dies,
they required tools. These, in the main, consisted of the spears and
arrow-heads used as weapons of the chase, and the axes and knives used
as constructive tools.

Rough stone gave place to flint because the latter would take a better
edge. For the same reason the people of central Europe sent to the
deserts of central Asia for jade wherewith to make axes and knives.
Again, for the same reason, jade was discarded, because an alloy of
copper and tin produced a bronze that would not only take a sharper edge
than stone, but it was hard enough to cut and dress the latter. Egypt
rose to a commanding position because of her control of the copper mines
in the Sinaitic peninsula, and subsequently of the gold products coming
from the upper Nile.

A meridian drawn through Cairo, Egypt, practically divides the world
into two kinds of civilization. East of this meridian the population is
almost wholly agricultural and, excepting Japan and India, the
character of the civilization has changed but little in the past 2,000
years. West of the line the population is essentially characterized as
metal-workers. It controls the world--not especially by virtue of a high
degree of intellectual development, but because it has availed itself of
the properties and characteristics of metals and their applications to
commerce.

The four metals that have had the greatest influence on western
civilization are gold, silver, iron, and copper. The discovery of gold
and silver has always resulted in a rapid settlement of the regions in
which the discoveries were made, and usually in the building of great
industrial centres. Thus, the discovery of gold in California was the
first step in making the United States a world power. The acquisition of
so large an amount of gold caused an industrial expansion that hurried
the Civil War, and led to the manufacture of iron and steel both for
agricultural machinery and railroad transportation. This, in turn,
brought the country so closely in touch with the affairs of China and
Japan, that European and American diplomacy in eastern Asia are a common
concern. The commercial position of Great Britain is very largely due to
her iron mines.

The production of Bessemer steel at a price far less than that of iron
at the beginning of the nineteenth century lowered the cost of
transporting commodities to the extent that large areas, once of
necessity very moderately productive of food-stuffs, are now densely
pe