Then, the event most to be feared was the persistence of the storm, and, consequently, the increase of the inundation.  Thirty feet of water on the plain would cover the cone with eighteen feet of water, and bear on the air within with the pressure of an atmosphere.

Now, after reflecting well upon it, Dick Sand was led to fear that this inundation might increase considerably.

In fact, it could not be due solely to that deluge poured out by the clouds.  It seemed more probable that a neighboring watercourse, swelled by the storm, had burst its banks, and was spreading over this plain lying below it.  What proof had they that the ant-hill was not then entirely submerged, and that it was full time to leave it by the top part, which would not be difficult to demolish?

Dick Sand, now extremely anxious, asked himself what he ought to do.  Must he wait or suddenly announce the probable result of the situation, after ascertaining the condition of things?

It was then three o’clock in the morning.  All, motionless, silent, listened.  The noise from outside came very feebly through the obstructed orifice.  All the time a dull sound, strong and continued, well indicated that the contest of the elements had not ceased.

At that moment old Tom observed that the water level was gradually rising.

“Yes,” replied Dick Sand, “and if it rises, as the air cannot escape from within, it is because the rising of the waters increases and presses it more and more.”

“It is but slight so far,” said Tom.

“Without doubt,” replied Dick Sand; “but where will this level stop?”

“Mr. Dick,” asked Bat, “would you like me to go out of the ant-hill?  By diving, I should try to slip out by the hole.”

“It will be better for me to try it,” replied Dick Sand.

“No, Mr. Dick, no,” replied old Tom, quickly; “let my son do it, and trust to his skill.  In case he could not return, your presence is necessary here.”

Then, lower: 

“Do not forget Mrs. Weldon and little Jack.”

“Be it so,” replied Dick Sand.  “Go, then, Bat.  If the ant-hill is submerged, do not seek to enter it again.  We shall try to come out as you will have done.  But if the cone still emerges, strike on its top with the ax that you will take with you.  We will hear you, and it will be the signal for us to demolish the top from our side.  You understand?”

“Yes, Mr. Dick,” replied Bat.

“Go, then, boy,” added old Tom, pressing his son’s hand.

Bat, after laying in a good provision of air by a long aspiration, plunged under the liquid mass, whose depth then exceeded five feet.  It was a rather difficult task, because he would have to seek the lower orifice, slip through it, and then rise to the outside surface of the waters.

That must be done quickly.

Nearly half a minute passed away.  Dick Sand then thought that Bat had succeeded in passing outside when the black emerged.