Harry, besides a large lantern, took a safety lamp, which would burn for twelve hours.
It was more than was necessary for the journey there and back, including the time for the working--supposing a working was possible.
"To work! to work!" shouted Ford, when the party reached the further end of the passage; and he grasped a heavy crowbar and brandished it.
"Stop one instant," said Starr.

"Let us see if any change has taken place, and if the fire-damp still escapes through the crevices." "You are right, Mr.Starr," said Harry.

"Whoever stopped it up yesterday may have done it again to-day!" Madge, seated on a rock, carefully observed the excavation, and the wall which was to be blasted.
It was found that everything was just as they left it.

The crevices had undergone no alteration; the carburetted hydrogen still filtered through, though in a small stream, which was no doubt because it had had a free passage since the day before.

As the quantity was so small, it could not have formed an explosive mixture with the air inside.