works.

[Illustration: Iron Products.]

I have here some iron ore, some old iron, some nails; here are some
clock springs, and here are some springs of watches. This iron ore is as
it is dug from the earth. It is called the native iron, but mixed with
it there is much earth and stone and dross, which must be separated from
it in order to make it pure. This is done by casting the ore, together
with limestone and other materials, into a huge furnace, where the fire
is so intensely hot that all are melted and thus the iron is separated
from the dross, or stone and earth, which is now mixed with the ore.
When the iron is thus separated and molded into large bars, it is worth
from a fraction of a cent to two cents per pound, according to quality
and market price. After it has been cast into great iron bars, and is
known as pig iron, it is afterward bought and melted over again and
molded into the form of stoves and wheels, such as are used in
factories, and a variety of other forms for manufacturing and other
uses.

[Illustration: Nail, Pen and Clock Spring.]

Now, here I have some pieces of iron, such as boys call "old iron." They
often find pieces of this kind of iron, which have been thrown away, and
gather and sell them at a price varying from one-quarter to a cent or
more a pound, according to circumstances. Then it is melted over again
and made into stoves, or whatever the manufacturer may desire. Now, here
are some nails, such as sell at five cents a pound, and here are some
steel pens, which are worth from one to four and five dollars a pound.
Here are some springs, such as are used in the construction of clocks.
These are the springs which make clocks go. When you wind up the clock
you simply tighten this spring, thus storing the power which is
necessary to keep the clock in motion for twenty-four hours, for eight
days, or even a longer period.

Now here are some springs, such as are used in watches. These springs
are worth, according to their size and quality, from twenty to fifty or
sixty dollars a pound. Here also are some little screws, such as are
used in the construction of watches, and which are worth even a hundred
dollars a pound.

While these different articles are all made of the same material, you
see there is a great difference in their value. One is not worth a
single cent a pound, and another may be worth one hundred dollars a
pound. Now this difference in value is due to two things. One is,