rhaps within the existence of the human race. A
few hundred thousand years from now it will be one or more Aladdin
palaces.

Find on the map the great Walhalla Plateau in the east of the canyon.
Note that its base is nearly separated from the parental rim; a thousand
centuries or so and its isolation will be complete. Not long after that,
as geologists reckon length of time, it will divide into two plateaus;
it is easy to pick the place of division. The tourist of a million years
hence will see, where now it stands, a hundred glowing castles.

Let us look again at our photographs, which now we can see with
understanding. To realize the spectacle of the canyon, let imagination
paint these strata their brilliant colors. It will not be difficult; but
here again we must understand.

It is well to recall that these strata were laid in the sea, and that
they hardened into stone when the earth's skin was pushed thousands of
feet in air. Originally they were the washings of distant highlands
brought down by rivers; the coloring of the shales and sandstones is
that of the parent rock modified, no doubt, by chemical action in
sea-water. The limestone, product of the sea, is gray.

As these differently colored strata were once continuous across the
canyon, it follows that their sequence is practically identical on both
sides of the canyon. That the colors seem confused is because, viewing
the spectacle from an elevation, we see the enormous indentations of the
opposite rim in broken and disorganized perspective. Few minds are
patient and orderly enough to fully disentangle the kaleidoscopic
disarray, but, if we can identify the strata by form as well as color,
we can at least comprehend without trouble our principal outline; and
comprehension is the broad highway to appreciation.

To identify these strata, it is necessary to call them by name. The
names that geologists have assigned them have no scientific significance
other than identity; they are Indian and local.

Beginning at the canyon rim we have a stalwart cliff of gray limestone
known as the Kaibab Limestone, or, conversationally, the Kaibab; it is
about seven hundred feet thick. Of this product of a million years of
microscopic life and death on sea-bottoms is formed the splendid
south-rim cliffs from which we view the chasm. Across the canyon it is
always recognizable as the rim.

Below the talus of the Kaibab is the Coconino sandstone, light
yellowish-gray, coar