red 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 directly
into the channels of swift rivers, scarcely one of their wedged and
interlacing boulders has moved since the day of their creation; and
though mostly made up of huge blocks of granite, many of them from ten
to fifty feet cube, weighing thousands of tons with only a few small
chips, trees and shrubs make out to live and thrive on them and even
delicate herbaceous plants--draperia, collomia, zauschneria, etc.,
soothing and coloring their wild rugged slopes with gardens and groves.

I was long in doubt on some points concerning the origin of those
taluses. Plainly enough they were derived from the cliffs above them,
because they are of the size of scars on the wall, the rough angular
surface of which contrasts with the rounded, glaciated, unfractured
parts. It was plain, too, that instead of being made up of material
slowly and gradually weathered from the cliffs like ordinary taluses,
almost every one of them had been formed suddenly in a single avalanche,
and had not been increased in size during the last three or four
centuries, for trees three or four hundred years old are growing on
them, some standing at the top close to the wall without a bruise or
broken branch, showing that scarcely a single boulder had ever fallen
among them. Furthermore, all these taluses throughout the Range seemed
by the trees and lichens growing on them to be of the same age. All
the phenomena thus pointed straight to a grand ancient earthquake. But
for years I left the question open, and went on from canyon to canyon,
observing again and again; measuring the heights of taluses throughout
the Range on both flanks, and the variations in the angles of their
surface slopes; studying the way their boulders had been assorted and
related and brought to rest, and their correspondence in size with the
cleavage joints of the cliffs from whence they were derived, cautious
about making up my mind. But at last all doubt as to their formation
vanished.

At half-past two o'clock of a moonlit morning in March, I was awakened
by a tremendous earthquake, and though I had never before enjoyed a
storm of this sort, the strange thrilling motion could not be mistaken,
and I ran out of my cabin, both glad and frightened, shouting, "A noble
earthquake! A noble ea