And now after this general view, mark how sharply
the ribs and buttresses and summits of the mountains
are defined, excepting the portions veiled by the
banners; how gracefully and nobly the banners are
waving in accord with the throbbing of the wind flood;
how trimly each is attached to the very summit of
its peak like a streamer at a mast-head; how bright
and glowing white they are, and how finely their fading
fringes are penciled on the sky! See how solid
white and opaque they are at the point of attachment
and how filmy and translucent toward the end, so that
the parts of the peaks past which they are streaming
look dim as if seen through a veil of ground glass.
And see how some of the longest of the banners on
the highest peaks are streaming perfectly free from
peak to peak across intervening notches or passes,
while others overlap and partly hide one another.
As to their formation, we find that the main causes
of the wondrous beauty and perfection of those we
are looking at are the favorable direction and force
of the wind, the abundance of snow-dust, and the form
of the north sides of the peaks. In general, the
north sides are concave in both their horizontal and
vertical sections, having been sculptured into this
shape by the residual glaciers that lingered in the
protecting northern shadows, while the sun-beaten south
sides, having never been subjected to this kind of
glaciation, are convex or irregular. It is essential,
therefore, not only that the wind should move with
great velocity and steadiness to supply a sufficiently
copious and continuous stream of snow-dust, but that
it should come from the north. No perfect banner
is ever hung on the Sierra peaks by the south wind.
Had the gale today blown from the south, leaving the
other conditions unchanged, only swirling, interfering,
cloudy drifts would have been produced; for the snow,
instead of being spouted straight up and over the
tops of the peaks in condensed currents to be drawn
out as streamers, would have been driven over the
convex southern slopes from peak to peak like white
pearly fog.
It appears, therefore, that shadows in great part
determine not only the forms of lofty ice mountains,
but also those of the snow banners that the wild winds
hang upon them.
Earthquake Storms
The avalanche taluses, leaning against the walls at
intervals of a mile or two, are among the most striking
and interesting of the secondary features of the Valley.
They are from about three to five hundred feet high,
made up of huge, angular, well-preserved, unshifting
boulders, and instead of being slowly weathered from
the cliffs like ordinary taluses, they were all formed
suddenly and simultaneously by a great earthquake
that occurred at least three centuries ago. And
though thus hurled into existence in a few seconds
or minutes, they are the least changeable of all the
Sierra soil-beds. Excepting those which were launched
Copyrights
The Yosemite from Project Gutenberg. Public domain.
