with ruinous sides, such as are known in this Western land as _mesas_ or
_buttes_. They were Nature's enormous mockery of the most ambitious
architecture of man, the pyramids of Egypt and the platform of Baalbek.
Terrace above terrace of shattered wall; escarpments which had been
displaced as if by the explosion of some incredible mine; ramparts which
were here high and regular, and there gaping in mighty fissures, or
suddenly altogether lacking; long sweeps of stairway, winding dizzily
upwards, only to close in an impossible leap: there was no end to the
fantastic outlines and the suggestions of destruction.

Nor were the open spaces between these rocky mounds less remarkable. In
one valley, the course of a river which vanished ages ago, the power of
fire had left its monuments amid those of the power of water. The
sedimentary rock of sandstone, shales, and marl, not only showed veins of
ignitible lignite, but it was pierced by the trap which had been shot up
from earth's flaming recesses. Dikes of this volcanic stone crossed each
other or ran in long parallels, presenting forms of fortifications, walls
of buildings, ruined lines of aqueducts. The sandstone and marl had been
worn away by the departed river, and by the delicately sweeping,
incessant, tireless wings of the afreets of the air, leaving the iron-like
trap in bold projection.

Some of these dikes stretched long distances, with a nearly uniform height
of four or five feet, closely resembling old field-walls of the solidest
masonry. Others, not so extensive, but higher and pierced with holes,
seemed to be fragments of ruined edifices, with broken windows and
shattered portals. As the trap is columnar, and the columns are horizontal
in their direction, the joints of the polygons show along the surface of
the ramparts, causing them to look like the work of Cyclopean builders.
The Indians and Mexicans of the expedition, deceived by the similarity