Perhaps some torrent had formerly dashed through it; but now it was as dry as if it had been cut some thousand feet lower, through granite rocks.

At the same time, the air circulated freely, which showed that certain natural vents placed it in communication with the exterior atmosphere.
This observation, made by the engineer, was correct, and it was evident that the ventilation of the new mine would be easily managed.

As to the fire-damp which had lately filtered through the schist, it seemed to have been contained in a pocket now empty, and it was certain that the atmosphere of the gallery was quite free from it.

However, Harry prudently carried only the safety lamp, which would insure light for twelve hours.
James Starr and his companions now felt perfectly happy.

All their wishes were satisfied.