jared long, the new englander, and quincal, the native helper, were the sentinels on duty in the immediate vicinity of the camp.

the professor was wearied from a hard day's work, and, feeling that everything possible had been done for the safety of all, stretched out upon his blanket on the soft ground and was soon asleep.

he expected to assume his duty as guardsman in the course of a few hours, and needed all the rest he could get before that time.

bippo and pedros were so disturbed by what they had witnessed, that, though they lay down at the same time, it was a good while before they closed their eyes in slumber. their homes were near the mouth of the xingu, and, even at that remote point, they had heard so many fearful accounts of the ferocious savages that infested the upper portions of the river, that they never would have dared to help in an attempt to explore the region but for the liberal pay promised, and their unbounded faith in the white men and their firearms.

the poor fellows would have given all they had, or expected to have, to be transported down the xingu and out of the reach of the terrible natives who used their poisoned arrows and javelins with such effect; but, behold! the explorers, undaunted by what had taken place, had no thought of turning back, but were resolved to push on for an unknown distance, and bippo and his friends had no choice but to go with them, for to run away would insure certain death at the hands of these people who seemed to be all around them.

jared long had so little faith in the usefulness of the servant quincal as sentinel, that he arranged to place the least dependence possible on him. with no supposition that any danger was likely to come from the woods behind them, he sent the fellow a short distance back, instructing him to keep his ears and eyes open, since if he failed to do so, some wild animal was likely to devour him.

in crossing the xingu below the falls, the rapid current had swept the canoe downward, so that it lay against the bank at a point fully two hundred yards below. it was here that the american stationed himself, standing, like fred ashman, just far enough from the water to be shrouded in the slight but increasing shadow made as the moon slowly worked over and beyond the zenith.

looking across to the other shore, he could discern nothing upon which to hang a suspicion; but the first thing, perhaps trifling in itself, which attracted notice, was the unusual quantity of driftwood which appeared to be coming through the rapids and floating past.

as has been stated, in such a wooded country as the matto grasso there was always more or less of this, and long had taken a critical survey of the rapids and noted the stuff which went plunging and dancing through them. now, however, he was sure there was an increase, and a good deal of it consisted of large trees and logs, which must have been brought down by some cause more than ordinary.

had there been anything else to occupy his attention, the fact would have escaped him, but the sentinel who is alive to his duty, notes little things, even when they seem to have no bearing on the great subject which engages all his energies.

it was a long way from the camp to the source of the xingu, and in such a vast country as brazil, there might have been a violent storm raging at that moment above and below them without the least evidence, so far as they could see, around them. like all countries, that portion of empire is ravaged at times by fierce hurricanes and cyclones, which might have uprooted scores of trees and flung them into the waters which were now bearing them toward the amazon and the broad atlantic.

the sentinel naturally gave his chief attention to the other side of the xingu, where so many stirring scenes had taken place that afternoon and evening. the camp-fire, which had been left burning, had smouldered so low that none of the embers were discernible, and only a thin column of smoke crept slowly upward marking where it had been. but this vapor was so clearly seen in the wonderful moonlight that it was easy to fix the precise point where the trail entered the wilderness.

it was just there, as long believed, that the savages would debouch into sight, and renew the warfare which thus far had been only one series of disasters to them.

he was not mistaken, when, shortly after he had noticed the increasing number of logs and driftwood, he fancied he detected something going on at the very point on which his gaze was fixed.

as was the case with fred ashman, it was some time before he could so much as conjecture its nature. the glimpses were so faint and momentary that nothing tangible resulted, though he was positive that some of their enemies were there.

at the moment he uttered an exclamation of impatience, he made out three figures of the natives, who advanced far enough from the wood for him to identify them.

not only that, but they walked stealthily to the edge of the river and stood several minutes, as if looking across at the canoe.

long was confident that he could drop one of them at least, and he was tempted to do so. the most effective way of keeping the savages off was by nipping their schemes in the bud, and filling them with additional terror of the white strangers.

but he decided to wait a while, suspecting, as he did, that some scheme whose nature he could not guess was under way, and that if the projectors were undisturbed, it would soon be revealed.

jared long, we say, was convinced that the natives were scrutinizing the canoe and seeking to learn something about the occupants, whom they had doubtless watched as they made their way from the water to the shelter of the wood. such was his belief, and yet he was altogether mistaken.

it struck him as odd that the savages acted as they did, when it would seem that they could see just as well from the edge of the wood, where they were not exposed to the fire of their enemies; but he reflected that there was precious little about the conduct of the natives from the first that could be explained on the line of common sense and consistency.

the trio stood in view less than five minutes, when they darted back to cover, as if afraid of being seen by the whites, a theory altogether untenable under the circumstances.

the natural supposition of the sentinel was that a large number of the savages had gathered under the bank and were making ready for some demonstration, which would soon take place.

it was not yet time to awaken the professor and the natives. in fact, the plucky new englander half believed that with his repeating rifle he would be able to beat off any approach from the other shore.

at this moment, he was amazed to see one of the savages do an extraordinary thing.

darting out from the wood behind him, he ran to the smouldering camp-fire seized a brand that was covered with ashes, and circled it so swiftly about his head that it was fanned into a roaring blaze.

while doing this, he stood apparently with one foot in the margin of the xingu, and evidently with not the slightest fear of the white strangers within gun-shot. he not only swung the brand forward several times, but reversed and spun it in the other direction, with a velocity that made it look like a solid ring of fire.

suddenly the truth flashed upon the bewildered sentinel: the savage was signaling to some friend or friends on the other bank! that being the case, it followed that the friend or friends were most uncomfortably close to the camp of the white men.

and still long failed to attach any importance to the unusual quantity of logs and driftwood that was sweeping down the xingu in front of him.