You are living in a world in which science,

technology, and nature are very important. You see

something about science almost every day. It might

be on television, in the newspaper, in a book at

school, or in some other place. Often you want more

information about what you see. The Raintree

Illustrated Science Encyclopedia will help you find

what you want to know. The Raintree encyclopedia

has information on many science subjects. You may

want to find out about mathematics, biology,

agriculture, computer science, lasers, or rockets, for

example. They are all in The Raintree lllustrated

Science Encyclopedia. And there are many, many

other subjects. "

There are twenty volumes in the encyclopedia.

The articles, which are called entries, are in

alphabetical order through the first 19 volumes. On

the spine of each volume, below the volume

number, are some letters. The letters above the line

are the first three letters of the first entry in that

volume. The letters below the line are the first three

letters of the last entry in that volume. In Volume l,

for example, you see that the first entry begins with

aar and that the last entry begins with art. Using

the letters makes it easy to find the volume you

need.

In the front of Volume 20, there are interesting

projects that you can do on your own. The projects

are fun to do, and they illustrate important science

principles.

Also in Volume 20, there are two special features

-- an index and a bibliography. They are described

in Volume 20.

Main Entries. The titles of the main entries in

The Raintree Illustrated Science Encyclopedia are

printed in capital letters. They look like this:

CAMERA.

The titles of some of the longer or more important

entries are printed in larger capital letters.

At the beginning of each entry, you will see a

phonetic pronunciation of the entry title. On page

viii, there is a pronunciation key. Use it the same

way you use your dictionary key.

At the end of each entry, there are two sets of

initials. They look like this: S.R.G./W.R.S. The first

set belongs to the person who wrote the entry. The