essed and made the greatest servant
of all the forces of Nature.

The discovery of powder led to the making of guns so destructive that
dozens of birds could be killed at one shot.

Some people became greedy and used all these wonderful discoveries to
rob Nature. It seemed as if in some places all the wild life would be
destroyed. Fires were allowed to burn the forest unhindered. The soil
was made to produce crops until it grew poor.

If we become selfish and indifferent and neglect to care for the
treasures which Nature has placed in our hands, very serious things will
happen to us, as they have happened to other people. How to use the
storehouse of Nature without wasting or destroying these treasures is
what we mean by _conservation_.

CHAPTER TWO

HOW OUR NEEDS DIFFER FROM THOSE OF THE FIRST MEN

We have seen that the first men, like the other animals, depended upon
the food that Nature supplied them, and when this was lacking they went
hungry. When men had learned the use of fire they took the first step in
making Nature serve them better than she did the lower animals. Today
she works for us in so many ways that we can hardly name them all.

After the use of fire the next thing that men learned was to make better
homes, to tame some of the wild animals, and to raise a part of their
food supplies, instead of depending entirely upon what they could pick
up here and there.

As the number of people increased, the question of securing food became
more and more important. Would it not seem pretty hard to have to go out
and hunt for your breakfast in the woods, or fields, or along the water?
If you were alone you might find enough to eat, but if there were
thousands of other people doing the same thing, you would probably go
hungry. For this reason people began to cultivate berries, fruits,
roots, and grains, and to take better care of their herds.

Living as they did, in those parts of the world where the climate was
warm, they usually found an abundance of food. But when these places
became too crowded, and some of them had to move to new regions, they
often found less food and a climate not always comfortable.

In this way people spread into the colder and drier parts of the earth.
The need for things which they did not have there sharpened the wits of
these people. It led to one discovery after another. New needs were felt
and new ways of satisfying them were sought. They kept finding out more
abou