and it would be on the
Sunday following that we made a great discovery. Hitherto we had always
gone up-stream; on that day, however, we laid aside our rods, and,
taking some provisions, set off for a long ramble in the opposite
direction. The day was warm, and we trudged along leisurely enough,
stopping about mid-day to eat our lunch upon a great flat rock near the
riverbank. Afterward we sat and smoked awhile, resuming our walk only
when we were tired of inaction.

For perhaps another hour we wandered onward, chatting quietly and
comfortably on this and that matter, and on several occasions stopping
while my companion--who is something of an artist--made rough sketches
of striking bits of the wild scenery.

And then, without any warning whatsoever, the river we had followed so
confidently, came to an abrupt end--vanishing into the earth.

"Good Lord!" I said, "who ever would have thought of this?"

And I stared in amazement; then I turned to Tonnison. He was looking,
with a blank expression upon his face, at the place where the river
disappeared.

In a moment he spoke.

"Let us go on a bit; it may reappear again--anyhow, it is worth
investigating."

I agreed, and we went forward once more, though rather aimlessly; for we
were not at all certain in which direction to prosecute our search. For
perhaps a mile we moved onward; then Tonnison, who had been gazing about
curiously, stopped and shaded his eyes.

"See!" he said, after a moment, "isn't that mist or something, over
there to the right--away in a line with that great piece of rock?" And
he indicated with his hand.

I stared, and, after a minute, seemed to see something, but could not be
certain, and said so.

"Anyway," my friend replied, "we'll just go across and have a glance."
And he started off in the direction he had suggested, I following.
Presently, we came among bushes, and, after a time, out upon the top of
a high, boulder-strewn bank, from which we looked down into a wilderness
of bushes and trees.

"Seems as though we had come upon an oasis in this desert of stone,"
muttered Tonnison, as he gazed interestedly. Then he was silent, his
eyes fixed; and I looked also; for up from somewhere about the center of
the wooded lowland there rose high into the quiet air a great column of
hazelike spray, upon which the sun shone, causing innumerable rainbows.

"How beautiful!" I exclaimed.

"Yes," answered Tonnison, thoughtfully. "There must be a water