Rockstone, the last outpost of civilization, had been left far behind and many miles of river had been covered when at last Colcord turned the boat’s bow towards shore and ran the craft alongside a fallen tree that sloped from the high bank into the water.

Although the boys had seen much to interest them as they paddled upstream, yet they were cramped and tired, for, with the exception of a short stop for lunch at noon, they had been seated in the boat for nearly ten hours. Moreover, after the first few miles, the river and its banks were merely a constant repetition of what they had seen: walls of tangled jungle like a vast green velvet curtain rising from the river; vivid flowering trees; great azure blue butterflies; noisy carrion hawks; chattering parrots and ungainly yelping toucans along the shore--all reflected as in a mirror by the oily brown water.

They had expected to see Indians and to have the thrill of navigating rapids, but Mr. Thorne explained that these would not be reached until the following day and the boys were glad indeed to step on dry land and stretch their cramped legs when the boat at last was run ashore and preparations were made to camp.

Rapidly and with perfect system, the Indians commenced work, cutting poles and stakes and in an incredibly short time a big tarpaulin had been spread between the trees, hammocks were stretched and ready and the savory odors of coffee, bacon, and broiling meat were wafted from the campfire where Sam was presiding as cook.

Presently Joseph approached, naked save for a scarlet loin cloth, and looking the thoroughly primitive Indian with a long bow and arrows in his hand.

“Mebbe you likeum sabby how Buckman shootum fish,” he remarked.

“You bet we would!” cried Frank, jumping up. And then, remembering that he must talk the Indian’s jargon, he added, “Me likeum too much. Me come see.”

The Indian grinned and, without a word, turned and slipped silently into the forest with the two boys at his heels. For a short distance he led the way among the trees and then, turning towards the river, came out upon a jutting rocky point. Raising his hand as a signal for caution, he stopped, fitted a six-foot arrow to his bow, and stepped silently towards the water’s edge. Intently the two boys watched, utterly at a loss as to what Joseph intended to do. Then they saw him suddenly straighten up and quickly draw the huge bow. Like a streak of light the long arrow darted into the river. The next instant he threw aside his bow, rushed forward, and, seizing the floating arrow, dragged a big silvery fish upon the rocks.

“Gosh!” exclaimed Tom, as the two boys rushed forward to where the Indian was extracting a barbed iron arrow point from the fish. “I never saw anything like that! Why, he shot the fish with his arrow.”

“Say, that is a new way of fishing!” cried Frank, as he examined the weapon. “This arrow’s just like a harpoon with a head fastened to a line and not to the shaft. Gee, I wish Mr. Rawlins could have seen that.”

Joseph grinned, picked up his bow and arrow, and a moment later had shot a second fish. Absolutely fascinated, the boys watched him as fish after fish was secured in this novel manner and then, as darkness was rapidly coming on, the three made their way back to camp.

Mr. Thorne chuckled as the boys enthusiatically related what they had seen. “I forgot to tell you about that,” he said. “You should see them shoot fish in the rapids. That’s really exciting. And they call them too.”

“Oh, now you’re fooling!” exclaimed Frank. “How can they call fish?”

“I don’t know how they can, but I know they do,” replied the explorer. “They stand near the water and wiggle their fingers and whistle and the fish come up. I’ve seen it scores of times and I’ll wager you’ll see it done too.”

“Well, I suppose we’ll have to believe it, if you say it’s true,” said Tom, “but it does sound like a fish story.”

Sam’s cooking proved highly successful, and as they were busily eating, Colcord suddenly jumped up and stood listening attentively. The next moment the boys heard a slight splash and a grating noise and one of the Indians uttered a low cry in his native tongue. Immediately from the river came an answering call and a moment later, a canoe appeared in the reflection of the firelight on the river. About it the Indians gathered.

“By glory, we’ve got visitors!” exclaimed Rawlins. “Wonder who they are.”

“Indians,” replied Mr. Thorne. “Know who they are, Colcord?”

“No, Chief,” replied the Boviander. “I ’spect they’s Wapisianas or Macusis from topside.”

As he spoke two bronze-skinned figures approached the fire, clad only in their scarlet “laps” or loin cloths. Without uttering a word they passed around the fire, shaking hands with each member of the party, and then, squatting down, remained motionless and silent for a full minute. Evidently this was bush etiquette for Colcord and Mr. Thorne seemed to regard it as a matter of course. Then the explorer passed the new arrivals a tin of tobacco, Colcord filled a tin dish full of food and set it before them, and, as the Indians began to eat, the explorer spoke.

“You fellow makeum walk Rockstone?” he asked. “Come all time topside?”

“Makeum walk Bartica,” responded one of the red men. “Come Pakarima like so.”

“How you callum, Macusi mebbe?” inquired the explorer.

“Arekuna,” replied the other Indian.

“Eh, eh! Arekuna!” exclaimed Mr. Thorne. “You sabby white man makeum fly all same bird like so?” The explorer made a sound like the exhaust of an airplane’s motor.

The Indians glanced sharply at the explorer and muttered some words in their own tongue.

“Me sabby,” vouchsafed one of the two at last. “Me hearum. No sabby him white man. Me sabby him peai. No likeum plenty.”

“Ah, we’re getting on the trail!” exclaimed Mr. Thorne, turning towards Mr. Pauling. “They’ve seen or heard the plane, that’s certain.”

“But what do they mean by ‘peai’?” asked Tom.

“Magic, witchcraft,” replied Mr. Thorne. “Anything a Buck doesn’t understand, or fears, or thinks supernatural, is peai.”

Then, again addressing the Arekunas, he asked. “Where you seeum? You sabby what side him go?”

“No seeum,” replied the Indian. “Makeum noise like so. Him plenty peai. Him go Maipurisi side.”

“Good!” cried the explorer. “Trust the Bucks to know where they went even if they didn’t see the plane. I’ll bet they’re over in that lake on the Maipurisi. Just the place for them.”

“Didn’t I say they couldn’t sneak around here without being seen?” cried Rawlins.

“Hmm, it doesn’t look as if we’d have much trouble in tracing them at all events,” remarked Mr. Pauling. “How far is Maipurisi from here?”

The explorer turned to Colcord. “How far is it, Colcord?” he asked.

The Boviander considered a minute and then spoke rapidly to the Arekunas in their own native tongue. Then, when the Indians had answered, he replied, “Two days coming down, Chief.”

“That means about six days going up,” commented Mr. Thorne. “There are some pretty bad falls to haul over.”

Suddenly Tom was seized with an idea and, whispering to Frank, rose and began rummaging in a chest.

“What are you boys up to?” asked Mr. Pauling.

“Going to set up our radio receivers,” replied Tom. “Perhaps we may hear something. We ought to be listening whenever we can.”

“Good idea,” commented his father. “After this, we’d better keep one set ready in the boat all the time.”

As the two boys busied themselves connecting the instruments, the Indians and Colcord watched them closely, the red men seemingly fascinated by the mysterious-looking cabinets and their bright, nickel-plated binding posts and glowing bulbs. Little by little they edged nearer and nearer until a circle of naked bronze bodies and keen black eyes was formed about the boys and their instruments.

“I’ll say they think that’s ‘peai,’” chuckled Rawlins. “I wonder what they’d do if a signal did come in.”

“Be scared half to death,” declared Mr. Thorne. “Those are fine instruments you have, boys.”

“We made them all ourselves,” replied Tom. “That is, all except the resonance coil. We got that from the sub.”

As Tom spoke, he adjusted the receivers, while; Frank moved the coil slowly about. To the Indians this evidently savored of some mysterious religious ceremony or incantation, and the boys could not help grinning as they saw the eager eyes of their Buck friends following every motion of the coil.

For some time Frank tried it towards the south, but no sound came to Tom’s ears, and it was evident that if the plane were in that direction its occupants were not sending.

“Swing it around to the north,” directed Tom “We’ll see if we can pick up anything from Georgetown or any ship.”

Turning, Frank moved the resonance coil around, and the next instant the sharp “dee-dah” of a dot and dash signal buzzed clearly from the receiver. With one accord the Indians tumbled head over heels as they strove to get away from the spot and, with frightened exclamations and terrified faces, picked themselves up and cowered near the fire.

“Peai!” they exclaimed. “Plenty peai! Me tellum no likeum him fellow!” Every one burst out laughing and the Indian paddlers rather shamefacedly attempted to grin at their own fright. But the two Arekunas would have none of it and jabbered together earnestly in their own tongue.

“By glory!” exclaimed the diver. “If they’re that scared at the code signals, wouldn’t they get a jolt if they heard a voice coming in!”

“Thank Heaven they didn’t!” said Mr. Thorne. “If they had, I’m afraid they would all have deserted.”

Meanwhile the sharp “dees” and “dahs” were coming in on the instruments, and Tom, from force of habit, was mentally forming them into letters and words.

“It’s some cipher message,” he announced presently. “No sense to it at all.”

“Take it down,” exclaimed his father, suddenly interested. “It may be for those rascals with the plane.”

Once more the message was coming in and Tom rapidly jotted down the words and handed the paper to his father. “They’re sending the same thing over and over again,” he said. “That’s the third time it’s been repeated.”

Mr. Pauling eagerly scanned the message and slowly a smile and an expression of satifaction spread across his features.

“It’s for us!” he ejaculated. “Good news. The Devon’s taken! Jove! It seems little short of uncanny to be getting word from Maidley way up here in the jungle.”

“I’ll say ’tis!” cried Rawlins. “Bully for the Colonel! Where did they get her?”

“Hurrah!” cried the boys. “Now these fellows up the river are in a fix!”

“He doesn’t say where,” replied Mr. Pauling. “Didn’t want to use any name, I suppose--no cipher word for that--just says: ‘Ship taken. All on board held.’ He’s no fool, Maidley. He knew the plane would hear this and took no chances of saying anything to make them suspicious. I expect he thought we might be listening and broadcasted the message in hopes we’d get it.”

“Good old scout,” declared the explorer. “Just like him to do that.”

“Can you send a message back acknowledging this?” asked Mr. Pauling, turning to Tom.

“No,” replied Tom. “We didn’t bring our sending set. We thought if we received it would be all we needed.”

“Hmm, too bad,” commented his father. “Sorry Maidley won’t know we got it and will keep on sending. Those fellows may get suspicious if they hear the same message coming in night after night.”

“He’ll know we got it before to-morrow night,” declared Mr. Thorne. “I’ll send word to him.”

“How?” asked Mr. Pauling. “What magic do you use?”

“Easily enough,” replied the explorer. “These Arekunas are going to Bartica. They’ll be there before noon to-morrow and there’s a telegraph line from there to Georgetown. Write a message to Maidley and they’ll take it to Bartica and give it to the telegraph office there. It will be in Maidley’s hands by noon.”

“By Jove!” exclaimed Mr. Pauling. “I didn’t realize we were so closely in touch with civilization.”

The message was soon written and Mr. Thorne handed it to one of the still frightened Arekunas. “Must for takeum Bartica like so,” he instructed the Indian. “No looseum. When makeum Bartica side giveum Mr. Fowler. You sabby him fellow?”

The Arekuna slipped the folded paper into a jaguar skin pouch hanging from his neck, “Me sabby,” he said. “Takeum Mr. Fowler same way.”

“Can you depend on those fellows?” asked Mr. Henderson.

“Absolutely,” Mr. Thorne assured him. “I’ve never known an Indian to lose or forget a message and they’re strictly honest and trustworthy. I’ve known an Indian to travel over three hundred miles through the bush to return ten shillings he’d borrowed.”

“Not much like our redskins in the States,” commented Mr. Henderson.

“I don’t know about that,” declared the explorer. “I’ve always found primitive men honest--it’s civilization that ruins them. These Bucks are little more than vagabonds and scalawags once they become civilized and live near the settlements.”

Presently the Arekunas silently withdrew, the Indian boatmen sought their hammocks, and the white men and boys followed their example. Although the boys had become somewhat accustomed to the noises of a bush night while at Colcord’s house, yet here in their forest camp beside the mighty river, they felt strange and nervous. The boom and croak of frogs and the incessant sounds of myriads of insects were the same as they had already heard, but far louder and more numerous than at Colcord’s, and in addition there were a thousand and one other noises for which the boys could not account and which kept their sleepy tired eyes wide open. But the Indians were sleeping soundly; from Rawlins’ hammock, came lusty snores and the boys, despite their nervousness, finally lost consciousness and did not awaken until aroused by the sounds of the Indians starting the fire at dawn.

The Arekunas had already slipped away downstream, and, by the time breakfast was ready, camp had been broken, everything was neatly packed in the boat, and the Indian paddlers were waiting in their places.

For hour after hour they paddled upstream. Rocky islands appeared in the river--some bare and carved and worn by the water into odd grotesque forms,--others covered with trees. The current flowed more swiftly and just before noon a dull roaring sound reached the boys’ ears, and, peering ahead, they saw a line of flashing white stretching across the river from shore to shore.

“First rapids,” Mr. Thorne informed them. “We’ll have lunch before hauling through, Colcord.”

“Gosh, I call those falls and not rapids!” declared Tom as the boat was run ashore on the sandy beach of a tiny island. “I don’t see how you expect to get this big boat through that.”

“Wait and see,” chuckled the explorer.

As Colcord leaped ashore he stopped, bent down, and examined the sand.

“Water Haas!” he exclaimed, pointing to a number of small indentations in the beach.

“What are ‘water haas’?” asked Tom. “Some kind of animals?”

“Capybara--sort of giant Guinea pigs,” replied Mr. Thorne. “They’re likely to be in the brush here. Get your guns and you may be able to shoot one. They’re good meat.”

Eager for the chance to secure game, the boys and Rawlins got out the rifles they had brought and started up the beach, following the little trail left by the water haas. Presently they noticed that, instead of one, there were half a dozen tracks and at Rawlins’ suggestion they separated and cautiously approached a tangle of palms and small trees near the upper end of the island.

Gaining the edge of the thicket, Frank, who was nearest the river, peered through the screen of foliage. As he carefully parted the leaves and branches, there was a startled snort and three big, clumsy-looking brown creatures leaped from the damp ground and stood for an instant staring towards the boy and sniffing the air suspiciously. So surprised was Frank at the sudden appearance of the beasts that, for a moment, he forget to shoot, and the next second the three animals were scurrying out of sight. Hastily throwing up his rifle, Frank blazed away at the retreating forms.

“What was it? What did you shoot?” yelled Tom, as he and Rawlins came running at the report of Frank’s rifle.

“Don’t know if I shot anything or what they were,” replied Frank. “I was so surprised I didn’t fire till they were running away. They went over there.”

Hurrying to the other side of the thicket, Rawlins, who was in advance, gave a shout. “I’ll say you shot him!” he cried. “Guess it’s one of those water haas.”

The two boys hurried forward and found the diver bending over the dead animal, a curious-looking creature with short stiff hair, an enormous head and broad blunt snout.

“Why, he’s got webbed feet!” exclaimed Frank who was examining his prize.

“And he does look like a huge Guinea pig,” declared Tom.

Elated at their success, the boys picked up the animal and hurried back to the boat.

“Yes, it’s a water haas or capybara,” declared Mr. Thorne. “Now we’ll have a fine feast to-night.”

“But he’s got webbed feet,” said Frank. “Can they swim?”

“Can they!” exclaimed the explorer. “Like a fish. That’s why they’re called water haas--it’s Dutch for water horse. They’re as amphibious as seals almost.”

“Say, let’s take a swim!” suggested Tom. “I’m hot and the water looks fine.”

“Don’t you try it!” cried the explorer. “The place is full of perai and you’d surely be eaten alive.”

“Why, what do you mean?” demanded Tom, puzzled. “I thought perai was magic or witchcraft. How can that eat us?”

Mr. Thorne burst out laughing and Colcord, who stood near, shook with merriment.

“Peai is witchcraft,” explained the explorer. “Perai is a kind of fish--‘cannibal fish,’ they’re called sometimes. They’re the most deadly and savage creatures in the bush. They’ll tear anything that’s flesh to bits, in a moment. It’s lucky I stopped you in time.”

“Is that really true?” asked Mr. Pauling. “I’ve read travelers’ tales of them, but I always supposed they were real ‘fish stories.’”

“Not at all,” Mr. Thorne assured him. “Let me demonstrate it.”

Picking up a bit of meat, the explorer stepped close to the water and tossed it into the river. Instantly there was a splash, a flash of silver, and the meat was dragged under. The next moment the water fairly boiled with leaping, darting fish, and the onlookers gazed with amazement as the voracious, savage creatures tore and snapped and bit.

“Gee, I’m glad I’m not in there!” exclaimed Frank. “They’re like hungry wolves.”

“Worse,” declared Mr. Thorne. “They seem to go blind mad at the smell of flesh, and their jaws are so powerful and their teeth so sharp they can bite a piece out of a plank. A man would be torn to bits--eaten alive--if he went in there.”

“Jiminy, I’d hate to tumble overboard!” exclaimed Tom.

“That’s the odd thing about them,” remarked Mr. Thorne as they started back towards the boat. “They won’t touch a man if he has clothes on--apparently do not recognize flesh if covered by garments. In some parts of the rivers they are harmless--never touch people--and the natives bathe freely.”

“Well, I’m not taking any chances,” declared Tom. “I’ll go without a bath for a while.”

Embarking once more, the boat was paddled upstream and at the foot of the roaring, rushing falls, which the boys now saw were really a series of steep rapids, dashing and foaming over the jagged black rocks, the craft was run alongside a smooth ledge.

“All out!” cried Mr. Thorne, leaping ashore.

Filled with interest to discover how the Indians would get the heavy boat through that tumbling seething mass of water to the river level, twenty feet above, the boys scrambled up over the rocks and watched every move of Colcord and his men.

“This isn’t a bad spot,” commented the explorer. “They’ll get through without discharging. But, in many places, everything has to be taken from the boat and portaged for a mile or more around the rapids. Sometimes a score of such portages must be made in order to travel a dozen miles upstream, so you can understand how tedious and slow traveling in the interior is.”

“This looks bad enough to suit me,” declared Tom. “I should think the boats would get smashed all to bits.”

“They’re built for the purpose,” replied Mr. Thorne. “Tough native wood and with spoon-shaped bottoms, so they slide off a rock in any direction.” Some of the Indians had now uncoiled a long light rope and were moving upstream, jumping and scrambling from rock to rock, at times plunging into the swirling water up to their armpits or even swimming through the racing current, until at last they gained a precarious foothold upon a projecting ledge in midstream, well above the falls. In the meantime, others had attached a second line to the stern of the boat and stood waiting for orders close to the water’s edge, while the bowman and Colcord braced themselves in bow and stern, grasping their immense paddles.

For a moment the Boviander glanced about, studying the lashing white foam and the jagged, black rocks, casting his eyes over the waiting Indians to see that all were ready. Then, with a sharp “Hi-yi!”, he dug his great paddle into the water. Instantly the bowman shoved the craft from shore into the current; the men on the bow rope hauled and tugged with all their strength; the captain shouted orders and threw his weight on his six foot paddle; the bowman paddled furiously; the men at the stern line bent to their task; and slowly the boat forged ahead. With consummate skill the Boviander and the bowman swung the craft to right and left, clearing the rocks by inches; the stern line kept it headed into the torrent; and foot by foot the boat crept up the falls. How the captain and bowman ever kept their balance as the boat rocked and pitched and seemed about to stand on end was a mystery to the boys, but with bodies swaying to the jerking, tossing craft they strained at their paddles--sweating, grunting, shouting, while about the bow the angry waters foamed and seethed and the hungry waves leaped above the gunwhales. For a moment the craft stood motionless, shaking and trembling to the terrific strain, and then human muscles and human brains won. The craft shot forward, the Indians yelled and rapidly gathered in slack, and the next instant the boat was safe from the torrent in a calm backwater above the falls.

“Gosh, that was great!” cried Tom, as, leaping from rock to rock, the boys made their way towards the boat.

“I’ll say ’twas!” exclaimed Rawlins. “But, by golly, if a rope had parted we’d have been in a nice fix.”

By the time the passengers were seated the lines had been coiled away, the Indians were once more in their places, and a moment later the boat was speeding upstream over a stretch of tranquil water.

But now the character of the river had changed. Sand bars and wooded islands broke its surface; the trees along the banks towered upward for over one hundred feet; the stream twisted and turned and flowed swiftly in dark, wine-colored currents between the islands; and even the birds and foliage seemed different. Little fresh water flying fish skittered away from the boat, great flocks of twittering swallows flitted about, clouds of brilliant yellow butterflies floated back and forth across the stream, and once or twice the boys caught glimpses of otters swimming in the river ahead.

In places, too, gaudy flowers that had fallen from the great trees covered the surface of the river with a solid mass of color, and the boat seemed to be passing over some gorgeous carpet, while the reflections of foliage and trees were so perfect that the boys had the strange sensation of being suspended in mid-air between two forests.

Very soon, however, the tranquil water came to an end and another series of rapids barred the way. Once more the men labored and tugged and dragged the boat up the falls, and time after time, as the falls were reached, the process was repeated. Then Mr. Thorne announced that they were approaching a really dangerous spot and as the boat rounded a bend the occupants saw a plunging, rock-strewn cataract, half hidden in the mist rising from the roaring water at its base. Here all the baggage was taken out and carried over the rocks and with only the empty boat the Indians and the Bovianders prepared for a tug of war with the falls. Over and over again they strove to gain a foothold on the slippery rocks, and a dozen times they were swept struggling downstream. But they laughed and yelled and shouted and seemed to enjoy the excitement and at last won a stand, waist deep in the flood, and by almost superhuman efforts dragged their craft to the water above the cataract. But the most dangerous part was yet to come. A short distance above the falls was a huge whirlpool--a dark, sinister mass of water in a basin of steep walled rock; deep, threatening, with its current rotating silently, swiftly around and around while, at its center, at the very vortex, masses of foam, bubbles and driftwood had been drawn and were constantly being sucked suddenly out of sight or thrust bobbing above the surface.

“Ugh! Isn’t that a nasty looking spot!” cried Tom. “Say, have we got to cross that?”

Mr. Thorne nodded. “Yes, just sit tight and don’t jump and you’ll be all right,” he declared. “If a paddle doesn’t break we’ll get through safely. It’s the only way and the worst spot on the river.”

As he spoke the captain was testing each paddle, examining the blades and handles for possible cracks and at last, with the baggage stowed snugly, the Indians and Sam in their places, Colcord told them that all was ready.

With fast beating hearts the boys seated themselves, Mr. Thorne, Mr. Pauling, Mr. Henderson and Rawlins took their accustomed places and with a “Yip-yi!” from the Boviander the paddles dug into the water and the coorial shot out upon the swirling black surface of the pool.

With every ounce of their strength, with their muscles straining under their bronze skins, the men plied their paddles and Colcord and the bowman swung their weight upon their huge paddles at bow and stern. For an instant the boat hung motionless, the bow quivered and vibrated to the drag of the current and then the craft darted ahead. High above the gunwales boiled the maelstrom as the centre of the whirlpool was reached, the boat seemed actually to stand on end, it slid up a hill of water and ere the boys realized it was accomplished the coorial had dashed beyond the danger point and was safe in a narrow, swiftly flowing channel above the pool. And at this instant, just as the boat had gained safety, there was a sharp report and one of the Indians tumbled head over heels as his paddle broke short at the blade!

“Gee!” cried Frank. “It was lucky that didn’t happen a minute sooner!”

“I’ll say ’twas!” agreed Rawlins. “We’d have been goners if it had, sure.”

“A miss is as good as a mile,” laughed Mr. Thorne. “You have to trust a lot to luck in this work.”

“Same as in diving,” remarked Rawlins.

“Well, Colcord, I guess we can call this a day’s work,” said the explorer as the boat swung into the broader river and tranquil water. “Find a good spot and we’ll make camp for the night.”

The boat was soon run ashore, the tarpaulin was quickly stretched and the crew lolled about, glad of a chance to rest their weary muscles.

“I suppose we might as well listen and see if we hear anything,” suggested Tom, as Sam busied himself with the cooking.

“Yes, take every chance you get,” said his father. “We’re getting nearer and nearer to the spot all the time.”

But no sound came into the receivers and with Sam’s call to dinner the instruments were laid aside.

But when dinner was over, the boys once more adjusted their receivers and prepared to listen to anything that might be passing through the air. Tom clamped the phones to his ears, Frank turned the resonance coil about and as it pointed towards the south, Tom fairly leaped from his seat.

“Jumping Jiminy!” he exclaimed. “They’re talking!”

“What?” cried Mr. Pauling. “Are you sure? Get what they say!”

Tense with excitement, leaning forward with breaths coming fast, all were silent, listening with straining ears to the faint buzzing sounds from the instrument while Tom rapidly jotted down the message. “They’ve stopped!” he announced at last. “I guess--Gosh! What’s that?”

As he had been speaking, Frank, thinking the signals over, had turned around and as he did so, sharp “dees and dahs” once more issued from the receiver. Instantly all were again silent, glancing at one another with wonder and amazement on their features, for the signals were coming in with the coil pointed to the east! A moment later the sounds ceased and Tom handed the slip of paper to his father.

“By glory!” ejaculated Rawlins. “Some one must have answered them!”

“Sounded like it,” agreed Mr. Henderson. “But it couldn’t be any one on the Devon. We know she’s captured.”

“And it did not come from the direction of Georgetown,” said Mr. Thorne. “Whoever was sending that message is to the east--in Dutch Guiana I think.”

“It’s meaningless gibberish,” declared Mr. Pauling who had been studying the sheet of paper. “Just numbers and nothing more.”

“Cipher, of course,” commented Mr. Henderson. “Well, that proves they were talking to some one who replied. Otherwise the two messages would not be in the same cipher.”

“I can decode it--if I take time,” declared Mr. Pauling. “But I suppose if I do, it will be of little use--probably in Russian.”

“Well it’s blamed good news anyway,” cried the diver. “It proves the old rascal and the plane are still ‘topside’ as the Indians say.”

“And also that we haven’t rounded up all the gang yet,” added Mr. Pauling.

“No doubt they landed some one from the Devon,” suggested Mr. Thorne, “or already had confederates in Surinam.”

“In a way I’m glad they have,” declared Mr. Pauling. “Otherwise they’d not have any one to talk with. Better listen a while longer, boys.”

But no other signals came in and at last, yawning and tired, the two boys put away their instruments and with the others crawled into their hammocks and fell instantly to sleep.