The Columbia River passes through the Cascade
Mountains, where it forms the Columbia
River Gorge.
BRITANNICA STUDENT ENCYCLOPEDIA Columbus 161
Many new factories were built in
Columbus after 1940. The city began to
grow greatly in the late 20th century.
#More to explore
Ohio
Columbus,
Christopher
Christopher Columbus opened the
world of the Americas to his fellow
Europeans. Europeans called Vikings
had reached the Americas hundreds of
years before Columbus first arrived
there in 1492. However, the Vikings
did not establish long-lasting
settlements. Columbus explored the
area and brought back more Europeans
with him on later trips. Columbus’
voyages therefore had many more
lasting effects.
Columbus began an unstoppable wave
of European settlement in the Americas.
This settlement brought European culture
to theWestern Hemisphere. It also
brought great hardship to the Native
Americans there. They suffered from
diseases brought by the Europeans. They
were also enslaved and forced to mine
gold for the Europeans.
Early Life
Cristoforo Colombo was born in Genoa,
Italy, in 1451. He is known as Christopher
Columbus to English-speaking
people. He was the son of a weaver and
had little schooling.
In about 1476 Columbus settled in Portugal.
In the 1480s he started planning a
voyage to discover a sea route to Asia.
Europeans were eager for Asian goods.
However, these goods were costly
because they had to be brought to
Europe over a dangerous land route.
Columbus knew that Earth was round.
He thought that Asia must lie to the
west, across the Atlantic Ocean.
The Portuguese king refused to pay for
Columbus’ voyage. Columbus then
The city of Columbus, Ohio, overlooks the
Scioto River.
Christopher Columbus
162 Columbus, Christopher BRITANNICA STUDENT ENCYCLOPEDIA
lost all four of his ships. He had to be
rescued.
Last Years
Columbus returned to Spain in November
1504. He died on May 20, 1506.
Until his death he remained convinced
that he had reached Asia.
#More to explore
Americas, Exploration and Settlement of
the • Exploration • Ferdinand and
Isabella • Native Americans
Comanche
The Comanche people are a Native
American tribe that once roamed the
southern Great Plains of North America.
They were one of the first tribes to use
horses extensively. Horses eventually
changed the way that all Plains Indians
lived.
The Comanche were originally a branch
of the Shoshone people ofWyoming.
The Comanche moved southward in
stages, attacking and displacing other
Plains tribes.
The Comanche got horses from the
Spanish in the 1600s. They became
skilled horse breeders. The Comanche
used their horses to hunt bison (buffalo).
Their main source of food was
bison meat, and they used the animals’
hides for clothing and as coverings for
their tepees.
During their travels the Comanche
introduced the use of horses to other
tribes. By the early 1800s the
Comanche had become a powerful
tribe.
In the mid-1800s the southern branch
of the Comanche were settled on a reservation
in the Indian Territory (now
Oklahoma). The northern branch of the
tribe fought to protect its hunting
grounds against white settlers. Many
people were killed in violent battles
between the Comanche and U.S. troops.
The Comanche lost most of their land.
In the late 20th century about 10,000
Comanche lived in the United States.
About 3,000 of them lived on private
lands in the area of Lawton, Oklahoma.
#More to explore
Native Americans • Shoshone
Quanah Parker was a
Comanche chief of the late
1800s and early 1900s.
164 Comanche BRITANNICA STUDENT ENCYCLOPEDIA
Combustion
Combustion is a chemical reaction that
produces heat and light. The most
common form of combustion is fire.
Most forms of combustion happen
when the gas oxygen joins with another
substance. For example, when wood
burns, oxygen in the air joins with
carbon in wood.
Many common substances can undergo
combustion—for example, paper, cloth,
and natural gas. Combustion begins
when the substance reaches a temperature
called its ignition point. At this
temperature oxygen combines with the
substance fast enough to produce a
flame. Different substances have different
ignition points. For example, the
ignition point of paper is about 451° F
(233° C).
A substance may reach its ignition point
by being heated, struck by a spark, or
exposed to strong light. For example, a
hot match can raise the temperature of a
piece of paper to its ignition point. A
spark can do the same thing. So can
sunlight that is focused through a magnifying
glass.
Very fast combustion can cause an
explosion. This type of combustion happens
in a bomb or a firecracker. During
an explosion air heats up so fast that it
expands and moves outward with great
force.
#More to explore
Bomb • Chemistry • Fire
Comet
A comet is a small chunk of dust and ice
that orbits, or travels around, the sun. It
is sometimes described as a “dirty snowball.”
There are billions of comets in the
solar system, but most never pass close
by Earth. The best-known comet is
A bomb explodes in military
training. During an explosion air
expands and moves outward
with great force.
A shining comet streaks across the sky.
