rnblendic granite, its deck-houses, shapen with perfect accuracy of
imitation, still remaining in their place, and a weird-looking demon at
the wheel steering it on to some invisible destruction. This naval
statue (if its bulk forbid not the name) was carved out of a coarse
millstone-grit by the chisel of the wind, with but slight assistance
from the infrequent rain-storms of this region. In Colorado I first
began to perceive how vast an omission geologists had been guilty of in
their failure to give the wind a place in the dynamics of their science.
Depending for a year at a time, as that Territory sometimes does, upon
dews and meltings from the snow-peaks for its water, it is nevertheless
fuller than any other district in the world of marvellous architectural
simulations, vast cemeteries crowded with monuments, obelisks, castles,
fortresses, and natural colossi from two to five hundred feet high, done
in argillaceous sandstone or a singular species of conglomerate, all of
which owe their existence almost entirely to the agency of wind. The
arid plains from which the conglomerate crops out rarefy the
superincumbent air-stratum to such a degree that the intensely chilled
layers resting on the closely adjoining snow-peaks pour down to
reestablish equilibrium, with the wrathful force of an invisible
cataract, eight, ten, even seventeen thousand feet in height. These
floods of cold wind find their appropriate channels in the
characteristic _canons_ which everywhere furrow the whole Rocky-Mountain
system to its very base. Most of these are exceedingly tortuous, and the
descending winds, during their passage through them, acquire a spiral
motion as irresistible as the fiercest hurricane of the Antilles, which,
moreover, they preserve for miles after they have issued from the mouth
of the _canon_. Every little cold gust that I observed in the Colorado
country had this corkscrew character. The moment the spiral reaches a
loose sand-bed, it sweeps into its vortex all the particles of grit
which it can hold. The result is an auger, of diameter varying from an
inch to a thousand feet, capable of altering its direction so as to bore
curved holes, revolving with incalculable rapidity, and armed with a
cutting edge of silex. Is it possible to conceive an instrument more
powerful, more versatile? Indeed, practically, there is no description
of surface, no kind of cut, which it is not capable of making. I have
repeatedly seen it in oper