boys now got on so well, and dug so much out, that I had hard work to
throw up the earth on the bank.

One day, as Jack stuck his pick in at the back of the cave, which was
now more than eight feet from the front, a great mass of the rock fell
in, and he cried out, "Look here! I have got through."

"Through what?" said I. "Not through your hand, I hope."

"No, no, but through the rock."

At this, Fritz set up a loud laugh.

"Why not say through the world at once, and push your crow bar in till
you reach EU-ROPE, which, Ernest says, lies in a straight line from
our feet. I should like to have a peep down, such a hole, for I might
thus get a sight of our dear Swiss home."

Fritz and I went up to the wall and found that Jack was right, for he
had come to a clear space. His first thought was to jump in; but as I
knew that there might be foul air in the cave, I would not let him risk
his life.

The boys then set fire to some dry grass, and thrust it in the hole,
but it went out at once, which was a sure sign that the air was not fit
to breathe.

I knew that we had brought from the wreck a box full of fire works,
which were used on board to make signs to ships far out at sea. I sent
Fritz to Tent House for these, though I thought that they might be too