needed with an astonishing faculty of making it answer their needs. They
once almost occupied the world. Such were those who, so far as we know,
were once the exclusive owners of this continent. They were an
agricultural, industrious and home-loving people. [Footnote: The Mound
Builders and Cave Dwellers. They knew only lead and copper.]

Then came, with a strange leaving out of the plentiful and easily worked
metals which are the subject of this chapter, the great Age of Bronze.
This next stage of progress after stone was marked by a skillful alloy,
requiring even now some scientific knowledge in its compounding of
copper and tin. A thousand theories have been brought forward to account
for this hiatus in the natural stages of human progress, the truth
probably being that both tin and copper are more fusible than iron-ores,
and that both are found as natural metals. Some accident such as
accounts for the first glass, [Footnote: The story is told by Pliny.
Some sailors, landing on the eastern coast of Spain, supported their
cooking utensils on the sand with stones, and built a fire under them.
When they had finished their meal, glass was found to have been made
from the niter and sea-sand by the heat of their fire. The same thing
has been done, by accident, in more recent times, and may have been done
before the incident recounted. It is also done by the lightning striking
into sand and making those peculiar glass tubes known as
_Fulmenites_, found in museums and not very uncommon.] some
camp-fire unintended fusion, produced the alloy that became the metal of
all the arms and arts, and so remained for uncounted centuries. In this
connection it is declared that the Age of Bronze knew something that we
cannot discover; the art of tempering the alloy so that it would bear an
edge like fine steel. If this be true and we could do it, we should by
choice supplant the subject of this chapter for a thousand uses. As the
matter stands, and in our ignorance of a supposed ancient secret, the