Britannica Student Encyclopedia - 2010

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Saint Kitts and Nevis

Bastille Day

The French celebrate their freedom each

year on July 14. On that day in 1789 an

angry mob attacked the Bastille, a state

prison in Paris. The mob associated the

prison with the harsh rule of the king of

France. The attack is therefore considered

the beginning of the French Revolution,

which forced the king to give up

control of the country. French people

celebrate the day much as Americans

celebrate the Fourth of July, with

parades, speeches, and fireworks.

Bastille Day was first celebrated in 1790,

but it did not become a French national

holiday until 1880. Long before that,

the Bastille itself was torn down.

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French Revolution

Bat

Bats are the only mammals that can

truly fly. Sometimes people mistake bats

for birds. But bats are more closely

related to other mammals—including

humans—than they are to birds. And

bats do not have feathers.

Where Bats Live

There are about 900 species, or types, of

bat. Bats are found worldwide, especially

in the tropics. They usually rest in dark

places such as caves, hollow trees, or

attics.

Physical Features

Bats have fur that is usually gray, tan,

brown, or black. They vary greatly in

size, depending on the species. Their

wings can measure from 6 inches (15

centimeters) to 5 feet (1.5 meters) across

when spread open. Their ears point forward

and are usually very large.

Jets trail the French national colors

at a Bastille Day parade in

Paris, France.

A leaf-nosed bat flies in the night.

38 Bastille Day BRITANNICA STUDENT ENCYCLOPEDIA

 

The wings consist of thin layers of bare

skin. They stretch from the long arms

down to the legs.

Behavior

Most kinds of bat live in large groups.

Nearly all bats rest during the day. Most

bats eat flying insects. Some kinds eat

small animals such as birds, frogs, mice,

and fish. Other kinds eat fruit or the

pollen and nectar from flowers. The

vampire bats of South and Central

America feed on the blood of mammals

and large birds.

While flying, most bats send out a cry.

This cry is so high-pitched that people

cannot hear it. The sounds bounce off

objects and echo back to the bat. The

bat can figure out the distance and size

of the objects based on the returning

sounds. Bats use this information to

avoid flying into objects in their paths

and also to find insects to eat.

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Animal • Mammal

Baton Rouge

Population

(2000 census),

city, 227,818;

(2007 estimate)

227,071

Baton Rouge is the capital of the U.S.

state of Louisiana. The city is located on

theMississippi River. It is one of the

leading U.S. ports. Goods brought to the

port by rail and river are transferred to

oceangoing ships. Baton Rouge is also a

center of industry and services. Its chief

industries process oil and natural gas.

The French founded Baton Rouge in

1719. The city and its surrounding area

changed hands several times. The British

gained control of Louisiana in 1763. But

the Spanish captured it in 1779. In

1800 France again took control of Louisiana.

A few years later the United States

bought Louisiana from France. Louisiana

became a U.S. state in 1812. Baton

Rouge became the state capital in 1849.

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Louisiana

Battery

Batteries give electric power to flashlights,

radios, cell phones, handheld

games, and many other types of equipment.

A battery is a sort of container

that stores energy until it is needed.

Chemicals inside the battery store the

energy. When the battery is used, the

chemical energy changes into electric

energy.

How BatteriesWork

Inside a battery there are two pieces of

metal in a liquid or a paste. The metal

parts are called electrodes. The liquid or

paste, called an electrolyte, is a mix of

chemicals. Each electrode has a point,

called a terminal, that sticks out of the

battery.

“Baton rouge”

means “red

stick” in

French. French

settlers named

the town for a

post they saw

that marked a

boundary

between

Native American

territories.

BRITANNICA STUDENT ENCYCLOPEDIA Battery 39

 

For a battery to work, the terminals

must be linked by an outside wire. Then

the chemicals in the electrolyte cause

tiny particles called electrons to flow out

of one electrode’s terminal (the negative

terminal). The electrons travel along the

wire back to the other terminal (the

positive terminal). This flow of electrons

is an electric current. The wire usually

runs through a lightbulb or other device

before returning to the battery. The current

flowing through the wire makes the

device work.

Types of Batteries

There are two basic types of batteries. A

battery that can be used only once is

called a primary battery. When the metals

or electrolyte is used up, the battery

can no longer make electricity. The batteries

used in flashlights, radios, and toys

are primary batteries.

A battery that can be used more than

once is a secondary battery. Car batteries

and some batteries used in telephones

and medical equipment are secondary

batteries. Secondary batteries can be

recharged with an electric current from

another source. For example, a person

can recharge a cell phone battery by

plugging the cell phone into an electric

socket in a wall.

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