His high spirits considerably dashed by his misadventure, Quatty sat soberly enough on the transom till Frank ordered him forward to give the young captain sailing directions. They were now racing through the air above the Everglades themselves. Everywhere below them spread the yellowish brown expanse of saw-grass and water-course with here and there a clump of cabbage-palms marking an occasional dry spot. Far on the horizon, like a blue cloud, rested the nearest of the islets on one of which lay their goal. Beyond it like other cloud fragments, lay dim in the distance other patches of elevated land.
Save for the bird-life they could see about them there was no signs of animate existence beneath the aeroplane. Not even a canoe threaded any of the numerous water-courses that spread like a net over the ’glades. A more doleful scene could hardly be imagined.
“How did these men ever find their way to the interior?” wondered Frank.
“Dey must have had a guide, massa,” replied Quatty promptly, “nobody dat don’ know de ’glades can find him way in dem.”
“Where could they get such a guide?” questioned Frank.
“Plenty ob dem,” replied Quatty, “plenty ob Injuns take ’em whereber dey want.”
“But you said your tribe was opposed to them?” objected Harry.
“Don’ know nuffin’ ’bout ‘suppose to dem,’ Massa Harry; but dere ubber tribes in de ’glades dan ours. Some ob dem don’ lak us neider.”
“Then you think they secured guides from some other tribe?” asked Frank.
“Mus’ ab,” rejoined Quatty, “none of my fren’s would guide dem.”
The nearest island rapidly assumed shape and resolved itself into a charming bower of tropical vegetation rising at its highest point about forty or fifty feet above the monotonous level of the ’glades As it grew nearer the boys were astonished to see that its summit was bare of trees and formed a plateau of some area which was flat as the top of a table. It was as if some giant had lopped off the top of it with a huge knife.
“That’s very extraordinary,” said Frank, as they gazed at it, “one would almost say that it had been formed artificially.”
The air-ship circled about the islet under Frank’s skilled control while the youthful aerial navigators scanned it with eager eyes. They could now plainly perceive that in the center of the flat top a sort of altar, about seven feet long by four feet high, had been erected.
“A sacrificial altar of some ancient tribe,” cried Harry.
“I’m not so sure,” replied Frank as the Golden Eagle II heeling over, circled slowly about the object of their mystification. “What do you know about this, Quatty?” he asked.
“Quatty thinks him used by Injuns to make smoke signals,” said the old negro scanning the altar narrowly. “When an Injun he wants to signal he builds a fire on dere and den makes de smoke rise or fade away by covering it wid a green branch,” he further explained.
“That is undoubtedly the correct explanation,” said Frank, “of course there was an ancient race of mound-builders in Florida and this may be one of their mounds, but I have never read that they had any sacrificial rites. As Quatty says, the Seminoles must have used this old mound-builders’ hill, which the aborigines may have utilized as a fort, or as a convenient place for signaling from.”
He headed the aeroplane on her course again after this explanation and the adventurers had proceeded perhaps a mile through the air when Quatty who, with his hand shading his eyes, had been searching the horizon, suddenly cried:
“Hol’ on der, Massa Frank.”
“What’s the matter?” asked the boy.
“See dar. Ef dat ain’t smoke ’way off dere call me an ignerent sabage!”
He pointed to a small islet a couple of points to the southward of the course on which they were heading. The boys’ gaze followed his pointing finger. Their eyes, not so keen as the wilderness dweller’s, however, could perceive nothing but a small blue eminence of land not in any way different from several other similar ones dotted along the horizon.
“Don’ you see smoke ober dere?” asked Quatty, wonderingly.
“No,” cried both boys.
“Lordy, lordy, you eyes are dim as bats’ fo’ sho’.” cried the negro shaking his head.
Frank reached into the pocket in which the glasses were kept. With their powerful lenses he swept the horizon. He confirmed the correctness of Quatty’s eyesight the next minute.
From the nebulous mass,—which seen through the glasses proved to be an islet very like the one over which they had just passed—a column of smoke was certainly rising.
“It may be Indians,” said Harry, after he too had taken a long look.
“Injuns,” snorted old Quatty, “dems no Injuns. Dat ain’t de color ob Injuns’ smoke. Ah knows whar ah is now ah do—dat’s de place where dose men you come all dis way ter look foh makes de debbil stuff dat blows de holes in de ground.”
A hasty consultation between the boys followed. At the distance they then were from the islet it was unlikely that their presence in the air had been noted. It would be useless to keep on in broad daylight as their usefulness might end as soon as the plotters discovered their presence and knew their plant had been discovered. On all accounts it seemed best to camp on the mound-builders’ island for the night and wireless to Camp Walrus their views.
Accordingly the aeroplane was put about and a short time after was resting on the summit of the mound-builders’ hill. The boys were far from satisfied with the location but there was no other available landing-place and they decided to run the risk of being sighted before dark.
The wireless apparatus was at once put in order for the transmission of messages and Frank started to call Camp Walrus. Again and again the spark leaped crackling across the gap,—transmitting the call of C-W, C-W, C-W,—before an answer came.
Everything, it seemed, was going on well at the camp and they had heard that morning from the Tarantula. The destroyer was cruising about the archipelago awaiting news of the success or failure of the boys’ expedition and Frank, as he was doubtful of being able to “pick up” the vessel at the distance inland they then were, asked Lathrop to transmit to Lieutenant Selby the news that they had discovered the hiding-place of the plotters and would inform him of their next move when they made it. The instrument was then cut out and the usual preparations for making camp gone about, with Quatty’s assistance.
This done the boys, guns in hand, started to explore the mound on which they found themselves. A steep path, apparently well trodden once but now overgrown with creepers and weeds, led to its base. There was nothing else remarkable about it, except, as has been said, its bald summit. It swarmed with game, however, and several doves, quail and rabbits fell to the boys’ guns during the afternoon. Quatty cooked the game deliciously in an oven of his own invention. He first dug a hole which he lined with stones, heated almost red hot in a fire previously prepared. This done he lined it again with green stuff and covered the whole with leaves and branches. Then he covered in the entire oven with more leaves and tapped them off with earth at the top to enable it to retain the heat.
“Now we leab ole Muvver Erf to do our cookin’,” he remarked when he had completed these preparations.
The next task to occupy the boys’ attention was the setting up of the canvas boat. The craft was a large pea-pod shaped pocket of the strongest grade of brown duck, which was stretched into boat form by steel spreaders and held rigidly in shape by locking clamps. It was a boat eminently fitted to navigate the Everglades, where there are no sharp rocks or rapid waters to be encountered, though hardly suited for more strenuous work. It was about twenty feet in length and capable of carrying five hundred pounds. The boys carried the compact bundle in which it was packed to the water’s edge and put it together there. When afloat on the water it looked not unlike a big, brown pumpkin seed.
“Now where’s de poles?” asked Quatty, looking about him.
“Poles? What for? We’ve got paddles for it,” said Harry.
“Paddles not much good in de ’glades, Massa Harry,” replied Quatty, “we need poles to git ober de groun’.”
After some hunting among the dense undergrowth Quatty finally found two straight sticks of tough second growth timber, about fifteen feet long, that satisfied him. He cut these off with his heavy sailor’s knife with the remark:
“Soon we hab two berry good canoe poles.”
He whittled both sticks to a sharp point at one end and then cut two triangular bits of wood from another tree which he affixed with vine lashings to the poles about six inches from the bottom. The contrivance was exactly like the steps that are affixed to stilts but there were two of them.
“What are you putting those on for?” asked the boys.
“Plenty ob mud in de ’glades sometimes,” replied Quatty, “dese lilly steps keeps de poles from diggin’ in too deep.”
“Well, Quatty, you are a genius,” exclaimed Frank.
“Oh dese not my inwention, Massa Frank,” modestly confessed Quatty. “Seminoles use him many, many years befo’ Quatty come here.”
The boys had decided on a daring plan. It was nothing less than, as soon as the night fell, to pole and paddle their way through the water-courses till they reached a spot near the camp of the kidnappers of Lieutenant Chapin and there reconnoiter and, if possible, overhear enough to give them a clue to the lieutenant’s whereabouts. Their first object being of course to rescue him. The recovery of the formula of his invention was—though important in the extreme—a secondary consideration.
After a hasty supper everything about the camp was put in order and with their revolvers freshly oiled and plenty of ammunition in their pockets the adventurers descended by the mound-builders’ path to where they had moored the canvas boat. Quatty accompanied them. He put on a great assumption of bravery but inwardly he was quaking till his teeth chattered. Still he decided in his own mind he would rather a thousand times accompany the boys—however dangerous their errand—than spend the night alone in a spot which he firmly believed was haunted by the ghosts of the ancient tribesmen who had erected it.
The last thing Frank did before leaving was to call up Camp Walrus on the wireless. He bade his young friends and companions there a hearty “good-bye” and received their aerial “good-luck.”
As the night noises of the jungle began to arise, and the evening chill of the ’glades crept over the lower levels like a cold pall, the boys shoved off and under Quatty’s guidance began to pole toward the southeast.