this sudden revelation that mrs. weldon was acquainted with the true state of things left dick speechless. even had he been capable of replying, she gave him no opportunity, but immediately retired to the side of her son. the various incidents of the march had all gradually enlightened her, and perhaps the exclamation of cousin benedict on the preceding evening had crowned them all; anyhow the brave lady now knew the worst. dick felt, however, that she did not despair; neither would he.

he lay and longed for the dawn, when he hoped to explore the situation better, and perchance to find the watercourse which he was convinced could not be far distant. moreover, he was extremely anxious to be out of the reach of the natives whom, it was only too likely, negoro and harris might be putting on their track.

but as yet no glimmer of daylight penetrated the aperture of the cone, whilst the heavy rumblings, deadened as they were by the thickness of the walls, made it certain that the storm was still raging with undiminished fury. attentively dick listened, and he could distinctly hear the rain beating around the base of the ant-hill; the heavy drops splashed again as they fell, in a way altogether different to what they would upon solid ground, so that he felt sure that the adjacent land was by this time completely flooded. he was getting very drowsy when it suddenly occurred to him that it was not unlikely the aperture was getting blocked up with damp clay; in that case he knew that the breath of the inmates would quickly vitiate the internal atmosphere. he crept along the ground and had the satisfaction of finding that the clay embankment was still perfectly dry; the orifice was quite unobstructed, allowing not only a free passage to the air, but admitting the glare of the occasional flashes of lightning, which the descending volumes of water did not seem to stay.

having thus far satisfied himself that all was well, and that there was no immediate danger, dick thought that he might now resign himself to sleep as well as the rest: he took the precaution, however, of stretching himself upon the embankment within easy reach of the opening, and with his head supported against the wall, after a while dozed off.

how long his light slumber had lasted he could not say, when he was aroused by a sensation of cold. he started up, and to his horror discovered that the water had entered the ant-hill and was rising rapidly; it could not be long, he saw, before it reached the cells which were occupied by hercules and tom. he woke them at once, and told them what he had observed. the lantern was soon lighted, and they set to work to ascertain what progress the water was making it rose for about five feet, when it was found to remain stationary.

"what is the matter, dick?" inquired mrs. weldon, disturbed by the movements of the men.

"nothing very alarming," answered dick promptly; "only some water has found its way into the lower part of the place; it will not reach your upper cells; probably some river has overflowed its boundaries."

"the very river, perhaps," suggested hercules assuringly, "that is to carry us to the coast."

mrs. weldon made no reply.

cousin benedict was still sleeping as soundly as if he were himself a white ant; the negroes were peering down on to the sheet of water which reflected back the rays of the lantern, ready to carry out any orders given by dick, who was quietly gauging the inundation, and removing the provisions and fire-arms out of its reach.

[illustration: they set to work to ascertain what progress the water was making.]

"did the water get in at the opening, mr. dick?" asked tom.

"yes, tom, and consequently we are coming to the end of our stock of fresh air," was dick's reply.

"but why should we not make another opening above the water level?" tom inquired.

"a thing to be thought about," said dick; "but we have to remember that if we have five feet of water here inside, there is probably a depth of six or seven outside. in rising here the flood has compressed the air, and made it an obstacle to further progress, but if we allow the air to escape, we may perhaps only be letting the water rise too high for our safety. we are just as if we were in a diving-bell."

"then what is to be done?" asked the old negro.

"no doubt," replied dick, "we must proceed very cautiously. an inconsiderate step will jeopardize our lives." dick sands was quite correct in comparing the cone to an immersed diving-bell. in that mechanical contrivance, however, the air can always be renewed by means of pumps, so that it can be occupied without inconvenience beyond what is entailed by a somewhat confined atmosphere; but here the interior space had already been reduced by a third part through the encroachment of the water, and there was no method of communicating with the outer air except by opening a new aperture, an operation in which there was manifest danger.

dick did not entertain the slightest apprehension that the ant-hill would be carried away bodily by the inundation; he knew that it would adhere to its base as firmly as a beaver-hut; what he really dreaded was that the storm would last so long that the flood would rise high above the plain, perhaps submerging the ant-hill entirely, so that ultimately all air would be expelled by the persistent pressure.

the more he pondered the more he felt himself driven to the conviction that the inundation would be wide and deep. it could not be, he felt sure, entirely owing to the downpour from the clouds that the rapid flood was rising; there must have been the sudden overflowing of some stream to cause such a deluge over the low-lying plain. it could not be proved that the ant hill was not already under water, so that escape might be no longer possible, even from its highest point.

with all dick's courage, it was yet evident that he was very uneasy; he did not know what to do, and asked himself again and again whether patient waiting or decisive action would be his more prudent course.

it was now about three o'clock in the morning. all within the ant-hill were silent and motionless, listening to the incessant turmoil which told that the strife of the elements had not yet ceased.

presently, old tom pointed out that the height of the water was gradually increasing, but only by very slow ascent. dick could only say that if the flood continued to rise, however slowly, it must inevitably drive out the air.

as if struck by a sudden thought, bat called out,-

"let me try and get outside. perhaps i might dive and get through the opening."

"i think i had better make that experiment myself," answered dick.

"that you never shall," interposed tom peremptorily; "you must let bat go. it may not be possible to get back, and your presence is indispensable here. think, sir, think of mrs. weldon, and master jack," he added in a lower tone.

"well, well," dick assented, "if it must be so, bat shall go."

and turning to bat, he continued,

"do not try to come back again; we will try, if we can, to follow you the same way; but if the top of the cone is still above water, knock hard on it with your hatchet, and we shall take it as a signal that we may break our way out. do you understand?"

"all right!" he said, "all right, sir."

and after wringing his father's hand, he drew a long breath, and plunged into the water that filled the lower section of the ant-hill.

it was an exploit that required considerable agility; the diver would have to find the orifice, make his way through it, and, without loss of a moment, let himself rise to the surface outside. full half a minute elapsed, and dick was making sure that the negro had been successful in his effort, when his black head emerged from the water. there was a general exclamation of surprise.

"it is blocked up," gasped bat, as soon as he had recovered breath enough to speak.

"blocked up?" cried tom.

"yes," bat affirmed; "i have felt all round the wall very carefully with my hand, and i am sure there is no hole left; i suppose the water has dissolved the clay."

"if you cannot find a hole," exclaimed hercules, "i can very soon make one;" and he was just about to plunge his hatchet into the side of the ant-hill, when dick prevented him.

"stop, stop! you must not be in such a hurry!"

he reflected for a few moments, and went on,-

"we must be cautious; an impetuous step may be destruction; perhaps the water is over the top; if it is allowed to enter, then at once is an end of all."

"but whatever we do," urged tom, "must be done at once; there is no time to lose."

he was right; the water had risen till it was quite six feet deep; none but mrs. weldon, jack, nan, and cousin benedict, who were lodged in the upper cells, were fairly above its surface.

dick now came to his determination. at about a foot above the water-level, that is, about seven feet from the ground, he resolved to bore a hole through the clay. if he should find himself in communication with the open air, he would have the proof he desired that the top of the cone was still uncovered; if, on the other hand, he should ascertain that he had pierced the wall below the surface of the external water, he would be prepared to plug up the hole instantaneously, and repeat the experiment higher up. it was true that the inundation might have risen even fifteen feet above the plain; in that case the worst had come, and there was no alternative but that they must all die of asphyxia.

carefully considering the chances of his undertaking, dick calmly and steadily set about his task. the best instrument that suggested itself for his purpose was the ramrod of a gun, which, having a sort of corkscrew at the end for extracting the wadding, would serve as an auger. the hole would be very small, but yet large enough for the requisite test. hercules showed him all the light he could by holding up the lantern. there were several candles left, so that they were not in fear of being altogether in darkness.

the operation hardly took a minute; the ramrod passed through the clay without difficulty; a muffled sound was distinguished as of air-bubbles rushing through a column of water. as the air escaped, the water in the cone rose perceptibly. the hole had been pierced too low. a handful of clay was immediately forced into the orifice, which was thus effectually plugged; and dick turned round quietly, and said,-

"we must try again."

the water had again become stationary, but its last rise had diminished the amount of breathing space by more than eight inches. the supply of oxygen was beginning to fail, respiration was becoming difficult, and the flame of the candle burned red and dim.

about a foot higher than the first hole, dick now set about boring a second. the experiment might again prove a failure, and the water rise yet higher in the cone; but the risk must be run.

just as the auger was being inserted, a loud exclamation of delight was heard proceeding from cousin benedict's cell. dick paused, and hercules turned the lantern towards the excited naturalist, who seemed beaming with satisfaction.

"yes, yes; i see it all well enough," he cried; "i know now why the termites left their home; they were wide-awake; they were more clever than we are; they knew that the storm was coming!"

finding that this was all the worthy entomologist had

[illustration: all fired simultaneously at the nearest boat.]

to communicate, dick, without comment, turned back again to his operation. again the gurgling noise! again the water's upward rush! for the second time he had failed to effect an aperture to the outer air!

the situation was to the last degree alarming. the water had all but reached mrs. weldon, and she was obliged to take her boy into her arms. every one felt nearly stifled. a loud singing was heard in the ears, and the lantern showed barely any light at all. a few minutes more and the air would be incapable of supporting life. one chance alone remained. they must bore another hole at the very summit of the cone. not that they were unaware of the imminent danger of this measure, for if the ant-hill were really submerged the water from below would immediately expel the remaining air and death must be instantaneous. a few brief words from dick explained the emergency of the crisis. mrs. weldon recognized the necessity,-

"yes, dick, do it; there is nothing else to be done."

while she was speaking the light flickered out, and they were in total darkness.

mounted on the shoulders of hercules, who was crouching in one of the side-cells, his head only just above water, dick proceeded to force the ramrod into the clay, which at the vertex of the ant-hill was considerably harder and thicker than elsewhere.

a strange mingling of hope and fear thrilled through dick sands as he applied his hand to make the opening which was to admit life and air, or the flood of death!

the silence of the general expectation was broken by the noise of a sharp hissing; the water rose for eight inches, but all at once it ceased to rise; it had found its level. no need this time to close the orifice; the top of the ant-hill was higher than the top of the flood; and for the present, at least, they could all rejoice that their lives were spared!

a general cheer, led by the stentorian voice of hercules, involuntarily broke from the party; cutlasses were brought into action, and the clay crumbled away beneath the vigorous assault that was made upon it. the welcome air was admitted through the new-made aperture, bringing with it the first rays of the rising sun. the summit of the ant-hill once removed, it would be quite easy to clamber to the top, whence it was hoped they would soon get away to some high ground out of reach of the flood.

dick was the first to mount the summit; but a cry of dismay burst from his lips!

a sound only too well known to travellers in africa broke upon his ear; that sound was the whizzing of arrows.

hardly a hundred yards away was a large encampment; whilst, in the water, quite close to the ant-hill where he stood, he saw some long boats full of natives. from one of these had come the volley of arrows which had greeted his appearance above the opening of the cone.

to tell his people what had happened was the work of a moment. he seized his gun, and made hercules, bat, and actã¦on take theirs, and all fired simultaneously at the nearest boat. several of the natives were seen to fall; but shouts of defiance were raised, and shots were fired in return.

resistance was manifestly useless. what could they do against a hundred natives? they were assailed on every hand. in accordance with what seemed a preconcerted plan, they were carried off from the ant-hill with brutal violence, in two parties, without the chance of a farewell word or sign.

dick sands saw that mrs. weldon, jack, and cousin benedict were placed on board one boat, and were conveyed towards the camp, whilst he himself, with the five negroes and old nan, was forced into another, and taken in a different direction. twenty natives formed a body-guard around them, and five boats followed in their rear.

useless though it were, dick and the negroes made one desperate attempt to maintain their freedom; they wounded several of their antagonists, and would doubtless have paid their lives as a penalty for their daring, if there had not been special orders given that they should be taken alive.

the passage of the flood was soon accomplished. the boat had barely touched the shore, when hercules with a

[illustration: the giant clave their skulls with the butt end of his gun.]

tremendous bound sprang on to the land. instantly two natives rushed upon him. the giant clave their skulls with the butt end of his gun, and made off. followed though he was by a storm of bullets, he escaped in safety, and disappeared beneath the cover of the woods.

dick sands and the others were guarded to the shore, and fettered like slaves.