in, or where they obtained it.<40>

Cortez, in one of his letters, speaks of the use of small pieces of tin
as money. But we have already seen that the natives had not risen to the
conception of money. They certainly had copper tools, and bronze ones.
It seems, however, that their bronze was a natural production and not
an artificial one--that is to say, the ores of copper found in Mexico
contain more or less gold, silver, and tin. So, if melted, just as
nature left them, the result would be the production of bronze.<41> They
were then ignorant of the knowledge of how to make bronze artificially.
This shows us that they had not attained to a true Bronze Age; and yet
the discovery could not have been long delayed. Sooner or later they
would have found out that tin and copper melted together would produce
the light copper that experience had taught them was the most valuable.

Illustration of Yucatan Axes.---------------

The most important tool they made of copper was the ax. The ax, in both
Mexico and Yucatan, was made as represented in this illustration. From
their shape and mode of hafting them, we see at once they are simply
models of the stone ax; and this recalls what we learned of the Bronze
Age in Europe. At first they contented themselves with copying the forms
in stone.

Illustrations of Carpenter's Ax, Mexican Carpenter, and Copper
Tool.------------------------

Nature, everywhere, conducts her children by the same means to the same
ends. This form of ax is a representation of a carpenter's hatchet. The
next cut is from the Mendoza collection, and represents a carpenter at
work. He holds one of these hatchets in his hand, and is shaping a
stick of timber. The other cut represents a form of copper tool found in
Oaxaca, where they were once used in abundance. The supposition is that
this implement was used for agricultural purposes--probably as a hoe.
The pieces of T-shaped copper said to have been used as money, are
diminutive forms of this same tool. The statement is sometimes made that
they had a way of hardening copper. "This," says Mr. Valentine, "is
a hypothesis, often noted and spoken of, but which ranges under the
efforts made for explaining what we have no positive means to verify or
to ascertain." The presence of metals necessarily implies some skill in
mining; but their ability to mine was certainly very limited. Gold and
silver were collected by washing the sands. We do not know how
copp