But it was asphyxia, it was immediate death, if the result of this last attempt should prove fruitless. The air remaining inside would escape through the upper sheet of water, and the water would fill the whole cone.

"Mrs. Weldon," then said Dick Sand, "you know the situation. If we delay, respirable air will fail us. If the third attempt fails, water will fill all this space. Our only chance is that the summit of the cone is above the level of the inundation. We must try this last experiment. Are you willing?"

"Do it, Dick!" replied Mrs. Weldon.

At that moment the lantern went out in that medium already unfit for combustion. Mrs. Weldon and her companions were plunged in the most complete darkness.

Dick Sand was perched on Hercules's shoulders. The latter was hanging on to one of the lateral cavities. Only his head was above the bed of water.

Mrs. Weldon, Jack, and Cousin Benedict were in the last story of cells.

Dick Sand scratched the wall, and his ramrod pierced the clay rapidly. In this place the wall, being thicker and harder also, was more difficult to penetrate. Dick Sand hastened, not without terrible anxiety, for by this narrow opening either life was going to penetrate with the air, or with the water it was death.

Suddenly a sharp hissing was heard. The compressed air escaped--but a ray of daylight filtered through the wall. The water only rose eight inches, and stopped, without Dick Sand being obliged to close the hole. The equilibrium was established between the level within and that outside. The summit of the cone emerged. Mrs. Weldon and her companions were saved.

At once, after a frantic hurra, in which Hercules's thundering voice prevailed, the cutlasses were put to work. The summit, quickly attacked, gradually crumbled. The hole was enlarged, the pure air entered in waves, and with it the first rays of the rising sun. The top once taken off the cone, it would be easy to hoist themselves on to its wall, and they would devise means of reaching some neighboring height, above all inundations.

Dick Sand first mounted to the summit of the cone.

A cry escaped him.

That particular noise, too well known by African travelers, the whizzing of arrows, passed through the air.

Dick Sand had had time to perceive a camp a hundred feet from the ant-hill, and ten feet from the cone, on the inundated plain, long boats, filled with natives.

It was from one of those boats that the flight of arrows had come the moment the young novice's head appeared out of the hole.

Dick Sand, in a word, had told all to his companions. Seizing his gun, followed by Hercules, Acteon, and Bat, he reappeared at the summit of the cone, and all fired on one of the boats.

Several natives fell, and yells, accompanied by shots, replied to the detonation of the fire-arms.

But what could Dick Sand and his companions do against a hundred Africans, who surrounded them on all sides?

The ant-hill was assailed. Mrs. Weldon, her child, and Cousin Benedict, all were brutally snatched from it, and without having had time to speak to each other or to shake hands for the last time, they saw themselves separated from each other, doubtless in virtue of orders previously given.

A last boat took away Mrs. Weldon, little Jack and Cousin Benedict. Dick Sand saw them disappear in the middle of the camp.

As to him, accompanied by Nan, Old Tom, Hercules, Bat, Acteon and Austin, he was thrown into a second boat, which went toward another point of the hill.

Twenty natives entered this boat.

It was followed by five others.

Resistance was not possible, and nevertheless, Dick Sand and his companions attempted it. Some soldiers of the caravan were wounded by them, and certainly they would have paid for this resistance with their lives, if there had not been a formal order to spare them.

In a few minutes, the passage was made. But just as the boat landed, Hercules, with an irresistible bound, sprang on the ground. Two natives having sprung on him, the giant turned his gun like a club, and the natives fell, with their skulls broken.