e should have stopped there amusing ourselves for the next
hour, pitching down stones and making the vipers vicious; but our
childish pursuit was ended by the doctor, who clapped Jack on the
shoulder.

"Come, Jack," he said, "if we leave you there you'll fall asleep and
topple to the bottom."

Jack drew up his legs and climbed once more to his feet, looking very
hot and languid, but he shouldered his piece and stepped out as we
slowly climbed along the edge of the chasm for about a quarter of a
mile, when it seemed to close up after getting narrower and narrower, so
that we continued our journey on what would have been its farther side
had it not closed.

Higher and higher we seemed to climb, with the path getting more
difficult, save when here and there we came upon a nice bare spot free
from stones, and covered with a short kind of herb that had the
appearance of thyme.

But now the heat grew less intense. Then it was comparatively cool, and
a soft moist air fanned our heated cheeks. The roar of the falls grew
louder, and at any moment we felt that we might come upon the sight, but
we had to travel on nearly half a mile along what seemed to be a steep
slope. It was no longer arid and barren here, for every shelf and
crevice was full of growth of the most vivid green. For a long time we
had not seen a tree, but here tall forest trees had wedged their roots
in the cracks and crevices, curved out, and then shot straight up into
the air.

The scene around was beautiful, and birds were once more plentiful,
dashing from fruit to flower, and no doubt screaming and piping
according to their wont, but all seemed to be strangely silent, even our
own voices sounded smothered, everything being overcome by the awful
deep loud roar that came from beyond a dense clump of trees.

We eagerly pressed forward now, ready, however, to find that we had a
long distance to go, and the doctor leading we wound our way in and out,
with the delicious shade overhead, and the refreshing moist air seeming
to cool our fevered faces and dry lips.

"Why, we're walking along by the very edge," said Jack Penny suddenly.
"This is the way;" and stepping aside he took about a dozen steps and
then the undergrowth closed behind him for the moment, but as we parted
it to follow him we caught sight of his tall form again and then lost
it, for he uttered a shrill "Oh!" and disappeared.

"Doctor! quick!" I cried, for I was next, and I sprang forwa