nshine begins to
sift through their laden spires; then the dense masses on the ends of
the leafy branches begin to shift and fall, those from the upper
branches striking the lower ones in succession, enveloping each tree in
a hollow conical avalanche of fairy fineness; while the relieved
branches spring up and wave with startling effect in the general
stillness, as if each tree was moving of its own volition. Hundreds of
broad cloud-shaped masses may also be seen, leaping over the brows of
the cliffs from great heights, descending at first with regular
avalanche speed until, worn into dust by friction, they float in front
of the precipices like irised clouds. Those which descend from the brow
of El Capitan are particularly fine; but most of the great Yosemite
avalanches flow in regular channels like cascades and waterfalls. When
the snow first gives way on the upper slopes of their basins, a dull
rushing, rumbling sound is heard which rapidly increases and seems to
draw nearer with appalling intensity of tone. Presently the white flood
comes bounding into sight over bosses and sheer places, leaping from
bench to bench, spreading and narrowing and throwing off clouds of
whirling dust like the spray of foaming cataracts. Compared with
waterfalls and cascades, avalanches are short-lived, few of them lasting
more than a minute or two, and the sharp, clashing sounds so common in
falling water are mostly wanting; but in their low massy thundertones
and purple-tinged whiteness, and in their dress, gait, gestures and
general behavior, they are much alike.

Avalanches

Besides these common after-storm avalanches that are to be found not
only in the Yosemite but in all the deep, sheer-walled canyon of the
Range there are two other important kinds, which may be called annual
and century avalanches, which still further enrich the scenery. The only
place about the Valley where one may be sure to see the annual kind is
on the north slope of Clouds' Rest. They are composed of heavy, compacted
snow, which has been subjected to frequent alternations of freezing and
thawing. They are developed on canyon and mountain-sides at an elevation
of from nine to ten thousand feet, where the slopes are inclined at an
angle too low to shed off the dry winter snow, and which accumulates
until the spring thaws sap their foundations and make them slippery;
then away in grand style go the ponderous icy masses without any fine
snow-dust. Those of