Table of Contents
Britannica
Student
Encyclopedia
Volume 1 ..........................................A
Volume 2...........................................B
Volume 3 ..........................................C
Volume 4......................................D, E
Volume 5 ......................................F, G
Volume 6 ......................................H, I
Volume 7 ..................................J, K, L
Volume 8 .........................................M
Volume 9.....................................N, O
Volume 10.........................................P
Volume 11 ...................................Q, R
Volume 12 .........................................S
Volume 13.........................................T
Volume 14 ...................................U, V
Volume 15..........................W, X, Y, Z
Volume 16 ..............................INDEX
Britannica
Student
Encyclopedia
Chicago London New Delhi Paris Seoul Sydney Taipei Tokyo
Volume 1
EDITOR
Mary Rose McCudden
SENIOR EDITORS
Michael J. Anderson
Andrea R. Field
ASSOCIATE EDITORS
Heather M. Campbell
Sherman Hollar
Sandra Langeneckert
Gene O. Larson
Robert M. Lewis
Sarah Forbes Orwig
Amy Tikkanen
ASSISTANT EDITOR
Joan Hibler
COPY DEPARTMENT
Sylvia Wallace, Director
Glenn Jenne, Supervisor
Julian Ronning, Supervisor
Laura M. Browning, Copy Editor
John Cunningham, Copy Editor
Michael Ray, Copy Editor
Sue Schumer, Copy Editor
Dennis Skord, Supervisor
INFORMATION MANAGEMENT
AND RETRIEVAL
Carmen-Maria Hetrea, Director
Paul Cranmer, Retrieval Specialist
Mansur Abdullah, Classifier
Noelle Borge, Content Analyst
Wang-fai Wong, Content Analyst
COMPOSITION TECHNOLOGY
AND DESIGN
Steven N. Kapusta, Director
Carol A. Gaines, Composition Supervisor
Cate Nichols, Composition Coordinator
Lara C. Mondae, Designer
ART
Susana Darwin, Associate Managing
Editor
Kathy Nakamura, Photo Department
Manager
Karen M. Koblik, Senior Photo Editor
Nicole DiGiacomo, Photo Editor
Illustrators
David Alexovich, Illustration Manager
Thomas J. Spanos, Lead Illustrator
Christine McCabe, Senior Illustrator
Jerry Kraus, Senior Illustrator
Katherine D. Burgess, Illustrator
Claudiu Varan, Illustrator
Judie Anderson, Fable and Mythology
Illustrations
Media Asset Management
Jeannine Deubel, Manager
Kimberly Cleary, Media Assets Supervisor
Kurt Heintz, Senior Technician
Nadia Venegas, Assistant Media
Coordinator
CARTOGRAPHY
Michael Nutter, Senior Map Editor
PRODUCTION CONTROL
Marilyn L. Barton, Senior Coordinator
EDITORIAL TECHNOLOGIES
Steven Bosco, Director
Bruce Walters, Senior Systems Coordinator
Mark Wiechec, Principal Engineer
PUBLISHING TECHNOLOGIES
Lisa S. Braucher, Data Editor
MANUFACTURING
Kim Gerber, Director
ENCYCLOP.DIA BRITANNICA
Jacob E. Safra,
Chairman of the Board
Jorge Aguilar-Cauz,
President
Michael Ross,
Senior Vice President Corporate
Development
Dale H. Hoiberg,
Senior Vice President and Editor
Marsha Mackenzie,
Managing Editor and Director of
Production
Anita Wolff,
Executive Editor
Staff
2010 Britannica Student Encyclopedia
Copyright © 2010 by Encyclop.dia Britannica, Inc.
Britannica, Encyclop.dia Britannica, and the thistle logo are registered trademarks of Encyclop.dia Britannica, Inc.
All rights reserved. Copyright under International Copyright Union
No part of this work may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying,
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International Standard Book Number: 978-1-61535-363-7
eBook edition January, 2010
How to go to your page
This eBook contains ................volumes. Each volume has its own page
numbering scheme, consisting of a volume number and a page number,
separated by a colon.
For example, to go to page 5 of Volume 1, type V..:5 in the "page #" box
at the top of the screen and click "Go." To go to page 5 of Volume 2,
type V2:5 and so forth.
The 16 volumes of the Britannica Student Encyclopedia from
Encyclop.dia Britannica contain articles on more than 2,200 topics.
The articles are arranged in alphabetical order from
How to Use the Britannica
Student Encyclopedia
Getting Started
There are several ways to find the information you
want.
If you are looking for a particular title you can go
to the volume that contains articles that start with
the same letter and search for your topic there. For
example, if you want to read the article on the
American Revolution, you can go to the A volume.
The words at the top of each page tell you
which article is on that page. When you are looking
for an article you can page through quickly by
looking at those words.
Sometimes there are different ways of naming the
same subject. A feature called a title cross-reference
can help guide you to the title that we have used.
For example, if you look for an article called Car
in the C volume you will find a note that says
Aardvark in Volume 1 to Zuni in Volume 15.
The last volume is the index.
Then you can look for the Automobile article in
the A volume.
You can also search for your topic in the index. If
there is an article on your topic the index will tell
you which volume and page number to go to to
find that article. Sometimes a topic does not have
its own article, but you can still find information
about that topic in the encyclopedia. The index
can tell you where you can find that information.
For example, if you look up the topic dragon in
the index you will see that there is information
about dragons in the article called Animals,
Legendary even though there is no article on
dragons.
Car
#see Automobile.
Article Features
In addition to the text of the articles, there are
many special features that add information.
Most articles have at least one photograph, illustration,
or map. Many have more than one.
At the end of most articles, there is a feature called
More to explore. This feature tells you which
articles to go to to get more information about the
topic or about something that was mentioned in
the article.
Did You Know? boxes provide quick facts about
many different articles throughout the set.
Certain articles have additional special features.
The continents, countries, U.S. states, and
Canadian provinces have colored backgrounds to
tell you what kind of unit it is. The continents are
purple, the countries are yellow, and the states and
provinces are green. These articles also have fact
boxes. The fact boxes contain basic information,
including population and area figures.
Some of the countries also have timelines of major
events in the countrys history.
The U.S presidents have timelines of major events
in the lives of each president.
4 How to Use the Britannica Student Encyclopedia BRITANNICA STUDENT ENCYCLOPEDIA
kept slaves of their own. These slaves
worked on large farms that supplied
food for the army and the royal court.
The empire grew larger and stronger
throughout the 1700s. After Great Britain
and other countries outlawed the
slave trade in the 1800s Dahomey
started selling palm oil instead of slaves.
At the end of the 1800s France conquered
Dahomey. The French combined
it with other regions to form a colony
that was also called Dahomey. This
colony gained its independence in 1960.
It kept the name of Dahomey until
1975, when it became Benin.
#More to explore
Benin Slavery
Daisy
Daisies are flowers with flat petals that
surround a round center. Daisies belong
to the aster family, which also includes
chrysanthemums, dahlias, marigolds,
sunflowers, and zinnias.
Common types of daisy include the
oxeye daisy; the English, or true, daisy;
and the Shasta daisy. These daisies grow
in Europe, North America, and other
parts of the world. Oxeye and English
daisies grow in gardens and in the wild.
The Shasta daisy is mainly a garden
plant.
Daisy plants often grow to about 2 to 3
feet (61 to 91 centimeters) tall. Two
types of flower make up each flower
head. Ray flowers are what people call
petals. The ray flowers may be long or
short. Tiny disk flowers make up the
center. The center may be flat or
rounded. Depending on the type of
daisy, the flower heads are from 1 to 4
inches (2.5 to 10 centimeters) wide.
Oxeye and Shasta daisies have a ring of
white ray flowers around a bright yellow
center. The ray flowers of the English
daisy may be white, purple, pink, or red.
#More to explore
Flower Marigold Plant Sunflower
Dakar
Population
(2002 estimate)
1,983,093
Dakar is the capital of Senegal, a country
in West Africa. It is the largest city in
People often use colorful daisies to brighten
flower arrangements.
Daisies are
perennials,
which means
that they
bloom year
after year
without having
to be
replanted.
6 Daisy BRITANNICA STUDENT ENCYCLOPEDIA
Daisies are
perennials,
which means
that they
bloom year
after year
without having
to be
replanted.
Africa
Africa is the worlds second largest continent.
More than 50 countries make up
the continent. More than one eighth of
the worlds population lives there.
Land and Climate
Africas landscape is varied. The northern
and western parts of the continent
are generally lower and more level than
the eastern and southern areas. Africa is
the oldest continent. Therefore most of
its mountains are not as high as those on
other continents. They have been worn
down over millions of years by wind and
water.
Africas most striking feature is a series
of great rifts, or troughs, in the east
known as the Rift Valley system. These
rifts span two continents, from western
Asia through eastern Africa. In Africa
they are deep, long, narrow valleys.
The worlds longest river, the Nile, flows
through northern Africa. The continents
other long rivers include the
Congo in central Africa, the Niger in the
west, and the Zambezi in the south.
Eastern Africa has a chain of lakes
known as the great lakes.
The continent is crossed midway by the
equator. This means that most of
Africathe middle portionlies within
the tropics, an area where it is hot yearround.
In the lowlands near the equator,
rain falls throughout the year. To the
north and south of this rainy area are
large regions that have a rainy season
followed by a dry season. It is very hot
A pair of giraffes is at home near Mount Kilimanjaro in Tanzania.
38 Africa BRITANNICA STUDENT ENCYCLOPEDIA
Cameroon
The West African country of Cameroon
takes its name from the Rio dos Camaroes
(River of Shrimps), the name the
Portuguese gave to the Wouri River. The
capital is Yaounde.
Cameroon is bordered by Nigeria,
Chad, the Central African Republic,
Republic of the Congo, Gabon, and
Equatorial Guinea. The Atlantic Ocean
lies to the west. Mountains run through
the north and west. The country has hot
temperatures year-round.
Rain forests are in the south. Mangroves
grow along the coasts and rivers. Monkeys
live in the forests. Elephants,
baboons, and antelope live in the
wooded grasslands of the north.
The ethnic groups of Cameroon include
the Fang, the Bamileke, the Duala, and
the Fulani. English and French are the
official languages, but people speak many
other languages. The majority of the
people follow Christianity or traditional
religions. The north is mostlyMuslim.
Cameroons economy is based on farming.
The main crops include cassava,
sugarcane, corn, bananas, and sorghum.
The country also produces petroleum
(oil), lumber, and cocoa for export.
Humans have lived in what is now
Cameroon for at least 50,000 years.
Eventually Bantu people settled in the
south and the west, and the Fulani settled
in the north. In the 1470s the Portuguese
established sugar plantations and a slave
trade. Germany gained control in the late
1800s. AfterWorldWar I Cameroon was
divided into French and British zones. In
1960 the French zone became the
independent republic of Cameroon.
#More to explore
Yaounde
People gather to buy and sell goods at a
market in Maroua, Cameroon.
Facts About
CAMEROON
Population
(2005 estimate)
16,988,000
Area
183,569 sq mi
(475,442 sq km)
Capital
Yaounde
Form of
government
Republic
Major cities
Douala, Yaounde,
Garoua, Maroua,
Bafoussam
22 Cameroon BRITANNICA STUDENT ENCYCLOPEDIA
Connecticut
The state of Connecticut was
named for the Connecticut
River. Algonquian Indians called the
river Quinnehtukqut, meaning land on
the long tidal river. Connecticut is
nicknamed the Constitution State
because its early settlers wrote a set of
laws to govern themselves that later provided
ideas for the U.S. Constitution.
Those laws, known as the Fundamental
Orders of Connecticut, were created in
1638 and covered such issues as elections,
powers of officials, and taxation.
The capital of Connecticut is Hartford.
Geography
Connecticut is the southernmost New
England state. It is bordered by Massachusetts
on the north, Rhode Island on
the east, New York on the west, and the
Long Island Sound on the south.
Connecticut has highlands in the west
and east with a lowland in the middle.
The northern part of the western highlands
is called the Litchfield Hills. They
include Mount Frissell, which is the
states highest point at 2,380 feet (725
meters). The central lowland includes
the fertile Connecticut River valley. The
eastern highlands are low, wooded hills
with many rivers.
People
At the time of the first U.S. census, in
1790, almost all of Connecticuts people
were English. In the 1800s Irish, French
Canadian, Italian, Polish, and other
European immigrants settled in the
state. Today more than four fifths of
Connecticuts residents are of European
heritage. African Americans and Hispanics
each make up about 9 percent of the
population. The states Asian American
and Native American groups are small.
Connecticut has a large population for
its size. As a result, it is one of the countrys
most crowded states. Most of its
people live in cities or towns. Bridgeport,
on the coast, is the largest city.
Other large cities are Hartford, New
Haven, and Stamford.
Economy
Real estate, finance, and the insurance
industry are major parts of Connecticuts
economy. Hartford is known as the
Insurance Capital of theWorld because
of the many insurance companies with
offices there. Manufacturing businesses
in Connecticut produce jet aircraft
engines, computer equipment, chemicals,
machinery, and other goods. Hart-
184 Connecticut BRITANNICA STUDENT ENCYCLOPEDIA
Facts About
CAMEROON
Population
(2005 estimate)
16,988,000
Area
183,569 sq mi
(475,442 sq km)
Capital
Yaounde
f
Bush, George
After serving two terms as vice president,
George Bush became the 41st
president of the United States in 1989.
The main event of Bushs presidency
was the Persian GulfWar.
Early Life
George HerbertWalker Bush was born
on June 12, 1924, in Milton, Massachusetts.
His family later moved to Greenwich,
Connecticut. George was the
second of five children born to Prescott
Sheldon Bush and DorothyWalker
Bush. His father was a banker and later a
U.S. senator.
In 1942 Bush joined the U.S. Naval
Reserve. As a Navy pilot, he flew many
missions in the Pacific duringWorld
War II. In 1945 Bush married Barbara
Pierce. After the war he attended Yale
University and earned a degree in economics.
Bush then moved to Texas,
where he helped start three companies
dealing in oil and drilling equipment.
Political Career
As a member of the Republican Party,
Bush ran for the U.S. Senate in 1964
June 12,
1924 1966 1976 1980 1988 1991 1992
Bush is born
in Milton,
Massachusetts.
Bush is elected
to the U.S.
House of
Representatives.
Bush becomes
the head of
the Central
Intelligence
Agency.
Bush is elected
vice president
under President
Ronald
Reagan.
Bush is elected
president.
The United
States and
allies defeat
Iraq in the
Persian Gulf
War.
Bush loses the
presidential
election to Bill
Clinton.
T I M E L I N E
George Bush was the 41st president of the
United States.
154 Bush, George BRITANNICA STUDENT ENCYCLOPEDIA
June 12,
1924 1966 1976
Bush is born
in Milton,
Massachusetts.
Bush is elected
to the U.S.
House of
Representatives.
the Cent
Intelligen
Agency.
#More to explore
Flower Marigold Plant Sunflower
Acropolis means city at the
top in Greek.
(See Acropolis.)
Airships float in the air like
balloons, but they have engines
and can be steered.
(See Airship.)
Alchemists were people who
were famous for trying to turn
lead into gold.
(See Alchemy.)
Almonds are commonly called
nuts, but they are actually
seeds.
(See Almond.)
At least six types of amoeba
are found in human beings.
(See Amoeba.)
Knights in Europe once wore
armor made of large steel or
iron plates.
(See Armor.)
Aa
Aardvark
The unusual mammal called the aardvark
was named by South Africans in
the early 1800s. In the local language,
Afrikaans, aardvark means earth pig.
This name aptly describes a large,
heavily built animal with thin hair and
short, stumpy legs. The scientific name
of the aardvark is Orycteropus afer.
Aardvarks live in dry places in Africa
south of the Sahara Desert. The aardvark
can reach a length of 6 feet (1.8 meters).
Its head has huge donkeylike ears, a long
snout, and drooping eyelids with long
lashes. During the day aardvarks sleep in
underground burrows. At night they dig
underground for their favorite food,
termites. They break open the termites
nests with their massive, flattened claws.
Then they suck up the insects with their
long tongue.
Female aardvarks give birth to one baby
per year. After a few weeks the baby
begins to follow its mother around. It
goes off on its own before it is 1 year
old. Aardvarks can live for more than 20
years in zoos.
Aaron, Hank
On April 8, 1974, major league baseball
star Hank Aaron hit his 715th home
run. That home run broke Babe Ruths
record of 714, which had stood since
1935. Aaron broke several other batting
records as well. Because he hit so well he
was sometimes called Hammerin Hank.
Early Life
Henry Louis Aaron was born on February
5, 1934, in Mobile, Alabama. Even
as a young boy Hank hoped to play professional
baseball. At age 16 he began
playing shortstop with the semiprofessional
Mobile Black Bears baseball team.
Career
Aaron began his professional career in
1952. He played a few months as a
shortstop with the Indianapolis Clowns
of the Negro American League. In 1954
Although aardvarks look like anteaters, they
are actually related to elephants, manatees,
and dugongs.
Hank Aaron
6 Aardvark BRITANNICA STUDENT ENCYCLOPEDIA
Aaron joined the Boston Braves of the
National League, where he played
mostly as an outfielder.
In 1955 Aaron established himself as a
star. He had a .314 batting average, 27
home runs, and 106 runs batted in
(RBI). In 1957 he helped lead the
Braves to their firstWorld Series title.
The Braves moved to Atlanta, Georgia,
at the end of 1965, and Aaron moved
with them. After the 1974 baseball season,
he was traded to the Milwaukee
Brewers of the American League.
Retirement
Aaron retired after the 1976 season with
a lifetime batting average of .305. He
was elected to the Baseball Hall of Fame
on January 13, 1982. At the time he held
several career batting records, including
755 home runs, 1,477 extra-base hits,
and 2,297 RBIs. His home run record
was broken in 2007 by Barry Bonds.
..More to explore
Baseball Ruth, Babe
Abacus
Long before the invention of the electronic
calculator or the computer, people
counted and did calculations with a
device called an abacus. On this instrument,
calculations are made with beads,
or counters, instead of numerals. The
beads are arranged on wires stretched
across a frame. Each wire represents the
ones, tens, hundreds, and so on.
The abacus was probably invented in
Mesopotamia by an ancient group of
people known as Sumerians. The
ancient Egyptians, Greeks, Romans, and
Chinese all used the abacus as well.
In about AD 700 the Hindus invented a
numeral system that made adding with
written numbers as easy as adding on an
abacus. The Arabs soon adopted this
system, and they introduced it into
Europe more than 1,000 years ago. As
written calculations became easier, the
abacus passed out of use in Europe. But
it continues to be used by people in
China, Japan, and the Middle East.
Abbreviation
An abbreviation is a shortened form of a
word or a phrase. People use abbreviations
to save time and space. People are
always creating new abbreviations, and
old ones are sometimes forgotten.
Some abbreviations are official, such as
the codes that the U.S. Postal Service
uses for the states. Others are more
informal. People often use the abbrevia-
An abacus
expert can
add numbers
almost as fast
as a person
with a pocket
calculator.
The abacus is an ancient device to help
solve math problems.
BRITANNICA STUDENT ENCYCLOPEDIA Abbreviation 7
tion ad for the word advertising, for
example.
There are a few different kinds of abbreviations.
People often abbreviate words
by writing only the first letter, one or a
few other letters in the word, and a
period. For instance, the word teaspoon
is abbreviated as tsp.
People abbreviate phrases by writing
only the first letter of each word. This
type of abbreviation is usually written in
capital letters with no periods between
them. For example, the abbreviation for
as soon as possible is ASAP.
One of the most common types of
abbreviation is called an acronym. Acronyms
combine the first letters of a group
of words to create a new word. NASA,
which stands for National Aeronautics
and Space Administration, is an acronym.
It is pronounced NA-suh, not
N-A-S-A.
Some Common Abbreviations
AD anno Domini (in the year of
the Lord)
AM ante meridiem (before noon)
Ave. Avenue
BC before Christ
Blvd. Boulevard
C Celsius, centigrade
CD-ROM compact disc read-only
memory
cm, m, km centimeter, meter, kilometer
Dr. Doctor
DVD digital videodisc
F Fahrenheit
ft foot, feet
g, kg gram, kilogram
IOU I Owe You
Jr. Junior
l liter
mph miles per hour
no. numero (number)
oz. ounce
PM post meridiem (after noon)
Rd. Road
Sr. Senior
St. Saint, Street
vs. versus (against)
U.S. Postal Codes
AK Alaska
AL Alabama
AR Arkansas
AZ Arizona
CA California
CO Colorado
CT Connecticut
DC District of Columbia
DE Delaware
FL Florida
GA Georgia
HI Hawaii
IA Iowa
ID Idaho
IL Illinois
IN Indiana
KS Kansas
KY Kentucky
LA Louisiana
MA Massachusetts
MD Maryland
ME Maine
MI Michigan
MN Minnesota
MO Missouri
MS Mississippi
MT Montana
NC North Carolina
ND North Dakota
NE Nebraska
NH New Hampshire
NJ New Jersey
NM New Mexico
NV Nevada
NY New York
OH Ohio
OK Oklahoma
OR Oregon
PA Pennsylvania
RI Rhode Island
SC South Carolina
SD South Dakota
TN Tennessee
TX Texas
UT Utah
VA Virginia
VT Vermont
WA Washington
WI Wisconsin
WV West Virginia
WY Wyoming
8 Abbreviation BRITANNICA STUDENT ENCYCLOPEDIA
Some acronyms become so common
that they begin to be used as real words
rather than as abbreviations. The word
laser started out as an acronym. Its full
scientific meaning is light amplification
by stimulated emission of radiation.
Abernathy, Ralph
Ralph Abernathy was a leader of the civil
rights movement in the United States.
He worked closely with Martin Luther
King, Jr.
Ralph David Abernathy was born on
March 11, 1926, in Linden, Alabama. In
1948 he became a minister in the Baptist
church. In 1950 he graduated from Alabama
State University with a degree in
mathematics. Then he studied sociology
at Atlanta University in Atlanta, Georgia.
In 1951 Abernathy became pastor of the
First Baptist Church in Montgomery,
Alabama. A few years later he met Martin
Luther King, Jr. The two men began
fighting laws that kept blacks and whites
separated.
One such law forced blacks and whites
to sit in separate parts of buses. In 1955
Abernathy and King organized a protest
of the Montgomery bus system. Blacks
refused to ride the buses until the seating
rules were changed. This protest
helped start the civil rights movement.
In 1957 King and Abernathy started the
Southern Christian Leadership Conference
(SCLC). The SCLC was an organization
that worked to win equal rights
for blacks. After King was murdered in
1968, Abernathy became president of
the SCLC.
Abernathy resigned as president of the
SCLC in 1977. Then he went back to
being a pastor in Atlanta. He died there
on April 17, 1990.
#More to explore
Civil Rights Movement King, Martin
Luther, Jr.
Abidjan
Population
(2005 estimate)
urban area,
3,576,000
Abidjan is the largest city of Cote dIvoire
inWest Africa. It was the countrys
capital until 1983. Then Yamoussoukro
was made the capital. Even after that
Ralph Abernathy
BRITANNICA STUDENT ENCYCLOPEDIA Abidjan 9
date, however, Abidjan remained the site
of most government functions.
Abidjan is located in the southern part
of the country. It has a port even though
it is separated from the Atlantic Ocean
by a sandbar. The Vridi Canal connects
the port to the sea.
Because of the port, Abidjan is a center
ofWest African trade. Cocoa, coffee,
timber, bananas, pineapples, and fish are
shipped from the port. The city also
manufactures beer, soap, matches, and
automobiles.
Abidjan became the capital of the
French colony of Ivory Coast in 1934.
Ivory Coast became the independent
country of Cote dIvoire in 1960.
Abidjan remained the capital.
#More to explore
Cote dIvoire Yamoussoukro
Abnaki
The Abnaki (or Abenaki) were a group
of Native American tribes who originally
lived in what are now New England and
eastern Canada. They included the Passamaquoddy,
the Penobscot, and the
Pennacook.
The Abnaki hunted animals such as
bear, deer, and moose in the forests.
They fished in lakes and rivers. The
coastal tribes caught lobsters and gathered
oysters and clams. The southern
tribes planted fields of corn, squash, and
beans.
The Abnaki generally lived in small
bands of related families. Bands lived
part of the year in permanent villages
and part of the year in hunting camps.
Their houses were cone-shaped wigwams
made from a wooden frame covered
with bark.
In the early 1600s Europeans began
arriving in Abnaki territory. Most were
traders who offered metal tools and
other European goods in exchange for
furs. But the Europeans also brought
diseases such as smallpox that killed
tribespeople by the thousands.
The coastal city of Abidjan is an important
business center of Cote dIvoire.
Abnaki Native Americans perform a traditional
dance in Vermont.
10 Abnaki BRITANNICA STUDENT ENCYCLOPEDIA
After the American Revolution (1775
83) the Americans took over much of
the tribes territory.Without land, the
Abnaki could no longer live in their
traditional way. Some managed to
change their way of life and survive. In
the late 20th century about 1,000
Abnaki lived in Quebec, Canada. More
than 6,000 Abnaki lived in the United
States.
#More to explore
Native Americans
Abolitionist
Movement
In the late 1700s people who were
opposed to slavery began a movement to
abolish, or end, the practice. This was
called the abolitionist movement. Followers
of the movement were known as
abolitionists.
Europeans had begun using Africans as
slaves in the late 1400s. After Europeans
discovered the Americas they set up
colonies there. Soon many Africans were
being shipped to the Americas to work
on the sugar and cotton plantations in
the colonies.
In the 1600s certain people in the British
colonies of North America condemned
slavery on religious grounds.
There were few other protests, however,
until the 1700s. Slowly but steadily,
more and more people became opposed
to the idea of holding other human
beings as private property.
Antislavery Efforts Around
theWorld
The first formal organization to emerge
in the abolitionist movement was the
Abolition Society, founded in 1787 in
Britain. By 1807 Britain had abolished
the slave trade with its colonies. By 1833
all slaves in the British colonies in the
Western Hemisphere were freed. Other
countries in Europe soon followed this
example. France outlawed the slave trade
by 1819, and in 1848 slavery was
banned in all French colonies.
Slavery was abolished country by country
in South America. In Chile the first
antislavery law was passed as early as
1811. Slavery finally ended in South
America when Brazil passed an antislavery
law in 1888.
United States
In the United States the slave trade was
officially abolished in 1807, but the
smuggling of slaves continued until the
CivilWar. As cotton plantations devel-
An antislavery meeting is pictured in London,
England, in 1840.
BRITANNICA STUDENT ENCYCLOPEDIA Abolitionist Movement 11
oped in the South, the demand for
slaves increased. The Southern states
thus supported slavery. In contrast, by
1804 all of the states north of Maryland
had abolished slavery. The North
became the center of the abolitionist
movement in the United States.
The best-known leader of this movement
was William Lloyd Garrison. He
founded the American Anti-Slavery
Society in 1833. The U.S. abolitionists
did not always agree about how to end
slavery, however. Some wanted the government
to pass laws to end slavery.
Others tried to help individual slaves
gain their freedom. They established the
Underground Railroad to help escaping
slaves reach places of safety in the North
or in Canada.
The abolitionist movement gained
strength as more and more people
learned about the evils of slavery. People
were disgusted by the cruelty of the slave
hunters who brought escaped slaves back
to their owners. Harriet Beecher Stowes
novel Uncle Toms Cabin (1852) presented
powerful descriptions of how
slaves were mistreated. The book became
extraordinarily popular.
In November 1860 Abraham Lincoln
was elected president of the United
States. Lincoln opposed the spread of
slavery. The South felt threatened. Over
the next three months a series of Southern
states separated from the United
States and formed the Confederacy. This
led to the American CivilWar (1861
65). During the fighting, in 1863, Lincoln
issued the Emancipation
Proclamation. This document freed all
slaves in the Confederate states. In 1865
the Confederacy was defeated. Then
slavery was abolished in the United
States by the 13th Amendment to the
Constitution.
#More to explore
American CivilWar Brown, John
Emancipation Proclamation Lincoln,
Abraham Slavery Stowe, Harriet
William Lloyd Garrison Beecher Underground Railroad
An abolitionist
named John
Brown stole
weapons from
the U.S. government
in
1859. He
wanted to start
a slave rebellion.
He was
killed but
became an
abolitionist
hero.
Cassius Marcellus Clay worked to end slavery
even though he was from a slaveholding
family in the South.
12 Abolitionist Movement BRITANNICA STUDENT ENCYCLOPEDIA
Aboriginal
Peoples
Aboriginal peoples, or aborigines, are
groups of people who have lived in one
area for many thousands of years. In the
past, aborigines lived in areas far from
other cultures. They were unknown
until outsiders came into their lands.
Today there are only a few places left in
the world where outsiders have not
affected aboriginal cultures. Aborigines
still live in the rain forests of South
America, on the island of New Guinea,
and in the mountains of Malaysia and
the Philippines. They have kept many of
their original ways of life.
The Australian Aborigines are probably
the best-known aboriginal society. They
came to Australia more than 40,000
years ago. They still live there today.
Australian Aborigines were originally
hunter-gatherer tribes that moved from
place to place to find food and water.
They lived in caves or built short-term
shelters from branches, bark, and animal
skins. The men fished and hunted for
animals. The women gathered plants,
eggs, and other food.
The Aborigines lives changed when
Europeans arrived in Australia more
than 200 years ago. The Europeans
forced the Aborigines to move off their
land and to change their way of life.
Many Aborigines died defending their
land. Many others died from diseases
brought by the Europeans.
Today Aborigines live in all parts of Australia
and do all kinds of work. But
many Aborigines are poor. They do not
have the same opportunities as most
other Australians.
..More to explore
Australia Culture
Abraham
Abraham is an important figure in the
Jewish, Christian, and Islamic religions.
He is considered to be the patriarch, or
founding father, of the nation of Israel.
The story of Abraham is told in Genesis,
the first book of the Bible. In modern
times archaeologists have found ancient
clay tablets that tell more of the story.
According to the Bible, Abraham came
from Ur in Mesopotamia (now Iraq).
His people were sheepherders who
moved from place to place. About 4,000
years ago they settled near Haran, in
An Australian Aborigine stands before a
large rock known as Uluru/Ayers Rock.
Parts of the rock and the land around it are
sacred to the Aborigines of the area.
BRITANNICA STUDENT ENCYCLOPEDIA Abraham 13
what is now Turkey. There God
instructed Abraham to leave his people
and move to a new land. Abraham
obeyed.
At age 75 he journeyed to Canaan (the
land that is now Israel) with his wife,
Sarah, and others. God told him that he
and his children would inherit that land.
At first Abraham and Sarah thought
they were too old to have children.
Abrahams first child, Ishmael, was born
to a servant of Sarahs. But Isaac was
born later to Sarah. The Bible says that
Abraham died at the age of 175.
Isaac inherited the land of Canaan. After
his death the land went to his son,
Jacob. God changed Jacobs name to
Israel. His descendants were the Jewish
people. In Christianity, Abraham is considered
to be the father of all who
believe in God. Abraham is important to
Muslims as well. They are said to be the
descendants of Abrahams son Ishmael.
In the Koran, the holy book of Islam, it
is said that Abraham and Ishmael built
the Kaaba. The Kaaba, a shrine in
Mecca, Saudi Arabia, is the holiest place
in the Islamic world.
#More to explore
Bible Christianity Islam Judaism
Koran Mecca Mesopotamia
Absaroka
#see Crow.
Abu Bakr
Abu Bakr was an adviser to the prophet
Muhammad, the founder of Islam. After
Muhammads death, Abu Bakr took
charge of the Islamic world. He is
known as the first caliph.
Christians, Jews, and Muslims all see Abraham
as an important religious figure. A
painting shows Abraham during his journey
to Canaan.
Abu Bakr (second from left) was an
important Islamic leader.
14 Absaroka BRITANNICA STUDENT ENCYCLOPEDIA
Abu Bakr was born in the Arabian town
of Mecca (now in Saudi Arabia), which
was also the birthplace of Muhammad.
His daughter !A#ishah became one of
Muhammads wives.
While Muhammad was dying, he called
upon Abu Bakr to lead prayers and pilgrimages
in his place. By that time
Muhammad was more than the religious
leader of the Islamic lands; he was their
political ruler as well. After Muhammad
died in 632, Abu Bakr ruled as caliph.
Caliph means successor (one who
comes afterward). The Islamic lands
were called the Caliphate.
As caliph, Abu Bakr fought wars against
Arabian tribes who rebelled against him.
He soon brought the tribes of Arabia
under Muslim rule. Abu Bakr then sent
armies into what are now Syria and Iraq.
This began a series of conquests that
spread Islam far beyond Arabia. Abu
Bakr died in 634.
..More to explore
Caliphate Islam Mecca
Muhammad
Abu Dhabi
Population
(2007 estimate)
633,140
Abu Dhabi is the capital of the United
Arab Emirates, a union of Arab states on
the Arabian Peninsula. It is also the capital
of Abu Dhabi kingdom, the largest of
the seven states.
The city of Abu Dhabi occupies most of
a small triangular island in the Persian
Gulf. The island is connected to the
mainland by a short bridge.
Local tribesmen settled Abu Dhabi in
1761. Through most of its history the
town remained small and undeveloped.
This changed when rich oil fields were
discovered in Abu Dhabi in 1958. Oil
revenues were used to modernize the
town. Electricity, running water, and a
central sewage system were installed.
Modern buildings and a new port were
built.With modernization, the population
grew.
The United Arab Emirates gained independence
from Great Britain in 1971.
Abu Dhabi became the permanent capital
of the federation in the early 1990s.
..More to explore
United Arab Emirates
The Sultan Zayed Mosque in Abu Dhabi
was named for a longtime ruler of the
United Arab Emirates. The sultan was buried
in the mosque when he died in 2004.
BRITANNICA STUDENT ENCYCLOPEDIA Abu Dhabi 15
Abuja
Population
(2006 census),
Federal Capital
Territory,
1,405,201
Abuja is the capital of the African country
of Nigeria. It was built in the 1980s
to replace the crowded coastal city of
Lagos as the capital.
Abuja is located near the center of Nigeria
in an area called the Federal Capital
Territory. It is about 300 miles (480
kilometers) northeast of Lagos. The city
is built on the grass-covered Chukuku
Hills. The climate is cooler and less
humid than that of Lagos.
Abuja is divided into two zones. The
central area contains the government
buildings. The other zone provides
housing, shopping facilities, and other
services for the people who live there.
The government started planning the
new city of Abuja in 1976. It took more
than 10 years to build the city, but the
population grew even before it was finished.
Abuja officially became the capital
in 1991.
..More to explore
Nigeria
Accra
Population
(2003 estimate)
1,847,432
Accra is the capital and largest city of the
West African country of Ghana. Its
name comes from the word nkran in the
Akan language. This refers to the black
ants that thrive in the area. Accra is situated
on the Gulf of Guinea.
Accra is the site of Ghanas main government
offices. It is also the economic
center of Ghana. It contains the head
offices of all the countrys large banks
and trading firms. The city also has large
open markets. Its main products are
processed food, lumber, and textiles.
The city of Accra was formed in 1877.
By that time the British had gained control
of the whole area. It became known
as the colony of the Gold Coast. Accra
was the capital of the colony. The modern
city of Accra was carefully planned
and laid out between 1920 and 1930.
The Nigerian presidential palace is located
in the hills of the countrys capital, Abuja.
16 Abuja BRITANNICA STUDENT ENCYCLOPEDIA
When the Gold Coast gained independence
as Ghana in 1957, Accra
remained the capital.
#More to explore
Ghana
Acid and Base
Acids and bases are two related groups of
chemicals. They are important to living
things and have many uses in industry.
Acids
Some acids are found in food. They
include acetic acid in vinegar, lactic acid
in milk, and citric acid in lemons. They
often have a sour taste. Other acids are
found in animals. The stomach makes
an acid that helps break down food.
Some acids do not come from living
things. These can be so strong that they
can corrode, or break down, metals.
They should not be tasted or touched.
Sulfuric acid is one example. It is used to
make fertilizers, dyes, drugs, explosives,
and certain batteries. When an acid is
dissolved in water the result is called an
acidic solution.
Bases
Bases may feel slippery in water. Some
are used in foods or medicines. These
often have a bitter taste. Examples of
bases include baking soda and milk of
magnesia. Other bases are used in
manufacturing. These are too strong to
be tasted or touched. Sodium hydroxide,
or lye, breaks down animal and plant
tissues. It is used to make soap, paper,
and artificial fibers. When water is combined
with a base the result is called a
basic, or alkaline, solution.
Acid-Base Reactions
When acids and bases are combined
they produce water and compounds
called salts. They have a salty taste and
none of the characteristic properties of
either acids or bases. The reactions
between acids and bases can be quite
strong. One result is that they can
quickly produce gases. This is why baking
soda is useful for baking pastries and
cakes. When it is combined with an acid
such as lemon juice or sour cream in a
dough mixture, it releases gases that
make the dough rise.
Identifying Acids and Bases
Acids and bases make some materials
change color. A special kind of paper
called litmus paper is one type of mate-
A strip of litmus paper shows
that a solution contains an acid.
If the solution contained a base
the paper would have turned
blue.
BRITANNICA STUDENT ENCYCLOPEDIA Acid and Base 17
rial that does this. An acid in water turns
litmus paper red. A base in water turns
the paper blue. A neutral substance,
such as pure water, gives litmus paper a
color midway between red and blue.
Acid Rain
Acid rain is a form of air pollution.
When coal and petroleum are burned in
automobiles, electric power plants, and
factories, they release certain harmful
gases into the air. These gases combine
with the oxygen and water in the air.
When the water in the air comes down
as rain, sleet, hail, or snow, it carries
with it these gases. This is known as acid
rain. Acid rain is very damaging to all
life forms.
Acid rain can pollute lakes and streams,
killing the fish and other organisms that
live in them. Acid rain also damages
various kinds of vegetation, including
farm crops and trees. In addition, acid
rain corrodes, or wears away, surfaces of
buildings and other structures.
By the early 1990s tens of thousands of
lakes had been destroyed by acid rain.
The problem has been most severe in
Norway, Sweden, and Canada. Damage
from acid rain is not limited to the
countries that produce the pollution.
This is because winds carry the pollution
around the globe.
Despite much discussion between many
countries, there is still no clear solution
to the problem. The chief reason is that
it is expensive to control the pollution.
However, since the damage from acid
rain to the environment is permanent,
the environmental costs are greater.
Acne
Most teenagers and some adults experience
a skin condition called acne. Some
cases of acne are very mild and go away
without leaving any signs. Others are
more serious and may cause scarring.
Boys are more likely than girls to have
severe acne.
Lesions (abnormal bumps or spots) on
the skin are the main symptom of acne.
Acne lesions are commonly known as
pimples. They occur especially on the
face and neck.
Acne is caused by changes inside the
body that affect the skin. These changes
occur naturally as a boy or girl reaches
puberty, or matures. At that time the
body produces more of chemicals called
Acid rain can be very damaging to trees
and other plants. The branch on the left has
been affected by acid rain. It looks much
different than the branch on the right.
18 Acid Rain BRITANNICA STUDENT ENCYCLOPEDIA
hormones. Some of those hormones
speed up the skins production of oil.
The extra oil clumps together with dead
skin cells to clog pores, or tiny openings
in the skin. As the oil gland under a
clogged pore makes more oil, the pore
swells up to form a pimple.
There is very little a person can do to
prevent acne. However, there are treatments
for clearing up acne and ways of
preventing acne from getting worse.
Washing the skin twice a day with a
mild soap can be helpful. This removes
some oil and dead skin cells that help to
clog skin pores.
In some cases a doctor may prescribe
medicine to treat infections caused by
acne. Doctors may also suggest medicated
lotions or creams that can be put
on the skin.
#More to explore
Hormone Skin
Acropolis
Ancient cities were often built around a
fortress on top of a hill. When a city
spread to the area below, the high part
came to be called the acropolis, which
means city at the top in Greek. The
best-known acropolis is in Athens,
Greece.
The buildings of the Athens Acropolis
were made mostly of white marble. Parts
of some of the buildings, including a
temple called the Erechtheum, are still
standing today. The Erechtheum had a
porch with marble columns in the shape
of female figures.
The most famous surviving building is
the Parthenon. The Parthenon was built
almost 2,500 years ago and was dedicated
to the goddess Athena. Athens was
later ruled by Christians who made the
Bumps called pimples are the main sign of
acne.
The ruins of the Parthenon stand out on the
Acropolis in Athens, Greece.
BRITANNICA STUDENT ENCYCLOPEDIA Acropolis 19
Parthenon a church. In the 1400s Turkish
forces took control of the Acropolis
and made the Parthenon an Islamic
mosque. In 1687, during a war, some
gunpowder stored there exploded,
destroying the middle of the building.
In 1801 a British diplomat named Lord
Elgin took many sculptures and carved
panels from the Parthenon and brought
them to England. They were put on
display at the British Museum. The
Greek government, however, asked for
their return to Greece. The sculptures
remained on display while the dispute
continued into the 21st century.
#More to explore
Athena Athens
Acupuncture
Acupuncture is an ancient Chinese form
of healing. It involves piercing the skin
with thin needles to relieve pain. Today
acupuncture is also popular in Europe,
the Americas, and Australia.
Modern doctors accept that acupuncture
can control pain and nausea. Some doctors
recommend acupuncture along with
regular medical treatments for such ailments
as asthma, high blood pressure,
indigestion, and stress. Doctors in China
have even used acupuncture instead of
drugs to stop pain during surgery.
People who practice acupuncture must
take courses to learn how to do it correctly.
In many places only medical doctors
may perform acupuncture.
During treatment the patient lies on a
table while the acupuncturist sticks special
needles into certain points on the
body. The needles are made of metal and
are about as thick as a human hair. They
normally go less than 0.5 inch (1 centimeter)
into the skin. There are hundreds
of possible points where the needles can
be stuck, each with a different effect.
Doctors are not sure how acupuncture
works. Some think that the needles
cause the body to produce pain-killing
chemicals. Others think that the needles
block pain signals from traveling along
the nerves to the brain. Some think that
acupuncture acts like a placeboa treatment
that works only because patients
believe it will.
Adams, Abigail
Abigail Adams was the wife of President
John Adams and the mother of Presi-
A woman receives an acupuncture
treatment.
20 Acupuncture BRITANNICA STUDENT ENCYCLOPEDIA
dent John Quincy Adams. Her reading
and her family life gave her a good
understanding of politics. She strongly
favored American independence and
universal liberty. She was also determined
to overcome the limits that were
placed on women at the time.
Abigail Smith was born on November
22, 1744, inWeymouth, Massachusetts.
As a girl she studied the books in her
fathers large library.Women could not
go to college then, but Abigail received a
good education at home.
In 1759 Abigail met the young lawyer
John Adams. They shared interests in
reading, writing, and politics. They married
in 1764 and settled on a farm in
Braintree (now Quincy), Massachusetts.
They had five children. Abigail, John
Quincy, Charles, and Thomas survived
to adulthood.
John Adams law practice and political
duties kept him away from home much
of the time. Abigail Adams stayed in
touch with her husband and other
family members by letter. Her letters
are full of her opinions on the
important issues of the day. This was
during the time when the American
colonies began to fight for
independence from Great Britain. She
wrote in favor of American
independence. Like her husband, she
also believed that slavery had no place
in a country dedicated to freedom.
In 1789 John Adams became the first vice
president of the United States. Eight years
later he became the second president.
Even during those terms Abigail was
often inMassachusetts running the
family farm. In 1800, however, she
moved with the president into the White
House, which was unfinished at the time.
After Adams term as president he and
Abigail returned to Quincy and settled
comfortably into retirement. Abigail
died on October 28, 1818.
#More to explore
Adams, John Adams, John Quincy
American Revolution White House
Adams, Ansel
U.S. photographer Ansel Adams is
famous for his striking images of
Western landscapes. He was among the
first people to promote photography as
an art form. Adams also was known for
his love of nature.
Ansel Adams was born in San Francisco,
California, on February 20, 1902. He
was originally a student of music. Photography
was only a hobby for him until
Abigail
Adams
supported
womens
rights. She told
her husband
John Adams to
remember the
ladies during
the fight
for U.S.
independence.
Abigail Adams
BRITANNICA STUDENT ENCYCLOPEDIA Adams, Ansel 21
1927. That year he published his first
collection of photographs.
In 1940 Adams helped found the
worlds first museum collection of photographs
at the Museum of Modern Art
in New York City. In 1946 he established
the first academic department to
teach photography as a profession. He
did that at the California School of Fine
Arts in San Francisco.
Adams was a nature lover throughout
his life. He published many collections
of photographs that he took in the wilderness
areas of the United States. They
include My Camera in the National Parks
and Photographs of the Southwest.
In 1980 Adams was awarded the Presidential
Medal of Freedom, the highest
nonmilitary honor in the United States.
He died on April 22, 1984, in Carmel,
California.
Adams, John
As a lawyer in the American colonies,
John Adams fought for independence
from Great Britain. He went on to
become the first vice president and the
second president of the new United
States.
Early Life
John Adams was born in Braintree (now
Quincy), Massachusetts, on October 30,
1735. His father was a farmer and a
community leader. After graduating
from Harvard College in 1755, Adams
became a lawyer. In 1764 Adams married
Abigail Smith. They had five children.
One daughter died in infancy.
Revolutionary Era
Adams became a leader in the fight
against British laws in the colonies. Still,
Ansel Adams prepares to take a
photograph along the coast of
California.
John Adams was the second president of
the United States.
22 Adams, John BRITANNICA STUDENT ENCYCLOPEDIA
as a lawyer, Adams defended British
soldiers who had killed five colonists in
the Boston Massacre of 1770. This made
him unpopular for a time among the
other colonists. But Adams believed that
everyones legal rights should be protected.
In 1774 Massachusetts colonists elected
Adams to the Continental Congress.
There he asked GeorgeWashington to
serve as commander of the Continental
Army, the military force of the colonies
during the American Revolution. He
also chose Thomas Jefferson to write the
Declaration of Independence.
In 1779 Adams served at the Massachusetts
Constitutional Convention. He
wrote the document that became the
states constitution of 1780. Adams then
joined Benjamin Franklin in Paris,
France. There he helped to produce the
Treaty of Paris, which ended the American
Revolution.
Vice Presidency
In 1789 Adams finished second to
GeorgeWashington in the presidential
election. Under the system of the time,
Adams became vice president. Voters
reelected the two men in 1792.
Political parties began to form during
Washingtons presidency. Adams and
Alexander Hamilton led the Federalists,
who supported a strong central government.
They opposed the Democratic-
Republicans, led by Jefferson, who
wanted the states to have more power.
Presidency
Adams won a narrow victory over Jefferson
in the election of 1796. Adams was
not a popular president. He followed his
own principles instead of others opinions.
Adams even disagreed with other
Federalists, notably Hamilton.
During Adams presidency a dispute
between the United States and France
October 30, July 4,
1735 1774 1783 1789 1796 1800 1826
Adams is born
in Braintree
(now Quincy),
Massachusetts.
Adams joins
the Continental
Congress.
Adams helps
create the
Treaty of Paris,
which ends the
American
Revolution.
Adams
becomes vice
president under
President
George
Washington.
Adams is
elected
president.
Adams loses
the presidency
to Thomas
Jefferson.
Adams dies in
Quincy,
Massachusetts.
T I M E L I N E
BRITANNICA STUDENT ENCYCLOPEDIA Adams, John 23
almost led to war. The French had
expected the United States to support
them in their war with Britain. The
United States refused, and the French
began seizing U.S. ships. Hamilton and
others called for war with France.
Adams, however, thought the United
States was not ready for another war.
Going against his party, he made peace
with France.
Adams faced more criticism for the passage
of the Alien and Sedition Acts in
1798. Those harsh laws made it more
difficult for new immigrants to stay in
the country. They also punished critics
of the government.
Defeat and Death
Adams lost to Jefferson in the presidential
election of 1800. Adams died within
hours of Jefferson on July 4, 1826, the
50th anniversary of the signing of the
Declaration of Independence.
#More to explore
American Revolution Continental
Congress Hamilton, Alexander
Jefferson, Thomas United States
Adams, John
Quincy
Son of President John Adams, John
Quincy Adams became the sixth president
of the United States in 1825.
Although he was intelligent and dedicated
to his country, Adams was not
very popular. His accomplishments as a
diplomat and congressman overshadowed
his uneventful presidency.
Early Life
John Quincy Adams was born on July
11, 1767, in Braintree (now Quincy),
Massachusetts. He grew up during the
American Revolution. His father was a
member of the Continental Congress.
His mother, Abigail Adams, also was a
patriot. Adams studied in Europe and in
Massachusetts at Harvard College. After
graduating in 1787, he studied law and
became a lawyer in Boston.
In 1797 Adams married Louisa Catherine
Johnson. The couple had four children,
a daughter and three sons. One of
their sons, Charles Francis Adams,
became a member of the House of Representatives
and a diplomat.
Early Career
In 1794 President GeorgeWashington
made Adams the U.S. minister to The
John Adams
was the first
president who
lived in the
White House.
He moved in
on November
1, 1800.
John Quincy Adams was the
sixth president of the United
States.
24 Adams, John Quincy BRITANNICA STUDENT ENCYCLOPEDIA
Netherlands. In 1797 Adams father,
now president, made Adams ambassador
to Prussia. In 1802 Adams was elected
to the Massachusetts Senate. In 1803 he
was elected to the U.S. Senate. After five
years he resigned from the Senate to
practice law.
In 1809 President James Madison
appointed Adams minister to Russia. In
1815 Adams became minister to Great
Britain. He returned to the United
States in 1817 and became secretary of
state under President James Monroe. In
that role Adams helped persuade Spain
to give control of Florida to the United
States. He also helped create the Monroe
Doctrine, a warning to European countries
not to extend their power in the
Western Hemisphere.
Presidency
In 1824 Adams was one of four candidates
for the presidency. Andrew Jackson
received the most electoral votes, followed
by Adams. No one had a majority
of the votes, however, so the House of
Representatives had to pick the winner.
The House chose Adams. He took office
in 1825.
The country prospered during Adams
presidency, but he was not a successful
leader. He wanted to create a national
university and expand the countrys
roads. However, Jacksons supporters in
Congress blocked most of Adams bills.
In the election of 1828 Adams lost to
Jackson.
Later Career and Death
Adams retired in 1829, but his retirement
was brief. In 1830 Massachusetts
elected him to the House of Representatives.
In Congress Adams argued against
the expansion of slavery. He also helped
start the Smithsonian Institution, which
today runs several museums inWashington,
D.C. Adams suffered a stroke in
1848 while speaking in the House. He
July 11, February 23,
1767 1803 1817 1824 1828 1831 1848
Adams is born
in Braintree
(now Quincy),
Massachusetts.
Adams is
elected to the
U.S. Senate.
President James
Monroe makes
Adams
secretary of
state.
Adams is
elected the
sixth president
of the United
States.
Adams loses
the presidential
election to
Andrew
Jackson.
Adams
enters the
U.S. House of
Representatives.
Adams dies in
Washington,
D.C.
T I M E L I N E
BRITANNICA STUDENT ENCYCLOPEDIA Adams, John Quincy 25
died in the Capitol two days later, on
February 23, 1848.
#More to explore
Adams, John Jackson, Andrew
United States
Adams, Samuel
A strong attachment to the cause of
independence made Samuel Adams a
leader of the American Revolution. As a
politician and as a writer he stirred the
colonists against British rule.
Samuel Adams was born in Boston,
Massachusetts, on September 27, 1722.
His second cousin was John Adams, the
second president of the United States.
Sam graduated from Harvard College in
1740 and soon entered local politics.
In the 1760s Adams led protests against
the British, who ruled the colonies at the
time. He served in the Massachusetts
legislature from 1765 to 1774. In 1772
he helped organize a committee of correspondence.
This was a group that
coordinated anti-British activity.
Adams was among the first to call for
complete independence for the American
colonies. As a member of both Continental
Congresses, he said that
Americans must be ready to fight. In
1776 he signed the Declaration of Independence.
In 1794 Adams was elected
governor of Massachusetts. He died on
October 2, 1803.
#More to explore
Adams, John American Revolution
Continental Congress Declaration of
Independence
Adaptation
Plants and animals have special characteristics,
or traits, that help them survive
in their surroundings. They develop
these traits through a process called
adaptation.
Many animals have traits that help them
hide from other animals that want to
attack them. Some insects look like a
leaf or a twig. Deer are colored shades of
brown, like the trees in the forests where
they live. In both cases, these animals
become almost invisible to their predators,
or attackers, because they blend in
with their surroundings.
Other animals have features that help
them deal with some part of their surroundings.
Frogs, alligators, and hippopotamuses
all spend a great deal of time
in the water. They all have their eyes and
Samuel Adams nostrils near the top of the head. This
26 Adams, Samuel BRITANNICA STUDENT ENCYCLOPEDIA
means that the animal may remain
almost completely underwater and yet
be able to see and breathe.Water birds
have webbed feet to help them paddle in
the water. Cactus plants, which live in
dry places, can store a lot of water. A
cactus has thick skin and a waxy surface.
This keeps the plant from losing water
through evaporation.
Organisms with helpful traits tend to
thrive, to reproduce, and to pass those
traits on to their own offspring. Similar
organisms that do not have these traits
do not survive as well and do not have as
much chance to reproduce. Therefore
the helpful traits are passed on and eventually
become permanent. This process
is called natural selection. It is part of
the process of evolution.
#More to explore
Animal Evolution Plant
Addams, Jane
The social worker Jane Addams devoted
her life to helping the poor and promoting
world peace. She founded Hull
House to serve needy immigrants in
Chicago, Illinois. It was one of the first
agencies of its kind in North America.
Jane Addams was born on September 6,
1860, in Cedarville, Illinois. She gradu-
Many animals have developed features to help them survive in their habitat. Hippopotamuses
eyes and nostrils are on the top of the snout. This allows them to spend a lot of time
almost completely underwater. Ducks have webbed feet to help them swim. Walruses have
thick skin to protect against the cold.
Jane Addams
BRITANNICA STUDENT ENCYCLOPEDIA Addams, Jane 27
ated from college in 1882 and then went
to Europe. In a poor section of London,
England, she visited Toynbee Hall. University
graduates lived there and worked
to improve life in the neighborhood. It
was known as the worlds first social
settlement. Addams took this idea back
to the United States.
In 1889 Addams and a classmate, Ellen
Gates Starr, rented a big house in Chicago.
They moved in and opened the
house to immigrants who were trying to
succeed in their new country. Addams
and Starr called their social settlement
Hull House after its builder, Charles
Hull. Hull House workers started a day
care center, a kindergarten, a gymnasium,
and an employment agency. They
taught many kinds of classes and even
set up a theater. All these programs
eventually filled 13 buildings.
Addams became involved in many social
causes. She worked to pass laws against
child labor, to protect workers rights,
and to win women the right to vote.
Addams believed that countries should
settle their disagreements peacefully. She
spoke out againstWorldWar I even
though her opinion made her less popular.
In 1931 she won a share of the
Nobel peace prize.
Addams lived at Hull House until her
death on May 21, 1935. The original
Hull mansion has been preserved as a
museum that honors her.
..More to explore
Chicago
Addis Ababa
Population
(2006 estimate)
2,973,000
Addis Ababa is the capital and largest
city of the East African country of
Ethiopia. It is situated on a plateau high
in the central mountains of Ethiopia.
Ethiopias government ministries and
houses of parliament are located in
Addis Ababa. The city also contains the
headquarters of the African Union.
Most of Ethiopias trade passes through
Addis Ababa. In the western part of the
city is the Mercato. It is one of the largest
open-air markets in Africa. Goods manufactured
in the city include textiles, food,
beverages, plastics, and wood products.
Addis Ababa became the capital of
Ethiopia in the late 1800s. Before that
Worshippers gather at an Ethiopian Orthodox
church in Addis Ababa.
28 Addis Ababa BRITANNICA STUDENT ENCYCLOPEDIA
the capital was Entoto, a cold, windswept
town just to the north. In 1887
the empress Taitu persuaded her husband,
Emperor Menelik II, to move the
capital to its present site.
From 1935 to 1941 Italian forces occupied
Addis Ababa as well as the rest of
Ethiopia. The Italians paved roads and
constructed European-style buildings.
Development of the city was slow from
1941 until 1960. Beginning in the
1960s, however, Addis Ababa grew rapidly
in population.
#More to explore
Ethiopia
Adena Culture
The ancient Native Americans of the
Adena culture lived in a large area centered
in what is now southern Ohio.
The Adena people thrived from about
500 BC to AD 100. They are known
mostly for the earthen mounds they
built. The term Adena comes from the
name of a place where archaeologists
found Adena mounds in the early
1900s.
The Adena settled in hundreds of small
villages along the Ohio River. They lived
in cone-shaped houses and fed themselves
by hunting, fishing, and gathering
fruits and wild plants. They made tools
from wood, bone, and copper. They also
wove cloth and molded simple pots
from clay.
The Adena constructed hundreds of
earthen mounds in the area that now
makes up Ohio, Indiana, Kentucky,
West Virginia, and Pennsylvania. Many
of the mounds were burial sites. The
Adena built many mounds in simple
shapes such as circles and rectangles.
They shaped other mounds like animals.
The most famous is the Great Serpent
Mound near Peebles, Ohio. This mound
looks like a giant snake and is nearly
1,300 feet (400 meters) long.
No one knows for sure what happened
to the Adena people after about AD 100.
Some scientists think that they joined
the Hopewell people, who developed a
similar culture in the territory where the
Adena had lived.
#More to explore
Hopewell Culture Native Americans
Adobe
Adobe is a type of clay that is used to
make bricks. People in many dry parts
The largest burial mound of the Adena culture
can be seen in what is now northern
West Virginia. It was built more than 2,000
years ago.
BRITANNICA STUDENT ENCYCLOPEDIA Adobe 29
of the world use adobe bricks to build
buildings. This is partly because there
are few trees in these regions to supply
wood for building.
People make adobe bricks by wetting
clay and then adding straw or another
type of fiber. They mix the material and
pour it into molds. The molds have four
sides and are open at the top. People
then lay the bricks out in the sun to dry,
which can take several weeks. When
they are dry, the adobe bricks are ready
to use.
Adobe buildings usually start with a base
of stone or concrete.Workers stack the
adobe bricks on this base. They stick the
bricks together with a mudlike material
called mortar. Adobe buildings are very
strong and last for hundreds of years.
Adobe buildings also stay warm in winter
and cool in summer.
People have used adobe for thousands of
years. Ancient peoples east of the Mediterranean
Sea, in North Africa, and in
southern Spain made adobe bricks.
American Indians in the driest parts of
North and South America also built
with adobe. For example, the Pueblo
Indians built many adobe houses in
what is now the southwestern part of the
United States.
#More to explore
Clay Pueblo Indians
Adolescence
Adolescence is the time in a young persons
life between childhood and adulthood.
Adolescence starts when a person
is about 12 years old and ends at about
the age of 19. A person in this age group
is called an adolescent, or a teenager.
Adolescence is a time of great change.
Adolescents experience changes in their
bodies. They also experience changes in
their emotions, or feelings, as well as
their thoughts and beliefs. They often
see the world differently, and they act
differently than they did when they were
children.
The buildings of Taos Pueblo in New
Mexico are made of adobe. Some have
been lived in for more than 1,000 years.
Relationships with their friends are very
important to most adolescents.
30 Adolescence BRITANNICA STUDENT ENCYCLOPEDIA
Changes in the Body
During adolescence, the reproductive
system develops. The reproductive
organs are the parts of the body that
allow men and women to make babies.
Girls and boys bodies change in different
ways. Boys grow facial hair, and their
voices deepen. They also develop stronger
muscles. Girls grow breasts and wider
hips, and they start having menstrual
periods. This means that they are able to
become pregnant.
Emotional Changes
Adolescence is an exciting time. It is also
a time that can be very confusing. Boys
and girls become much more interested
in each other. At the same time they
may worry about their appearance, and
they are sometimes easily embarrassed.
During adolescence, most boys and girls
care a lot about what other adolescents
think of them. They may also be very
concerned with how they fit into their
world. Often adolescents choose to
spend time with their friends rather than
with their families.
Growing Independence
As adolescents grow emotionally, they
begin to take on new responsibilities and
gain new freedoms. They act and think
more independently. They also start to
find a balance between family and
friends. These changes mean that adolescents
are on their way to becoming
adults.
..More to explore
Child Development Reproductive
System
Adriatic Sea
The Adriatic Sea separates Italy from the
Balkan Peninsula of eastern Europe. It
was probably named after the port town
of Adria, which prospered during
ancient Roman times.
The Adriatic is about 500 miles (800
kilometers) long and has an average
width of 100 miles (160 kilometers). Its
maximum depth is 4,100 feet (1,250
meters). The sea has a high salt content.
The climate is Mediterranean. This
means that it has clear, warm, and dry
summers and mild, humid winters.
The Adriatic extends from the Gulf of
Venice, in the north, southeastward to
the Strait of Otranto, which leads to the
Ionian Sea near Albania. Its western, or
Italian, coast is low and straight. The
eastern coast is rocky and mountainous.
The countries of Slovenia, Croatia, Bosnia
and Herzegovina, and Montenegro
border the sea to the east.
The Adriatic is an important part of
tourism in the region. Many holiday
Bosnia and
Herzegovinas
seacoast on
the Adriatic is
only 12 miles
(20 kilometers)
long.
BRITANNICA STUDENT ENCYCLOPEDIA Adriatic Sea 31
resorts are located on its shores. The
fishing catch on the Adriatic includes
lobsters, sardines, and tuna.
Advertising
Whenever people give information to
the public about an event, a product, or
a service, they are using advertising. A
piece of advertising is called an advertisement,
or ad.
The goal of most advertising is to make
the public want to buy whatever is being
advertised. People also use advertising to
make the public form opinions about
things. For example, an ad could try to
make the public believe that a company
treats its workers well. Another ad could
try to make voters choose a certain candidate
for president.
Ads appear almost everywhere. They are
found in newspapers and magazines.
They appear on television, radio, and
the Internet. Ads are also posted as signs
in all kinds of public places.
The Media and Advertising
When advertisers want many people to
see or hear their ads, they pay the media
to have the ads published or broadcast.
Newspapers and magazines publish, or
print, ads between their articles. Television
and radio networks broadcast, or
play, ads during their programs. (Television
and radio ads are also called commercials.)
Web sites, buses, movie
theaters, and many other places also
display ads in exchange for money.
Control of Advertising
Advertisers are regulated, or controlled,
in several ways. Governments usually
pass laws to make sure that ads are
truthful and do not offend consumers.
Also, the media usually set their own
rules that advertisers must follow.
History of Advertising
Signs were the first form of advertising.
Even thousands of years ago people created
hand-lettered signs to advertise
their goods and services. The invention
of the printing press in the 1400s
expanded this type of advertising. Merchants
could print dozens of the same
posters and fliers to advertise what they
were selling. In the 1600s and 1700s
newspapers appeared in Europe, the
Americas, and Japan. Advertising then
became even more widespread.
Today advertising is a huge part of business
around the world. A major corpora-
Bright advertisements compete for attention
in New York City.
32 Advertising BRITANNICA STUDENT ENCYCLOPEDIA
tion may spend hundreds of millions of
dollars a year just on advertising.
#More to explore
Magazine Newspaper Radio
Television
Aegean
Civilization
The earliest European civilization arose
sometime after 3000 BC, in the region of
the Aegean Sea. It took place on the
islands and the mainland of what is now
the country of Greece. This civilization
went through several stages. It began on
the island of Crete. That early part is now
called theMinoan civilization.On the
mainland of Greece it developed later.
That is now calledMycenaean
civilization.
Minoans
The Minoan civilization lasted from
about 2500 BC to about 1400 BC. The
Minoans are named for their legendary
king Minos. Their capital city was Knossos.
The palace at Knossos was enormous,
covering 5.5 acres (2.2 hectares)
of ground. Large towns spread around
other Minoan palaces. Houses were
often two stories high. They were built
with stones, timber, and mud bricks.
The Minoans painted their pottery and
walls with images of plants, flowers,
animals, and goddesses. They worshipped
a mother goddess.
The wealth of the Minoans was based
on seafaring and trading, especially trade
with the Middle East and Egypt. Pottery
made on Crete has been found in Egypt,
and ancient Egyptian pottery has been
found on Crete. A powerful navy protected
Knossos.
Mycenaeans
The Mycenaean civilization developed
in the 1500s BC, when Greek-speaking
people settled down on the Greek mainland.
The Mycenaeans conquered the
Minoans in about 1400 BC. Their civilization
is named after Mycenae, its most
important city.
A king headed the society. Kings built
fortresses with strong walls. This was
because the Mycenaeans fought many
wars, includingaccording to legend
the TrojanWar. There were also landowners,
farmers, slaves, and priests. Like
the Minoans, the Mycenaeans decorated
their walls with paintings. They were
skilled jewelers and goldsmiths.
Mycenaean trade extended to Sicily,
Egypt, Palestine, Troy, Cyprus, and
The throne room of the palace in Knossos
still holds the throne of the ancient Minoan
kings.
Ancient Greek
mythology tells
of the Minotaur,
a fierce
monster of the
Minoan kingdom.
The
Minotaur had
the body of a
man and the
head of a bull.
BRITANNICA STUDENT ENCYCLOPEDIA Aegean civilization 33
Macedonia. The Mycenaeans imported
food, cloth, and copper. They probably
exported woolen goods, olive oil, timber,
and silver.
TheMycenaeans adopted theMinoan
system of writing on clay tablets. Unlike
theMinoan language, however, the
Mycenaean language has been translated.
It is the oldest known form of Greek.
Toward the end of the 1200s BC, the
Mycenaean civilization fell apart. Many
people moved away to other lands.
Scholars think that the decline may have
been due to drought, bad harvests, lack
of food, disease, or anger about the high
taxes the people had to pay.
In about 1100 BC Greece was taken over
by tribes from the north. These peoples
were the ancestors of the modern
Greeks. It is with them that the history
of ancient Greece began.
..More to explore
Aegean Sea Greece Greece, Ancient
Aegean Sea
An arm of the Mediterranean Sea, the
Aegean Sea lies between the countries of
Greece and Turkey. The region was the
site of two great ancient civilizations,
those of Crete and Greece.
The Aegean Sea is about 380 miles (610
kilometers) long and 185 miles (300
kilometers) wide. In the northeast it
connects to the Black Sea through a
series of narrow straits. The sea has hundreds
of islands stretching from Greece
to the shores of Asia. The islands are
actually the mountain peaks of an
underwater landmass called Aegeis.
The Aegean contains few nutrients so
very little plant life grows there. Its
warm waters, however, encourage fish to
enter it from the Black Sea to breed.
The chief products of the islands are
wheat, wine, oil, figs, raisins, honey,
vegetables, marble, and minerals. Fishing
and tourism are also important. Visitors
come to see the villages of
whitewashed houses as well as the ruins
of ancient civilizations.
The clear blue waters of the Aegean Sea
lap at the shores of a beach in Greece.
34 Aegean Sea BRITANNICA STUDENT ENCYCLOPEDIA
Scientists believe that people began to
explore the Aegean about 15,000 years
ago. By the 1st century BC the Roman
Empire ruled over the area of the Aegean
and the Mediterranean. The region later
came under the control of the Byzantine
Empire, the Ottoman Empire, and
finally the independent country of
Greece.
#More to explore
Aegean Civilization Greece
Aesop
Hundreds of stories called fables are
credited to a person named Aesop.
Ancient scholars claimed that Aesop
lived in the kingdom of Thrace in the
500s BC. It is now known that many of
the stories are even older and that Aesop
probably never existed. But the fables
that are credited to him are still used to
teach children.
The fables of Aesop were probably part
of an oral historystories that were told
aloud. About 2,000 years ago the
Roman writer Phaedrus wrote down
some of the fables. Later the stories were
translated into other languages. An early
English-language version of the stories
was published in 1692. The fables familiar
to readers today were translated into
English during the 1800s. Most of the
fables are about animals with human
characteristics. Most end with a moral,
or a statement of the lesson that the
fable teaches.
#More to explore
Fable Folktale
In Aesops fable of The Hare and the Tortoise,
a speedy hare teases a tortoise
about his slow pace. The tortoise challenges
the hare to a race. The hare is so sure that
he will win that he takes a nap. When he
wakes up, the tortoise has already won. The
moral is Slow but steady wins the race.
BRITANNICA STUDENT ENCYCLOPEDIA Aesop 35
Afghanistan
The country of Afghanistan lies at the
heart of central Asia. The capital is
Kabul.
Geography
Afghanistan borders Iran, Pakistan,
Turkmenistan, Uzbekistan, and Tajikistan.
The Amu Darya river forms part of
the northern border. A narrow piece of
land called the Vakhan, orWakhan Corridor,
connects Afghanistan with China.
Afghanistan is a mountainous country.
The main range is the Hindu Kush, in
the northeast. North of the central
mountains are fertile plains. Deserts,
including the sandy Rigestan, lie in the
southwest. Afghanistan generally has a
dry climate with cold winters and hot
summers.
Plants and Animals
Southern Afghanistan has little vegetation.
Cedar, oak, walnut, alder, and ash
trees grow in the north. The mountains
have forests of pine and fir.
Wolves, foxes, hyenas, jackals, bears, and
wild goats roam the mountains.
Gazelles, wild dogs, and wild cats are
widespread. The countrys birds include
vultures and eagles.
People
The people of Afghanistan, known as
Afghans, are a mixture of many different
groups. The Pashtuns make up about
half of the population. Tajiks make up
about a fifth of the population. Other
ethnic groups include the Hazara,
Uzbeks, Chahar Aimaks, and Turkmen.
Pashto, the language of the Pashtuns,
and Dari (Persian) are the two official
languages, but others are spoken. Almost
all Afghans are Muslims.
Kabul is the largest city, but most
Afghans live in rural areas. Farmers live
in villages along the rivers. Nomads live
in tents and move from place to place.
Few people live in the mountains or the
deserts.
Economy
Afghanistan is one of the poorest countries
in the world. Most people grow
crops and raise animals for their own
use. The main food crops are wheat,
rice, grapes, barley, and corn. Sheep,
goats, and cattle are the main livestock.
Some farmers grow opium poppies,
which are used to make illegal drugs.
36 Afghanistan BRITANNICA STUDENT ENCYCLOPEDIA
Manufacturers make processed foods,
leather, fur, and textiles. The country has
deposits of natural gas, but warfare has
prevented Afghans from using them.
History
Major trade routes crossed what is now
Afghanistan thousands of years ago. The
Persians and Macedonian king Alexander
the Great ruled the land more
than 2,300 years ago. In the AD 600s
Arab invaders introduced the religion of
Islam. In 1219 Genghis Khan made the
area part of his Mongol Empire. Beginning
in the 1300s Turkic peoples, the
Mughal Empire, and the Persians ruled
parts of the land.
Ahmad Shah Durrani, a Pashtun leader,
unified Afghanistan under his rule in
1747. Great Britain invaded in the
1800s. After winning independence
from Britain in 1919, Afghanistan continued
as a monarchy. In 1973 Afghans
overthrew the king. The countrys new
leaders made Afghanistan a republic, led
by a prime minister.
Soviet Invasion
In 1978 Communists seized control of
Afghanistans government. The Soviet
Union invaded in December 1979. For
nearly a decade Islamic forces known as
mujahideen fought the Soviets. Millions
of Afghans left the country for Pakistan
and Iran. The Soviet Army left in 1989.
The Taliban
Various Afghan groups then fought for
control. By the late 1990s a group called
the Taliban had gained control over
most of Afghanistan. The Taliban ruled
according to a strict version of Islamic
law.
The Taliban angered other countries by
allowing terrorists to live in Afghanistan.
When the Taliban refused to hand over
suspected terrorist Osama bin Laden,
the United States and its allies bombed
Afghanistan in October 2001.Within
months the Taliban abandoned Kabul.
In 2004 Afghanistan adopted a new
constitution and elected a president. But
fighting continued between U.S. forces
and the Taliban.
..More to explore
Alexander the Great bin Laden, Osama
Communism Islam Kabul
Mongol Empire Mughal Empire
Persia Union of Soviet Socialist
Republics
The blue-tiled mosque in Mazar-e Sharif,
Afghanistan, is important to all Muslims. It
marks the tomb of !Ali, the son-in-law of the
prophet Muhammad.
Facts About
AFGHANISTAN
Population
(2008 estimate)
28,266,000
Area
249,347 sq mi
(645,807 sq km)
Capital
Kabul
Form of
government
Islamic republic
Major cities
Kabul, Kandahar
(Qandahar),
Herat, Mazar-e
Sharif
BRITANNICA STUDENT ENCYCLOPEDIA Afghanistan 37
Africa
Africa is the worlds second largest continent.
More than 50 countries make up
the continent. More than one eighth of
the worlds population lives there.
Land and Climate
Africas landscape is varied. The northern
and western parts of the continent
are generally lower and more level than
the eastern and southern areas. Africa is
the oldest continent. Therefore most of
its mountains are not as high as those on
other continents. They have been worn
down over millions of years by wind and
water.
Africas most striking feature is a series
of great rifts, or troughs, in the east
known as the Rift Valley system. These
rifts span two continents, from western
Asia through eastern Africa. In Africa
they are deep, long, narrow valleys.
The worlds longest river, the Nile, flows
through northern Africa. The continents
other long rivers include the
Congo in central Africa, the Niger in the
west, and the Zambezi in the south.
Eastern Africa has a chain of lakes
known as the great lakes.
The continent is crossed midway by the
equator. This means that most of
Africathe middle portionlies within
the tropics, an area where it is hot yearround.
In the lowlands near the equator,
rain falls throughout the year. To the
north and south of this rainy area are
large regions that have a rainy season
followed by a dry season. It is very hot
A pair of giraffes is at home near Mount Kilimanjaro in Tanzania.
38 Africa BRITANNICA STUDENT ENCYCLOPEDIA
BRITANNICA STUDENT ENCYCLOPEDIA Africa 39
and dry year-round in Africas major
desertsthe Sahara in the north and the
Kalahari and the Namib in the south.
Plants and Animals
The vegetation growing in each region
depends on the rainfall it receives. Near
the equator, where it rains year-round,
there are dense rain forests. These forests
contain thousands of different types of
trees and other plants. Between the rain
forests and the great deserts to the north
and south are the savannas. These are
open grasslands scattered with trees such
as acacias and baobabs. Few plants grow
in the deserts.
A serious problem in the savanna is that
the vegetation is being used up, leaving
the land bare. As the population
increases, more and more of the trees are
being used for fuel and for building supplies.
Some scientists are concerned that
removing the vegetation may cause the
savanna to become more desertlike.
Africa has many different kinds of animals,
though their numbers were greatly
reduced in the 1900s. This loss occurred
because of overhunting and because
large areas of their natural habitats were
taken over for farming. Today many
species are threatened with extinction.
Several countries have set aside land to
help protect wild animals. These wildlife
preserves are home to such animals as
elephants, giraffes, zebras, hippopotamuses,
antelopes, lions, jackals, and
hyenas. The rain forests support monkeys,
bats, flying squirrels, gorillas, leopards,
and mongooses. The native
animals of northern Africa include types
of wild sheep and goat, the African red
deer, and the jerboa (a small leaping
animal like a gerbil). Fish, birds, and
reptiles also are abundant.
People
Africa has the most physically varied
population in the world. Most of the
population consists of black peoples
belonging to almost 3,000 different ethnic
groups. In the north there are also
large numbers of Arabs. Mainly in the
south there are some descendants of
Europeans who established colonies in
Africa hundreds of years ago.
The number of languages spoken in
Africa probably exceeds 1,000, though
some are spoken by only a small number
of people. Arabic is the major language
of northern Africa. Most Africans who
live south of the equator speak one of
the many Bantu languages. In general,
Islam is the religion of northern Africa
South African boys pose in front
of a painting in Cape Town,
South Africa.
40 Africa BRITANNICA STUDENT ENCYCLOPEDIA
and Christianity of southern Africa.
Traditional religions are also practiced.
Many African countries are comparatively
poor. In all African countries the
government provides public education.
But most governments cannot afford to
provide education for everyone. Millions
of Africans remain unable to read or
write. Much of the money for health
care comes from other countries. Infectious
diseases, such as malaria, continue
to be a serious problem in Africa, and
about 70 percent of all AIDS cases are in
Africa.
Economy
Most of Africa is underdeveloped. But
the continent has some of the worlds
largest shares of minerals, including oil,
natural gas, and coal; metals such as
gold; and gems such as diamonds.
Farming is a very important part of the
African economy. The chief food crops
vary by region. They include yams in the
tropical forests of the west; corn, millet,
and rice in the savannas; and corn in the
south. The tropical grasslands are also
suitable for cattle farming. Most African
countries do not produce enough food
to feed all their people. Therefore they
must import food.
In many parts of Africa certain crops are
produced for sale to other countries.
Africa is the worlds largest supplier of
cocoa beans, which are used in making
chocolate. Africa also exports much cotton,
sisal (a fiber), tea, coffee, palm oil,
yams, and peanuts, as well as wood from
the forests.
Although Africa still earns most of its
money by exporting raw materials and
food, many of its countries are developing
industries. Some industries process
raw materials produced in local farms
and forests. Others manufacture goods
for use in Africa. South Africa is the
most industrialized African country.
History
Africa is thought to be the place where
humans first developed, more than 1
million years ago. The African continent
had many kingdoms and empires during
its early history. One of the worlds earliest
civilizations, ancient Egypt, devel-
Facts About
AFRICA
Area
11,678,801 sq mi (30,247,722 sq km)
Population
(2008 estimate) 955,761,100
Largest Country by Area
Sudan: 966,757 sq mi (2,503,890 sq km)
Smallest Country by Area
Seychelles: 176 sq mi (455 sq km)
Largest Country by Population
Nigeria: (2008 estimate) 146,255,000
Smallest Country by Population
Seychelles: (2008 estimate) 85,500
Largest Cities
Cairo, Egypt; Lagos, Nigeria; Johannesburg,
South Africa; Kinshasa, Congo; Khartoum,
Sudan
Longest River
Nile River: 4,132 mi (6,650 km)
Largest Lake
Lake Victoria: 26,828 sq mi (69,785 sq km)
BRITANNICA STUDENT ENCYCLOPEDIA Africa 41
oped in the lower Nile River valley
nearly 5,000 years ago.
The region called Nubia was south of
Egypt. The powerful Nubian kingdom
called Kush ruled Egypt for a while in
the 700s and 600s BC. In the AD 300s
the kingdom of Aksum conquered Kush
from the south.
The African people have a long history
of contact with other powers. In about
the 700s BC the Phoenicians established
the city of Carthage in what is now
Tunisia. In the 100s BC the Roman
Empire took control of part of North
Africa. Arabs from the Middle East
spread into Africa in the AD 600s. Great
trading states, including the Ghana,
Mali, and Songhai empires, flourished in
western Africa. In eastern and central
Africa, powerful city-states such as
Mogadishu and Mombasa traded with
Arabia.
The first Europeans to arrive in Africa
were the Portuguese, in the late 1400s.
Soon the British, the Dutch, and the
French had also set up towns and trading
centers. They traded slaves from
Africa to the Americas from the 1500s
to the early 1800s. The Europeans did
not actually take control of the African
territories they entered during this
period, however.
Starting in the late 1800s Britain,
France, Belgium, Portugal, and Germany
ruled most of Africa as colonies.
The Europeans took raw materials such
as minerals and timber from their colonies
and shipped them back to Europe.
The African people had no say in how
they were ruled. They were also often
forced off the best land so that the Europeans
could take it. Many African
people resisted European control
throughout the colonial period.
In the 1900s the colonies were finally
granted independence. Many African
countries faced great unrest after gaining
independence. Ethnic violence led to
many deaths, and in many cases civil
war broke out as individuals and groups
struggled to establish control. The poor
economies of the countries added to the
problems. In 2002 African countries
formed an organization called the African
Union to try to solve these problems.
International agencies such as the
United Nations helped, too.
#More to explore
African Union Aksum Colony
Continent Egypt, Ancient Ghana
Empire Human Origins Kush Mali
Empire Nile River Nubia Rain
Forest Sahara Slavery Songhai
Empire
Ruins of a casbah, or fort, stand in Morocco
in North Africa.
42 Africa BRITANNICA STUDENT ENCYCLOPEDIA
African
Americans
African Americans are people in the
United States who have ancestors from
Africa. Many African Americans have
non-African ancestors as well. African
Americans are also known as black
Americans.
Slavery
Most African Americans have ancestors
who were slaves. Slaves were people
taken from their African homelands and
shipped to the Americas. There, white
people forced them to work without pay
and in harsh conditions. English settlers
brought the first African slaves to the
colony of Virginia in the early 1600s. By
1790 black people made up nearly one
fifth of the population of the United
States. Most slaves lived and worked on
plantations, or large farms, in the South.
Many people called abolitionists worked
to end slavery. These included black
people as well as white people. Harriet
Tubman, a black abolitionist, organized
the Underground Railroad, which was a
way for slaves to escape to the North.
The American CivilWar
The American CivilWar broke out in
1861. This was a war between the
Northern and Southern states, partly
over the issue of slavery. In 1863 President
Abraham Lincoln issued the Emancipation
Proclamation. This document
freed the slaves in the Southern states.
The North won the CivilWar in 1865.
That year the 13th Amendment to the
U.S. Constitution ended slavery
throughout the United States. In 1868
the 14th Amendment gave African
Americans U.S. citizenship. In 1870 the
15th Amendment guaranteed them the
right to vote.
Reconstruction
The period following the war was
known as Reconstruction. African
Americans were finally free, but most of
them lived in terrible poverty. In the
South many worked as sharecroppers.
This meant that they farmed a piece of
land owned by someone else. Their pay
was a share of the crops they produced.
In addition, African Americans continued
to suffer from discrimination (unfair
treatment) and violence. Schools and
other public places were often segregated.
This meant that blacks and whites
could not mix in those places. Violent
groups like the Ku Klux Klan kept most
blacks from voting in the South. These
groups also hurt or killed many blacks.
First Civil Rights Efforts
In the late 1800s a former slave named
Booker T.Washington became a powerful
voice for African Americans. He
believed in training African Americans
to do certain jobs so that they could find
work.
Other African American leaders disagreed
withWashington. W.E.B. Du
Bois thought that the government
should guarantee to blacks the same
rights that whites had. These
February is
Black History
Month in the
United States.
In that month
schools and
other organizations
help
everyone learn
about the African
American
experience.
BRITANNICA STUDENT ENCYCLOPEDIA African Americans 43
rightssuch as the right to vote or the
right to go to a public schoolare called
civil rights. Du Bois and others formed
the National Association for the
Advancement of Colored People
(NAACP) to help African Americans to
gain full civil rights.
Great Migration
DuringWorldWar I (191418) large
numbers of African Americans began to
leave the South. They moved to cities in
the North andWest. There they hoped
to find jobs and to escape discrimination.
However, many were forced to live
in poor, segregated areas.
This movement from the South, called
the Great Migration, continued through
the 1960s. By 1970 about 6 million
African Americans had left the South.
Civil Rights Movement
By the 1950s the NAACP had begun to
use the court system to fight for civil
rights for African Americans. One major
success came in 1954. In that year the
U.S. Supreme Court outlawed segregation
in public schools.
These efforts soon turned into an organized
fight for equal rights. This was
called the civil rights movement. A Baptist
minister named Martin Luther King,
Jr., became the leader of the movement.
In 1963 he led a major protest called the
March onWashington.
In 1964 the U.S. Congress passed the
Civil Rights Act. This law banned discrimination
based on race in schools,
jobs, and many other areas.
Black Power Movement
Despite these successes, some African
Americans grew impatient with the
slow pace of change. They began a
African Americans at the 1968
Olympics show their support of
the black power movement with
a raised-fist salute.
In May 1954 the U.S. Supreme
Court ruled that segregation in
schools was illegal. Lawyers
George Hayes (left), Thurgood
Marshall (center), and James M.
Nabrit (right) join hands outside
the U.S. Supreme Court to celebrate
the decision.
44 African Americans BRITANNICA STUDENT ENCYCLOPEDIA
more extreme movement called the
black power movement. Malcolm X
and a group called the Black Panthers
were among the movements leaders.
They believed that blacks should use
violence, if necessary, to get power and
justice.
During the 1960s violent riots did break
out in black neighborhoods in many
cities. The African Americans who
rioted were angry about violent treatment
by police, a lack of jobs, and poor
housing.
Political Progress
After the 1960s the civil rights movement
broke into many separate groups.
Still, African American leaders continued
their work to end discrimination.
In addition, many African Americans
gained positions of power. In 1967
Thurgood Marshall became the first
African American justice of the U.S.
Supreme Court. In 2001 Colin Powell
became the first black U.S. secretary of
state, and in 2008 Barack Obama
became the first African American to be
elected president of the United States.
African Americans Today
In 2000 there were about 36 million
Americans with African roots. They
made up about 13 percent of the total
U.S. population. One quarter of African
Americans lived in poverty, and discrimination
against African Americans
remains a problem today. Nevertheless,
African Americans have made great
gains since the end of slavery more than
140 years ago.
..More to explore
Civil Rights Movement King, Martin
Luther, Jr. Malcolm X Marshall,
Thurgood National Association for the
Advancement of Colored People
Slavery Tubman, Harriet
Washington, Booker T.
African National
Congress
A political party in South Africa, the
African National Congress (ANC) supported
the rights of black and mixedrace
people through the apartheid era.
Nelson Mandela, the first black president
of South Africa, belonged to the
ANC.
In the early 1900s whites ruled South
Africa. Blacks made up most of the
Author Toni Morrison writes about the experiences
of African Americans. She won the
Nobel prize for literature in 1993.
BRITANNICA STUDENT ENCYCLOPEDIA African National Congress 45
countrys population but did not have
equal rights. In 1912 black Africans who
wanted equality formed the party that
became the ANC.
In 1950 the South African government
introduced apartheid. This system kept
whites and nonwhites apart and denied
nonwhites almost all their legal rights.
The ANC protested. In 1960 the party
was banned, but its members continued
to protest, sometimes violently. The
government arrested ANC leaders,
including Mandela. In 1964 Mandela
was sent to prison.
During the 1970s and 1980s the ANC
gained support among South Africas
people. In 1990 the government lifted
the ban on the party and freed Mandela.
In 1994 an election open to all races was
held. The ANC won control of the legislature,
and Mandela became South Africas
first black president.
#More to explore
Apartheid Mandela, Nelson South
Africa
African Union
In 2002, 53 African countries joined
together to form the African Union
(AU). The leaders of these countries felt
that the union would benefit all the
countries people, governments, and
businesses. The headquarters of the AU
is in Addis Ababa, Ethiopia.
The AU took the place of the Organization
of African Unity (OAU). The OAU
had been formed in 1963. Around that
time Africa was undergoing great
changes. Colonies that had been under
the control of European powers were
Thabo Mbeki stands in front of a
board showing election results.
Mbeki followed Nelson Mandela
as leader of the ANC.
People carry pictures of African
leaders at a ceremony celebrating
the first meeting of the African
Union.
46 African Union BRITANNICA STUDENT ENCYCLOPEDIA
becoming independent countries. The
new countries faced many challenges.
The countries set up the OAU so that
they could help each other.
African leaders formed the AU to
improve what the OAU had been doing.
One of the AUs goals is to promote
unity, or togetherness, between African
countries. Other goals are to defend the
member countries and to encourage economic
development. The AU also works
for peace and stability, the end of hunger,
and the protection of human rights.
The leaders of the AU hope to bring all
of Africa under a single, central government
someday. The AU already has its
own parliament, or lawmaking body.
The leaders are also planning a court
system for all of Africa. In addition, they
want the countries of the AU to use a
single form of money.
#More to explore
Addis Ababa Africa
Aging
All living things, from their first
moment of existence, begin the process
of aging, or growing older. As children
move toward adulthood, they become
taller, stronger, and more independent.
At some point in adulthood, however, a
slow decline begins. The onset of aging
happens at different times for different
people. Most people start to feel some
effects of aging in their 40s or 50s.
As people age, their hair often thins and
turns gray, and their skin wrinkles. Their
muscles begin to shrink and their bones
become more fragile. They often lose
some of their height or part of their
vision or hearing. They think more
slowly, and their short-term memory
may suffer. Scientists are not exactly sure
what causes the effects of aging. The
cells of the body might have a built-in
time limit. That limit would determine
how long the cells can remain healthy
and able to create new cells.
Several factors affect how long people
live. One factor is heredity. Long lives
seem to run in families. Another factor
is lifestyle. Physically fit people who do
not smoke will probably age more slowly
and live longer than others. Poverty also
affects how long people live. People who
cannot afford to eat well and go to a
doctor when they are sick may die
before they become old.
Animals age at different rates and live
for different lengths of time. These aging
People of all ages can enjoy spending time
together.
BRITANNICA STUDENT ENCYCLOPEDIA Aging 47
rates depend on the type of animal. Rats
may be said to be old at about 2 years,
dogs at about 10 years, and elephants at
about 40 years. For humans, people in
their 60s and older are commonly considered
to be old.
Agriculture
Agriculture is another word for farming.
It includes both growing and harvesting
crops and raising animals, or livestock.
Agriculture provides the food and many
of the raw materials that humans need
to survive.
Raising Plants and Animals
The products of agriculture that people
eat come from both plants and animals.
Plant foods include fruits, vegetables,
and grains. Meat, dairy (milk) products,
and eggs are some of the most common
animal foods.
Plants and animals also supply such
natural materials as cotton, flax, wool,
and hides.Workers process these materials
into thread, cloth, and leather. Then
people use the materials to make such
things as clothing, draperies, shoes, furniture
coverings, and many other items.
Growing trees is another important agricultural
job. Lumber from tree farms is
used to make buildings, furniture, boats,
and many other things. Christmas trees
often come from tree farms, too.
Location andWeather
People practice agriculture on farms, on
ranches, and in orchards all over the
world. Farmers raise crops and livestock
in every climate and in all kinds of different
soil. Some regions receive a lot of
sunlight or rainfall. Others have colder
or drier weather. All places have their
own kinds of agriculture.
Plants and livestock need air, water, and
nourishment to stay alive. If a plant does
not have the kind of soil it needs, it may
die. Similarly, animals also need to have
the right climate and the right food to
survive. Farmers try to raise the kinds of
livestock and plants that will do well in
their region. If they do not have perfect
natural conditions, they try to create the
best conditions possible. For example,
many farmers in dry areas use irrigation,
or artificial watering.
History
Humans may have begun taming animals
and growing small crops as early as
10,000 years ago. However, many early
people were nomads, or wanderers who
moved from place to place. They found
their foods in the wild as they traveled.
They hunted, fished, and gathered nuts,
An ox helps a man plant rice in Vietnam. berries, and roots.
48 Agriculture BRITANNICA STUDENT ENCYCLOPEDIA
Eventually people learned to keep some
animals in herds. They stopped roaming
and began to settle in one place for longer
times. They built homes and started to
grow their own crops on the land around
them. The crops provided a more
dependable food supply than hunting
and gathering. Small settlements grew
into villages, towns, and cities.
About 200 years ago the Industrial
Revolution brought great changes to
agriculture. In the past people had used
hand tools and animals to help them
plant and harvest. Machines invented
during the Industrial Revolution made
that work easier. As a result, not as many
workers were needed on farms. Many
people moved away from farms to cities
in search of jobs.
Today most agriculture takes place far
outside big cities. Huge companies control
much of the worlds farmland.
Crops grow on large plots of land with
the help of irrigation and special chemicals.
Farmers raise healthy livestock with
the help of medicine. In poor countries,
however, many people still depend on
their own small farms to survive.
#More to explore
Industrial Revolution Irrigation Soil
AIDS
AIDS is a serious disease. The name
stands for acquired immunodeficiency
syndrome. Millions of people have died
from AIDS since the 1980s. Scientists
have not yet found a cure, but they can
treat the disease effectively.
Causes
Tiny particles called viruses cause many
diseases. The particular virus that causes
AIDS is called human immunodeficiency
virus (HIV). HIV enters the body
through contact with infected blood or
other body fluids. Coughing, sneezing,
and handshaking do not spread the
virus.
HIV kills helper T cells in the body.
Helper T cells are a type of white blood
Some farmers use special irrigation systems
to water their crops.
The AIDS Memorial Quilt is displayed in
Washington, D.C. The quilt honors people
who have died of the disease.
BRITANNICA STUDENT ENCYCLOPEDIA AIDS 49
cell. They are part of the bodys immune
system, which fights off disease. The
body loses its ability to fight off disease
when its helper T cells die.
Symptoms
A new HIV infection often causes symptoms,
or signs, that are similar to those
of influenza (flu). They usually last only
a week or two. After they clear up, an
infected person may show no signs of
illness for years. However, such a person
can still pass the virus to other people.
Because of their weak immune systems,
most HIV-infected people eventually
come down with other infections. A
person who has these infections is said
to have AIDS.
The most common infections include
tuberculosis and a certain type of
pneumonia. People with AIDS also
frequently develop a cancer called Kaposi
sarcoma. The AIDS virus may also attack
the nervous system and cause brain and
eye damage. Death often follows.
Prevention and Treatment
People can prevent HIV infection. The
main way to do this is to keep out of
contact with possibly infected blood or
body fluids.
If a person is infected, certain drugs can
stop HIV from doing damage. Drug
treatment has added years to the lives of
many people with HIV infections.
#More to explore
Disease, Human Immune System
Virus
Ailey, Alvin
Alvin Ailey was a famous modern
dancer. He was also a highly respected
choreographera person who creates
dances and directs dancers. His dance
company toured around the world,
bringing recognition to African Americans
in dance.
Ailey was born in Rogers, Texas, on
January 5, 1931. His family moved to
Los Angeles when he was 12. Ailey
began to study modern dance at the
Lester Horton Dance Theater in 1949.
He became the companys director and
choreographer in 1953.
In 1954 Ailey moved to New York City,
where he studied with modern dance
pioneer Martha Graham and others. He
created the Alvin Ailey American Dance
Theater in 1958. The troupe performed
many kinds of works, but Ailey particularly
wanted to bring African American
culture to modern dance.
Members of the Alvin Ailey American
Dance Theater rehearse a scene from the
dance called Revelations.
AIDS exists
everywhere in
the world.
However, the
disease is a
particularly
big problem in
parts of
Africa.
50 Ailey, Alvin BRITANNICA STUDENT ENCYCLOPEDIA
In 1958 Ailey achieved his first big success
as a choreographer with Blues Suite.
One of his most famous dances is Revelations
(1960), which is set to African
American spirituals. His works combine
ballet and modern dance.
In 1965 Ailey retired from dancing, but
he continued choreographing. He died
in New York City on December 1,
1989. His company remained in operation
after his death.
#More to explore
Dance Graham, Martha
Air
All living things need air to breathe.
Animals and plants would die without
it. Air also holds airplanes and kites
above the ground, and it is used to
inflate tires and balloons. Air surrounds
Earth as the atmosphere. Air has no
color, taste, or odor. Although air is
invisible, people can hear air when the
wind howls. And they can feel air brush
against their skin when the wind blows.
Air consists of a mixture of gases. These
gases consist of tiny particles called molecules.
They are so small that they cannot
be seen. Molecules are combinations
of different chemical elements. In air the
most common of these elements are
nitrogen and oxygen. Oxygen is an
important component of air because
humans and other animals need it to
survive. In addition to nitrogen and
oxygen, air consists of small amounts of
the gases argon, neon, helium, and
methane. Besides gases, air also contains
water vapor, dust, pollen, and bacteria.
The water vapor in air is the source of
rain and snow.
The oxygen in air comes from plants.
Through a process called respiration, or
breathing, humans and other animals
take in oxygen and force out carbon
dioxide. Carbon dioxide is a molecule
made of oxygen and carbon. Plants take
in the carbon dioxide and use it to make
food. This is part of the process known
as photosynthesis. Plants break down
the molecule, use the carbon, and then
release the oxygen into the air. In this
way the carbon dioxide and oxygen in
the air are constantly used and replaced.
#More to explore
Atmosphere Molecule Photosynthesis
Air Force
An air force is the part of a countrys
military that conducts warfare in the
skies. Its pilots fly airplanes and other
aircraft armed with weapons. They use
these aircraft to attack enemy aircraft as
A kite takes flight on a windy day.
BRITANNICA STUDENT ENCYCLOPEDIA Air Force 51
well as targets on the ground and in the
water, mostly during wars.
An air force is usually one of several
branches of a countrys military. In the
United States the other major branches
are the Army and the Navy (which
includes the Marine Corps).
Basic Functions and Aircraft
Most air forces perform a variety of military
functions, or jobs. During wars an
air force uses aircraft to observe the
enemys activities. It also gathers information
about possible battlefields and
targets.
Another basic job of an air force is to
gain control of the air over a particular
area. To do this, it uses aircraft called
fighters to drive away or destroy enemy
aircraft. Fighters are jet airplanes
designed to fly very fast. They can also
change direction quickly. Fighters carry
missiles, machine guns, or other weapons
on board.
An air force also uses aircraft to drop
bombs. It often uses large aircraft called
bombers to bomb targets in an enemys
country. It uses attack aircraft to help its
countrys troops fighting on the ground.
Pilots fly attack aircraft close to the
ground while bombing or shooting at
enemy troops below. Attack aircraft are
smaller and lighter than bombers.
Another duty of an air force is to move
troops and military supplies from place
to place. It normally uses helicopters or
large transport planes to do this.
History
Inventors created the first successful
airplanes in the early 1900s. Several
European countries used fighter aircraft
and bombers duringWorldWar I, from
1914 to 1918. Air warfare was a major
part ofWorldWar II in the 1940s.
Air forces have used many new inventions
to improve their aircraft and weapons
over the years. For example, the jet
engine was invented in the middle of the
1900s. This allowed planes to fly much
faster. Computer technology has also
helped in many ways. It has made it
possible to bomb faraway targets with
great accuracy. Computers are also used
to help train pilots to fly airplanes and
to keep airplanes on course.
#More to explore
Airplane Army Bomb Navy
Airplane
Humans have always envied birds for
their ability to fly. In the 1700s and
U.S. Air Force planes called F-16 Fighting
Falcons fly in formation.
The United
Kingdoms
Royal Air
Force was
formed in
1918. It was
the worlds first
air force.
52 Airplane BRITANNICA STUDENT ENCYCLOPEDIA
1800s humans flew in lighter-than-air
ships such as balloons, but not until
1903 did people build the first heavierthan-
air craftthe airplane.
The term airplane, which is often shortened
to plane, usually refers to any type
of power-driven aircraft that has fixed
wings and is heavier than air. An airplane
moves through the air with the
help of its engine and wings. The wings
are shaped in a particular way so that air
flows over them and gives them lift. By
contrast, balloons and airships are lifted
by gases that are lighter than air. Helicopters
are lifted by spinning blades.
Types of Airplanes
Airplanes can be grouped into many
different categories. One way of classifying
them is by the number of wings they
have. Many early airplanes were
biplanes, meaning that they had two
pairs of wings, one above the other.
Triplanes were also built in the early
days of aviation. Today most airplanes
are monoplanes, with one pair of wings.
Most airplanes take off and land from
dry land, but some operate on water.
Seaplanes have special landing gear that
supports them in the water.
Airplanes can also be grouped by their
purpose. Airplanes used for military
purposes by the armed forces include
fighters, bombers, spy planes, troop
transports, and tankers that refuel other
military planes while in flight. The
familiar airliners that carry large numbers
of people from city to city are called civil,
or commercial, aircraft.Other kinds of
Modern passenger airplanes can carry hundreds of people to almost anywhere in the world.
Seaplanes have special landing gear that
allow them to take off from and land on the
water.
BRITANNICA STUDENT ENCYCLOPEDIA Airplane 53
civil aircraft carry cargo. Still others are
flown by their owners as a hobby.
Parts of an Airplane
To understand how an airplane can fly,
it is first necessary to know its different
parts. The major parts are the airframe,
the power system, and the flight controls
and instruments.
Airframe
The airframe includes the fuselage,
wings, tail, and landing gear. The fuselage
is the body of the aircraft. It consists
of a rigid frame and a covering of aluminum,
magnesium, or molded plastic or
fiberglass.
The wings of an airplane have several
moving parts. Flaps and slats are hinged
parts that the pilot adjusts to increase
the size of the wing surface. This
changes the amount of force made by
the wing. Ailerons are hinged parts that
the pilot moves to turn the airplane.
The rear of the plane is called the tail.
The horizontal stabilizer is a part of the
54 Airplane BRITANNICA STUDENT ENCYCLOPEDIA
tail that often looks like a small wing. It
prevents the plane from pitching, or
bucking up and down. The elevator is
hinged to the horizontal stabilizer. It
raises or lowers the nose, or front end, of
the plane. The vertical stabilizer often
looks like a fin. It prevents the aircraft
from yawing, or swinging from side to
side. The rudder is connected to the
vertical stabilizer. It controls side-to-side
movement.
The landing gear consists of rubber tires
and shock-absorbing devices. Most
planes have two main wheels or sets of
wheels and another wheel to support the
tail. Some planes have wheels that fold
up when the plane is in the air.
Power System
A planes power system includes one or
more engines and sometimes propellers.
The two main types of engines are
reciprocating engines and jet engines. A
BRITANNICA STUDENT ENCYCLOPEDIA Airplane 55
reciprocating, or piston, engine turns a
propeller. The turning of the propeller
provides most of the power to move the
plane forward. Reciprocating engines
are usually found on smaller airplanes.
A jet engine moves a plane forward by
shooting exhaust gases out the back. Jet
engines are common on large
commercial planes and military aircraft.
Some small planes have a turboprop
engine, which is a jet engine that turns
a propeller.
Flight Controls and Instruments
Flight controls help a pilot to regulate
the movement and position of an airplane.
The control wheel or stick is used
to adjust the elevator and the ailerons.
Foot pedals allow the pilot to control the
rudder. A throttle controls the engine
power. The pilot also controls the wing
flaps and slats.
Flight instruments are used for navigation,
checking engine performance, and
monitoring other equipment. In addition
to these instruments, there are a
variety of indicators that monitor the
engines and other parts of the planes
mechanical and electrical systems.
How Airplanes Fly
The science of flight is called aerodynamics.
Four main aerodynamic forces
act on an airplane in flight. They are
called drag, thrust, gravity (or weight),
and lift.
As a plane flies, the air slows it down.
This is the effect of drag. To overcome
drag a plane needs the forward-moving
force of thrust. Thrust is produced by
the planes engines or propellers.
An airplane is heavier than air. It will fall
to the ground under the influence of
gravity unless lift is applied. The planes
wings are able to produce the necessary
lift because of their shape. The upper
surface is curved, while the lower surface
is flat. To get past the curved surface, the
air that flows over the wing has to go
fartherand therefore fasterthan the
air that flows under it. This creates a
difference in air pressure between the
upper and lower surfaces as the plane
moves forward. The air underneath is
under greater pressure and therefore
pushes the wing up. The faster the air
flows past the wings, the greater the lift.
For this reason, an airplane takes off
most easily when it faces the wind.
Pilots use flaps and slats to change the
amount of lift. Lowering the flaps
increases the curved surface of the wing,
which provides more lift for takeoff.
Slats also increase lift by allowing air to
flow more smoothly over the wing. Rais-
A plane with turboprop engine uses both jet
power and propellers. Turboprop engines
are used only in small planes.
56 Airplane BRITANNICA STUDENT ENCYCLOPEDIA
ing the flaps reduces lift, which slows
down the plane for landing.
History
Before humans took to the air in airplanes,
they flew in lighter-than-air
craft. In 1783 the Montgolfier brothers
of France made the first balloon that
could carry people high into the air.
Their balloon rose because they filled it
with hot air, which is lighter than
unheated air.
The 1800s saw much experimentation
in both lighter-than-air and heavierthan-
air craft. Several people worked
with gliders to establish the principles of
airplane design. Gliders are similar to
airplanes but they have no motor. Once
they are launched, they move through
the air as a plane does.
Early Aviation
On December 17, 1903, in Kitty Hawk,
North Carolina, Orville andWilbur
Wright made the first flight in an
engine-powered airplane. TheWright
brothers had experimented with gliders.
They chose the North Carolina coast for
their testing because of its strong winds.
Their first plane flight, with Orville
piloting, lasted 12 seconds and covered
120 feet (37 meters). By 1905 the
Wright brothers had improved their
plane to the point that it could fly 24
miles (39 kilometers) in 38 minutes.
During WorldWar I (191418) airplanes
began to change the nature of
war. Planes were first used to observe the
enemy from the air. Eventually countries
discovered that they could use planes for
dropping bombs. Pilots also learned to
shoot at each other in the sky.
Development of Modern Aviation
After the war people began to use planes
for commercial purposes, including
delivering mail. Pilots also began to
experiment with seeing how far they
could fly. A U.S. airmail pilot named
Charles Lindbergh became famous in
1927 for making the first solo flight over
the Atlantic Ocean.
Jet-powered aircraft were introduced on
a small scale duringWorldWar II
(193945). After the war jet planes were
improved and came into wide use.
Regular passenger jet services across the
Atlantic were started in 1958. Today
passenger jets fly people all around the
world every day.
Air Travel Safety
Airline safety became an important issue
in the second half of the 20th century.
In the United States a government
agency called the Federal Aviation
An early airplane flies over Chicago,
Illinois, in 1911.
Only a few
experimental
airplanes have
used rocket
engines. A
rocketpowered
airplane
called
the X-15 set
records for
speed and
height of
flight.
BRITANNICA STUDENT ENCYCLOPEDIA Airplane 57
Administration (FAA) was created in
1958 to monitor aircraft and to investigate
accidents. The FAA also operates
the air traffic control system, which
keeps planes out of each others way.
Human error, equipment failure, and
weather can cause accidents. But flying
is still far safer than traveling by car.
#More to explore
Balloon Glider Helicopter Wright,
Wilbur and Orville
Airship
The large aircraft that are often seen
floating over sporting events are commonly
known as blimps. These are actually
a type of lighter-than-air craft called
an airship. Airships were developed from
principles of ballooning. Like balloons,
they are filled with a gas that allows
them to float in the air. Unlike balloons,
airships are driven by engine-powered
propellers and steered with rudders. For
this reason they are also called
dirigiblesafter the French word
diriger, meaning to steer.
Most airships are long and cigar-shaped.
Some airships have a rigid frame supporting
the crafts surface fabric. Nonrigid
airships are simply big balloons
that rely on the gas to keep their shape.
Nonrigid airships are also known as
blimps. The main section of an airship is
filled with a gas that is lighter than air.
Helium is the most commonly used gas.
A car, or gondola, suspended below the
gas balloon holds the airships crew and
passengers.
Airships rely on several different features
to enable them to fly. The gas inside the
ship lifts the craft into the air. Engines
then propel the craft forward. The pilot
uses a rudder to steer the craft. Most of
the ship is filled with the lighter-than-air
gas. There are also compartments filled
with normal air. The pilot can make the
ship go up or down by controlling the
amount of air in these compartments.
The first propeller-driven airship flew in
1852 in France. Its engine was powered
by steam. The first rigid airship, with a
body made of aluminum, was built in
Germany in 1897. Ferdinand von Zeppelin,
the famous German builder, completed
his first rigid airship in 1900.
Akimel Oodham
#see Pima.
Akmola,
Kazakhstan
#see Astana.
A colorful airship flies over Dodger Stadium
in Los Angeles, California.
58 Airship BRITANNICA STUDENT ENCYCLOPEDIA
Aksum
Aksum, or Axum, was a powerful trading
empire that flourished in northeastern
Africa hundreds of years ago. Aksum
also was the name of the kingdoms
capital. It remains a city in northern
Ethiopia.
Aksums location between the Red Sea
and the Nile River helped to make it
one of the most important and wealthy
trading centers of its day. The items that
moved in and out of its ports included
ivory, hippopotamus hides, perfumes,
gold, and animals.
The kingdom was also known for its
architecture. Still standing in the central
square of the city of Aksum are some of
the carved granite obelisks made in the
kingdom. An obelisk is a tall, thin pillar
with a pyramid at the top. (TheWashington
Monument is an obelisk.) Some
Aksum obelisks may have marked
underground tombs of the kingdoms
rulers.
Aksum expanded as it grew more powerful.
In the AD 300s Aksum conquered
the kingdom of Kush to the north.
Aksums rulers then pushed west across
the Red Sea into southern Arabia. In the
600s and 700s the kingdoms hold
weakened as the Muslim Arabs emerged
as a power.
The people had been Christian since
the 300s. The Arabs allowed them to
keep the Christian religion because they
had once given refuge to followers of
Islams founder, the prophet
Muhammad. Today Aksum is
considered a holy city of the Ethiopian
Orthodox church.
#More to explore
Arabian Peninsula Eastern Orthodox
Churches Ethiopia Islam Kush
Muhammad
One of the obelisks from the kingdom of
Aksum stands in the modern city of the
same name.
BRITANNICA STUDENT ENCYCLOPEDIA Aksum 59
Alabama
The state of Alabama is located
in the center of the Deep South
of the United States. Because of its location,
the land that is now Alabama
played a role in many of the major conflicts
that shaped the United States.
These included battles with Native
Americans over control of the area, the
American CivilWar, and the civil rights
movement of the 1960s. Montgomery is
Alabamas capital.
Geography
Alabama lies in the southeastern United
States. The southern parts of the Appalachian
Mountains cover most of northern
Alabama. The land is rugged, with forested
hills and ridges. Southern Alabama
is a mostly flat plain. The climate is
mild. Summers are long and warm.
Winters are short and moderate.
People
People of European ancestry make up
almost three quarters of Alabamas
population. About one quarter of the
population is African American. Slightly
more than half of the people live in cities
or towns. Birmingham is Alabamas
largest city and industrial center. Mobile
is a port city on Mobile Bay. Tuscaloosa
is the home of the University of Alabamas
main campus.
Economy
Trade and tourism are important service
industries in Alabama. Tourists are
drawn to Alabama because of its warm
weather and recreational activities.
Manufacturing, especially of paper and
metal products, is also important.
Soybeans are a valuable crop in Alabama.
Other farm products include peanuts,
cotton , corn, and pecans. Shellfish
and fish, such as shrimp and catfish, are
also harvested.
History
The early Native Americans of Alabama
are sometimes called mound builders.
They lived in villages built around large
earthen mounds. By the 1700s the
Cherokee, the Creek, the Choctaw, and
the Chickasaw were the main Native
American tribes in the region.
60 Alabama BRITANNICA STUDENT ENCYCLOPEDIA
The Spaniard Hernando de Soto
explored the area in about 1540. In the
early 1700s the French built settlements
in several places. In 1763 France gave its
land in North America, including Alabama,
to Great Britain. During the
American Revolution Spanish troops
captured Mobile. In 1783 Britain surrendered
Alabama to the United States.
In 1813 the United States seized Mobile
from the Spanish.
Alabama became a state in 1819. It prospered
because of cotton farming. Black
slaves did most of the work on the cotton
farms. Alabama, like other Southern
states, feared that the U.S. government
would outlaw slavery. In 1861 Alabama
withdrew from the United States. It
joined with other Southern states to
form a separate government called the
Confederacy. U.S. forces defeated the
Confederacy in the CivilWar, which
ended in 1865. Alabama rejoined the
United States in 1868.
Although the CivilWar ended slavery,
African Americans continued to struggle
in Alabama. Several major events of the
civil rights movement took place in the
state. Martin Luther King, Jr., led a bus
boycott in Montgomery in 195556. In
1965 he led a protest march from Selma
to Montgomery. New laws passed during
the civil rights movement helped
improve conditions for African Americans
in Alabama. Since the 1960s many
black candidates have been elected to
public office in the state.
..More to explore
American CivilWar Appalachian
Mountains Civil Rights Movement
Confederate States of America King,
Martin Luther, Jr. Montgomery
A machine called a combine is used to harvest ripe cotton. Cotton is an important crop in
Alabama.
Facts About
ALABAMA
Flag
Population
(2000 census)
4,447,100
rank, 23rd state;
(2008 estimate)
4,661,900
Capital
Montgomery
Area
52,419 sq mi
(135,765 sq
km)rank, 30th
state
Statehood
December 14,
1819
Motto
Audemus Jura
Nostra Defendere
(We Dare
Maintain Our
Rights)
State bird
Yellowhammer
State flower
Camellia
BRITANNICA STUDENT ENCYCLOPEDIA Alabama 61
Alamo
In the 1830s the people of Texas fought
several battles to gain their independence
from Mexico. One of the most
famous battles took place at the chapel
of a mission in San Antonio called the
Alamo. More than 180 Texas fighters
died while fighting against soldiers from
Mexico. When Texans later won their
independence from Mexico, their battle
cry was, Remember the Alamo!
The Mission San Antonio de Valero was
founded in about 1716 by Roman
Catholic priests. They abandoned it
before the end of the century. Afterward
the chapel became known as the Alamo
(Spanish for cottonwood) because it
stood near a grove of cottonwood trees.
In 1835, during Texas war for independence
from Mexico, the Texans captured
San Antonio. Afterward, however, fewer
than 150 men were left there to defend
the city. A few others arrived later,
including the frontiersman Davy Crockett.
On February 22, 1836, about 5,000
Mexican soldiers arrived in San Antonio.
On February 23 the Texas troops moved
into the Alamo, prepared to resist an
attack. The Mexicans surrounded the
Alamo and the battle began.
On the morning of March 6 the Mexicans
stormed the building through a
hole in the outer wall.Within a few
hours all of the defenders were dead.
Texas finally gained independence later
that year, and in 1845 it became a U.S.
state.
#More to explore
Crockett, Davy Texas
The Alamo has been preserved as a historic site. It is a reminder of the time when Texans
fought for independence from Mexico.
62 Alamo BRITANNICA STUDENT ENCYCLOPEDIA
Alaska
The U.S. state of Alaska is an immense
region of great natural beauty but few
people. Nicknamed the Last Frontier,
Alaska includes rugged coastlines, massive
glaciers, and the tallest mountains in
North America. The capital is Juneau.
Geography
Alaska is the largest state in the country.
When it became a state, the land area of
the United States increased by one fifth.
The most northerly state, Alaska is not
connected to the other 48 states of the
mainland United States. Instead, it juts
westward from Canada into the Arctic
Ocean and the Bering Sea. The Aleutian
Island chain extends southwest from
mainland Alaska. To the southeast is a
strip of land called the panhandle, which
borders the Canadian province of British
Columbia.
Northern Alaska lies within the Arctic
regions. Along the northern coast is flat,
treeless land called tundra. The ground
there stays frozen year-round. South of
the tundra are the mountains of the
Brooks Range. The middle part of
Alaska is a vast plain with many forests,
marshes, and lakes. The Yukon, Alaskas
largest river, flows through this region.
Two mountain chainsthe Alaska
Range and the Aleutian Rangecurve
along Alaskas southern coast. Mount
McKinley, in the Alaska Range, rises to
a height of 20,320 feet (6,194 meters).
It is the highest point in North America.
People
Alaskas population is spread
unevenly throughout the state,
with vast areas having few or no
people. More than a third of Alaskans
live in or around Anchorage, the largest
city. Native AlaskansEskimo (Inuit),
Aleut, and American Indiansmake up
about one sixth of the population. Common
nationalities among the rest of the
people include Russian, Filipino, Japanese,
and Chinese.
Economy
Alaskas economy is based on oil, tourism,
and fishing. Oil has brought Alaska
so much wealth that the state has no
income tax. In addition, every year the
state gives each resident some of the
money earned from oil sales. Service
businesses such as airlines, restaurants,
and hotels cater to tourists. About one
fourth of all employed Alaskans work
for the federal, state, or local government.
Salmon is one of the states lead-
BRITANNICA STUDENT ENCYCLOPEDIA Alaska 63
ing products. Other catches include
crab, halibut, herring, and shrimp. The
main manufacturing industry is fish and
seafood processing.
History
Hunters and gatherers from Asia first
settled in what is now Alaska thousands
of years ago. In 1728 a Russian expedition
led by the Danish explorer Vitus
Bering arrived there. In 1784 Russia
established a settlement and fur-trading
post on Kodiak Island, off the southern
coast. Russia owned Alaska until the
United States bought it in 1867. U.S.
Secretary of State William H. Seward
negotiated the deal. Because many
Americans thought the purchase was a
waste of money, Alaska was sometimes
called Sewards Folly.
Gold discoveries in neighboring parts of
Canada and in Alaska itself drew people
to the area in the 1890s and early 1900s.
A half century later, in 1959, Alaska
became the 49th state in the Union.
Oil discoveries, especially along the Arctic
coast, changed the states economy.
In the 1970s the Trans-Alaska pipeline
was built to transport oil from the Arctic
oil fields. The pipeline made Alaska second
only to Texas in U.S. oil production.
In the early 21st century
environmental groups, government officials,
and business leaders debated
whether to open up more governmentowned
land in Alaska to oil exploration.
..More to explore
Aleut Arctic Regions Eskimo
Juneau Tundra
A visitor looks across a bay at a glacier in Alaskas Wrangell-Saint Elias National Park.
Facts About
ALASKA
Flag
Population
(2000 census)
626,932rank,
48th state; (2008
estimate)
686,293rank,
47th state
Capital
Juneau
Area
663,267 sq mi
(1,717,854 sq
km)rank, 1st
state
Statehood
January 3, 1959
Motto
North to the
Future
State bird
Willow
ptarmigan
State flower
Forget-me-not
64 Alaska BRITANNICA STUDENT ENCYCLOPEDIA
Albania
The Republic of Albania in eastern
Europe is the smallest country on the
Balkan Peninsula. During most of its
history Albania has been ruled by other
countries and empires. The capital is
Tirane.
Geography
Albania is bordered by Greece, Macedonia,
Kosovo, and Montenegro. Its
western border is the Adriatic Sea. Most
of Albania is mountainous. The highest
mountain is Korab, at 9,026 feet (2,751
meters). Albanias only lowland area lies
along the coast. The longest river is the
Drin. Albania has warm, dry summers
and mild, wet winters. Temperatures are
more extreme in the mountain regions
than on the coast.
Plants and Animals
Forests once covered much of Albania.
After centuries of clearing and livestock
grazing, many areas now have only
bushes and scrub. The remaining forests
have oak, beech, and pine trees.
Hunting has left few wild animals,
except in the remote forests. Among
them are wolves, jackals, wild hogs,
bears, deer, and chamois (goatlike animals).
The mild climate attracts many
birds, however.
People and Culture
The people of Albania are divided into
two major groups: the northern Gegs
and the southern Tosks. Each group
speaks its own dialect, or variation, of
the Albanian language. Minority groups,
including Vlachs and Greeks, make up
about 8 percent of Albanias population.
The citadel, or fortress, at Kruje was the
stronghold of Albanias national hero,
Skanderbeg. In the 1400s he fought to keep
the Ottoman Turks from invading Albania.
BRITANNICA STUDENT ENCYCLOPEDIA Albania 65
About 39 percent of Albanians are Muslim.
Others are Eastern Orthodox,
Roman Catholic, or not religious.
Economy
The Albanian economy is one of the
poorest in Europe. More than half of the
workers are farmers. Albanias chief
crops are vegetables, grains, melons, and
potatoes. Sheep, goats, cattle, and poultry
are the major livestock.
Albania manufactures textiles, glass
products, leather, iron, steel, and office
machinery. Its mines provide chromium
and copper. The southwestern part of
the country is rich in petroleum (oil)
and natural gas.
History
The Illyrians, ancient ancestors of the
Albanians, were likely the first people to
live in what is now Albania. The Gegs
were Illyrians who settled in the north.
The Tosks were Illyrians of the south.
The Romans invaded in the 100s BC. In
AD 395 the Roman Empire split into
two halves. Albania was in the eastern
part, the Byzantine Empire. Bulgaria
and Serbia later controlled the area.
In the late 1300s Albania became part of
the Islamic Ottoman Empire. The Ottoman
Turks ruled the country for almost
500 years. Albania gained its independence
in 1912.
In 1928 Albanias president declared
himself King Zog I. After Italy invaded
Albania in April 1939, Zog fled the
country. Germany took over from 1943
to 1944.
In 1944 Communist leader Enver
Hoxha took over the Albanian government.
Hoxha led Albania for four
decades. During this period the Communist
country was cut off from the rest
of the world. After Hoxhas death in
1985, Albania reopened relations with
many countries.
In 1998 and 1999 fighting broke out
between Serbs and Albanians living in
Kosovo. At the time, Kosovo was a province
of Serbia that bordered Albania,
and most of its residents were ethnic
Albanians. Many of them crossed into
Albania from Kosovo. Most of the refugees
returned to Kosovo after the fighting
ended, but some stayed in Albania.
In 2008, Albanians rejoiced when
Kosovo declared independence from
Serbia.
..More to explore
Balkan Peninsula Byzantine Empire
Communism Islam Kosovo
Ottoman Empire Tirane
Albanian women tend to their crops.
Facts About
ALBANIA
Population
(2008 estimate)
3,194,000
Area
11,082 sq mi
(28,703 sq km)
Capital
Tirane (Tirana)
Form of
government
Republic
Major cities
Tirane (Tirana),
Durres, Elbasan,
Shkoder
66 Albania BRITANNICA STUDENT ENCYCLOPEDIA
Albany
Population
(2000 census)
95,658; (2007
estimate)
94,172
Albany is the capital of the U.S. state of
New York. The citys port on the Hudson
River has long been a major shipping
center. The port lies along a water
route that links the Great Lakes to the
Atlantic Ocean. State government also
plays a large role in Albanys economy.
The first permanent settlement was
founded on the site in 1624. Later the
Dutch and then the English controlled
the village. The English named it
Albany in 1664. An important meeting
called the Albany Congress was held in
the city in 1754. At that meeting
Benjamin Franklin proposed a plan to
unite all the American Colonies under
one government. Albany became the
capital of New York in 1797. In the
early 1800s a railroad and the Erie
Canal were built through Albany. They
helped the city grow as a center of
transportation.
..More to explore
Albany Congress Erie Canal
Albany Congress
The Albany Congress was a meeting
held in Albany, New York, in 1754. Representatives
of some of Great Britains
American Colonies met with members
of the Native American Iroquois Confederacy.
The main purpose of the meeting
was to discuss plans for the French
and IndianWar, which was just beginning.
But the meeting is now remembered
for its plan to unite the colonies.
The plan was written mostly by Benjamin
Franklin. It called for one government
for all the colonies. The leader was
The statehouse in Albany is the center of
New York States government.
In 1754 representatives of the American
Colonies put together a plan of union at the
Albany Congress. Benjamin Franklin published
a cartoon to show why he thought
the union was important.
BRITANNICA STUDENT ENCYCLOPEDIA Albany Congress 67
to be a president-general appointed by
the English king. The legislature was to
be appointed by the existing colonial
legislatures.
The congress passed the plan but it
never went into effect. Both the king
and the colonies thought it gave too
much power to the other side. However,
the plan served as a model when the
colonies united to form the United
States 22 years later.
#More to explore
Franklin, Benjamin French and Indian
War
Albatross
Albatrosses are large ocean birds with
very long, narrow wings. They can fly
long distances with little effort. They
glide gracefully for hours, even in heavy
storms. However, these birds make
clumsy crash landings. They also
attract mates with funny-looking dances
and displays. For these reasons sailors
sometimes call them gooney birds.
There are more than 10 species, or
types, of albatross. They belong to the
family of birds called Diomedeidae.
Albatrosses are birds of the open sea.
They sleep on the surface of the water.
They have no need to visit land except
during breeding season. Most types fly
over the South Pacific, Indian, and
South Atlantic oceans. A few types fly
over the North Pacific Ocean. Albatrosses
breed and nest on islands.
Albatrosses are among the largest flying
birds. They can weigh as much as 25
pounds (11 kilograms). The wingspan of
the wandering albatross may be more
than 11 feet (3 meters)longer than
that of any other living bird. An albatross
has a big head, a hooked bill, and
webbed toes. Most adult albatrosses have
white body feathers with black, brown,
or white wing feathers. A few types have
brown feathers all over.
Albatrosses can soar on air currents for
hours without flapping their wings. But
they have difficulty flying in calm air.
Albatrosses eat mainly squid and sometimes
fish. They also eat food scraps cast
off by passing ships.
#More to explore
Bird
The wings of a black-browed albatross can
measure more than 7 feet (2.1 meters) from
tip to tip.
68 Albatross BRITANNICA STUDENT ENCYCLOPEDIA
Alberta
The province of Alberta in western
Canada is one of the countrys three
Prairie Provinces, but it is known for its
minerals as well as its crops. The province
was named after Princess Louise
Caroline Alberta, a daughter of Queen
Victoria, when Great Britain ruled
Canada. The capital is Edmonton.
Geography
Alberta borders British Columbia on the
west and the Northwest Territories on
the north. To the east is Saskatchewan,
another of the Prairie Provinces. To the
south is the U.S. state of Montana.
Most of Albertas land is a flat plain. In
the south the plain is treeless prairie, but
in the north it is forested. The province
is dotted with many lakes, especially in
the north. In the southwestern part of
Alberta are the Canadian Rocky Mountains.
The scenic Banff and Jasper
national parks lie in the
Rockies.
People
People with English, Scottish, or Irish
ancestors make up the largest ethnic
groups in Alberta. Many other residents
have German, French, or Ukrainian
origins. Though Albertas American
Indian population is fairly small, the
province has more Metis than any other
province. Metis have a mixed Indian and
European background.
Four of every five people in Alberta live
in cities or towns. The largest cities are
Calgary and Edmonton. Calgary is a
A mountain is reflected in Lake
Louise. The lake is part of Banff
National Park in Alberta.
BRITANNICA STUDENT ENCYCLOPEDIA Alberta 69
financial center and a shipping point for
products of the surrounding farms and
ranches. Edmonton is called the Gateway
to the North because it is farther north
than any other large Canadian city. It is a
center of the oil and gas industry. The
University of Alberta is in Edmonton.
Economy
Services, including banking, education,
and health care, make up the biggest
part of Albertas economy. The provinces
spectacular mountain scenery
attracts many visitors and makes tourism
a leading service industry. Albertas
single largest industry, however, is
energy production. The province produces
half of Canadas oil and most of
its natural gas. Alberta also mines almost
half the coal produced in Canada.
Refined oil and chemicals made from oil
and natural gas are among the leading
manufactured products. Food and wood
products are also important.
Albertas leading crop is wheat. Albertas
farms also produce barley, alfalfa, canola,
and hay. Millions of beef cattle graze on
the grasslands of the province. Farmers
and ranchers also raise sheep, hogs, and
horses.
History
The first American Indians to live in
what is now Alberta arrived about
10,000 years ago. The first Europeans
did not arrive until 1754. They came to
trap animals for their fur and to trade
for furs with the Indians. Employees of
the two main fur-trading companies, the
Hudsons Bay Company and the North
West Company, explored the region and
built trading posts and forts.
In 1869 the new country of Canada
purchased the Hudsons Bay Companys
lands, which included all of what is now
Alberta. Soon the area was opened to
settlers, and many ranchers came.
Alberta was made part of the Northwest
Territories in 1882. Settlement increased
after 1883, when the Canadian Pacific
Railway reached Calgary from the east.
Farmers moved in after new kinds of
wheat were developed that could grow
in the short northern summer. In 1905
the Canadian government made Alberta
a province.
In 1914 oil was discovered at Turner
Valley, near Calgary. In 1947 more oil
was discovered at Leduc, near Edmonton.
Energy production then became
more important than farming in
Alberta.
..More to explore
Canada Fur Trade Hudsons Bay
Company Rocky Mountains
Calgary is one of the largest cities in
Alberta. It is located in the southern part of
the province.
Facts About
ALBERTA
Flag
Population
(2006 census)
3,290,350
Area
255,541 sq mi
(661,848 sq km)
Capital
Edmonton
Motto
Fortis et Liber
(Strong and Free)
When Alberta
Became a
Province
1905
70 Alberta BRITANNICA STUDENT ENCYCLOPEDIA
Alchemy
Hundreds of years ago people called
alchemists tried to change lead into
gold. They also tried to make potions
that would allow people to live forever.
Their field of study was called alchemy.
Alchemists experimented with metals,
salts, acids, and other chemicals. They
also developed many nonscientific and
magical beliefs about the world. For
instance, alchemists thought that the
positions of the stars in the sky could
affect their chemical experiments. Today
scientists do not recognize alchemy as a
science. However, some scientists believe
that alchemists helped to lay the
foundations for the modern science of
chemistry.
In ancient times people practiced various
forms of alchemy in China, India,
Greece, and the Middle East. In about
the 1100s people in Europe learned
about some of these ancient practices.
Some of them began their own experiments.
They tried to change lead into
gold by heating it and mixing it with
many other substances. They kept most
of their procedures secret.
Alchemists were never able to make gold
or to make people live forever. However,
they made some useful discoveries. They
figured out how to produce chemicals
called mineral acids from other chemicals.
They also learned how some chemicals
react when mixed together.
#More to explore
Chemistry Metals
Alcott,
Louisa May
U.S. author Louisa May Alcott is best
known for her novel LittleWomen. The
book was based on her own experience
growing up in a close-knit New England
A painting shows three alchemists at work.
Louisa May Alcott
BRITANNICA STUDENT ENCYCLOPEDIA Alcott, Louisa May 71
family. It is one of several of her stories
that are still cherished by young readers.
Alcott was born in Germantown,
Pennsylvania, on November 29, 1832.
She grew up in Boston and Concord,
Massachusetts. Louisa received most of
her schooling from her father, who was
a teacher and philosopher. She began
writing at a young age. By the 1860s
her poems and stories were being
published in The Atlantic Monthly
magazine.
Alcott published LittleWomen in 1868.
The book was instantly popular with
younger readers, and it remains a favorite
today. Alcotts other books for young
readers include Little Men (1871) and
Jos Boys (1886).
Alcott spent most of the last 20 years of
her life in Boston and Concord. She
spent her time writing and caring for her
sick parents. Alcott died in Boston on
March 6, 1888.
Aleut
The Aleut are a native people of the
Aleutian Islands, which are part of
Alaska. They also live on the western
portion of the Alaska Peninsula, a piece
of land in southwestern Alaska that
extends into the Pacific Ocean. The
name Alaska comes from an Aleut word
meaning mainland. The Aleut are
closely related to the Eskimo (Inuit).
The Aleuts early ancestors, the Paleo-
Aleut, arrived in the Aleutian Islands
from the Alaskan mainland about 4,000
years ago. Traditionally, the Aleut lived
off the sea. They fished and hunted animals
such as seals, sea otters, whales, sea
lions, and walruses.
The Aleut kept their traditional way of
life until Russian settlers arrived in the
1700s. Conditions were harsh under
Russian control, and many Aleuts died
from disease or warfare. At the end of
the 20th century fewer than 12,000
Aleuts lived in the United States.
#More to explore
Alaska Eskimo
Alexander the
Great
Alexander III, king of Macedonia, is
known as Alexander the Great. In his
The Aleut call
themselves the
Unanax.
A young girl is one of the Aleut
who still live on the islands off
Alaska.
72 Aleut BRITANNICA STUDENT ENCYCLOPEDIA
short life he conquered almost all parts
of the world that were known to his
people.
Alexander was born in 356 BC in Pella,
the capital of Macedonia, a kingdom to
the north of Greece. The Greek philosopher
Aristotle gave him lessons. But
Alexanders chief interest was war. In
338 BC Alexanders father, Philip II,
brought all the Greek city-states except
Sparta under his rule. Young Alexander
commanded one part of the Macedonian
army.
In 336 BC Philip II was killed and Alexander
became king. He soon won the
loyalty of nearly all of Greece. In 334 BC
he brought together a large army and
invaded the empire controlled by Persia.
He freed the Greek settlements in Asia
Minor (now Turkey) from Persian rule
and made them his allies.
In 333 BC Alexander defeated King
Darius III of Persia, at Issus. Alexander
then marched southward along the coast
of Phoenicia (present-day Lebanon).
Late in 332 BC Alexander took Egypt
from the Persians and became pharaoh,
or king. He then controlled the whole
A painting shows Alexander the
Great dressed for battle.
BRITANNICA STUDENT ENCYCLOPEDIA Alexander the Great 73
eastern Mediterranean. Near the Nile
River he founded the city of Alexandria.
In 331 BC Alexander went back into
Asia and again defeated Darius. Then he
was called king of Asia. Soon afterward
he captured Babylon, in what is now
Iraq, and Susa, the Persian capital.
Many of Alexanders men wanted to go
home, but instead he had them advance
further into Asia. In 327 BC Alexander
went to India. There he fought his last
great battle. He defeated the Indians and
founded two cities. At this point Alexanders
men refused to go farther. In
324 BC Alexander returned to Susa.
The next year Alexander went to Babylon.
Weakened by his travels and battles,
he died there of a fever. His body was
eventually placed in a golden coffin in
Alexandria, Egypt. His generals divided
up his empire.
..More to explore
Alexandria Egypt, Ancient Greece,
Ancient Persia
Alexander, Lloyd
U.S. childrens author Lloyd Alexander
is probably best known for his Prydain
novels. This five-book series follows a
young hero named Taran from the lowly
status of assistant pig keeper to the
throne of the kingdom of Prydain.
Lloyd Chudley Alexander was born on
January 30, 1924, in Philadelphia,
Pennsylvania. As a child, he enjoyed
fairy tales and mythology.
Alexanders first published works were a
novel for adults and several books about
his own experiences. His first fantasy for
children was Time Cat: The Remarkable
Journeys of Jason and Gareth (1963). He
began the Prydain fantasies the following
year with The Book of Three. The
series also includes The Black Cauldron
(1965), The Castle of Llyr (1966), and
TaranWanderer (1967). The final book
of the series, The High King (1968), won
the Newbery Medal in 1969.
Alexander created the kingdom of Westmark
as the setting for another series of
novels: Westmark (1981), The Kestrel
(1982), and The Beggar Queen (1984).
Alexanders later books include The
Illyrian Adventure (1986), and How the
Cat Swallowed Thunder (2000). He died
on May 17, 2007.
Alexandria
The city of Alexandria was founded by
Alexander the Great when he conquered
ancient Egypt in 332 BC. For hundreds
of years it was Egypts capital. Today it is
the countrys main seaport. It lies on the
Lloyd Alexander
One of the
cities that
Alexander
founded in
India was
Bucephala. It
was named
for Alexanders
horse
Bucephalus.
74 Alexander, Lloyd BRITANNICA STUDENT ENCYCLOPEDIA
coast of the Mediterranean Sea northwest
of Cairo.
Alexandria has stone structures that date
back to when the city was part of the
Roman Empire. They include an amphitheater
and Pompeys Pillar, which was
built in AD 297. There are also ancient
tombs called catacombs.
The chief economic activities of Alexandria
include shipping, banking, and the
manufacturing of cloth. The city
accounts for about a third of the industrial
products made in Egypt. Cotton is
the main export.
Alexander the Great, the Greek conqueror,
founded Alexandria as a naval
base and trade center. After his death in
323 BC, control of the city passed to one
of his generals, Ptolemy I Soter. Ptolemy
made Alexandria the capital of Egypt,
and it soon became the most important
city in the world. Greek scholars and
scientists went there to study in its great
library. The Pharos, a lighthouse built in
Alexandrias harbor, was one of the
SevenWonders of theWorld.
Alexandria came under Roman rule in
30 BC and Arab rule in AD 642. The
Arabs built a new capital at Cairo and
neglected Alexandria. In 1517 Alexandria
was conquered again, this time by
the Turks. By the late 1700s it was just a
small fishing village. Alexandria revived
as a trade center in the 1800s after
canals were built to link the city to the
Nile River. Today Alexandria remains a
thriving port city.
#More to explore
Alexander the Great Cairo Egypt
Egypt, Ancient Nile River
Alfred the Great
More than 1,000 years ago a king
named Alfred saved part of England
from falling under the control of Denmark.
At the time, England was divided
into several small kingdoms, andWessex
was one of those. Alfred was king of
Wessex. Although the other kingdoms
fell to the Danes, Alfred keptWessex
free. One of Englands best-loved kings,
he is known as Alfred the Great.
Battles Against the Danes
Alfred was born in 849. He was the
youngest son of Aethelwulf, king of
Wessex. Alfreds older brother Aethelred
Few structures remain from Alexandrias
early history. A monument
called Pompeys Pillar and
a sphinx were once part of a
temple of a god called Sarapis.
BRITANNICA STUDENT ENCYCLOPEDIA Alfred the Great 75
became king after Aethelwulf. When
Aethelred died in 871, Alfred became
king.
Alfreds people were the Saxons. They
had come to Britain from Germany several
hundred years earlier, along with the
Angles and the Jutes. All were now
threatened by the Danes, who were
invaders from northern Europe. The
Danes were also called Vikings.
Several English kingdoms fell to the
Danes. In 871 and again between 876
and 878 AlfredsWessex forces fought
against the invaders. In the end the
Danish king surrendered to Alfred.
In 886 Alfred went beyondWessex and
freed London. All the English people
who were not ruled by Danes then
accepted him as king. Alfreds son and
grandsons eventually gained control over
all of England.
Role as a King
Alfred was not only a bold warrior. He
was also a smart organizer who knew
how to build forts, use ships, and
arrange alliances. In peace he was a wise
ruler who tried to protect the weak from
bad judges. He also gave his people better
laws.
Alfred loved learning. He read books in
Latin and hired scholars to translate
them into English. Sometimes he did
the translating himself. The Anglo-
Saxon Chronicle, a record of Englands
early history, was begun in his reign.
Alfred died in 899.
#More to explore
England Vikings
Algae
Algae are organisms, or living things,
that are found all over the world. Algae
are very important because they make
much of Earths oxygen, which humans
and other animals need to breathe.
Some algae, such as seaweeds, look like
plants. However, algae are actually neither
plants nor animals. Instead they
belong to a group of living things called
protists.
There are about 27,000 different
species, or types, of algae. They are
most common in water, such as oceans,
rivers, lakes, streams, ponds, and
marshes. Some species live in soil or on
leaves, wood, and stones. Algae even
grow on animals such as turtles and
polar bears.
Alfred the Great
76 Algae BRITANNICA STUDENT ENCYCLOPEDIA
Algae can be green, blue, red, or brown.
They vary greatly in size. Some species
are so small that they can only be seen
through a microscope. On the other
hand, the algae called kelp can reach
200 feet (60 meters) in length.
Algae differ from plants in several ways.
They do not have stems or leaves, and
their roots are different from plant roots.
Algae also do not produce flowers or
seeds, as plants do. Like plants, however,
algae make their own food through a
process called photosynthesis. Photosynthesis
also releases oxygen into the air.
In addition to making oxygen, algae are
important for other reasons.Water animals
such as whales, seals, fish, octopuses,
and starfish depend on algae for
food. People also eat some types of algae.
In many parts of the world farmers use
seaweeds as fertilizer (a material to help
crops grow).
#More to explore
Living Things Protist Photosynthesis
An alligator hides in algae-covered water.
A magnified view of red algae shows that it looks like a plant. But algae belong to a group
of living things called protists.
BRITANNICA STUDENT ENCYCLOPEDIA Algae 77
Algeria
Algeria is a country on the north coast of
Africa. It is the second largest country on
the continent. Its history, language, customs,
and Islamic religion make it a part
of the Arab world. The capital is Algiers.
Geography
Algeria is bordered by Tunisia, Libya,
Niger, Mali, Mauritania,Western
Sahara, and Morocco. The Mediterranean
Sea lies to the north.
The northern part of the country is
known as the Tell. Most of the people
live there. The Atlas Mountains separate
the Tell from the Sahara Desert, which
takes up about four fifths of the country.
The Sahara contains plateaus and large
areas of sand called ergs. It also features
Algerias highest peak, Mount Tahat,
which rises to 9,573 feet (2,918 meters).
Northern Algeria has warm, dry summers
and mild, rainy winters. The
Sahara can be very hot or quite cold,
depending on the season and time of
day. It rarely rains there.
Plants and Animals
Plants in Algeria survive without much
water. The Tell region has evergreen
shrubs and low trees. In the desert are
tufts of grass, shrubs, and acacia and
jujube trees.
Hyenas, jackals, monkeys, hawks, and
desert snakes are native to Algeria. So are
some antelope, hares, rodents, and wild
boars. Scorpions are common in the
Sahara.
People
Most Algerians have Berber or Arab
ancestors. The Berbers were the people
who lived in North Africa before the
arrival of the Arabs. Arabs now make up
more than 70 percent of the population.
Almost all Algerians are Muslim.
The Erg Admer is a large area of sand
dunes in southern Algeria.
78 Algeria BRITANNICA STUDENT ENCYCLOPEDIA
Economy
The Algerian government controls the
economy. Algerias main products are
petroleum (oil) and natural gas. However,
most Algerians work in the government,
the military, or in agriculture.
Crops include wheat, potatoes, tomatoes,
barley, dates, onions, oranges,
olives, and grapes. Sheep and goats are
the main livestock. Manufacturers make
food and tobacco products; cement,
bricks, and tiles; and iron and steel
products.
History
Mainly Berbers lived in ancient Algeria.
Waves of invadersPhoenicians,
Carthaginians, Romans, and Vandals
conquered them at different times. Muslim
Arabs invaded in the 600s and 700s.
The Turkish Ottoman Empire gained
control of northern Algeria in 1518.
France invaded in 1830 and made Algeria
a French colony.
In the 1920s Algerians began to seek
more rights. In 1954 a group called the
National Liberation Front (FLN) began
a war against France. Algeria won independence
in 1962. The FLN controlled
the new government.
Algeria held its first elections in 1991.
One of the parties in the election was
the Islamic Salvation Front (FIS), which
wanted to establish an Islamic state.
When it appeared likely that the FIS
would win the largest number of seats,
the military canceled the elections and
took over the government. That action
sparked a devastating civil war. In 1999
Algerians elected Abdelaziz Bouteflika,
their first nonmilitary president since
1965. However, the violence continued
into the 21st century as various groups
continued to protest the actions of the
government.
..More to explore
Algiers Arabs France Islam Sahara
Algeria borders the Mediterranean Sea to the north. In ancient times the land was part of
several different empires that stretched along the sea.
Facts About
ALGERIA
Population
(2008 estimate)
34,574,000
Area
919,595 sq mi
(2,381,741 sq
km)
Capital
Algiers
Form of
government
Republic
Major cities
Algiers, Oran,
Constantine,
Annaba
BRITANNICA STUDENT ENCYCLOPEDIA Algeria 79
Algiers
Population
(2004 estimate)
1,790,700
Algiers is the capital of the North African
country of Algeria. It is also Algerias
largest city and chief seaport. The city
lies along the Bay of Algiers.
A people called the Phoenicians created
a colony in the area in ancient times.
But the town was destroyed in the 400s.
Another group, called the Berbers,
rebuilt the town in the 900s as a center
of business. It became a prosperous city
in the 1600s under Turkish rule.
The French captured Algiers in 1830.
They made it the headquarters for
Frances colonies in North and West
Africa. During World War II
(193945) Algiers was the headquarters
of the Allied forces in North Africa.
Groups in Algeria began rebelling
against France in the 1950s. Much of
the fighting took place in Algiers. After
Algeria became an independent country
in 1962, Algiers grew as the countrys
capital.
#More to explore
Algeria
Algonquian
The Algonquians (or Algonkians) are a
group of Native American tribes that
traditionally spoke similar languages and
had similar ways of life. The Cree, the
Mohican, the Delaware (Lenni Lenape),
the Ojibwa, the Shawnee, and the
Algonquin are a few of the many Algonquian
tribes.
The Algonquians probably once lived in
southern Canada in the area north of
the Saint Lawrence River. Over time
they spread out, eventually occupying a
large portion of what are now the
United States and Canada. Their territory
included New England, the Atlantic
coast, the Great Lakes region, and
part of the Great Plains.
Most Algonquians built their villages
alongside rivers. They grew corn, beans,
and squash in nearby gardens. They
hunted deer, rabbits, and beaver and
sometimes larger animals such as elk,
moose, and bison (buffalo). They made
much of their clothing from animal
hides.
Most Algonquian tribes built domeshaped
houses called wigwams. Some
tribes built longhouses of wood and
The city of Algiers faces the Bay of Algiers. bark that were large enough to house
80 Algiers BRITANNICA STUDENT ENCYCLOPEDIA
several families. Others lived in coneshaped
tepees.
Religious practices varied among the
Algonquians. Most tribes shared a belief
in a great spirit called Manitou. They
believed that Manitou was present in all
things on Earth.
The Algonquians living along the Atlantic
coast were among the first Indians to
come in contact with settlers from
Europe. They greeted the Pilgrims and
the Jamestown settlers who arrived in
the early 1600s. Many Algonquians died
from diseases brought by the European
settlers. The settlers also gradually forced
the Indians to give up their land. By the
mid-1800s most Algonquians were living
on reservations. Thousands of
people of Algonquian heritage still live
in the United States and Canada.
#More to explore
Algonquin Cree Delaware Mohican
Native Americans Ojibwa Shawnee
Algonquin
The Algonquin (or Algonkin) people
traditionally lived along the Ottawa
River in what is now Canada. A version
of their tribal name is used to describe
one of the largest Native American language
groups, the Algonquians. Different
groups of Algonquin spoke different
Algonquian languages.
The Algonquin lived in scattered forest
villages. They made their houses from
wood and bark. They planted corn,
beans, and squash but got most of their
food by hunting and fishing.
The French began arriving in Algonquin
territory in the early 1600s. The Algonquin
traded animal furs to them in
exchange for European goods. This trade
made the Algonquin powerful for a
while. But the Huron soon replaced
them as the main trading partners of the
French.Warfare with the powerful Iroquois
eventually drove the Algonquin
from their homeland. Many Algonquin
joined other tribes. Some returned to
their territory once their relations with
the Iroquois had improved.
After the British defeated the French in
the French and IndianWar (175463),
the Algonquin became friends of the
British. However, British settlers who
moved into the Ottawa River valley took
away much of the Algonquin land. At
the end of the 20th century about 8,000
A drawing of an Algonquin village
shows homes and fields of
crops.
Many common
words that
have Native
American
roots come
from Algonquian
languages.
These
include moccasin,
powwow,
and
tomahawk.
BRITANNICA STUDENT ENCYCLOPEDIA Algonquin 81
Algonquin lived in Canada, most of
them on reserves.