“Gone, father! Fritz, my bar has gone through the mountain!”
“Run round and get it,” laughed Fritz; “perhaps it has dropped into Europe—you must not lose a good crowbar.”
“But, really, it is through; it went right through the rock; I heard it crash down inside. Oh, do come and see!” he shouted excitedly.
We sprang to his side, and I thrust the handle of my hammer into the hole he spoke of; it met with no opposition, I could turn it in any direction I chose. Fritz handed me a long pole; I tried the depth with that. Nothing could I feel. A thin wall, then, was all that intervened between us and a great cavern.
With a shout of joy, the boys battered vigorously at the rock; piece by piece fell, and soon the hole was large enough for us to enter. I stepped near the aperture, and was about to make a further examination, when a sudden rush of poisonous air turned me giddy, and shouting to my sons to stand off, I leaned against the rock.
When I came to myself I explained to them the danger of approaching any cavern or other place where the air has for a long time been stagnant. “Unless air is incessantly renewed it becomes vitiated,” I said, “and fatal to those who breathe it. The safest way of restoring it to its original state is to subject it to the action of fire, a few handfuls of blazing hay thrown into this hole may, if the place be small, sufficiently purify the air within to allow us to enter without danger.” We tried the experiment. The flame was extinguished the instant it entered. Though bundles of blazing grass were thrown in, no difference was made.
I saw that we must apply some more efficacious remedy, and sent the boys for a chest of signal-rockets we had brought from the wreck. We let fly some dozens of these fiery serpents, which went whizzing in, and disappeared at apparently a vast distance from us. Some flew like radiant meteors round, lighted up the
