een hidden from us ever since
that morning when we saw it from far out at sea, but now it rises on
our left, its upper half covered with snow of dazzling whiteness,--a
regular cone, for from this side the crater cannot be seen. It looks as
though one could walk half a mile or so across the valley and then go
straight up to the summit, but it is full thirty miles off. The air is
heated as by a furnace, and as we jolt along the road the clouds of
dust are suffocating. We go full gallop along such road as there is,
banging into holes, and across the trenches left by last year's
watercourses, until we begin to think that it must end in a general
smash. We came to understand Mexican roads and Mexican drivers better,
even before we got to the capital.

Before us and behind lay wide lakes, stretching from side to side of
the valley; but the lake behind followed us as steadily as the one
before us receded. It was only the mirage that tantalizes travellers in
these scorched valleys, all the long eight months of the rainless
season. It seemed beautiful at first, then monotonous; and long before
the day was out we hated it with a most cordial and unaffected hatred.

Soon a new appearance attracted our attention. First, clouds of dust,
which gradually took a well-defined shape, and formed themselves into
immense pillars, rapidly spinning round upon themselves, and travelling
slowly about the plain. At one place, where several smaller valleys
opened upon us, these sand-pillars, some small, some large, were
promenading about by dozens, looking much like the genie when the
fisherman had just let him out of the bottle, and saw him with
astonishment beginning to shape himself into a giant of monstrous size.
Indeed I doubt not that the story-teller was thinking of such
sand-pillars when he wrote that wonderful description. You may see them
in the East by thousands. As they moved along, they sucked up small
stones, dust, and leaves; and our driver declared that they had been
known to take the roofs off houses, and carry flocks of sheep into the
air; "but these that you see now," said he, "are no great matter." We
estimated the size of the largest at about four hundred feet in height,
and thirty in diameter; and this very pillar, walking by chance against
a house, most decidedly got the worst of it, and had its lower limbs
knocked all to pieces.

When the sun grows hot, the bare earth heats the air that lies upon it
so much that an upwa