Early
Transportation
Today
we take cars, trains, airplanes and power boats for
granted. But we haven't always had them.
People
have lived on earth for millions of years. But
until a few hundred years ago, there weren't that
many ways to get around ... besides
walking!
One
of the most important inventions was the wheel. The
wheel made it possible to move things by rolling,
instead of carrying them or dragging them on the
ground. The people of Mesopotamia first used wheels
between 3500 and 3000 B.C..
Let's
say you had to move a kid across the playground.
Would you rather drag the kid on a sweater, or push
the kid on a cart? The cart's rolling wheels reduce
friction.
Another
important invention was the boat. Before the boat,
people didn't really have any way of getting across
big bodies of water, like lakes and oceans. Do you
think Christopher Columbus would have gone to
America if he'd had to swim?
The
first boats were just rafts. People made them by
laying tree trunks or branches side by side and
tying them together. Later on they covered the
bottoms of the rafts with animal skins to try to
keep the water out.
Around
five thousand years ago, the Egyptians made the
first sailboats. The sails catch the wind and use
wind power to make the boat go. If there wasn't
enough wind, the Egyptians had to
paddle.
While
the Egyptians made the first sailboats, some other
people had found another way of getting around:
they could ride horses!
The
horses traveled a lot farther after the invention
of horseshoes. Horseshoes are metal shoes nailed to
the bottom of a horse's foot.
If
you had to go up a steep, rocky hillside, could you
climb it better barefoot or wearing shoes? Well, so
could a horse!
People
built roads to ride their horses and roll their
carts on. The Chinese had roads with speed limits
three thousands years ago. Officials stood on the
roads to decide who went first at
crossings.
In
Rome, writers complained about traffic jams
thousands of years ago. There were too many carts
and horses! No wonder; the Romans built fifty
thousand miles of roads.
But
horses, carts and sailboats didn't let people
travel nearly as quickly as we can today. People
lived close to their jobs, because they could only
get to work by walking or riding a
horse.
Then,
in 1804, an inventor named Richard Trevithick made
something very important.
|