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.