emerald as large as a hen's egg."

Donegan's face flushed with excitement.

"Professor Ditson," he said at last, "I've got to have one of those emeralds. Come in," he went on, getting up suddenly, "and I'll show you my collection."

Professor Ditson sat still.

"No, Mr. Donegan," he said, "it would be just a waste of time. To me, gems are just a lot of colored crystals."

The old lumber-king snorted.

"I suppose you prefer snakes," he said cuttingly.

Professor Ditson's face brightened at the word.

"There," he said enthusiastically, "is something worth while. I only wish that I had you in my snake-room. I could show you live, uncaged specimens which would interest you deeply."

"They sure would," returned Mr. Donegan, shivering slightly. "Well," he went on, "every man to his own taste. What's your idea about this emerald secret? Can we do business together?"

The professor's face assumed an air of what he fondly believed to be great astuteness.

"I would suggest," he said, "that you fit out an expedition to the Amazon basin under my direction, to remain there until I collect one or more perfect specimens of the bushmaster. Then I will guide the party to Eldorado and assist them, as far as I can, to recover the sunken treasure."

He came to a full stop.

"Well," queried the lumber-king, "what else?"

The professor looked at him in surprise. "I have nothing else to suggest," he said.

"Suppose we get emeralds which may be worth hundreds of thousands of dollars—what percentage will you claim?" persisted Mr. Donegan.

"I thought that I had made it plain," returned the professor, impatiently, "that I have no interest whatever in emeralds. If you will pay the expenses of the expedition and allow me to keep as my own property any specimens of bushmasters obtained, it will be entirely satisfactory to me. Of course," finished the scientist, generously, "if we catch several bushmasters, I should have no objections to your having one."

"Heaven forbid!" returned the lumber-king. "Professor," he went on with great emphasis, "I am perfectly willing that you shall have absolutely for your own use and benefit any and all bushmasters, crocodiles, snakes, toads, tarantulas, and any other similar bric-À-brac which you may find in South America. Moreover," he continued, "I'll fit out an expedition right here from Cornwall that will do the business for both of us. There's a good-for-nothin' old chap in this town named Jud Adams who has been all over the North huntin' an' trappin' an' prospectin'. In his younger days he was a pearl-diver. Then there're two young fellows here that went off last year with him for me and brought back the finest blue pearl in the world. I ain't got no manner of doubt but what all three of 'em will jump at the chance to go after emeralds and bushmasters."

"Bushmasters and emeralds, please," corrected the professor.

"Just as you say," responded the lumber-king. "Now you come right in and I'll put you up for the night and we'll send over at once for the crowd that I have in mind and get this expedition started right away."

"The sooner the better," responded the professor, heartily. "Any day, some collector may bring back a bushmaster and beat me out with the Smithsonian."

"I feel the same way," agreed the lumber-king. "I want Jim Donegan to have the first crack at those Inca emeralds."

While all this talk about gold and emeralds and bushmasters was going on in Big Jim's big house, over in a little house on the tiptop of Yelpin Hill, Jud Adams, the old trapper, was just sitting down to supper with two of his best friends. One of these was Will Bright, a magnificently built boy of eighteen with copper-colored hair and dark blue eyes, and the other his chum, Joe Couteau, silent, lithe, and swart as his Indian ancestors. Jud himself was not much over five feet tall, with bushy gray hair and beard and steel-sharp eyes. These three, with Fred Perkins, the runner, had won their way to Goreloi, the Island of the Bear, and brought back Jim Donegan's most prized gem, as already chronicled in "The Blue Pearl." They had learned to care for one another as only those can who have fought together against monsters of the sea, savage beasts, and more savage men. Joe and Will, moreover, had shared other life-and-death adventures together, as told in "Boy Scouts in the Wilderness," and, starting without clothes, food, or fire, had lived a month in the heart of the woods, discovered the secret of Wizard Pond, and broken up Scar Dawson's gang of outlaws. Will never forgot that Joe had saved him from the carcajou, nor Joe that it was Will who gave him the first chance of safety when the bloodhounds were hot on their heels through the hidden passage from Wizard Pond. Each one of the four, as his share of the blue pearl, and the sea-otter pelt brought back from Akotan, had received fifteen thousand dollars. Fred had invested his money in his brother's business in Boston, left Cornwall, and bade fair to settle down into a successful business man. Will and Joe had both set aside from their share enough to take them through Yale. As for Jud, the day after he received his winnings in the game which the four had played against danger and death, he had a short interview with his old friend Mr. Donegan.

"All my life long," began Jud, "I've been makin' money; but so far, I haven't got a cent saved up. I know how to tame 'most any other kind of wild animal, but money allers gets away from me. They do say, Jim," went on the old man, "that you've got the knack of keepin' it. Probably you wouldn't be worth your salt out in the woods, but every man's got somethin' that he can do better 'n most. So you just take my share of the blue-pearl money an' put it into somethin' safe an' sound that'll bring me an income. You see, Jim," he went on confidentially, "I ain't so young as I used to be."

"I should say you ain't!" exclaimed Big Jim, knowing how Jud hated to be called old. "You're 'most a hundred now."

"I ain't! I ain't!" howled Jud, indignantly. "I ain't a day over fifty—or thereabouts."

"Well, well," said his friend, soothingly, "we won't quarrel over it. I'll take care of your money and see that you get all that's comin' to you for the two or three years which you've got left"; and with mutual abuse and affection the two parted as good friends as ever.

To-night the old trapper and his guests had just finished supper when the telephone rang.

"Jud," came Mr. Donegan's voice over the wire, "what would you and Bill and Joe think of another expedition—after emeralds this time?"

"We'd think well of it," returned Jud, promptly. "The kids are here at my house now."

"Good work!" exclaimed the lumber-king. "All three of you come right over. I've got a scientist here who's going to guide you to where the emeralds grow."

"You got a what?" queried Jud.

"A scientist!" shouted Big Jim, "a perfesser. One of those fellows who know all about everything except what's useful."

"We'll be right over," said Jud, hanging up the receiver and breaking the news to his friends.

"Listens good," said Will, while Joe grunted approvingly.

"It's a pity old Jim ain't young and supple enough to go on these trips with us himself," remarked Jud, complacently.

"He ten years younger than you," suggested Joe, slyly, who always delighted in teasing the old trapper about his age.

"Where do you get such stuff?" returned Jud, indignantly. "Jim Donegan's old enough to be my father—or my brother, anyway," he finished, staring sternly at his grinning guests.

"You're quite right, Jud," said Will, soothingly. "Let's go, though, before that scientist chap gets away."

"He no get away," remarked Joe, sorrowfully, who had listened to the telephone conversation. "He go with us."

"I don't think much of that," said Jud, wagging his head solemnly. "The last perfesser I traveled with was while I was prospectin' down in Arizona. He sold a cure for snakebites an' small-pox, an' one night he lit out with all our cash an' we never did catch him."

Half an hour later found the whole party in Mr. Donegan's study, where they were introduced to Professor Ditson.

"What might you be a perfesser of?" inquired Jud, staring at him with unconcealed hostility.

The other stared back at him for a moment before he replied.

"I have specialized," he said at last, "in reptiles, mammals, and birds, besides some research work in botany."

"Didn't leave out much, did you?" sneered Jud.

"Also," went on the professor, more quietly, "I learned early in life something about politeness. You would find it an interesting study," he went on, turning away.

"Now, now," broke in Mr. Donegan, as Jud swallowed hard, "if you fellows are going treasure-hunting together, you mustn't begin by scrappin'."

"I, sir," returned Professor Ditson, austerely, "have no intention of engaging in an altercation with any one. In the course of collecting-trips in the unsettled portions of all four continents, I have learned to live on good terms with vagabonds of all kinds, and I can do it again if necessary."

"Exactly!" broke in Mr. Donegan, hurriedly, before Jud could speak; "that certainly shows a friendly spirit, and I am sure Jud feels the same way."

"I do," returned the latter, puffingly, "just the same way. I got along once with a perfesser who was no darn good, and I guess I can again."

"Then," said Mr. Donegan, briskly, "let's get down to business. Professor Ditson, show us, please, the map and manuscript with which you located Lake Eldorado."

For reply, the gaunt scientist produced from a pocket a small copper cylinder, from which he drew a roll of yellowed parchment. Half of it was covered with crabbed writing in the imperishable sepia ink which the old scriveners used. The other half was apparently blank. The lumber-king screwed his face up wisely over the writing.

"H'm-m," he remarked at last. "It's some foreign language. Let one of these young fellers who're going to college try."

Will took one look at the paper.

"I pass," he said simply; while Joe shook his head without even looking.

"You're a fine lot of scholars!" scoffed Jud, as he received the scroll. "Listen now to Perfesser Adams of the University of Out-of-Doors."

Then, to the astonishment of everybody, in his high-pitched voice he began to translate the labored lines, reading haltingly, like a school-boy:

"I, Alvarado, companion of Pizarro, about to die at dawn, to my dear wife Oriana. I do repent me of my many sins. I am he who slew the Inca Atahualpa and many of his people, and who played away the Sun before sunrise. Now it comes that I too must die, nor of the wealth that I have won have I aught save the Secret of Eldorado. On a night of the full moon, I myself saw the Golden Man throw into the lake the great Emerald of the Incas and a wealth of gold and gems. This treasure-lake lies not far from Orcos in which was thrown the Chain. I have drawn a map in the way thou didst show me long years ago. Take it to the king. There be treasure enough there for all Spain; and through his justice, thou and our children shall have a share. Forgive me, Oriana, and forget me not.

Alvarado"

There was a silence when he had finished. It was as if the shadow of the tragedy of that wasted life and vain repentance had drifted down the centuries and hung over the little company who had listened to the reading of the undelivered letter. The stillness was broken by Mr. Donegan.

"Where did you learn to read Spanish, you old rascal?" he inquired of Jud.

"Down among the Greasers in Mexico," chuckled the latter, delightedly.

"What does he mean by 'playing away the Sun' and the 'Chain'?" asked Will, of the scientist.

"When the treasures of the Incas were divided," explained Professor Ditson, precisely, "Alvarado had for his share a golden image of the sun over ten feet in diameter. This he gambled away in a single night. The Chain," continued Professor Ditson, "surrounded the chief Inca's residence. It was made of gold, and was two hundred and thirty-three yards long. It was being carried by two hundred Indians to Cuzco to form part of the chief's ransom—a room filled with gold as high as he could reach. When the gold came to his shoulder, he was killed. At the news of his death, the men who were bringing the Chain threw it into Lake Orcos."

"But—but," broke in the lumber-king, "where is the map? If you've got it with you, let's have a look at it."

Without speaking, Professor Ditson reached over and took the match from the table. Lighting it, he held the flame for an instant close to the parchment. On the smooth surface before their eyes, suddenly appeared a series of vivid green lines, which at last took the form of a rude map.

"What he learned from Oriana," explained Professor Ditson, "was how to make and use invisible ink."

"Fellows," broke in Mr. Donegan, earnestly, "I believe that Professor Ditson has found Eldorado, and I'm willing to go the limit to get one of the emeralds of the Incas. I'll finance the expedition if you'll all go. What do you say?"

"Aye," voted Will.

"Aye," grunted Joe.

"I assent," said Professor Ditson, with his usual preciseness.

Jud alone said nothing.

"How about it, Jud?" inquired Big Jim.

"Well," returned Jud, doubtfully, "who's goin' to lead this expedition?"

"Why, the professor here," returned the lumber-king, surprised. "He's the only one who knows the way."

"That's it," objected Jud. "It's likely to be a rough trip, an' treasure-huntin' is always dangerous. Has the perfesser enough pep to keep up with us younger men?"

Professor Ditson smiled bleakly.

"I've been six times across South America, and once lived among the South American Indians for two years without seeing a white man," he remarked acidly. "Perhaps I can manage to keep up with an old man and two boys who have never been in the country before. You should understand," he went on, regarding the old trapper sternly, "that specialization in scientific investigation does not necessarily connote lack of physical ability."

Jud gasped. "I don't know what he means," he returned angrily, "but he's wrong—specially that part about me bein' old."

"I feel it is my duty to warn you," interrupted Professor Ditson, "that this trip may involve a special danger outside of those usual to the tropics. When I was last in Peru," he went on, "I had in my employ a man named Slaughter. He was an expert woodsman, but sinister in character and appearance and with great influence over the worst element among the Indians. One night I found him reading this manuscript, which he had taken from my tent while I was asleep. I persuaded him to give it up and leave my employ."

"How did you persuade him?" queried Jud, curiously.

"Automatically," responded Professor Ditson. "At least, I used a Colt's automatic," he explained. "His language, as he left, was deplorable," continued the scientist, "and he declared, among other things, that I would have him to reckon with if I ever went again to Eldorado. I have no doubt that through his Indian allies he will be advised of the expedition when it reaches Peru and make trouble for us."

"What did he look like?" inquired Mr. Donegan.

"He was a giant," replied Professor Ditson, "and must have been over seven feet in height. His eyebrows made a straight line across his forehead, and he had a scar from his right eye to the corner of his jaw."

"Scar Dawson!" shouted Will.

"You don't mean the one who nearly burned you and Joe alive in the cabin?" said the lumber-king, incredulously.

"It must be," said Will. "No other man would have that scar and height. I'll say 'some danger' is right," he concluded, while Joe nodded his head somberly.

"That settles it!" said Jud. "It's evident this expedition needs a good man to keep these kids out of trouble. I'm on."