is still a thousand feet higher, but there
is not time to-day to reach it.

A magnificent vista is spread out upon every hand. Extending north
and south along the crest of the Cascade Range there is a line
of sharp snowy peaks with summer clouds floating about them. How
these peaks contrast with the dark blue of the surrounding forests!
Opposite us, upon the south, is the third Sister, white with snow
from top to bottom, while in the basin between this peak and the
ridge on which we are standing lie the remnants of a once mighty
glacier.

But it is time to return. The cold, foggy clouds are hiding the
summits and will soon envelop the spot where we stand. We go down
by a different path, but over almost continuous snow-fields, for
more than two miles. The return is much easier than the ascent,
although if one lost his footing upon some steep slope, it would
mean a long slide or tumble. The solid earth is reached without
accident. What a relief to have some firm hold for the feet again!
Climbing over a field of rough lava is easier than toiling through
soft snow.

[Illustration: FIG. 19.--A BOULDER LEFT BY A GLACIER]

The region about the Three Sisters is just as nature left it, for
the home of the nearest settler is many miles away. Although now
it has few visitors, this country will become attractive when its
wonderful volcanic and glacial phenomena are better known.

SOMETHING ABOUT EARTHQUAKES AND MOUNTAIN BUILDING

Our everyday experiences lead us to feel that nothing is more permanent
than the features of the earth upon which we live. Great cities
containing costly buildings are built by the water's edge with the
expectation that the ocean will remain where it is. The building
of railroads and canals, and the establishment of industries to make
the earth more fruitful and better adapted to our use, are based
upon the idea that the mountains and valleys with their various,
climates will not change.

The study of history, however, makes plain the fact that at different
times in the past certain portions of the earth have been visited by
destructive changes. Cities have been shaken down by earthquakes, and
the ocean has swept in over the land, drowning thousands of people.
Even the mountains, which stand upon broad and firm foundations,
sometimes bring disaster, by means of avalanches and land-slides,
to the people who live at their bases.

The truth is that the earth's surface is everywhere slowly and