Swiss Family Robinson

soaked, and two casks of powder utterly destroyed. We immediately spread such things as we hoped yet to preserve in the sun to dry.
    The pinnace was safe, but our faithful tub-boat was dashed in pieces, and the irreparable damage we had sustained made me resolve to contrive some safer and more stable winter-quarters before the arrival of the next rainy season. Fritz proposed that we should hollow out a cave in the rock, and though the difficulties such an undertaking would present appeared almost insurmountable, I yet determined to make the attempt; we might not, I thought, hew out a cavern of sufficient size to serve as a room, but we might at least make a cellar for the more valuable and perishable of our stores.
    Some days afterwards we left Falconhurst with the cart laden with a cargo of spades, hammers, chisels, pickaxes and crowbars, and began our undertaking. On the smooth face of the perpendicular rock I drew out in chalk the size of the proposed entrance, and then, with minds bent on success, we battered away.
    Six days of hard and incessant toil made but little impression; I do not think that the hole would have been a satisfactory shelter for even Master Knips ; but we still did not despair, and were presently rewarded by coming to softer and more yielding substance; our work progressed, and our minds were relieved.
    On the tenth day, as our persevering blows were falling heavily, Jack, who was working diligently with a hammer and crowbar, shouted:
    `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.*
    * What actually happens is that the oxygen supply becomes low. If there is sufficient oxygen to maintain a flame, the action of the flame increases air circulation, which then brings in more oxygen. The flame goes out if the oxygen supply is insufficient for its supply; in this case, it takes the fireworks to create adequate circulation. The next torch is able to blaze not because the air is purified, but because the oxygen is now sufficient to feed the fire.
    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 mighty circumference and displayed, as by a magician's wand, a sparkling glittering roof. They looked like avenging dragons driving a foul malignant fiend out of a beauteous palace.
    We waited for a little while after these experiments, and I then again threw in lighted hay. It burned clearly; the air was purified.
    Fritz and I enlarged the opening, while Jack, springing on his buffalo, thundered away to Falconhurst to bear the great and astonishing news to his mother.
    Great must have been the effect of Jack's eloquence on those at home, for the timbers of the bridge were soon again resounding under the swift but heavy tramp of his