d of a hammer, so he threw a hard nut against
a rock.
The nut did not crack.
So he kept on trying different ways.
At last he struck the nut with a stone.
Its hard shell broke.
How glad Bodo was!
He ate the kernel and then cracked some more nuts with the stone.
This stone was his first hammer.
Sometimes he used a rough stone.
Its rough edges hurt his hand, so he hunted for a smooth stone.
At other times he wrapped one end of a rough stone in grass.
The grass protected his hand.
This was the first handle to his hammer.
Bodo liked to use this hammer.
He liked to use smooth hammer-stones.
But sometimes the smooth stone slipped or bounded back and jarred his
hand.

[Illustration: "_Bodo cracked nuts with a stone_"]

One day he found a smooth stone that had a little pit on either side.
He put his thumb and finger into the pits and cracked a hard nut with
the stone.
This was just what he needed.
It neither slipped nor jarred his hand.
Some of the other Tree-dwellers tried it.
They wanted one like it, so they began to hunt for pitted stones.
They could not always find such stones, but they never thought of
making the pits.
People lived many years before they learned to do that.
Tree-dwellers simply used things that they found on the spot.

[Illustration: _The chipped pebble_]

They seldom changed their shape.
We have only a few weapons that we know they made.
They were found years ago deep down in some gravel.
They had lain there many long years.
Here is a picture of one.
It is only a chipped pebble.
Such a weapon is used nowadays only in play, but then it was used in
real work.
For a long time the Tree-dwellers did not have even this.
They used their teeth and nails instead.

[Illustration: _An antler used as a wedge_]

Some animals had larger and sharper teeth.
The Tree-dwellers found such teeth in the sand.
They found sharp claws there, too.
They often found sharp bones and horns.
They used such things for cutting for many long years, but at last
they made a knife.
It happened when Bodo was cracking a bone.
In some way he broke his hammer.
He picked up the pieces and looked at them.
They were sharp enough to cut with, but the edges hurt his hand.
So he found a smooth pebble and chipped flakes from one end.
Before long he had a sharp point.
He never hafted it; but he left one end smooth, so