sion of graceful convolutions like
the outside sprays of Yosemite Falls in flood time; then, sailing out
into the thin azure over the precipitous brink of the ridge they were
drifted together like wreaths of foam on a river. These higher and finer
cloud fabrics were evidently produced by the chilling of the air from
its own expansion caused by the upward deflection of the wind against
the slopes of the mountain. They steadily increased on the north rim of
the cone, forming at length a thick, opaque, ill-defined embankment from
the icy meshes of which snow-flowers began to fall, alternating with
hail. The sky speedily darkened, and just as I had completed my last
observation and boxed my instruments ready for the descent, the storm
began in serious earnest. At first the cliffs were beaten with hail,
every stone of which, as far as I could see, was regular in form,
six-sided pyramids with rounded base, rich and sumptuous-looking, and
fashioned with loving care, yet seemingly thrown away on those desolate
crags down which they went rolling, falling, sliding in a network of
curious streams.

After we had forced our way down the ridge and past the group of hissing
fumaroles, the storm became inconceivably violent. The thermometer fell
22 degrees in a few minutes, and soon dropped below zero. The hail gave
place to snow, and darkness came on like night. The wind, rising to the
highest pitch of violence, boomed and surged amid the desolate crags;
lightning flashes in quick succession cut the gloomy darkness; and the
thunders, the most tremendously loud and appalling I ever heard, made
an almost continuous roar, stroke following stroke in quick, passionate
succession, as though the mountain were being rent to its foundations
and the fires of the old volcano were breaking forth again.

Could we at once have begun to descend the snow slopes leading to the
timber, we might have made good our escape, however dark and wild the
storm. As it was, we had first to make our way along a dangerous
ridge nearly a mile and a half long, flanked in many places by steep
ice-slopes at the head of the Whitney Glacier on one side and by
shattered precipices on the other. Apprehensive of this coming darkness,
I had taken the precaution, when the storm began, to make the most
dangerous points clear to my mind, and to mark their relations with
reference to the direction of the wind. When, therefore, the darkness
came on, and the bewildering drift, I