A magic box can turn a room full of books into a library.lt is called "the card catalogus".It has many small drawers filled with cards kept in careful order.The cards give clues for finding the books on the shelves.
Each book in the library usually has two cards in the catalogue which belong to that book only.One is the "author card",which tells who wrote the book.Author cards are filed alphabetically by the author's last name.The other card is the "title card",giving the name of the book. Title cards are also filed alphabetically,but the words "The "and "A"are ignored if they came at the beginning of the litle.
Another card that may be found in the catalogue is the "subject card",which tells what the book is about.You can easily discover all the books the library has on any subject,because all the subject cards
for each subject are grouped together in the catalogue.
Non-fiction books-those that are not story books-have numbers written on the back edge,or spine,of the books,these numbers are known as "the Dewey Decimal Number",a term which refers to a system invented by Melvil Dewey,in 1890.Some libraries now use the "library of Congress Catalogue System"instead.The numbers appear on the catalogue cards,so that you can tell which shelf each book is kept on cards are added for each new book and removed when a book is worn out or lost.
Magazines,records,films,tapes, and other special items all have cards in the catalogus, too You probably noticed all that in your college library and, on a far wider scale, in the national library or any university or central library.