Hercules holding up the lantern lighted Dick Sand.  They had some wax candles to take its place, and they had not to fear lack of light from that source.

A minute after the beginning of the operation, the ramrod went freely through the wall.  At once a rather dull noise was produced, resembling that made by globules of air escaping through a column of water.  The air escaped, and, at the same moment, the level of the water rose in the cone, and stopped at the height of the hole.  This proved that they had pierced too low—­that is to say, below the liquid mass.

“Begin again,” the young novice said, coolly, after rapidly stopping the hole with a handful of clay.

The water was again stationary in the cone, but the reserved space had diminished more than eight inches.  Respiration became difficult, for the oxygen was beginning to fail.  They saw it also by the lantern’s light, which reddened and lost a part of its brightness.

One foot above the first hole, Dick Sand began at once to pierce a second by the same process.  If the experiment failed, the water would rise still higher inside the cone—­but that risk must be run.

While Dick Sand was working his auger, they heard Cousin Benedict cry out, suddenly: 

“Mercy! look—­look—­look why!”

Hercules raised his lantern and threw its light on Cousin Benedict, whose face expressed the most perfect satisfaction.

“Yes,” repeated he, “look why those intelligent termites have abandoned the ant-hill!  They had felt the inundation beforehand.  Ah! instinct, my friends, instinct.  The termites are wiser than we are, much wiser.”

And that was all the moral Cousin Benedict drew from the situation.

At that moment Dick Sand drew out the ramrod, which had penetrated the wall.  A hissing was produced.  The water rose another foot inside the cone—­the hole had not reached the open air outside.

The situation was dreadful.  Mrs. Weldon, then almost reached by the water, had raised little Jack in her arms.  All were stifling in this narrow space.  Their ears buzzed.

The lantern only threw a faint light.

“Is the cone, then, entirely under water?” murmured Dick Sand.

He must know; and, in order to know, he must pierce a third hole, at the very top.

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.