miles of lower country. Nevertheless among the mountains
themselves the ice gouged and scraped and smoothed and at its
lower edges deposited great moraines. Its work today makes the
cliffs and falls of the Yosemite one of the world's most famous
bits of scenery. This scenery is young and its beauty will pass
in a short time as geology counts the years, for in natural
scenery as in human life it is youth that makes beauty. The
canyons, waterfalls, and geysers of the cordillera share their
youth with the lakes, waterfalls, and rapids due to recent
glaciation in the east. Nevertheless, though youth is the
condition of most striking beauty, maturity and old age are the
condition of greatest usefulness. The young cordillera with its
mountains still in the making can support only a scanty
population, whereas the old eastern mountains, with the lines of
long life engraved upon every feature, open their arms to man and
let him live and prosper.

It is not enough that we should picture merely the four divisions
of the land of our continent. We must see how the land meets the
sea. In low latitudes in both the Old World and the New, the
continents have tended to emerge farther and farther from the sea
during recent geological times. Hence on the eastern side of both
North and South America from New Jersey to Brazil the ocean is
bordered for the most part by coastal plains, uplifted from the
sea only a short time ago. On the mountainous western side of
both continents, however, the sea bottom shelves downward so
steeply that its emergence does not give rise to a plain but
merely to a steep slope on which lie a series of old beaches
several hundred and even one thousand feet above the present
shore line. Such conditions are not favorable to human progress.